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Basis of Virulence in Enterotoxin-Mediated Staphylococcal Food Poisoning

Emilie L. Fisher, Michael Otto, Gordon Y. C. Cheung

Frontiers in Microbiology · 2018 · Review

doi:10.3389/fmicb.2018.00436

Abstract

The Staphylococcus aureus enterotoxins are a superfamily of secreted virulence factors that share structural and functional similarities and possess potent superantigenic activity causing disruptions in adaptive immunity. The enterotoxins can be separated into two groups; the classical (SEA-SEE) and the newer (SEG-SElY and counting) enterotoxin groups. Many members from both these groups contribute to the pathogenesis of several serious human diseases, including toxic shock syndrome, pneumonia and sepsis-related infections. Additionally, many members demonstrate emetic activity and are frequently responsible for food poisoning outbreaks. Due to their robust tolerance to denaturing, the enterotoxins retain activity in food contaminated previously with S. aureus. The genes encoding the enterotoxins are found mostly on a variety of different mobile genetic elements. Therefore, the presence of enterotoxins can vary widely among different S. aureus isolates. Additionally, the enterotoxins are regulated by multiple, and often overlapping, regulatory pathways, which are influenced by environmental factors. In this review, we also will focus on the newer enterotoxins (SEG-SElY), which matter for the role of S. aureus as an enteropathogen, and summarize our current knowledge on their prevalence in recent food poisoning outbreaks. Finally, we will review the current literature regarding the key elements that govern the complex regulation of enterotoxins, the molecular mechanisms underlying their enterotoxigenic, superantigenic, and immunomodulatory functions, and discuss how these activities may collectively contribute to the overall manifestation of staphylococcal food poisoning.

Full text

From PubMed Central, U.S. National Library of Medicine, as current on Oct 21, 2026. Paragraph numbers are ours, so an answer can point at one.

Introduction

Staphylococcus aureus is a dangerous human pathogen whose virulence potential predominantly relies on the production of an impressive catalog of protein toxins. These can work separately or in concert to cause a multitude of human diseases. Pneumonia, sepsis-related infections, toxic shock syndrome, and food poisoning are diseases that have traditionally been associated in particular with the production of enterotoxins (Lowy, ). However, recent studies suggest that the staphylococcal enterotoxins (SEs) have a broader role in the manifestation of a number of other human illnesses, including those associated with the respiratory tract (Pastacaldi et al.,; Huvenne et al., ) and the development of autoimmune diseases (Principato and Qian,; Li et al., ). The SEs are powerful non-specific T-cell stimulators (superantigens) that cause unregulated activation of the immune response (for detailed reviews see Fraser and Proft,; Spaulding et al., ). If this stimulation is sustained, a massive cytokine overload is produced preluding the clinical hallmarks of toxic shock syndrome, which is characterized by the fast onset of fever, organ failure and significant mortality (Lappin and Ferguson, ). Unlike the majority of other secreted toxins produced by S. aureus, the SEs require only minute quantities to be toxic in humans. Additionally, the SEs have a remarkable tolerance to extreme denaturing conditions, such as low pH (Schantz et al.,; Bergdoll, ), heating (Evenson et al.,; Asao et al., ) and proteolytic digestion (Humber et al.,; Regenthal et al., ). These combined qualities make the SEs, especially SEB, potential bioterrorism agents (Madsen, ). Notably, SEB is also classified as a Category B select agent by various United States federal agencies.

In addition to the toxic effects they have on the host, the SEs are potent emesis-inducing toxins. Reports of the involvement of enterotoxin-producing S. aureus in staphylococcal food poisoning (SFP) can be dated as far back as the 1900s. However, it was not until the 1930s that a link between the two were made (Dack, ). In healthy human individuals, SFP is an acute disease depicted by symptoms including nausea, vomiting, abdominal cramping, diarrhea, typically in the absence of fever, appearing within 3–9 h after the ingestion of food contaminated previously with enterotoxin-producing S. aureus. SFP is often self-limiting with recovery occurring 1–3 days after the onset of symptoms (Le Loir et al., ). However, symptoms may be more severe in the young, elderly and immunocompromised (Murray,; Argudin et al., ). The SEs' ability to traverse the harsh acidic conditions within the gut to reach the intestine means that the advancement of SFP can also occur in the absence of live bacteria. Typically, only high nanogram to low microgram quantities of enterotoxins are needed to induce the symptoms of SFP (Larkin et al., ).

Next to E. coli, Shigella, Bacillus spp., and Clostridium spp., S. aureus is among the leading toxin-producing bacterial causative agents of food poisoning. S. aureus is also frequently mentioned in national foodborne illness estimates (Gkogka et al.,; Bennett et al.,; Thomas et al.,; Kirk et al.,; Mangen et al.,; Park et al.,; Van Cauteren et al., ), and is identified as a main player in major food poisoning outbreaks worldwide (Asao et al.,; Do Carmo et al.,; Chiang et al.,; Ostyn et al.,; Sato'o et al.,; Ercoli et al., ). In the US alone, it is estimated that S. aureus accounts for more than 240,000 foodborne illnesses per year (Scallan et al., ). However, considering that SFP can be resolved in individuals without hospitalization, it is not unusual for many cases to go unreported. While SFP rarely develops into a life-threatening disease, its frequency has a significant impact on the economy, resulting in a loss in productivity. It also represents a serious financial burden, especially for the food industry, catering businesses, and public healthcare systems. The implementation of traditional hygiene practices and proper food safety measures are key to preventing foodborne illness (Hussain and Dawson, ).

The superfamily of staphylococcal enterotoxins; proteins and overview

The superfamily of SEs and enterotoxin-like (SEls) proteins (Table 1) share many common features; they are non-glycosylated, antigenically distinct, low molecular weight (19–29 kDa) single-chain proteins that all fold into homologous globular structures (Thomas et al., ). Since the first characterization of the classical SEs (SEA to SEE) in S. aureus (Bergdoll et al.,,,; Casman et al.,; Marrack and Kappler, ), advancements in the area of molecular biology during the 1980s led to the identification of a new set of genes encoding closely-related proteins with superantigenic and emetic activities (Table 1). This sudden increase in the number of described SEs spurred a move to standardize their nomenclature (Lina et al., ). Only enterotoxins with demonstrated emetic potential in monkeys were designated “SE,” whereas enterotoxins that failed to do so or have not been evaluated in non-human primate models of emesis are designated enterotoxin like (SEl-) toxins (Table 1). The only exception to this rule is Toxic Shock Syndrome Toxin-1 (TSST-1), which was originally designated SEF (Bergdoll et al.,; Reiser et al., ). This toxin's apparent lack of emetic activity, possibly due it being less stable than other SEs (Edwin and Kass, ), prompted the name change to TSST-1, which has remained in place ever since. Joining TSST-1, SElJ is the only other tested SE that is non-emetic (Munson et al.,; Orwin et al.,, ). SElX, SElU, SElW, SElV, and SElY have yet to be tested for emetic activity in non-human primates.

The SE genes are distributed across a variety of different genomic locations

When considering the locations of the enterotoxin genes, selx (Wilson et al., ) and sely (Ono et al., ) are unique as they are found exclusively on the genome. The selx gene can be found in ~95% of S. aureus strains, whereas sely appears less frequently and has only been detected in a handful of strains thus far. In contrast, the other enterotoxin genes are sometimes found alone, but more commonly in groups, on a variety of large mobile segments of DNA called mobile genetic elements (MGEs) (Fraser and Proft,; Argudin et al., ). These MGEs include prophages, plasmids, transposons, S. aureus pathogenicity islands (SaPIs), and the enterotoxin gene clusters (egc) (Table 1) (for a review on staphylococcal MGEs see, Malachowa and DeLeo, ). The egc locus is home to an operon of genes encoding SEG, SEI, SEM, SEN, SEO, and two pseudogenes, φent1 and φent2 (Jarraud et al.,; Monday and Bohach, ). Deletion, duplication and recombination events within this cluster make it a major hub for the generation of new types of SEs and variants (Letertre et al.,; Thomas et al., ). The acquisition of MGEs generally has a significant impact on core genomes by causing striking differences in genome size and structure. In S. aureus, a comparison of the presence of SE genes from several major lineages shows that SE gene composition is strongly linked to specific genetic backgrounds, emphasizing the importance of vertical transmission, rather than horizontal transmission, of SE-encoding MGEs (Goerke et al., ). Around 80% of S. aureus isolates, including commensal, clinical, and food-poisoning isolates, carry an average of 5–6 SE genes (Jarraud et al.,; Baba et al.,; Becker et al.,; Holtfreter et al.,,; Hait et al.,; Lv et al.,; Umeda et al., ).

The enterotoxins can be further separated based on nucleotide and amino acid sequences

The 24 currently identified SEs and SEls, can be further separated into several evolutionary groups based on a comparison of their nucleotide and amino acid sequences; the SEA group (SEA, SED, SEE, SElJ, SEH, SEN, SEO, SEP, SES), the SEB group (SEB, SECs, SEG, SER, SElU, SElW, previously known as SElU2), the SEI group (SEI, SEK, SEL, SEQ, SEM, SElV), and the SElX group (TSST-1, SET, SElX, SElY and members of another group of staphylococcal exotoxins called superantigen-like (SSL) toxins) (for reviews, see Fraser and Proft,; Ono et al., ) (Table 1). A fifth group, which is not produced by staphylococci, but only represented by a group of functionally and structurally similar superantigenic toxins produced by streptococci, will not be discussed further.

The presence or absence of two specific structural features predominantly defines the superantigenic and enterotoxigenic properties of the SEs and explains differences in activity between the evolutionary groups. First, enterotoxins belonging to the SElX and SEB groups only possess one low affinity α-chain major histocompatibility complex (MHC) II binding site, whereas enterotoxins from the SEA and SEI groups contain one low affinity α-chain MHC II and a second, high affinity β-chain MHC II binding site, which generally equates to superior superantigenic activity (Kozono et al., ). Additionally, differences in amino acid composition have given rise to variants of SEB (Kohler et al., ), SEC (Bohach and Schlievert,; Couch and Betley,; Marr et al., ), SED (Johler et al., ), SEG, SEI (Abe et al.,; Blaiotta et al., ), SEK (Aguilar et al., ), SEM, SEN, SEO, SElU, and SElV (Letertre et al.,; Collery et al., ). Compared to the parent toxins, variants of SEB (Kohler et al., ) and SEC (Deringer et al., ) demonstrate altered species tropism or reduced superantigenic activities. The production of these mutations in SEs may be part of a broader strategy of S. aureus to adapt to different host species (Marr et al.,; Edwards et al.,; Johler et al., ).

Second, a separate and distinct loop comprising 9–19 varying amino acids flanked by 2 cysteine residues creating a disulfide bridge, was originally thought to be an essential feature of emesis-inducing SE members from the SEA and SEB evolutionary groups. However, mutational analyses of that loop demonstrated that only the disulfide bond between the two cysteine residues, rather than the loop itself, was required for emesis (Hovde et al., ). These data are consistent with experiments demonstrating that SEs that lack the loop can still induce emesis in primates (Omoe et al., ), leading to the conclusion that there are additional unidentified emesis-associated structural determinant(s) in the SEs.

S. aureus has a complex network of regulatory pathways to control toxin production

S. aureus responds to changes in the environment using a combination of quorum-sensing (QS) (Waters and Bassler, ) and other two-component systems (TCS), of which at least 16 have been discovered in S. aureus to date (Haag and Bagnoli, ), as well as many trans-acting regulatory proteins (Bronner et al., ). S. aureus relies on these systems to quickly make changes in the regulation of genes associated with important physiological features, including drug resistance, metabolism, immune evasion, and virulence. Each system can directly or indirectly control the transcription of specific sets of genes. However, the regulation of one gene may be influenced by multiple systems, leading to additional layers of regulation.

The accessory gene regulator (Agr) QS system, which is activated at high cell densities, is comprised of two transcriptional units transcribed in opposing directions; RNAII, which codes for four genes (agrA, agrB, agrC, and agrD) (Novick et al., ) and RNAIII, a regulatory RNA. These transcripts are controlled by the promoters P2 and P3, respectively. AgrD, which contains the sequence for the autoinducing peptide (AIP), is processed and exported out of the cell by the combined actions of the membrane-associated export protein, AgrB (Ji et al.,,; Mayville et al., ) and a type I signal peptidase, SpsB (Kavanaugh et al., ). AIP acts as the ligand for the membrane bound histidine kinase, AgrC, leading to the phosphorylation of AgrA (Ji et al.,; Lina et al., ). Activated ArgA binds to the P2 and P3 promoters, resulting in the perpetuation of a positive feedback loop (Koenig et al., ).

Expression of agr is affected by various trans-activing regulators, such as the Sar family of regulatory proteins, (SarR, SarS, SarT, SarU, SarX, SarZ, SarV, MgrA, and Rot) (Cheung and Projan,; Heinrichs et al.,; Cheung et al., ), σB (Lauderdale et al., ), and SrrAB (Staphylococcal respiratory response AB) (Yarwood et al.,; Pragman et al., ). Additionally, σB and Rot can affect another important two-component system called SaeRS (Li and Cheung,; Kusch et al., ). Importantly, all these regulatory elements respond to various environmental stresses and stimuli; the SaeRS (S. aureus exoprotein expression) system responds to membrane attack by antimicrobial molecules produced by the innate host defense (Novick and Jiang,; Kuroda et al.,; Geiger et al.,; Cho et al., ), SarA largely responds to changes in microenvironments (Cheung et al., ), σB responds to high temperature, catabolites, alkaline pH, high salinity (Betley et al.,; Wu et al.,; Kullik and Giachino,; Kullik et al.,; Pané-Farré et al., ), whereas the SrrAB system has been shown to be particularly crucial for bacterial growth under anaerobic and hypoxic conditions (Yarwood et al.,; Pragman et al.,; Kinkel et al.,; Mashruwala and Boyd, ). Lastly, Rot, the global gene regulator (Saïd-Salim et al., ) is negatively regulated by RNAIII through an antisense mechanism (Geisinger et al.,; Boisset et al., ).

