Fecal carriage of MDROs in a population of Lebanese elderly: Dynamics and impact on bacterial fitness

Muti-Drug Resistant Organisms (MDROs) are problematic all over the world, especially in Lebanon. High fecal carriage rates of MDR Enterobacteriaceae were reported from Lebanese nursing homes. Some studies show that MDROs have a fitness cost as compared to sensitive isolates. In this study, the competitive growth of MDR Escherichia coli obtained from fecal samples from elderly is assessed.Fecal swabs from ten elderly patients from a Lebanese nursing home were obtained between June and December, 2015. Isolates were identified by API 20E and antimicrobial susceptibilities were determined. Production of ESBL (extended spectrum β lactamase), MBL (metallo β lactamse), AmpC and KPC (Klebsiella pneumonia carbapenemase) was detected phenotypically by the use of EDTA, PBA, cloxacillin, and DDSTs. In-vitro competition assays were performed using E. coli isolates with different combinations of bacterial resistance.A total of 117 isolates was obtained with 71.8% E. coli, 7.7% of which were ESBL and 5.1% AmpC producers. Sensitive E. coli isolates out-competed all other isolates when in competition, followed sequentially by ESBL, AmpC, and OXA-48 (oxacillin) producers.This study shows an advantage of sensitive E. coli strains obtained from fecal samples to out-compete resistant strains in specific in-vitro conditions. This ability could be exploited in the elimination of MDR organisms from the gut flora, after further investigation. Keywords: Multi-Drug Resistant Organisms, Fecal carriage, Fitness cost, Nursing homes

Abstract licence: CC BY-NC-ND

1. 10.

   Food and human gut as reservoirs of transferable antibiotic resistance encoding genes · 2013

2. 12.

   The fitness costs of antibiotic resistance mutations · 2014

35 more references, whose wording the paper’s licence keeps private.

A person counts once a day per paper. We keep no cookie and no address: a reader is a hash that changes every day. Any month under five reads shows no number.