AUTHOR=Moser Aline I. , Kuenzli Esther , Campos-Madueno Edgar I. , Büdel Thomas , Rattanavong Sayaphet , Vongsouvath Manivanh , Hatz Christoph , Endimiani Andrea 

TITLE=Antimicrobial-Resistant Escherichia coli Strains and Their Plasmids in People, Poultry, and Chicken Meat in Laos

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.708182

DOI=10.3389/fmicb.2021.708182

ISSN=1664-302X

ABSTRACT=<p>Antimicrobial resistant (AMR) Enterobacterales are widely distributed among the healthy population of the Indochinese peninsula, including Laos. However, the local reservoir of these pathogens are currently not known and possible sources such as agricultural settings and food have rarely been analyzed. In this work, we investigated the extended-spectrum cephalosporin- (ESC-) and colistin-resistant <italic>Escherichia coli</italic> strains (CST-R-<italic>Ec</italic>) isolated from the gut of local people, feces of poultry, and from chicken meat (60 samples each group) in Laos. Whole-genome sequencing (WGS) analysis based on both short- and long-read sequencing approaches were implemented. The following prevalence of ESC-R-<italic>Ec</italic> and CST-R-<italic>Ec</italic> were recorded, respectively: local people (70 and 15%), poultry (20 and 23.3%), and chicken meat (21.7 and 13.3%). Core-genome analysis, coupled with sequence type (ST)/core-genome ST (cgST) definitions, indicated that no common AMR-<italic>Ec</italic> clones were spreading among the different settings. ESC-R-<italic>Ec</italic> mostly possessed <italic>bla</italic><sub>CTX–M–15</sub> and <italic>bla</italic><sub>CTX–M–55</sub> associated to IS<italic>Ecp1</italic> or IS<italic>26</italic>. The majority of CST-R-<italic>Ec</italic> carried <italic>mcr-1</italic> on IncX4, IncI2, IncP1, and IncHI1 plasmids similar or identical to those described worldwide; strains with chromosomal <italic>mcr-1</italic> or possessing plasmid-mediated <italic>mcr-3</italic> were also found. These results indicate a high prevalence of AMR-<italic>Ec</italic> in the local population, poultry, and chicken meat. While we did not observe the same clones among the three settings, most of the <italic>bla</italic><sub>CTX–Ms</sub> and <italic>mcr-1/-3</italic> were associated with mobile-genetic elements, indicating that horizontal gene transfer may play an important role in the dissemination of AMR-<italic>Ec</italic> in Laos. More studies should be planned to better understand the extent and dynamics of this phenomenon.</p>