Regulation of the classical enterotoxins

It has been described early that there is unequal distribution of SE-associated MGEs among S. aureus isolates, and that thus, the host background has profound influences on enterotoxin production (Gaskill and Khan,; Compagnone-Post et al., ). Surprisingly, our understanding of how the enterotoxins are regulated is still rather incomplete, but we do know that enterotoxin regulation is strongly dependent on the regulatory systems described above (Figure 1). Several Agr-controlled staphylococcal toxins, such as alpha-toxin (Morfeldt et al., ) and the family of phenol-soluble modulins (PSMs) (Queck et al., ) are produced between the early logarithmic and stationary phases. Early observations showing that the production of SEB (Czop and Bergdoll,; Gaskill and Khan,; Derzelle et al., ), SEC (Otero et al.,; Regassa et al., ), and SED (Bayles and Iandolo, ) also occurred between the exponential to stationary phases of bacterial growth (Gaskill and Khan,; Regassa et al.,; Zhang and Stewart, ) suggested that they could be regulated by Agr. Indeed, isogenic S. aureus agr mutants showed significant decreases in SEC and SED production compared to the wild-type strain (Regassa et al., ). However, it was later shown that SEB, SEC, and SED is regulated indirectly by other factors. For instance, Agr-dependent regulation of SEB, SEC, and SED occurs via RNAIII-dependent inhibition of Rot (Regassa and Betley,; Tseng et al.,; Tseng and Stewart, ). In addition to Rot, SEB is also negatively regulated by σB (Ziebandt et al.,,; Pané-Farré et al.,; Rogasch et al., ).

In contrast, the production of bacteriophage-associated SEA is generally constitutive (Thomas et al., ), although S. aureus strains with distinct high and low SEA expression patterns have been described (Borst and Betley,; Wallin-Carlquist et al., ). Since the expression pattern of SEA was found to be different from that of SEB, SEC and SED, it was postulated and confirmed that SEA is regulated independently of Agr (Tremaine et al., ). The production of SEA was later discovered to be closely tied to the phage's life cycle (Cao et al., ) and to be inducible by bacterial stress (Zeaki et al., ).

Regulation of the newer enterotoxins

Information surrounding the regulation of the newer enterotoxins is only beginning to emerge. Unlike most of the classical enterotoxins, it appears that the regulation of several newer enterotoxins including SElJ (Zhang et al., ) and SEH (Lis et al., ), is Agr-independent. The expression of SFP-associated SEH, which is produced predominantly in the late exponential phase of bacterial growth (Sakai et al.,; Lis et al., ), was recently shown to be positively regulated by Rot, via direct binding to the seh promoter (Sato'o et al., ), σB (Kusch et al., ), several Sar homologs, and SaeR (Sato'o et al., ). Moreover, SaeRS appears to have a positive impact on SElX (Langley et al., ) and TSST-1 (Baroja et al., ) expression. In contrast, the production of enterotoxins encoded in the egc operon (SEG, SEI, SEM, SEN, SEO, and SElU) is highest in the earliest stages of exponential growth (Grumann et al., ) and dependent on σB (Kusch et al., ). Interestingly, one study showed that SEK production is dependent on the presence of SEB (Aguilar et al., ), whereas SEK and SEQ, which are also found on sea-associated phages, can be transcriptionally induced by mitomycin C (Sumby and Waldor, ). Taken together, the SEs are regulated by multiple regulatory elements that respond to a variety of different environmental signals. Likely, the delicate balance in enterotoxin expression facilitated by these regulatory elements has a profound impact on the commensal and pathogenic lifestyles of S. aureus.

Which staphylococcal enterotoxins contribute to SFP?

To control staphylococcal food poisoning and ensure food safety, the roles of both new and classical SEs must be considered. Although a wide variety of SE detection methods have been developed (Table 2), molecular detection of SE genes remains the most common method used for investigating the possible contribution of SEs toward SFP. Molecular studies spanning the last two decades have shown that egc-encoded genes (seg, seh, sei, or selj) are readily detected in S. aureus food poisoning isolates around the world (Blaiotta et al.,; Grumann et al.,; Yan et al.,; Viçosa et al.,; Chao et al.,; Johler et al.,; Cheng et al.,; Song et al.,; Shen et al.,; Umeda et al., ). Additionally, the detection of non egc-encoded enterotoxin genes, such as transposon associated-seh (McLauchlin et al.,; Ikeda et al.,; Jørgensen et al., ), plasmid-associated ser (Wattinger et al., ) and SaPI-associated seq (Chiang et al.,; Alibayov et al.,; Lv et al.,; Hu et al., ) suggest a role of these newer SEs in SFP.

While PCR is an invaluable tool, confirmation of the physical presence of toxin in food products suspected of contamination is needed to clearly verify their contribution to SFP. The immunological detection of the 5 classical SEs has helped to establish SEA as the top contributor (~80%) to SFP outbreaks (Pinchuk et al.,; Hennekinne et al., ), followed by SED, SEB, SEC, and SEE (Hu and Nakane, ). In contrast, due to the lack of sensitive detection methods, it has been impossible to draw such conclusions for the newer SEs. However, a steadily increasing number of immunological assays for the non-classical enterotoxins, such as SEG (Nagaraj et al., ), SEH (Su and Wong, ), SEI (Zhao et al., ), SEK (Aguilar et al., ), SEM (Zhao et al., ), and SEQ (Hu et al., ) have been developed within the last decade. They indicated that one or more of the newer enterotoxins are potential causes of SFP outbreaks. Although few studies have examined the physical presence of multiple enterotoxins, it is most likely that multiple SEs contribute to SFP. The expansion of existing multiplex assays (Liang et al.,; Adhikari et al., ) would be the most efficient strategy to detect all SEs simultaneously. However, each platform has its advantages and disadvantages (Table 2; Wu et al., for review). An ideal platform to detect all SEs would have high sensitivity, low cross-reactivity, and universal adaptability. Although creating such a system is not impossible, it would be an extremely difficult task, requiring considerable resources, and vigorous testing.

Humans and livestock are major reservoirs for the transmission of enterotoxin-producing S. aureus

S. aureus, a natural colonizer of humans, can be found on the skin (primarily on the hands, chest, and abdomen), gastrointestinal (GI) tract (Ridley,; Armstrong-Esther,; Wertheim et al., ), and nasopharyngeal cavities (Williams, ). All these sites represent possible reservoirs for the distribution of S. aureus causing human disease. Persistent colonization of the anterior nares with S. aureus, which currently is estimated to be around 20–30% of the population (Verhoeven et al., ), is believed to be the most important risk factor for infection, especially regarding health-care associated diseases (Von Eiff et al., ). While colonization of the GI tract by S. aureus has received significantly less attention, recent studies emphasize its underappreciated role in the association with and transmission of S. aureus disease (Nowrouzian et al.,,; Senn et al.,; Gagnaire et al., ). With regards to SFP, studies investigating the presence of enterotoxin genes in S. aureus isolates sampled from the nose (Nashev et al.,; Collery et al.,; Wattinger et al.,; Ho et al., ) and gut (Lis et al.,; Shin et al., ) indicate that these two sites are important sources of enterotoxin-producing S. aureus.

S. aureus is particularly renowned for its ability to acquire and develop resistance to multiple antibiotics, which is a key factor contributing to the difficultly of treating infections caused by this pathogen. A majority of S. aureus infections are caused by methicillin-resistant strains (MRSA), which, historically, have been associated with disease in hospitalized patients in a variety of public healthcare settings [hospital-associated (HA)-MRSA]. However, in the early 1990s, a new breed of genetically distinct MRSA strains started to appear in the community [community-associated (CA)-MRSA] (Otto, ). Compared to the HA-MRSA strains, CA-MRSA strains are exceptionally pathogenic (Chambers,; Cameron et al., ) because of the enhanced production and acquisition of a broad set of virulence factors that contribute to fitness, colonization and virulence (Otto, ). Additionally, MRSA infections in the community can be caused by strains initially associated with livestock [livestock-associated MRSA (LA-MRSA)] (Huijsdens et al.,; Lewis et al.,; Nemati et al., ). For instance, carriage, or infections caused by S. aureus in dairy cattle (e.g., mastitis) can lead to the contamination of dairy products and raw meat. In particular, unprocessed foods hold a substantial risk for the introduction of resistant microbes into the food chain, which can have a considerable economic impact, especially in countries with industrialized dairy sectors (Le Loir et al., ). Interestingly, epidemiological studies have indicated that LA-MRSA isolates belong to genetic lineages different from their HA- and CA-MRSA counterparts (for detailed reviews, see Fluit,; Cuny et al.,; Smith, ) and harbor unique genes that are essential for host adaptation (Lowder et al.,; Guinane et al.,; Price et al., ).

Unsurprisingly, several recent studies reported high levels of multiple antibiotic resistance in LA-MRSA (Kérouanton et al.,; Ge et al.,; Sahibzada et al.,; Abdi et al.,; Suleiman et al., ), but unlike other enteric pathogens, such as Salmonella and E. coli, for which antimicrobial resistance can impose serious health risks in humans (Doyle, ), antibiotic resistance in HA-, CA-, or LA-MRSA isolates had little influence on the ability of S. aureus to cause SFP (Sergelidis and Angelidis, ). These observations are consistent with the notion that SFP is not a disease that is typically treated with antibiotics, since the enterotoxin-driven manifestation of SFP can progress in the absence of bacteria.

Mechanisms underlying enterotoxin-induced emetic and diarrheal activity

Progress in understanding the molecular mechanisms underlying the enterotoxigenic effects of the SEs has been hampered by a lack of relevant animal models. Small rodents, such as mice and rats, are non-emetic and generally less susceptible to the enterotoxigenic effects of the SEs (Bergdoll, ) whereas non-human primates, which are considered the gold standard for testing the emetic activity of enterotoxins, are costly and riddled with complex requirements in animal care and husbandry. However, the house musk shrew, Suncus murinus, was recently identified as a suitable animal model and an alternative to using monkeys (Hu et al., ). Studies in the shrew confirmed that a network of branched connections linking multiple organs of the body with the brain, called the vagus nerve, was an essential element for SE-induced emesis, recapitulating earlier observations from monkeys (Sugiyama and Hayama, ). Further studies in shrews revealed that the MHC II-independent release of 5-hydroxytryptamine (5-HT/Serotonin) from mast cell granules by SEs was crucial for SE-induced emesis (Ono et al., ). Other agonists involved in the emetic response have also been reported (Scheuber et al.,; Alber et al.,; Jett et al., ). In addition to mast cells, the SEs appear to have an affinity for epithelial cells (Hamad et al.,; Shupp et al.,; Danielsen et al.,; Zhao et al., ) and goblet cells (Hirose et al., ). Unlike mast cells, SEs use epithelial cells (Danielsen et al., ) and mucus-producing goblet cells (Hirose et al., ) as gateways in order to traffic across the intestinal epithelia to reach other final targets. Importantly, the movement of enterotoxins through epithelial cells is thought to be a glycolipid-dependent transcytosis process that may be facilitated in the presence of other S. aureus virulence determinants (Edwards et al., ). Interestingly, a conserved stretch of 10-amino-acid peptides, located within the longest alpha-helical chain between the A and B domains of the enterotoxins, is an important structural determinant that promotes translocation (Shupp et al.,; Figure 2).

In contrast to strong induction of emesis, the clinical symptoms of diarrhea are oftentimes less apparent in SFP, which may be in part due to the inability of some SEs, such as SEA and SEC, to cause fluid exudation and dilation of the intestinal segments (Maina et al., ). However, the symptoms of diarrhea sometimes observed with SEB intoxication may be due to the inhibition of water and electrolyte reabsorption in the small intestine (Sullivan,; Sheahan et al., ). To this date, exactly how the SEs cause diarrhea is still far from understood. For a detailed review on other aspects of SE-induced emesis, see (Hu and Nakane, ).

The superantigenic activities of the enterotoxins

The molecular details underlying the superantigenic activity of the SEs have been dissected by numerous X-ray crystallography, structural and mutational analyses. Unlike with conventional antigens, the non-specific activation of T cells by SEs occurs independently of antigen processing and presentation to the T cells by antigen-presenting cells (APCs). Instead, SEs act as a bridge between APCs and T cells. In the majority of cases, SEs first bind to the MHC class II molecules found on APCs and coordinate binding to one or more variable beta (Vβ) chain(s) of T-cell receptors (TCRs) (Kappler et al.,; White et al.,; Choi et al.,; Jarraud et al., ). However, these molecular interactions are not exclusive and other receptors have been described to be involved. For instance, the variable alpha (Vα) chain can be targeted by SEH (Saline et al., ). Moreover, maximal superantigenic activity of SEB is dependent on additional co-stimulatory receptors, CD28 and B7-2, on T cells and APCs, respectively (Arad et al.,; Levy et al., ). Interestingly, the same CD28 binding site can be found on other SEs, such as SEA and TSST-1 (Arad et al., ). Regardless of the mechanism of cross-linking, characteristic for SE activity is a polyclonal activation of a large pool of CD4+ and CD8+ T cells (~20% of the total T cells) (Marrack et al.,; Miethke et al.,; Leder et al., ) followed by a massive release of an assortment of T helper 1 (Th1) cytokines, such as tumor necrosis factor (TNF) α, interleukin 1 (IL-1), IL-2, and interferon (IFN) γ (Carlsson et al.,; Tiedemann and Fraser, ), all of which contribute to the SE superantigenic effect (for a detailed reviews, see Krakauer,; Krakauer et al., ).

The enterotoxins are immunomodulators of multiple immune cell types

The superantigenic and enterotoxigenic activities of the SEs are the best studied mechanisms underlying their pathogenicity. However, recent studies show that the SEs possess functions in addition to these conventional activities. For example, both TSST-1 and SElX (Wilson et al., ) show similarity to another family of staphylococcal exotoxins, called the staphylococcal superantigen-like (SSL) toxins (reviewed in Fraser and Proft, ). Although the SSL toxins lack the ability to induce Vβ-specific T-cell proliferation, they have diverse roles in immune evasion, including the ability to interfere with complement activation and neutrophil function (reviewed in Langley et al., ). Recently, it was discovered that SElX has a unique sialic acid-binding motif. This motif allows SElX to interact with adhesion molecules on neutrophils involved in immune recognition and cell activation (Langley et al.,; Tuffs et al., ). Importantly, the ability of SElX to bind neutrophils, which are considered the first line of defense against S. aureus (Spaan et al., ), was crucial for disease progression in a rabbit model of necrotizing pneumonia. Together, these studies describe an unusual member of the SE family that has both superantigenic and SSL functions.

Neutrophils are the latest among a growing list of immune cell types recognized to be targeted directly or indirectly by the SEs. Others include γδ T cells (Maeurer et al.,; Morita et al., ), invariant natural killer T (iNKT) cells (Rieder et al.,; Hayworth et al., ), B cells (Stohl et al., ), mast cells (Scheuber et al.,; Lotfi-Emran et al., ), and mucosa-associated invariant T (MAIT) cells (Shaler et al., ). Activation of these cell types by SEs can have a considerable impact on the immune system, which may lead to non-conventional overstimulation of the immune system, as exemplified by B cell proliferation and differentiation into plasma cells (Stohl et al., ). Additionally, excessive inflammation, as a result of the direct activation of iNKT cells and γδ T cells, can cause the production of SE-associated inflammatory disease in the lungs (Rieder et al., ) and systemic infection, as demonstrated in mouse infection models (Szabo et al., ).

In contrast to the overstimulation of the immune response by SEs, the activation of MAIT cells appears to have the opposite effect (Shaler et al., ). MAIT cells have significant roles in innate host defense against a variety of pathogens (Napier et al., ). Notably, the activation of MAIT cells by SEs was shown to be induced in a TCR-independent manner (Shaler et al., ). While direct activation of the MAIT cells by SEs could not be excluded, MAIT cell activation was mediated mostly by IL-12 and IL-18 released from the direct activation of conventional T cells by SEs (Shaler et al., ). Following a period of hyper-activation, these MAIT cells rapidly undergo exhaustion and are unable to respond further, leaving behind a suppressed and severely crippled arc of innate host defense.

Could enterotoxicity be dependent on T-cell immunomodulation?

Whether the superantigenic function is needed for the enterotoxigenic activity of the SEs is an interesting question. Shock and fever, hallmarks of superantigen-induced disease, is generally low or absent in patients with SFP (Dinges et al., ), arguing against the activation of a systemic immune response. However, it was shown that 5 times more of an SEA protein derivative, which lacked superantigenic but retained emetic activity, was required to induce emesis in a monkey model compared to unaltered SEA (Hoffman et al., ). This observation implies that both superantigenic and enterotoxicity activities are likely needed for a maximal emetic response.

Another aspect of immune interaction that may need to be further investigated is the potential role of T cells in SE enterotoxic activities. MAIT cells for example, which have been shown to have a protective role against GI bacterial disease (Powell and Macdonald,; Salerno-Goncalves et al., ), represent ~10% of intestinal T cells (Treiner et al.,; Dusseaux et al., ) and ~50% of T cells in the intestines express γδ TCRs (Carding and Egan, ). Furthermore, γδ T cells that are present in the gut mucosa play an important role in mucosal immunity (Agace, ). Additionally, given that the SEs are highly potent at very low concentrations, enhanced expression of SEs may not be essential for the advancement of SE-mediated disease. In fact, when regulatory T cells (Tregs) are stimulated with lower concentrations of SEC, an immunosuppressed phenotype can be induced that may directly benefit S. aureus colonization and disease progression (Lee et al., ). In the healthy gut, Tregs play a crucial role in the maintenance of intestinal homeostasis by controlling inappropriate immune responses (Luu et al., ). Therefore, it is tempting to speculate that the combined targeting of MAIT cells, γδ T cells and Tregs in the gut by SEs may promote the pathogenesis of SFP. Whether MAIT, γδ T cells, and Tregs play any roles in SFP requires much more detailed investigation.

Conclusions

Although the classical enterotoxins have historically been considered the predominant contributors to SFP, a number of molecular studies suggest that many of the newer SEs also have a prominent role. However, in order to better determine which SEs are responsible for SFP, it is best for studies investigating SFP outbreaks to employ methods that can detect all SE genes as well as the physical presence of toxin in suspected contaminated foods. The ability to culture and accurately characterize SFP-causing S. aureus will significantly help understand true incidence and prevalence of SFP. It should also be noted that the inability to detect SEs in contaminated foods does not exclude that they contribute to SFP. Therefore, it is just as vital that we have a deeper understanding of what promotes SE production, especially in food environments. While it is accepted that multiple regulatory networks can have a significant impact on enterotoxin expression, it remains poorly understood how specific enterotoxins, especially the newer enterotoxins, are regulated.

In this review, we also provided an overview of the molecular mechanisms that contribute to SFP. Yet, compared to what we know about staphylococcal superantigen-associated disease, our comprehension of the structural elements and mechanisms by which SEs induce SFP has remained limited, especially considering that SFP is a common disease that continues to affect millions worldwide. A key gap in our knowledge is whether the superantigenicity of the SEs plays a pathogenic role in SFP. There is evidence that suggests that the manifestation of SFP does not solely rely on the enterotoxic function of SEs. Furthermore, we highlighted that different immune and non-immune cell types are susceptible to immunomodulation by the SEs. Any possible interaction between the SEs and these cell types, especially in the gut environment, is worth exploring. Overall, the molecular details involved in SE-mediated enterotoxigenic disease are slowly being uncovered; however, many basic questions remain. Future challenges therefore will consist of deciphering the series of events that lead to disease and whether there are other key cellular players, and identifying an appropriate animal model that is amenable to genetic manipulation.

Author contributions

EF, GC, and MO: contributed to the drafting of the manuscript and approved the final version.

Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

References 285

  1. 1.

    Abdi R. D. Gillespie B. E. Vaughn J. Merrill C. Headrick S. I. Ensermu D. B.. (2018 ). Antimicrobial resistance of Staphylococcus aureus isolates from dairy cows and genetic diversity of resistant isolates. Foodborne Pathog. Dis. [Epub ahead of print].

    Not in our library10.1089/fpd.2017.2362

  2. 2.

    Abe J. Ito Y. Onimaru M. Kohsaka T. Takeda T. (2000 ). Characterization and distribution of a new enterotoxin-related superantigen produced by Staphylococcus aureus. Microbiol. Immunol. 44, 79–88.

    Not in our library10.1111/j.1348-0421.2000.tb01250.x

  3. 3.

    Adhikari R. P. Haudenschild C. Sterba P. M. Sahandi S. Enterlein S. Holtsberg F. W.. (2016 ). Development of a novel multiplex electrochemiluminescent-based immunoassay for quantification of human serum IgG against 10 Staphylococcus aureus toxins. J. Immunol. Methods 430, 33–42.

    Not in our library10.1016/j.jim.2016.01.013

  4. 4.

    Agace W. W. (2008 ). T-cell recruitment to the intestinal mucosa. Trends Immunol. 29, 514–522.

    Not in our library10.1016/j.it.2008.08.003

  5. 5.

    Aguilar J. L. Varshney A. K. Wang X. Stanford L. Scharff M. Fries B. C. (2014 ). Detection and measurement of staphylococcal enterotoxin-like K (SEl-K) secretion by Staphylococcus aureus clinical isolates. J. Clin. Microbiol. 52, 2536–2543.

    Not in our library10.1128/jcm.00387-14

  6. 6.

    Alber G. Scheuber P. H. Reck B. Sailer-Kramer B. Hartmann A. Hammer D. K. (1989 ). Role of substance P in immediate-type skin reactions induced by staphylococcal enterotoxin B in unsensitized monkeys. J. Allergy Clin. Immunol. 84, 880–885.

    Not in our library10.1016/0091-6749(89)90383-7

  7. 7.

    Alibayov B. Zdenkova K. Sykorova H. Demnerova K. (2014 ). Molecular analysis of Staphylococcus aureus pathogenicity islands (SaPI) and their superantigens combination of food samples. J. Microbiol. Methods 107, 197–204.

    Not in our library10.1016/j.mimet.2014.10.014

  8. 8.
  9. 9.
  10. 10.

    Armstrong-Esther C. A. (1976 ). Carriage patterns of Staphylococcus aureus in a healthy non-hospital population of adults and children. Ann. Hum. Biol. 3, 221–227.

    Not in our library10.1080/03014467600001381

  11. 11.

    Asao T. Kumeda Y. Kawai T. Shibata T. Oda H. Haruki K.. (2003 ). An extensive outbreak of staphylococcal food poisoning due to low-fat milk in Japan: estimation of enterotoxin A in the incriminated milk and powdered skim milk. Epidemiol. Infect. 130, 33–40.

    Not in our library10.1017/s0950268802007951

  12. 12.

    Baba T. Takeuchi F. Kuroda M. Yuzawa H. Aoki K. Oguchi A.. (2002 ). Genome and virulence determinants of high virulence community-acquired MRSA. Lancet 359, 1819–1827.

    Not in our library10.1016/s0140-6736(02)08713-5

  13. 13.

    Baroja M. L. Herfst C. A. Kasper K. J. Xu S. X. Gillett D. A. Li J.. (2016 ). The SaeRS two-component system is a direct and dominant transcriptional activator of toxic shock syndrome toxin 1 in Staphylococcus aureus. J. Bacteriol. 198, 2732–2742.

    Not in our library10.1128/jb.00425-16

  14. 14.

    Bayles K. W. Iandolo J. J. (1989 ). Genetic and molecular analyses of the gene encoding staphylococcal enterotoxin D. J. Bacteriol. 171, 4799–4806.

    Not in our library10.1128/jb.171.9.4799-4806.1989

  15. 15.

    Becker K. Friedrich A. W. Lubritz G. Weilert M. Peters G. Von Eiff C. (2003 ). Prevalence of genes encoding pyrogenic toxin superantigens and exfoliative toxins among strains of Staphylococcus aureus isolated from blood and nasal specimens. J. Clin. Microbiol. 41, 1434–1439.

    Not in our library10.1128/jcm.41.4.1434-1439.2003

  16. 16.

    Bennett S. D. Walsh K. A. Gould L. H. (2013 ). Foodborne disease outbreaks caused by Bacillus cereus, Clostridium perfringens, and Staphylococcus aureus- United States, 1998-2008. Clin. Infect. Dis. 57, 425–433.

    Not in our library10.1093/cid/cit244

  17. 17.

    Bergdoll M. S. (1983 ). Enterotoxins, in Staphylococci and Staphylococcal Infections, eds Easton C. S. F. Adlam C. (London: Academic Press), 559–598.

    Not in our library

  18. 18.

    Bergdoll M. S. (1988 ). Monkey feeding test for staphylococcal enterotoxin. Methods Enzymol. 165, 324–333.

    Not in our library10.1016/s0076-6879(88)65048-8

  19. 19.

    Bergdoll M. S. Borja C. R. Avena R. M. (1965 ). Identification of a new enterotoxin as enterotoxin C. J. Bacteriol. 90, 1481–1485.

    Not in our library10.1128/jb.90.5.1481-1485.1965

  20. 20.

    Bergdoll M. S. Borja C. R. Robbins R. N. Weiss K. F. (1971 ). Identification of enterotoxin E. Infect. Immun. 4, 593–595.

    Not in our library10.1128/iai.4.5.593-595.1971

  21. 21.

    Bergdoll M. S. Crass B. A. Reiser R. F. Robbins R. N. Davis J. P. (1981 ). A new staphylococcal enterotoxin, enterotoxin F, associated with toxic-shock-syndrome Staphylococcus aureus isolates. Lancet 1, 1017–1021.

    Not in our library10.1016/s0140-6736(81)92186-3

  22. 22.

    Bergdoll M. S. Robbins R. N. Weiss K. Borja C. R. Huang Y. Chu F. S. (1973 ). The staphylococcal enterotoxins: similarities. Contrib. Microbiol. Immunol. 1, 390–396.

    Not in our library

  23. 23.

    Betley M. J. Borst D. W. Regassa L. B. (1992 ). Staphylococcal enterotoxins, toxic shock syndrome toxin and streptococcal pyrogenic exotoxins: a comparative study of their molecular biology. Chem. Immunol. 55, 1–35.

    Not in our library

  24. 24.

    Blaiotta G. Ercolini D. Pennacchia C. Fusco V. Casaburi A. Pepe O.. (2004 ). PCR detection of staphylococcal enterotoxin genes in Staphylococcus spp. strains isolated from meat and dairy products. Evidence for new variants of seg and sei in S. aureus AB-8802. J. Appl. Microbiol. 97, 719–730.

    Not in our library10.1111/j.1365-2672.2004.02349.x

  25. 25.

    Bohach G. A. Schlievert P. M. (1987 ). Nucleotide sequence of the staphylococcal enterotoxin C1 gene and relatedness to other pyrogenic toxins. Mol. Gen. Genet. 209, 15–20.

    Not in our library10.1007/bf00329830

  26. 26.

    Boisset S. Geissmann T. Huntzinger E. Fechter P. Bendridi N. Possedko M.. (2007 ). Staphylococcus aureus RNAIII coordinately represses the synthesis of virulence factors and the transcription regulator Rot by an antisense mechanism. Genes Dev. 21, 1353–1366.

    Not in our library10.1101/gad.423507

  27. 27.

    Borst D. W. Betley M. J. (1994 ). Promoter analysis of the staphylococcal enterotoxin A gene. J. Biol. Chem. 269, 1883–1888.

    Not in our library

  28. 28.

    Bronner S. Monteil H. Prévost G. (2004 ). Regulation of virulence determinants in Staphylococcus aureus: complexity and applications. FEMS Microbiol. Rev. 28, 183–200.

    Not in our library10.1016/j.femsre.2003.09.003

  29. 29.

    Bruno J. G. Kiel J. L. (2002 ). Use of magnetic beads in selection and detection of biotoxin aptamers by electrochemiluminescence and enzymatic methods. BioTechniques 32, 178–180, 182–183.

    Not in our library10.2144/02321dd04

  30. 30.

    Callahan J. H. Shefcheck K. J. Williams T. L. Musser S. M. (2006 ). Detection, confirmation, and quantification of staphylococcal enterotoxin B in food matrixes using liquid chromatography - mass spectrometry. Anal. Chem. 78, 1789–1800.

    Not in our library10.1021/ac051292v

  31. 31.

    Cameron D. R. Howden B. P. Peleg A. Y. (2011 ). The interface between antibiotic resistance and virulence in Staphylococcus aureus and its impact upon clinical outcomes. Clin. Infect. Dis. 53, 576–582.

    Not in our library10.1093/cid/cir473

  32. 32.

    Cao R. Zeaki N. Wallin-Carlquist N. Skandamis P. N. Schelin J. Rådström P. (2012 ). Elevated enterotoxin A expression and formation in Staphylococcus aureus and its association with prophage induction. Appl. Environ. Microbiol. 78, 4942–4948.

    Not in our library10.1128/aem.00803-12

  33. 33.

    Carding S. R. Egan P. J. (2002 ). Gammadelta T cells: functional plasticity and heterogeneity. Nat. Rev. Immunol. 2, 336–345.

    Not in our library10.1038/nri797

  34. 34.

    Carlsson R. Fischer H. Sjögren H. O. (1988 ). Binding of staphylococcal enterotoxin A to accessory cells is a requirement for its ability to activate human T cells. J. Immunol. 140, 2484–2488.

    Not in our library

  35. 35.

    Casman E. P. Bennett R. W. Dorsey A. E. Issa J. A. (1967 ). Identification of a fourth staphylococcal enterotoxin, enterotoxin D. J. Bacteriol. 94, 1875–1882.

    Not in our library10.1128/jb.94.6.1875-1882.1967

  36. 36.
  37. 37.

    Chao G. Bao G. Cao Y. Yan W. Wang Y. Zhang X.. (2015 ). Prevalence and diversity of enterotoxin genes with genetic background of Staphylococcus aureus isolates from different origins in China. Int. J. Food Microbiol. 211, 142–147.

    Not in our library10.1016/j.ijfoodmicro.2015.07.018

  38. 38.

    Cheng J. Wang Y. Cao Y. Yan W. Niu X. Zhou L.. (2016 ). The distribution of 18 enterotoxin and enterotoxin-like genes in Staphylococcus aureus strains from different sources in East China. Foodborne Pathog. Dis. 13, 171–176.

    Not in our library10.1089/fpd.2015.1963

  39. 39.

    Cheung A. L. Projan S. J. (1994 ). Cloning and sequencing of sarA of Staphylococcus aureus, a gene required for the expression of agr. J. Bacteriol. 176, 4168–4172.

    Not in our library10.1128/jb.176.13.4168-4172.1994

  40. 40.

    Cheung A. L. Bayer A. S. Zhang G. Gresham H. Xiong Y. Q. (2004 ). Regulation of virulence determinants in vitro and in vivo in Staphylococcus aureus. FEMS Immunol. Med. Microbiol. 40, 1–9.

    Not in our library10.1016/s0928-8244(03)00309-2

  41. 41.

    Cheung A. L. Nishina K. A. Trotonda M. P. Tamber S. (2008 ). The SarA protein family of Staphylococcus aureus. Int. J. Biochem. Cell Biol. 40, 355–361.

    Not in our library10.1016/j.biocel.2007.10.032

  42. 42.

    Chiang Y. C. Liao W. W. Fan C. M. Pai W. Y. Chiou C. S. Tsen H. Y. (2008 ). PCR detection of staphylococcal enterotoxins (SEs) N, O, P, Q, R, U, and survey of SE types in Staphylococcus aureus isolates from food-poisoning cases in Taiwan. Int. J. Food Microbiol. 121, 66–73.

    Not in our library10.1016/j.ijfoodmicro.2007.10.005

  43. 43.

    Cho H. Jeong D. W. Liu Q. Yeo W. S. Vogl T. Skaar E. P.. (2015 ). Calprotectin increases the activity of the SaeRS two component system and murine mortality during Staphylococcus aureus infections. PLoS Pathog. 11:e1005026.

    Not in our library10.1371/journal.ppat.1005026

  44. 44.

    Choi Y. W. Herman A. Digiusto D. Wade T. Marrack P. Kappler J. (1990 ). Residues of the variable region of the T-cell-receptor beta-chain that interact with S. aureus toxin superantigens. Nature 346, 471–473.

    Not in our library10.1038/346471a0

  45. 45.

    Collery M. M. Smyth D. S. Tumilty J. J. Twohig J. M. Smyth C. J. (2009 ). Associations between enterotoxin gene cluster types egc1, egc2 and egc3, agr types, enterotoxin and enterotoxin-like gene profiles, and molecular typing characteristics of human nasal carriage and animal isolates of Staphylococcus aureus. J. Med. Microbiol. 58, 13–25.

    Not in our library10.1099/jmm.0.005215-0

  46. 46.

    Compagnone-Post P. Malyankar U. Khan S. A. (1991 ). Role of host factors in the regulation of the enterotoxin B gene. J. Bacteriol. 173, 1827–1830.

    Not in our library10.1128/jb.173.5.1827-1830.1991

  47. 47.

    Couch J. L. Betley M. J. (1989 ). Nucleotide sequence of the type C3 staphylococcal enterotoxin gene suggests that intergenic recombination causes antigenic variation. J. Bacteriol. 171, 4507–4510.

    Not in our library10.1128/jb.171.8.4507-4510.1989

  48. 48.
  49. 49.

    Czop J. K. Bergdoll M. S. (1974 ). Staphylococcal enterotoxin synthesis during the exponential, transitional, and stationary growth phases. Infect. Immun. 9, 229–235.

    Not in our library10.1128/iai.9.2.229-235.1974

  50. 50.

    Dack G. M. (1937 ). Staphylococci in relation to food poisoning. Am. J. Public Health Nations. Health. 27, 440–443.

    Not in our library10.2105/ajph.27.5.440

  51. 51.

    Danielsen E. M. Hansen G. H. Karlsdóttir E. (2013 ). Staphylococcus aureus enterotoxins A- and B: binding to the enterocyte brush border and uptake by perturbation of the apical endocytic membrane traffic. Histochem. Cell Biol. 139, 513–524.

    Not in our library10.1007/s00418-012-1055-8

  52. 52.

    Deringer J. R. Ely R. J. Monday S. R. Stauffacher C. V. Bohach G. A. (1997 ). Vbeta-dependent stimulation of bovine and human T cells by host-specific staphylococcal enterotoxins. Infect. Immun. 65, 4048–4054.

    Not in our library10.1128/iai.65.10.4048-4054.1997

  53. 53.

    Derzelle S. Dilasser F. Duquenne M. Deperrois V. (2009 ). Differential temporal expression of the staphylococcal enterotoxins genes during cell growth. Food Microbiol. 26, 896–904.

    Not in our library10.1016/j.fm.2009.06.007

  54. 54.

    Dinges M. M. Orwin P. M. Schlievert P. M. (2000 ). Exotoxins of Staphylococcus aureus. Clin. Microbiol. Rev. 13, 16–34.

    Not in our library10.1128/cmr.13.1.16-34.2000

  55. 55.

    Do Carmo L. S. Cummings C. Linardi V. R. Dias R. S. De Souza J. M. De Sena M. J.. (2004 ). A case study of a massive staphylococcal food poisoning incident. Foodborne Pathog. Dis. 1, 241–246.

    Not in our library10.1089/fpd.2004.1.241

  56. 56.

    Doyle M. E. (2015 ). Multidrug-resistant pathogens in the food supply. Foodborne Pathog. Dis. 12, 261–279.

    Not in our library10.1089/fpd.2014.1865

  57. 57.

    Dusseaux M. Martin E. Serriari N. Péguillet I. Premel V. Louis D.. (2011 ). Human MAIT cells are xenobiotic-resistant, tissue-targeted, CD161hi IL-17-secreting T cells. Blood 117, 1250–1259.

    Not in our library10.1182/blood-2010-08-303339

  58. 58.

    Edwards L. A. O'neill C. Furman M. A. Hicks S. Torrente F. Pérez-Machado M.. (2012 ). Enterotoxin-producing staphylococci cause intestinal inflammation by a combination of direct epithelial cytopathy and superantigen-mediated T-cell activation. Inflamm. Bowel Dis. 18, 624–640.

    Not in our library10.1002/ibd.21852

  59. 59.

    Edwards V. M. Deringer J. R. Callantine S. D. Deobald C. F. Berger P. H. Kapur V.. (1997 ). Characterization of the canine type C enterotoxin produced by Staphylococcus intermedius pyoderma isolates. Infect. Immun. 65, 2346–2352.

    Not in our library10.1128/iai.65.6.2346-2352.1997

  60. 60.

    Edwin C. Kass E. H. (1989 ). Identification of functional antigenic segments of toxic shock syndrome toxin 1 by differential immunoreactivity and by differential mitogenic responses of human peripheral blood mononuclear cells, using active toxin fragments. Infect. Immun. 57, 2230–2236.

    Not in our library10.1128/iai.57.7.2230-2236.1989

  61. 61.

    Ercoli L. Gallina S. Nia Y. Auvray F. Primavilla S. Guidi F.. (2017 ). Investigation of a staphylococcal food poisoning outbreak from a Chantilly cream dessert, in Umbria (Italy). Foodborne Pathog. Dis. 14, 407–413.

    Not in our library10.1089/fpd.2016.2267

  62. 62.

    Evenson M. L. Hinds M. W. Bernstein R. S. Bergdoll M. S. (1988 ). Estimation of human dose of staphylococcal enterotoxin A from a large outbreak of staphylococcal food poisoning involving chocolate milk. Int. J. Food Microbiol. 7, 311–316.

    Not in our library10.1016/0168-1605(88)90057-8

  63. 63.

    Fluit A. C. (2012 ). Livestock-associated Staphylococcus aureus. Clin. Microbiol. Infect. 18, 735–744.

    Not in our library10.1111/j.1469-0691.2012.03846.x

  64. 64.

    Fraser J. D. Proft T. (2008 ). The bacterial superantigen and superantigen-like proteins. Immunol. Rev. 225, 226–243.

    Not in our library10.1111/j.1600-065x.2008.00681.x

  65. 65.

    Fulton F. (1943 ). Staphylococcal enterotoxin - With special reference to the kitten test. Br. J. Exp. Pathol. 24, 65–72.

    Not in our library

  66. 66.

    Gagnaire J. Verhoeven P. O. Grattard F. Rigaill J. Lucht F. Pozzetto B.. (2017 ). Epidemiology and clinical relevance of Staphylococcus aureus intestinal carriage: a systematic review and meta-analysis. Expert Rev. Anti Infect. Ther. 15, 767–785.

    Not in our library10.1080/14787210.2017.1358611

  67. 67.

    Gaskill M. E. Khan S. A. (1988 ). Regulation of the enterotoxin B gene in Staphylococcus aureus. J. Biol. Chem. 263, 6276–6280.

    Not in our library

  68. 68.

    Ge B. Mukherjee S. Hsu C. H. Davis J. A. Tran T. T. T. Yang Q.. (2017 ). MRSA and multidrug-resistant Staphylococcus aureus in U.S. retail meats, 2010-2011. Food Microbiol. 62, 289–297.

    Not in our library10.1016/j.fm.2016.10.029

  69. 69.

    Geiger T. Goerke C. Mainiero M. Kraus D. Wolz C. (2008 ). The virulence regulator Sae of Staphylococcus aureus: promoter activities and response to phagocytosis-related signals. J. Bacteriol. 190, 3419–3428.

    Not in our library10.1128/jb.01927-07

  70. 70.

    Geisinger E. Adhikari R. P. Jin R. Ross H. F. Novick R. P. (2006 ). Inhibition of rot translation by RNAIII, a key feature of agr function. Mol. Microbiol. 61, 1038–1048.

    Not in our library10.1111/j.1365-2958.2006.05292.x

  71. 71.

    Gkogka E. Reij M. W. Havelaar A. H. Zwietering M. H. Gorris L. G. (2011 ). Risk-based estimate of effect of foodborne diseases on public health, Greece. Emerg. Infect. Dis. 17, 1581–1590.

    Not in our library10.3201/eid1709.101766

  72. 72.

    Goerke C. Pantucek R. Holtfreter S. Schulte B. Zink M. Grumann D.. (2009 ). Diversity of prophages in dominant Staphylococcus aureus clonal lineages. J. Bacteriol. 191, 3462–3468.

    Not in our library10.1128/jb.01804-08

  73. 73.

    Goldman E. R. Anderson G. P. Tran P. T. Mattoussi H. Charles P. T. Mauro J. M. (2002 ). Conjugation of luminescent quantum dots with antibodies using an engineered adaptor protein to provide new reagents for fluoroimmunoassays. Anal. Chem. 74, 841–847.

    Not in our library10.1021/ac010662m

  74. 74.

    Grumann D. Scharf S. S. Holtfreter S. Kohler C. Steil L. Engelmann S.. (2008 ). Immune cell activation by enterotoxin gene cluster (egc)-encoded and non-egc superantigens from Staphylococcus aureus. J. Immunol. 181, 5054–5061.

    Not in our library10.4049/jimmunol.181.7.5054

  75. 75.

    Guinane C. M. Ben Zakour N. L. Tormo-Mas M. A. Weinert L. A. Lowder B. V. Cartwright R. A.. (2010 ). Evolutionary genomics of Staphylococcus aureus reveals insights into the origin and molecular basis of ruminant host adaptation. Genome Biol. Evol. 2, 454–466.

    Not in our library10.1093/gbe/evq031

  76. 76.

    Gupta G. Bhaskar A. S. Tripathi B. K. Pandey P. Boopathi M. Rao P. V.. (2011 ). Supersensitive detection of T-2 toxin by the in situ synthesized pi-conjugated molecularly imprinted nanopatterns. An in situ investigation by surface plasmon resonance combined with electrochemistry. Biosens. Bioelectron. 26, 2534–2540.

    Not in our library10.1016/j.bios.2010.10.050

  77. 77.

    Haag A. F. Bagnoli F. (2016 ). The role of two-component signal transduction systems in Staphylococcus aureus virulence regulation. Curr Top Microbiol. Immunol. 409, 145–198.

    Not in our library10.1007/82_2015_5019

  78. 78.

    Hait J. Tallent S. Melka D. Keys C. Bennett R. (2014 ). Prevalence of enterotoxins and toxin gene profiles of Staphylococcus aureus isolates recovered from a bakery involved in a second staphylococcal food poisoning occurrence. J. Appl. Microbiol. 117, 866–875.

    Not in our library10.1111/jam.12571

  79. 79.

    Hamad A. R. Marrack P. Kappler J. W. (1997 ). Transcytosis of staphylococcal superantigen toxins. J. Exp. Med. 185, 1447–1454.

    Not in our library10.1084/jem.185.8.1447

  80. 80.

    Harteveld J. L. Nieuwenhuizen M. S. Wils E. R. (1997 ). Detection of staphylococcal enterotoxin B employing a piezoelectric crystal immunosensor. Biosens. Bioelectron. 12, 661–667.

    Not in our library10.1016/s0956-5663(97)00024-9

  81. 81.

    Hayworth J. L. Mazzuca D. M. Maleki Vareki S. Welch I. Mccormick J. K. Haeryfar S. M. (2012 ). CD1d-independent activation of mouse and human iNKT cells by bacterial superantigens. Immunol. Cell Biol. 90, 699–709.

    Not in our library10.1038/icb.2011.90

  82. 82.

    Heinrichs J. H. Bayer M. G. Cheung A. L. (1996 ). Characterization of the sar locus and its interaction with agr in Staphylococcus aureus. J. Bacteriol. 178, 418–423.

    Not in our library10.1128/jb.178.2.418-423.1996

  83. 83.

    Hennekinne J. A. De Buyser M. L. Dragacci S. (2012 ). Staphylococcus aureus and its food poisoning toxins: characterization and outbreak investigation. FEMS Microbiol. Rev. 36, 815–836.

    Not in our library10.1111/j.1574-6976.2011.00311.x

  84. 84.

    Hirose S. Ono H. K. Omoe K. Hu D. L. Asano K. Yamamoto Y.. (2016 ). Goblet cells are involved in translocation of staphylococcal enterotoxin A in the intestinal tissue of house musk shrew (Suncus murinus). J. Appl. Microbiol. 120, 781–789.

    Not in our library10.1111/jam.13029

  85. 85.

    Ho J. Boost M. O'donoghue M. (2015 ). Prevalence of enterotoxin genes in Staphylococcus aureus colonising food handlers: does nasal carriage status matter? Eur. J. Clin. Microbiol. Infect. Dis. 34, 2177–2181.

    Not in our library10.1007/s10096-015-2465-z

  86. 86.

    Hoffman M. Tremaine M. Mansfield J. Betley M. (1996 ). Biochemical and mutational analysis of the histidine residues of staphylococcal enterotoxin A. Infect. Immun. 64, 885–890.

    Not in our library10.1128/iai.64.3.885-890.1996

  87. 87.

    Holtfreter S. Bauer K. Thomas D. Feig C. Lorenz V. Roschack K. (2004 ). egc-encoded superantigens from Staphylococcus aureus are neutralized by human sera much less efficiently than are classical staphylococcal enterotoxins or toxic shock syndrome toxin. Infect. Immun. 72, 4061–4071.

    Not in our library10.1128/iai.72.7.4061-4071.2004

  88. 88.

    Holtfreter S. Grumann D. Schmudde M. Nguyen H. T. Eichler P. Strommenger B.. (2007 ). Clonal distribution of superantigen genes in clinical Staphylococcus aureus isolates. J. Clin. Microbiol. 45, 2669–2680.

    Not in our library10.1128/jcm.00204-07

  89. 89.
  90. 90.

    Hovde C. J. Marr J. C. Hoffmann M. L. Hackett S. P. Chi Y. I. Crum K. K.. (1994 ). Investigation of the role of the disulphide bond in the activity and structure of staphylococcal enterotoxin C1. Mol. Microbiol. 13, 897–909.

    Not in our library10.1111/j.1365-2958.1994.tb00481.x

  91. 91.

    Hu D. L. Nakane A. (2014 ). Mechanisms of staphylococcal enterotoxin-induced emesis. Eur. J. Pharmacol. 722, 95–107.

    Not in our library10.1016/j.ejphar.2013.08.050

  92. 92.

    Hu D. L. Omoe K. Shimoda Y. Nakane A. Shinagawa K. (2003 ). Induction of emetic response to staphylococcal enterotoxins in the house musk shrew (Suncus murinus). Infect. Immun. 71, 567–570.

    Not in our library10.1128/iai.71.1.567-570.2003

  93. 93.

    Hu D. L. Omoe K. Shimura H. Ono K. Sugii S. Shinagawa K. (1999 ). Emesis in the shrew mouse (Suncus murinus) induced by peroral and intraperitoneal administration of staphylococcal enterotoxin A. J. Food Prot. 62, 1350–1353.

    Not in our library10.4315/0362-028x-62.11.1350

  94. 94.

    Hu D. L. Ono H. K. Isayama S. Okada R. Okamura M. Lei L. C.. (2017 ). Biological characteristics of staphylococcal enterotoxin Q and its potential risk for food poisoning. J. Appl. Microbiol. 122, 1672–1679.

    Not in our library10.1111/jam.13462

  95. 95.
  96. 96.

    Humber J. Y. Denny C. B. Bohrer C. W. (1975 ). Influence of pH on the heat inactivation of staphylococcal enterotoxin A as determined by monkey feeding and serological assay. Appl. Microbiol. 30, 755–758.

    Not in our library10.1128/am.30.5.755-758.1975

  97. 97.
  98. 98.

    Huvenne W. Hellings P. W. Bachert C. (2013 ). Role of staphylococcal superantigens in airway disease. Int. Arch. Allergy Immunol. 161, 304–314.

    Not in our library10.1159/000350329

  99. 99.

    Igarashi H. (1972 ). Staphylococcal enterotoxin D. Immunological identification with purified toxin. Jpn. J. Microbiol. 16, 483–491.

    Not in our library10.1111/j.1348-0421.1972.tb00688.x

  100. 100.

    Ikeda T. Tamate N. Yamaguchi K. Makino S. (2005 ). Mass outbreak of food poisoning disease caused by small amounts of staphylococcal enterotoxins A and H. Appl. Environ. Microbiol. 71, 2793–2795.

    Not in our library10.1128/aem.71.5.2793-2795.2005

  101. 101.

    Jarraud S. Peyrat M. A. Lim A. Tristan A. Bes M. Mougel C.. (2001 ). egc, a highly prevalent operon of enterotoxin gene, forms a putative nursery of superantigens in Staphylococcus aureus. J. Immunol. 166, 669–677.

    Not in our library10.4049/jimmunol.166.1.669

  102. 102.

    Jett M. Brinkley W. Neill R. Gemski P. Hunt R. (1990 ). Staphylococcus aureus enterotoxin B challenge of monkeys: correlation of plasma levels of arachidonic acid cascade products with occurrence of illness. Infect. Immun. 58, 3494–3499.

    Not in our library10.1128/iai.58.11.3494-3499.1990

  103. 103.

    Ji G. Beavis R. C. Novick R. P. (1995 ). Cell density control of staphylococcal virulence mediated by an octapeptide pheromone. Proc. Natl. Acad. Sci. U.S.A. 92, 12055–12059.

    Not in our library10.1073/pnas.92.26.12055

  104. 104.

    Ji G. Beavis R. Novick R. P. (1997 ). Bacterial interference caused by autoinducing peptide variants. Science 276, 2027–2030.

    Not in our library10.1126/science.276.5321.2027

  105. 105.

    Johler S. Giannini P. Jermini M. Hummerjohann J. Baumgartner A. Stephan R. (2015 ). Further evidence for staphylococcal food poisoning outbreaks caused by egc-encoded enterotoxins. Toxins 7, 997–1004.

    Not in our library10.3390/toxins7030997

  106. 106.

    Johler S. Sihto H. M. Macori G. Stephan R. (2016 ). Sequence variability in staphylococcal enterotoxin genes seb, sec, and sed. Toxins. 8:169.

    Not in our library10.3390/toxins8060169

  107. 107.

    Jørgensen H. J. Mathisen T. Løvseth A. Omoe K. Qvale K. S. Loncarevic S. (2005 ). An outbreak of staphylococcal food poisoning caused by enterotoxin H in mashed potato made with raw milk. FEMS Microbiol. Lett. 252, 267–272.

    Not in our library10.1016/j.femsle.2005.09.005

  108. 108.

    Kappler J. Kotzin B. Herron L. Gelfand E. W. Bigler R. D. Boylston A.. (1989 ). V beta-specific stimulation of human T cells by staphylococcal toxins. Science 244, 811–813.

    Not in our library10.1126/science.2524876

  109. 109.

    Kavanaugh J. S. Thoendel M. Horswill A. R. (2007 ). A role for type I signal peptidase in Staphylococcus aureus quorum sensing. Mol. Microbiol. 65, 780–798.

    Not in our library10.1111/j.1365-2958.2007.05830.x

  110. 110.

    Kérouanton A. Hennekinne J. A. Letertre C. Petit L. Chesneau O. Brisabois A.. (2007 ). Characterization of Staphylococcus aureus strains associated with food poisoning outbreaks in France. Int. J. Food Microbiol. 115, 369–375.

    Not in our library10.1016/j.ijfoodmicro.2006.10.050

  111. 111.

    Kientz C. E. Hulst A. G. Wils E. R. (1997 ). Determination of staphylococcal enterotoxin B by on-line (micro) liquid chromatography-electrospray mass spectrometry. J. Chromatogr. A. 757, 51–64.

    Not in our library10.1016/s0021-9673(96)00661-9

  112. 112.

    Kijek T. M. Rossi C. A. Moss D. Parker R. W. Henchal E. A. (2000 ). Rapid and sensitive immunomagnetic-electrochemiluminescent detection of staphyloccocal enterotoxin B. J. Immunol. Methods. 236, 9–17.

    Not in our library10.1016/s0022-1759(99)00234-3

  113. 113.

    Kinkel T. L. Roux C. M. Dunman P. M. Fang F. C. (2013 ). The Staphylococcus aureus SrrAB two-component system promotes resistance to nitrosative stress and hypoxia. mBio. 4:e00696-13.

    Not in our library10.1128/mbio.00696-13

  114. 114.

    Kirk M. Ford L. Glass K. Hall G. (2014 ). Foodborne illness, Australia, circa 2000 and circa 2010. Emerging Infect. Dis. 20, 1857–1864.

    Not in our library10.3201/eid2011.131315

  115. 115.

    Kocandrle V. Houttuin E. Prohaska J. V. (1966 ). Acute hemodynamic and gastrointestinal changes produced by staphylococcal exotoxin and enterotoxin in dogs. J. Surg. Res. 6, 50–57.

    Not in our library10.1016/s0022-4804(66)80070-7

  116. 116.

    Koenig R. L. Ray J. L. Maleki S. J. Smeltzer M. S. Hurlburt B. K. (2004 ). Staphylococcus aureus AgrA binding to the RNAIII-agr regulatory region. J. Bacteriol. 186, 7549–7555.

    Not in our library10.1128/jb.186.22.7549-7555.2004

  117. 117.

    Kohler P. L. Greenwood S. D. Nookala S. Kotb M. Kranz D. M. Schlievert P. M. (2012 ). Staphylococcus aureus isolates encode variant staphylococcal enterotoxin B proteins that are diverse in superantigenicity and lethality. PLoS ONE 7:e41157.

    Not in our library10.1371/journal.pone.0041157

  118. 118.

    Kozono H. Parker D. White J. Marrack P. Kappler J. (1995 ). Multiple binding sites for bacterial superantigens on soluble class II MHC molecules. Immunity 3, 187–196.

    Not in our library10.1016/1074-7613(95)90088-8

  119. 119.
  120. 120.

    Krakauer T. Pradhan K. Stiles B. G. (2016 ). Staphylococcal superantigens spark host-mediated danger signals. Front. Immunol. 7:23.

    Not in our library10.3389/fimmu.2016.00023

  121. 121.

    Kullik I. Giachino P. (1997 ). The alternative sigma factor sigmaB in Staphylococcus aureus: regulation of the sigB operon in response to growth phase and heat shock. Arch. Microbiol. 167, 151–159.

    Not in our library10.1007/s002030050428

  122. 122.

    Kullik I. Giachino P. Fuchs T. (1998 ). Deletion of the alternative sigma factor sigmaB in Staphylococcus aureus reveals its function as a global regulator of virulence genes. J. Bacteriol. 180, 4814–4820.

    Not in our library10.1128/jb.180.18.4814-4820.1998

  123. 123.

    Kuroda H. Kuroda M. Cui L. Hiramatsu K. (2007 ). Subinhibitory concentrations of beta-lactam induce haemolytic activity in Staphylococcus aureus through the SaeRS two-component system. FEMS Microbiol. Lett. 268, 98–105.

    Not in our library10.1111/j.1574-6968.2006.00568.x

  124. 124.

    Kusch K. Hanke K. Holtfreter S. Schmudde M. Kohler C. Erck C.. (2011 ). The influence of SaeRS and sigma(B) on the expression of superantigens in different Staphylococcus aureus isolates. Int. J. Med. Microbiol. 301, 488–499.

    Not in our library10.1016/j.ijmm.2011.01.003

  125. 125.

    Langley R. J. Ting Y. T. Clow F. Young P. G. Radcliff F. J. Choi J. M.. (2017 ). Staphylococcal enterotoxin-like X (SElX) is a unique superantigen with functional features of two major families of staphylococcal virulence factors. PLoS Pathog. 13:e1006549.

    Not in our library10.1371/journal.ppat.1006549

  126. 126.

    Langley R. Patel D. Jackson N. Clow F. Fraser J. D. (2010 ). Staphylococcal superantigen super-domains in immune evasion. Crit. Rev. Immunol. 30, 149–165.

    Not in our library10.1615/critrevimmunol.v30.i2.40

  127. 127.

    Lappin E. Ferguson A. J. (2009 ). Gram-positive toxic shock syndromes. Lancet Infect. Dis. 9, 281–290.

    Not in our library10.1016/s1473-3099(09)70066-0

  128. 128.

    Larkin E. A. Carman R. J. Krakauer T. Stiles B. G. (2009 ). Staphylococcus aureus: the toxic presence of a pathogen extraordinaire. Curr. Med. Chem. 16, 4003–4019.

    Not in our library10.2174/092986709789352321

  129. 129.

    Lauderdale K. J. Boles B. R. Cheung A. L. Horswill A. R. (2009 ). Interconnections between Sigma B, agr, and proteolytic activity in Staphylococcus aureus biofilm maturation. Infect. Immun. 77, 1623–1635.

    Not in our library10.1128/iai.01036-08

  130. 130.

    Le Loir Y. Baron F. Gautier M. (2003 ). Staphylococcus aureus and food poisoning. Genet. Mol. Res. 2, 63–76.

    Not in our library

  131. 131.

    Leder L. Llera A. Lavoie P. M. Lebedeva M. I. Li H. Sékaly R. P.. (1998 ). A mutational analysis of the binding of staphylococcal enterotoxins B and C3 to the T cell receptor beta chain and major histocompatibility complex class II. J. Exp. Med. 187, 823–833.

    Not in our library10.1084/jem.187.6.823

  132. 132.

    Lee J. Park N. Park J. Y. Kaplan B. L. F. Pruett S. B. Park J. W.. (2017 ). Induction of immunosuppressive CD8(+)CD25(+)FOXP3(+) regulatory T cells by suboptimal stimulation with staphylococcal enterotoxin C1. J. Immunol. 200, 669–680.

    Not in our library10.4049/jimmunol.1602109

  133. 133.

    Letertre C. Perelle S. Dilasser F. Fach P. (2003a ). Detection and genotyping by real-time PCR of the staphylococcal enterotoxin genes sea to sej. Mol. Cell. Probes. 17, 139–147.

    Not in our library10.1016/s0890-8508(03)00045-8

  134. 134.

    Letertre C. Perelle S. Dilasser F. Fach P. (2003b ). Identification of a new putative enterotoxin SEU encoded by the egc cluster of Staphylococcus aureus. J. Appl. Microbiol. 95, 38–43.

    Not in our library10.1046/j.1365-2672.2003.01957.x

  135. 135.

    Levy R. Rotfogel Z. Hillman D. Popugailo A. Arad G. Supper E.. (2016 ). Superantigens hyperinduce inflammatory cytokines by enhancing the B7-2/CD28 costimulatory receptor interaction. Proc. Natl. Acad. Sci. U.S.A. 113, E6437–E6446.

    Not in our library10.1073/pnas.1603321113

  136. 136.
  137. 137.

    Li D. Cheung A. (2008 ). Repression of hla by rot is dependent on sae in Staphylococcus aureus. Infect. Immun. 76, 1068–1075.

    Not in our library10.1128/iai.01069-07

  138. 138.

    Li J. Yang J. Lu Y. W. Wu S. Wang M. R. Zhu J. M. (2015 ). Possible role of staphylococcal enterotoxin B in the pathogenesis of autoimmune diseases. Viral Immunol. 28, 354–359.

    Not in our library10.1089/vim.2015.0017

  139. 139.

    Liang M. Zhang T. Liu X. Fan Y. Xia S. Xiang Y.. (2015 ). Development of an indirect competitive enzyme-linked immunosorbent assay based on the multiepitope peptide for the synchronous detection of staphylococcal enterotoxin A and G proteins in milk. J. Food Prot. 78, 362–369.

    Not in our library10.4315/0362-028x.jfp-14-323

  140. 140.

    Lina G. Bohach G. A. Nair S. P. Hiramatsu K. Jouvin-Marche E. Mariuzza R.. (2004 ). Standard nomenclature for the superantigens expressed by Staphylococcus. J. Infect. Dis. 189, 2334–2336.

    Not in our library10.1086/420852

  141. 141.

    Lina G. Jarraud S. Ji G. Greenland T. Pedraza A. Etienne J.. (1998 ). Transmembrane topology and histidine protein kinase activity of AgrC, the agr signal receptor in Staphylococcus aureus. Mol. Microbiol. 28, 655–662.

    Not in our library10.1046/j.1365-2958.1998.00830.x

  142. 142.

    Lis E. Korzekwa K. Bystron J. Zarczynska A. Dabrowska A. Molenda J.. (2009 ). Enterotoxin gene content in Staphylococcus aureus from the human intestinal tract. FEMS Microbiol. Lett. 296, 72–77.

    Not in our library10.1111/j.1574-6968.2009.01622.x

  143. 143.

    Lis E. Podkowik M. Bystron J. Stefaniak T. Bania J. (2012 ). Temporal expression of staphylococcal enterotoxin H in comparison with accessory gene regulator-dependent and -independent enterotoxins. J. Food Prot. 75, 238–244.

    Not in our library10.4315/0362-028x.jfp-11-336

  144. 144.

    Lotfi-Emran S. Ward B. R. Le Q. T. Pozez A. L. Manjili M. H. Woodfolk J. A.. (2017 ). Human mast cells present antigen to autologous CD4(+) T cells. J. Allergy Clin. Immunol. 141, 311.e10–321.e10.

    Not in our library10.1016/j.jaci.2017.02.048

  145. 145.

    Lowder B. V. Guinane C. M. Ben Zakour N. L. Weinert L. A. Conway-Morris A. Cartwright R. A.. (2009 ). Recent human-to-poultry host jump, adaptation, and pandemic spread of Staphylococcus aureus. Proc. Natl. Acad. Sci. U.S.A. 106, 19545–19550.

    Not in our library10.1073/pnas.0909285106

  146. 146.

    Lowy F. D. (2003 ). Antimicrobial resistance: the example of Staphylococcus aureus. J. Clin. Invest. 111, 1265–1273.

    Not in our library10.1172/jci18535

  147. 147.

    Luo L. R. Zhang Z. J. Chen L. J. Ma L. F. (2006 ). Chemiluminescent imaging detection of staphylococcal enterotoxin C-1 in milk and water samples. Food Chem. 97, 355–360.

    Not in our library10.1016/j.foodchem.2005.05.008

  148. 148.

    Luu M. Steinhoff U. Visekruna A. (2017 ). Functional heterogeneity of gut-resident regulatory T cells. Clin. Transl. Immunol. 6:e156.

    Not in our library10.1038/cti.2017.39

  149. 149.

    Lv G. Xu B. Wei P. Song J. Zhang H. Zhao C.. (2014 ). Molecular characterization of foodborne-associated Staphylococcus aureus strains isolated in Shijiazhuang, China, from 2010 to 2012. Diagn. Microbiol. Infect. Dis. 78, 462–468.

    Not in our library10.1016/j.diagmicrobio.2013.12.006

  150. 150.

    Madsen J. M. (2001 ). Toxins as weapons of mass destruction. A comparison and contrast with biological-warfare and chemical-warfare agents. Clin. Lab. Med. 21, 593–605.

    Not in our library

  151. 151.

    Maeurer M. Zitvogel L. Elder E. Storkus W. J. Lotze M. T. (1995 ). Human intestinal V delta 1+ T cells obtained from patients with colon cancer respond exclusively to SEB but not to SEA. Nat. Immun. 14, 188–197.

    Not in our library

  152. 152.

    Maina E. K. Hu D. L. Tsuji T. Omoe K. Nakane A. (2012 ). Staphylococcal enterotoxin A has potent superantigenic and emetic activities but not diarrheagenic activity. Int. J. Med. Microbiol. 302, 88–95.

    Not in our library10.1016/j.ijmm.2012.01.003

  153. 153.

    Malachowa N. DeLeo F. R. (2010 ). Mobile genetic elements of Staphylococcus aureus. Cell. Mol. Life Sci. 67, 3057–3071.

    Not in our library10.1007/s00018-010-0389-4

  154. 154.

    Mangen M. J. Bouwknegt M. Friesema I. H. Haagsma J. A. Kortbeek L. M. Tariq L.. (2015 ). Cost-of-illness and disease burden of food-related pathogens in the Netherlands, 2011. Int. J. Food Microbiol. 196, 84–93.

    Not in our library10.1016/j.ijfoodmicro.2014.11.022

  155. 155.

    Marr J. C. Lyon J. D. Roberson J. R. Lupher M. Davis W. C. Bohach G. A. (1993 ). Characterization of novel type C staphylococcal enterotoxins: biological and evolutionary implications. Infect. Immun. 61, 4254–4262.

    Not in our library10.1128/iai.61.10.4254-4262.1993

  156. 156.

    Marrack P. Kappler J. (1990 ). The staphylococcal enterotoxins and their relatives. Science 248, 705–711.

    Not in our library10.1126/science.2185544

  157. 157.

    Marrack P. Blackman M. Kushnir E. Kappler J. (1990 ). The toxicity of staphylococcal enterotoxin B in mice is mediated by T cells. J. Exp. Med. 171, 455–464.

    Not in our library10.1084/jem.171.2.455

  158. 158.
  159. 159.

    Matsui S. Terabe M. Mabuchi A. Takahashi M. Saizawa M. Tanaka S.. (1997 ). A unique response to staphylococcal enterotoxin B by intrahepatic lymphocytes and its relevance to the induction of tolerance in the liver. Scand. J. Immunol. 46, 230–234.

    Not in our library10.1046/j.1365-3083.1997.d01-118.x

  160. 160.
  161. 161.

    McLauchlin J. Narayanan G. L. Mithani V. O'neill G. (2000 ). The detection of enterotoxins and toxic shock syndrome toxin genes in Staphylococcus aureus by polymerase chain reaction. J. Food Prot. 63, 479–488.

    Not in our library10.4315/0362-028x-63.4.479

  162. 162.

    Miethke T. Wahl C. Heeg K. Echtenacher B. Krammer P. H. Wagner H. (1992 ). T cell-mediated lethal shock triggered in mice by the superantigen staphylococcal enterotoxin B: critical role of tumor necrosis factor. J. Exp. Med. 175, 91–98.

    Not in our library10.1084/jem.175.1.91

  163. 163.

    Monday S. R. Bohach G. A. (2001 ). Genes encoding staphylococcal enterotoxins G and I are linked and separated by DNA related to other staphylococcal enterotoxins. J. Nat. Toxins. 10, 1–8.

    Not in our library

  164. 164.

    Morfeldt E. Taylor D. Von Gabain A. Arvidson S. (1995 ). Activation of alpha-toxin translation in Staphylococcus aureus by the trans-encoded antisense RNA, RNAIII. EMBO J. 14, 4569–4577.

    Not in our library10.1002/j.1460-2075.1995.tb00136.x

  165. 165.

    Morita C. T. Li H. Lamphear J. G. Rich R. R. Fraser J. D. Mariuzza R. A.. (2001 ). Superantigen recognition by gammadelta T cells: SEA recognition site for human Vgamma2 T cell receptors. Immunity 14, 331–344.

    Not in our library10.1016/s1074-7613(01)00113-3

  166. 166.

    Munson S. H. Tremaine M. T. Betley M. J. Welch R. A. (1998 ). Identification and characterization of staphylococcal enterotoxin types G and I from Staphylococcus aureus. Infect. Immun. 66, 3337–3348.

    Not in our library10.1128/iai.66.7.3337-3348.1998

  167. 167.

    Murray R. J. (2005 ). Recognition and management of Staphylococcus aureus toxin-mediated disease. Intern. Med. J. 35(Suppl. 2), S106–S119.

    Not in our library10.1111/j.1444-0903.2005.00984.x

  168. 168.

    Nagaraj S. Ramlal S. Kingston J. Batra H. V. (2016 ). Development of IgY based sandwich ELISA for the detection of staphylococcal enterotoxin G (SEG), an egc toxin. Int. J. Food Microbiol. 237, 136–141.

    Not in our library10.1016/j.ijfoodmicro.2016.08.009

  169. 169.

    Napier R. J. Adams E. J. Gold M. C. Lewinsohn D. M. (2015 ). The role of mucosal associated invariant T cells in antimicrobial immunity. Front. Immunol. 6:344.

    Not in our library10.3389/fimmu.2015.00344

  170. 170.

    Nashev D. Toshkova K. Bizeva L. Akineden O. Lämmler C. Zschöck M. (2007 ). Distribution of enterotoxin genes among carriage- and infection-associated isolates of Staphylococcus aureus. Lett. Appl. Microbiol. 45, 681–685.

    Not in our library10.1111/j.1472-765x.2007.02254.x

  171. 171.

    Nedelkov D. Rasooly A. Nelson R. W. (2000 ). Multitoxin biosensor-mass spectrometry analysis: a new approach for rapid, real-time, sensitive analysis of staphylococcal toxins in food. Int. J. Food Microbiol. 60, 1–13.

    Not in our library10.1016/s0168-1605(00)00328-7

  172. 172.

    Neill R. J. Fanning G. R. Delahoz F. Wolff R. Gemski P. (1990 ). Oligonucleotide probes for detection and differentiation of Staphylococcus aureus strains containing genes for enterotoxins A, B, and C and toxic shock syndrome toxin 1. J. Clin. Microbiol. 28, 1514–1518.

    Not in our library10.1128/jcm.28.7.1514-1518.1990

  173. 173.

    Nemati M. Hermans K. Lipinska U. Denis O. Deplano A. Struelens M.. (2008 ). Antimicrobial resistance of old and recent Staphylococcus aureus isolates from poultry: first detection of livestock-associated methicillin-resistant strain ST398. Antimicrob. Agents Chemother. 52, 3817–3819.

    Not in our library10.1128/aac.00613-08

  174. 174.

    Nkouawa A. Sako Y. Nakao M. Nakaya K. Ito A. (2009 ). Loop-mediated isothermal amplification method for differentiation and rapid detection of Taenia species. J. Clin. Microbiol. 47, 168–174.

    Not in our library10.1128/jcm.01573-08

  175. 175.

    Novick R. P. Jiang D. (2003 ). The staphylococcal saeRS system coordinates environmental signals with agr quorum sensing. Microbiology 149, 2709–2717.

    Not in our library10.1099/mic.0.26575-0

  176. 176.

    Novick R. P. Projan S. J. Kornblum J. Ross H. F. Ji G. Kreiswirth B.. (1995 ). The agr P2 operon: an autocatalytic sensory transduction system in Staphylococcus aureus. Mol. Gen. Genet. 248, 446–458.

    Not in our library10.1007/bf02191645

  177. 177.

    Nowrouzian F. L. Dauwalder O. Meugnier H. Bes M. Etienne J. Vandenesch F.. (2011 ). Adhesin and superantigen genes and the capacity of Staphylococcus aureus to colonize the infantile gut. J. Infect. Dis. 204, 714–721.

    Not in our library10.1093/infdis/jir388

  178. 178.

    Nowrouzian F. L. Lina G. Hodille E. Lindberg E. Hesselmar B. Saalman R.. (2017 ). Superantigens and adhesins of infant gut commensal Staphylococcus aureus strains and association with subsequent development of atopic eczema. Br. J. Dermatol. 176, 439–445.

    Not in our library10.1111/bjd.15138

  179. 179.

    Omoe K. Hu D. L. Ono H. K. Shimizu S. Takahashi-Omoe H. Nakane A.. (2013 ). Emetic potentials of newly identified staphylococcal enterotoxin-like toxins. Infect. Immun. 81, 3627–3631.

    Not in our library10.1128/iai.00550-13

  180. 180.

    Omoe K. Imanishi K. Hu D. L. Kato H. Fugane Y. Abe Y.. (2005 ). Characterization of novel staphylococcal enterotoxin-like toxin type P. Infect Immun. 73, 5540–5546.

    Not in our library10.1128/iai.73.9.5540-5546.2005

  181. 181.

    Ono H. K. Hirose S. Naito I. Sato'o Y. Asano K. Hu D. L.. (2017 ). The emetic activity of staphylococcal enterotoxins, SEK, SEL, SEM, SEN and SEO in a small emetic animal model, the house musk shrew. Microbiol. Immunol. 61, 12–16.

    Not in our library10.1111/1348-0421.12460

  182. 182.

    Ono H. K. Nishizawa M. Yamamoto Y. Hu D. L. Nakane A. Shinagawa K.. (2012 ). Submucosal mast cells in the gastrointestinal tract are a target of staphylococcal enterotoxin type A. FEMS Immunol. Med. Microbiol. 64, 392–402.

    Not in our library10.1111/j.1574-695x.2011.00924.x

  183. 183.

    Ono H. K. Omoe K. Imanishi K. Iwakabe Y. Hu D. L. Kato H.. (2008 ). Identification and characterization of two novel staphylococcal enterotoxins, types S and T. Infect. Immun. 76, 4999–5005.

    Not in our library10.1128/iai.00045-08

  184. 184.

    Ono H. K. Sato'o Y. Narita K. Naito I. Hirose S. Hisatsune J.. (2015 ). Identification and characterization of a novel staphylococcal emetic toxin. Appl. Environ. Microbiol. 81, 7034–7040.

    Not in our library10.1128/aem.01873-15

  185. 185.

    Orwin P. M. Leung D. Y. Donahue H. L. Novick R. P. Schlievert P. M. (2001 ). Biochemical and biological properties of staphylococcal enterotoxin K. Infect. Immun. 69, 360–366.

    Not in our library10.1128/iai.69.1.360-366.2001

  186. 186.

    Orwin P. M. Leung D. Y. Tripp T. J. Bohach G. A. Earhart C. A. Ohlendorf D. H.. (2002 ). Characterization of a novel staphylococcal enterotoxin-like superantigen, a member of the group V subfamily of pyrogenic toxins. Biochemistry 41, 14033–14040.

    Not in our library10.1021/bi025977q

  187. 187.

    Ostyn A. De Buyser M. L. Guillier F. Groult J. Felix B. Salah S.. (2010 ). First evidence of a food poisoning outbreak due to staphylococcal enterotoxin type E, France, 2009. Euro Surveill. 15:19528

    Not in our library

  188. 188.

    Otero A. García M. L. García M. C. Moreno B. Bergdoll M. S. (1990 ). Production of staphylococcal enterotoxins C1 and C2 and thermonuclease throughout the growth cycle. Appl. Environ. Microbiol. 56, 555–559.

    Not in our library10.1128/aem.56.2.555-559.1990

  189. 189.

    Otto M. (2010 ). Basis of virulence in community-associated methicillin-resistant Staphylococcus aureus. Annu. Rev. Microbiol. 64, 143–162.

    Not in our library10.1146/annurev.micro.112408.134309

  190. 190.

    Otto M. (2012 ). MRSA virulence and spread. Cell Microbiol. 14, 1513–1521.

    Not in our library10.1111/j.1462-5822.2012.01832.x

  191. 191.

    Pané-Farré J. Jonas B. Förstner K. Engelmann S. Hecker M. (2006 ). The sigmaB regulon in Staphylococcus aureus and its regulation. Int. J. Med. Microbiol. 296, 237–258.

    Not in our library10.1016/j.ijmm.2005.11.011

  192. 192.

    Park M. S. Kim Y. S. Lee S. H. Kim S. H. Park K. H. Bahk G. J. (2015 ). Estimating the burden of foodborne disease, South Korea, 2008-2012. Foodborne Pathog. Dis. 12, 207–213.

    Not in our library10.1089/fpd.2014.1858

  193. 193.

    Pastacaldi C. Lewis P. Howarth P. (2011 ). Staphylococci and staphylococcal superantigens in asthma and rhinitis: a systematic review and meta-analysis. Allergy 66, 549–555.

    Not in our library10.1111/j.1398-9995.2010.02502.x

  194. 194.

    Pekdemir M. E. Ertürkan D. Külah H. Boyaci I. H. Ozgen C. Tamer U. (2012 ). Ultrasensitive and selective homogeneous sandwich immunoassay detection by Surface Enhanced Raman Scattering (SERS). Analyst 137, 4834–4840.

    Not in our library10.1039/c2an35471c

  195. 195.
  196. 196.

    Powell N. Macdonald T. T. (2017 ). Recent advances in gut immunology. Parasite Immunol. 39:e12430.

    Not in our library10.1111/pim.12430

  197. 197.

    Pragman A. A. Ji Y. Schlievert P. M. (2007 ). Repression of Staphylococcus aureus SrrAB using inducible antisense srrA alters growth and virulence factor transcript levels. Biochemistry 46, 314–321.

    Not in our library10.1021/bi0603266

  198. 198.

    Pragman A. A. Yarwood J. M. Tripp T. J. Schlievert P. M. (2004 ). Characterization of virulence factor regulation by SrrAB, a two-component system in Staphylococcus aureus. J. Bacteriol. 186, 2430–2438.

    Not in our library10.1128/jb.186.8.2430-2438.2004

  199. 199.

    Price L. B. Stegger M. Hasman H. Aziz M. Larsen J. Andersen P. S.. (2012 ). Staphylococcus aureus CC398: host adaptation and emergence of methicillin resistance in livestock. MBio. 3:e00520-12.

    Not in our library10.1128/mbio.00305-11

  200. 200.

    Principato M. Qian B. F. (2014 ). Staphylococcal enterotoxins in the etiopathogenesis of mucosal autoimmunity within the gastrointestinal tract. Toxins 6, 1471–1489.

    Not in our library10.3390/toxins6051471

  201. 201.

    Queck S. Y. Jameson-Lee M. Villaruz A. E. Bach T. H. Khan B. A. Sturdevant D. E.. (2008 ). RNAIII-independent target gene control by the agr quorum-sensing system: insight into the evolution of virulence regulation in Staphylococcus aureus. Mol. Cell. 32, 150–158.

    Not in our library10.1016/j.molcel.2008.08.005

  202. 202.

    Rasooly L. Rasooly A. (1999 ). Real time biosensor analysis of staphylococcal enterotoxin A in food. Int. J. Food Microbiol. 49, 119–127.

    Not in our library10.1016/s0168-1605(99)00053-7

  203. 203.

    Read R. B. Jr. Bradshaw J. Pritchard W. L. Black L. A. (1965 ). Assay of staphylococcal enterotoxin from cheese. J. Dairy Sci. 48, 420–424.

    Not in our library10.3168/jds.s0022-0302(65)88246-7

  204. 204.

    Regassa L. B. Betley M. J. (1993 ). High sodium chloride concentrations inhibit staphylococcal enterotoxin C gene (sec) expression at the level of sec mRNA. Infect. Immun. 61, 1581–1585.

    Not in our library10.1128/iai.61.4.1581-1585.1993

  205. 205.

    Regassa L. B. Couch J. L. Betley M. J. (1991 ). Steady-state staphylococcal enterotoxin type C mRNA is affected by a product of the accessory gene regulator (agr) and by glucose. Infect. Immun. 59, 955–962.

    Not in our library10.1128/iai.59.3.955-962.1991

  206. 206.

    Regenthal P. Hansen J. S. Andre I. Lindkvist-Petersson K. (2017 ). Thermal stability and structural changes in bacterial toxins responsible for food poisoning. PLoS ONE 12:e0172445

    Not in our library10.1371/journal.pone.0172445

  207. 207.

    Reiser R. F. Robbins R. N. Khoe G. P. Bergdoll M. S. (1983 ). Purification and some physicochemical properties of toxic-shock toxin. Biochemistry 22, 3907–3912.

    Not in our library10.1021/bi00285a028

  208. 208.

    Reiser R. F. Robbins R. N. Noleto A. L. Khoe G. P. Bergdoll M. S. (1984 ). Identification, purification, and some physicochemical properties of staphylococcal enterotoxin C3. Infect. Immun. 45, 625–630.

    Not in our library10.1128/iai.45.3.625-630.1984

  209. 209.

    Ridley M. (1959 ). Perineal carriage of Staph. aureus. Br. Med. J. 1, 270–273.

    Not in our library10.1136/bmj.1.5117.270

  210. 210.

    Rieder S. A. Nagarkatti P. Nagarkatti M. (2011 ). CD1d-independent activation of invariant natural killer T cells by staphylococcal enterotoxin B through major histocompatibility complex class II/T cell receptor interaction results in acute lung injury. Infect. Immun. 79, 3141–3148.

    Not in our library10.1128/iai.00177-11

  211. 211.

    Rogasch K. Rühmling V. Pané-Farré J. Höper D. Weinberg C. Fuchs S.. (2006 ). Influence of the two-component system SaeRS on global gene expression in two different Staphylococcus aureus strains. J. Bacteriol. 188, 7742–7758.

    Not in our library10.1128/jb.00555-06

  212. 212.

    Sahibzada S. Abraham S. Coombs G. W. Pang S. Hernández-Jover M. Jordan D.. (2017 ). Transmission of highly virulent community-associated MRSA ST93 and livestock-associated MRSA ST398 between humans and pigs in Australia. Sci. Rep. 7:5273.

    Not in our library10.1038/s41598-017-04789-0

  213. 213.

    Saïd-Salim B. Dunman P. M. Mcaleese F. M. Macapagal D. Murphy E. Mcnamara P. J.. (2003 ). Global regulation of Staphylococcus aureus genes by Rot. J. Bacteriol. 185, 610–619.

    Not in our library10.1128/jb.185.2.610-619.2003

  214. 214.

    Sakai F. Ihara H. Aoyama K. Igarashi H. Yanahira S. Ohkubo T.. (2008 ). Characteristics of enterotoxin H-producing Staphylococcus aureus isolated from clinical cases and properties of the enterotoxin productivity. J. Food Prot. 71, 1855–1860.

    Not in our library10.4315/0362-028x-71.9.1855

  215. 215.

    Salerno-Goncalves R. Luo D. Fresnay S. Magder L. Darton T. C. Jones C.. (2017 ). Challenge of humans with wild-type Salmonella enterica serovar Typhi elicits changes in the activation and homing characteristics of Mucosal-Associated Invariant T Cells. Front. Immunol. 8:398.

    Not in our library10.3389/fimmu.2017.00398

  216. 216.

    Saline M. Rodstrom K. E. Fischer G. Orekhov V. Y. Karlsson B. G. Lindkvist-Petersson K. (2010 ). The structure of superantigen complexed with TCR and MHC reveals novel insights into superantigenic T cell activation. Nat. Commun. 1:119.

    Not in our library10.1038/ncomms1117

  217. 217.

    Salomon L. L. Tew R. W. (1968 ). Assay of staphylococcal enterotoxin B by latex agglutination. Proc. Soc. Exp. Biol. Med. 129, 539–542.

    Not in our library10.3181/00379727-129-33364

  218. 218.

    Sato'o Y. Hisatsune J. Nagasako Y. Ono H. K. Omoe K. Sugai M. (2015 ). Positive regulation of staphylococcal enterotoxin H by Rot (Repressor of Toxin) protein and its importance in clonal complex 81 subtype 1 lineage-related food poisoning. Appl. Environ. Microbiol. 81, 7782–7790.

    Not in our library10.1128/aem.01936-15

  219. 219.

    Sato'o Y. Omoe K. Naito I. Ono H. K. Nakane A. Sugai M.. (2014 ). Molecular epidemiology and identification of a Staphylococcus aureus clone causing food poisoning outbreaks in Japan. J. Clin. Microbiol. 52, 2637–2640.

    Not in our library10.1128/jcm.00661-14

  220. 220.

    Saunders G. C. Bartlett M. L. (1977 ). Double-antibody solid-phase enzyme immunoassay for the detection of staphylococcal enterotoxin A. Appl. Environ. Microbiol. 34, 518–522.

    Not in our library10.1128/aem.34.5.518-522.1977

  221. 221.
  222. 222.

    Schantz E. J. Roessler W. G. Wagman J. Spero L. Dunnery D. A. Bergdoll M. S. (1965 ). Purification of staphylococcal enterotoxin B. Biochemistry 4, 1011–1016.

    Not in our library10.1021/bi00882a005

  223. 223.

    Scheuber P. H. Denzlinger C. Wilker D. Beck G. Keppler D. Hammer D. K. (1987 ). Staphylococcal enterotoxin B as a nonimmunological mast cell stimulus in primates: the role of endogenous cysteinyl leukotrienes. Int. Arch. Allergy Appl. Immunol. 82, 289–291.

    Not in our library10.1159/000234209

  224. 224.

    Scheuber P. H. Mossmann H. Beck G. Hammer D. K. (1983 ). Direct skin test in highly sensitized guinea pigs for rapid and sensitive determination of staphylococcal enterotoxin B. Appl. Environ. Microbiol. 46, 1351–1356.

    Not in our library10.1128/aem.46.6.1351-1356.1983

  225. 225.

    Schlievert P. M. Jablonski L. M. Roggiani M. Sadler I. Callantine S. Mitchell D. T.. (2000 ). Pyrogenic toxin superantigen site specificity in toxic shock syndrome and food poisoning in animals. Infect. Immun. 68, 3630–3634.

    Not in our library10.1128/iai.68.6.3630-3634.2000

  226. 226.

    Senn L. Clerc O. Zanetti G. Basset P. Prod'hom G. Gordon N. C.. (2016 ). The stealthy superbug: the role of asymptomatic enteric carriage in maintaining a long-term hospital outbreak of ST228 methicillin-resistant Staphylococcus aureus. MBio. 7, e02039–e02015.

    Not in our library10.1128/mbio.02039-15

  227. 227.

    Sergelidis D. Angelidis A. S. (2017 ). Methicillin-resistant Staphylococcus aureus: a controversial food-borne pathogen. Lett. Appl. Microbiol. 64, 409–418.

    Not in our library10.1111/lam.12735

  228. 228.
  229. 229.

    Sheahan D. G. Jervis H. R. Takeuchi A. Sprinz H. (1970 ). The effect of staphylococcal enterotoxin on the epithelial mucosubstances of the small intestine of rhesus monkeys. Am. J. Pathol. 60, 1–18.

    Not in our library

  230. 230.

    Shen M. Li Y. Zhang L. Dai S. Wang J. Li Y.. (2017 ). Staphylococcus enterotoxin profile of China isolates and the superantigenicity of some novel enterotoxins. Arch. Microbiol. 199, 723–736.

    Not in our library10.1007/s00203-017-1345-6

  231. 231.

    Shin E. Hong H. Park J. Oh Y. Jung J. Lee Y. (2016 ). Characterization of Staphylococcus aureus faecal isolates associated with food-borne disease in Korea. J. Appl. Microbiol. 121, 277–286.

    Not in our library10.1111/jam.13133

  232. 232.

    Shupp J. W. Jett M. Pontzer C. H. (2002 ). Identification of a transcytosis epitope on staphylococcal enterotoxins. Infect. Immun. 70, 2178–2186.

    Not in our library10.1128/iai.70.4.2178-2186.2002

  233. 233.

    Shylaja R. Murali H. S. Batra H. V. Bawa A. S. (2010 ). A novel multiplex PCR system for the detection of staphylococcal enterotoxin B, tsst, nuc and fem genes of Staphylococcus aureus in food system. J. Food Saf. 30, 443–454.

    Not in our library10.1111/j.1745-4565.2010.00218.x

  234. 234.

    Smith T. C. (2015 ). Livestock-associated Staphylococcus aureus: the United States experience. PLoS Pathog. 11:e1004564.

    Not in our library10.1371/journal.ppat.1004564

  235. 235.

    Song M. Shi C. Xu X. Shi X. (2016 ). Molecular typing and virulence gene profiles of enterotoxin gene cluster (egc)-positive Staphylococcus aureus isolates obtained from various food and clinical specimens. Foodborne Pathog. Dis. 13, 592–601.

    Not in our library10.1089/fpd.2016.2162

  236. 236.

    Soykut E. A. Dudak F. C. Boyaci I. H. (2008 ). Selection of staphylococcal enterotoxin B (SEB)-binding peptide using phage display technology. Biochem. Biophys. Res. Commun. 370, 104–108.

    Not in our library10.1016/j.bbrc.2008.03.065

  237. 237.

    Spaan A. N. Surewaard B. G. Nijland R. Van Strijp J. A. (2013 ). Neutrophils versus Staphylococcus aureus: a biological tug of war. Annu. Rev. Microbiol. 67, 629–650.

    Not in our library10.1146/annurev-micro-092412-155746

  238. 238.

    Spaulding A. R. Salgado-Pabón W. Kohler P. L. Horswill A. R. Leung D. Y. Schlievert P. M. (2013 ). Staphylococcal and streptococcal superantigen exotoxins. Clin. Microbiol. Rev. 26, 422–447.

    Not in our library10.1128/cmr.00104-12

  239. 239.

    Stohl W. Elliott J. E. Linsley P. S. (1994 ). Human T cell-dependent B cell differentiation induced by staphylococcal superantigens. J. Immunol. 153, 117–127.

    Not in our library

  240. 240.

    Su Y. C. Wong A. C. (1995 ). Identification and purification of a new staphylococcal enterotoxin, H. Appl. Environ. Microbiol. 61, 1438–1443.

    Not in our library10.1128/aem.61.4.1438-1443.1995

  241. 241.

    Su Y. C. Wong A. C. (1996 ). Detection of staphylococcal enterotoxin H by an enzyme-linked immunosorbent assay. J. Food Prot. 59, 327–330.

    Not in our library10.4315/0362-028x-59.3.327

  242. 242.

    Sugiyama H. Hayama T. (1965 ). Abdominal viscera as site of emetic action for staphylococcal enterotoxin in the monkey. J. Infect. Dis. 115, 330–336.

    Not in our library10.1093/infdis/115.4.330

  243. 243.

    Suleiman T. S. Karimuribo E. D. Mdegela R. H. (2018 ). Prevalence of bovine subclinical mastitis and antibiotic susceptibility patterns of major mastitis pathogens isolated in Unguja island of Zanzibar, Tanzania. Trop. Anim. Health Prod. 50, 259–266.

    Not in our library10.1007/s11250-017-1424-3

  244. 244.

    Sullivan R. (1969 ). Effects of enterotoxin B on intestinal transport in vitro. Proc. Soc. Exp. Biol. Med. 131, 1159–1162.

    Not in our library10.3181/00379727-131-34060

  245. 245.

    Sumby P. Waldor M. K. (2003 ). Transcription of the toxin genes present within the staphylococcal phage phiSa3ms is intimately linked with the phage's life cycle. J. Bacteriol. 185, 6841–6851.

    Not in our library10.1128/jb.185.23.6841-6851.2003

  246. 246.

    Sun S. Yang M. Kostov Y. Rasooly A. (2010 ). ELISA-LOC: lab-on-a-chip for enzyme-linked immunodetection. Lab Chip. 10, 2093–2100.

    Not in our library10.1039/c003994b

  247. 247.

    Szabo P. A. Rudak P. T. Choi J. Xu S. X. Schaub R. Singh B.. (2017 ). Invariant natural killer T Cells are pathogenic in the HLA-DR4-transgenic humanized mouse model of toxic shock syndrome and can be targeted to reduce morbidity. J. Infect. Dis. 215, 824–829.

    Not in our library10.1093/infdis/jiw646

  248. 248.

    Taylor S. L. Schlunz L. R. Beery J. T. Cliver D. O. Bergdoll M. S. (1982 ). Emetic action of staphylococcal enterotoxin A on weanling pigs. Infect. Immun. 36, 1263–1266.

    Not in our library10.1128/iai.36.3.1263-1266.1982

  249. 249.

    Tempelman L. A. King K. D. Anderson G. P. Ligler F. S. (1996 ). Quantitating staphylococcal enterotoxin B in diverse media using a portable fiber-optic biosensor. Anal. Biochem. 233, 50–57.

    Not in our library10.1006/abio.1996.0006

  250. 250.

    Thomas D. Y. Jarraud S. Lemercier B. Cozon G. Echasserieau K. Etienne J.. (2006 ). Staphylococcal enterotoxin-like toxins U2 and V, two new staphylococcal superantigens arising from recombination within the enterotoxin gene cluster. Infect. Immun. 74, 4724–4734.

    Not in our library10.1128/iai.00132-06

  251. 251.

    Thomas D. Chou S. Dauwalder O. Lina G. (2007 ). Diversity in Staphylococcus aureus enterotoxins. Chem. Immunol. Allergy 93, 24–41.

    Not in our library10.1159/000100856

  252. 252.

    Thomas M. K. Murray R. Flockhart L. Pintar K. Pollari F. Fazil A.. (2013 ). Estimates of the burden of foodborne illness in Canada for 30 specified pathogens and unspecified agents, circa 2006. Foodborne Pathog. Dis. 10, 639–648.

    Not in our library10.1089/fpd.2012.1389

  253. 253.

    Tiedemann R. E. Fraser J. D. (1996 ). Cross-linking of MHC class II molecules by staphylococcal enterotoxin A is essential for antigen-presenting cell and T cell activation. J. Immunol. 157, 3958–3966.

    Not in our library

  254. 254.

    Treiner E. Duban L. Bahram S. Radosavljevic M. Wanner V. Tilloy F.. (2003 ). Selection of evolutionarily conserved mucosal-associated invariant T cells by MR1. Nature 422, 164–169.

    Not in our library10.1038/nature01433

  255. 255.

    Tremaine M. T. Brockman D. K. Betley M. J. (1993 ). Staphylococcal enterotoxin A gene (sea) expression is not affected by the accessory gene regulator (agr). Infect. Immun. 61, 356–359.

    Not in our library10.1128/iai.61.1.356-359.1993

  256. 256.

    Tseng C. W. Stewart G. C. (2005 ). Rot repression of enterotoxin B expression in Staphylococcus aureus. J. Bacteriol. 187, 5301–5309.

    Not in our library10.1128/jb.187.15.5301-5309.2005

  257. 257.

    Tseng C. W. Zhang S. Stewart G. C. (2004 ). Accessory gene regulator control of staphyloccoccal enterotoxin D gene expression. J. Bacteriol. 186, 1793–1801.

    Not in our library10.1128/jb.186.6.1793-1801.2004

  258. 258.

    Tuffs S. W. James D. B. A. Bestebroer J. Richards A. C. Goncheva M. I. O'shea M.. (2017 ). The Staphylococcus aureus superantigen SElX is a bifunctional toxin that inhibits neutrophil function. PLoS Pathog. 13:e1006461.

    Not in our library10.1371/journal.ppat.1006461

  259. 259.

    Umeda K. Nakamura H. Yamamoto K. Nishina N. Yasufuku K. Hirai Y.. (2017 ). Molecular and epidemiological characterization of staphylococcal foodborne outbreak of Staphylococcus aureus harboring seg, sei, sem, sen, seo, and selu genes without production of classical enterotoxins. Int. J. Food Microbiol. 256, 30–35.

    Not in our library10.1016/j.ijfoodmicro.2017.05.023

  260. 260.

    Van Cauteren D. Le Strat Y. Sommen C. Bruyand M. Tourdjman M. Da Silva N. J.. (2017 ). Estimated annual numbers of foodborne pathogen-associated illnesses, hospitalizations, and deaths, France, 2008-2013. Emerg. Infect. Dis. 23, 1486–1492.

    Not in our library10.3201/eid2309.170081

  261. 261.

    Van Gessel Y. A. Mani S. Bi S. Hammamieh R. Shupp J. W. Das R.. (2004 ). Functional piglet model for the clinical syndrome and postmortem findings induced by staphylococcal enterotoxin B. Exp. Biol. Med. 229, 1061–1071.

    Not in our library10.1177/153537020422901011

  262. 262.

    Verhoeven P. O. Gagnaire J. Botelho-Nevers E. Grattard F. Carricajo A. Lucht F.. (2014 ). Detection and clinical relevance of Staphylococcus aureus nasal carriage: an update. Expert Rev. Anti Infect. Ther. 12, 75–89.

    Not in our library10.1586/14787210.2014.859985

  263. 263.

    Viçosa G. N. Le Loir A. Le Loir Y. De Carvalho A. F. Nero L. A. (2013 ). egc characterization of enterotoxigenic Staphylococcus aureus isolates obtained from raw milk and cheese. Int. J. Food Microbiol. 165, 227–230.

    Not in our library10.1016/j.ijfoodmicro.2013.05.023

  264. 264.

    Von Eiff C. Becker K. Machka K. Stammer H. Peters G. (2001 ). Nasal carriage as a source of Staphylococcus aureus bacteremia. Study Group. N. Engl. J. Med. 344, 11–16.

    Not in our library10.1056/nejm200101043440102

  265. 265.
  266. 266.

    Waters C. M. Bassler B. L. (2005 ). Quorum sensing: cell-to-cell communication in bacteria. Annu. Rev. Cell Dev. Biol. 21, 319–346.

    Not in our library10.1146/annurev.cellbio.21.012704.131001

  267. 267.

    Wattinger L. Stephan R. Layer F. Johler S. (2012 ). Comparison of Staphylococcus aureus isolates associated with food intoxication with isolates from human nasal carriers and human infections. Eur. J. Clin. Microbiol. Infect. Dis. 31, 455–464.

    Not in our library10.1007/s10096-011-1330-y

  268. 268.

    Wertheim H. F. Verveer J. Boelens H. A. Van Belkum A. Verbrugh H. A. Vos M. C. (2005 ). Effect of mupirocin treatment on nasal, pharyngeal, and perineal carriage of Staphylococcus aureus in healthy adults. Antimicrob. Agents Chemother. 49, 1465–1467.

    Not in our library10.1128/aac.49.4.1465-1467.2005

  269. 269.

    White J. Herman A. Pullen A. M. Kubo R. Kappler J. W. Marrack P. (1989 ). The V beta-specific superantigen staphylococcal enterotoxin B: stimulation of mature T cells and clonal deletion in neonatal mice. Cell 56, 27–35.

    Not in our library10.1016/0092-8674(89)90980-x

  270. 270.

    Williams R. E. (1963 ). Healthy carriage of Staphylococcus aureus: its prevalence and importance. Bacteriol. Rev. 27, 56–71.

    Not in our library10.1128/br.27.1.56-71.1963

  271. 271.
  272. 272.

    Wilson I. G. Cooper J. E. Gilmour A. (1991 ). Detection of enterotoxigenic Staphylococcus aureus in dried skimmed milk: use of the polymerase chain reaction for amplification and detection of staphylococcal enterotoxin genes entB and entC1 and the thermonuclease gene nuc. Appl. Environ. Microbiol. 57, 1793–1798.

    Not in our library10.1128/aem.57.6.1793-1798.1991

  273. 273.

    Wright A. Andrews P. L. Titball R. W. (2000 ). Induction of emetic, pyrexic, and behavioral effects of Staphylococcus aureus enterotoxin B in the ferret. Infect. Immun. 68, 2386–2389.

    Not in our library10.1128/iai.68.4.2386-2389.2000

  274. 274.

    Wu S. de Lencastre H. Tomasz A. (1996 ). Sigma-B, a putative operon encoding alternate sigma factor of Staphylococcus aureus RNA polymerase: molecular cloning and DNA sequencing. J. Bacteriol. 178, 6036–6042.

    Not in our library10.1128/jb.178.20.6036-6042.1996

  275. 275.

    Wu S. Duan N. Gu H. Hao L. Ye H. Gong W.. (2016 ). A review of the methods for detection of Staphylococcus aureus enterotoxins. Toxins 8:176.

    Not in our library10.3390/toxins8070176

  276. 276.

    Yan X. Wang B. Tao X. Hu Q. Cui Z. Zhang J.. (2012 ). Characterization of Staphylococcus aureus strains associated with food poisoning in Shenzhen, China. Appl. Environ. Microbiol. 78, 6637–6642.

    Not in our library10.1128/aem.01165-12

  277. 277.

    Yarwood J. M. Mccormick J. K. Schlievert P. M. (2001 ). Identification of a novel two-component regulatory system that acts in global regulation of virulence factors of Staphylococcus aureus. J. Bacteriol. 183, 1113–1123.

    Not in our library10.1128/jb.183.4.1113-1123.2001

  278. 278.

    Zeaki N. Susilo Y. B. Pregiel A. Rådström P. Schelin J. (2015 ). Prophage-encoded staphylococcal enterotoxin A: regulation of production in Staphylococcus aureus strains representing different sea regions. Toxins 7, 5359–5376.

    Not in our library10.3390/toxins7124889

  279. 279.

    Zhang S. Stewart G. C. (2000 ). Characterization of the promoter elements for the staphylococcal enterotoxin D gene. J. Bacteriol. 182, 2321–2325.

    Not in our library10.1128/jb.182.8.2321-2325.2000

  280. 280.

    Zhang S. Iandolo J. J. Stewart G. C. (1998 ). The enterotoxin D plasmid of Staphylococcus aureus encodes a second enterotoxin determinant (sej). FEMS Microbiol. Lett. 168, 227–233.

    Not in our library10.1111/j.1574-6968.1998.tb13278.x

  281. 281.

    Zhao W. Li Y. Liu W. Ding D. Xu Y. Pan L.. (2016a ). Transcytosis, antitumor activity and toxicity of staphylococcal enterotoxin C2 as an oral administration protein drug. Toxins 8:185.

    Not in our library10.3390/toxins8060185

  282. 282.

    Zhao Y. Zhu A. Tang J. Tang C. Chen J. (2017 ). Identification and measurement of staphylococcal enterotoxin M from Staphylococcus aureus isolate associated with staphylococcal food poisoning. Lett. Appl. Microbiol. 65, 27–34.

    Not in our library10.1111/lam.12751

  283. 283.

    Zhao Y. Zhu A. Tang J. Tang C. Chen J. Liu J. (2016b ). Identification and measurement of staphylococcal enterotoxin-like protein I (SEll) secretion from Staphylococcus aureus clinical isolate. J. Appl. Microbiol. 121, 539–546.

    Not in our library10.1111/jam.13181

  284. 284.

    Ziebandt A. K. Becher D. Ohlsen K. Hacker J. Hecker M. Engelmann S. (2004 ). The influence of agr and sigmaB in growth phase dependent regulation of virulence factors in Staphylococcus aureus. Proteomics 4, 3034–3047.

    Not in our library10.1002/pmic.200400937

  285. 285.

    Ziebandt A. K. Weber H. Rudolph J. Schmid R. Höper D. Engelmann S.. (2001 ). Extracellular proteins of Staphylococcus aureus and the role of SarA and sigma B. Proteomics 1, 480–493.

    Not in our library10.1002/1615-9861(200104)1:4<480::aid-prot480>3.0.co;2-o

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