AUTHOR=Mazumder Razib , Hussain Arif , Rahman Mohammad Mustafizur , Phelan Jody E. , Campino Susana , Abdullah Ahmed , Clark Taane G. , Mondal Dinesh 

TITLE=Genomic and functional portrait of multidrug-resistant, hydrogen sulfide (H2S)-producing variants of Escherichia coli

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1206757

DOI=10.3389/fmicb.2023.1206757

ISSN=1664-302X

ABSTRACT=<p>Atypical <italic>Escherichia coli</italic> forms exhibit unusual characteristics compared to typical strains. The H<sub>2</sub>S-producing variants of some atypical <italic>E. coli</italic> strains cause a wide range of illnesses in humans and animals. However, there are sparse reports on such strains worldwide. We performed whole-genome sequencing (WGS) and detailed characterization of four H<sub>2</sub>S-producing <italic>E. coli</italic> variants from poultry and human clinical sources in Dhaka, Bangladesh. All four isolates were confirmed as <italic>E. coli</italic> using biochemical tests and genomic analysis, and were multidrug-resistant (MDR). WGS analysis including an additional Chinese strain, revealed diverse STs among the five H<sub>2</sub>S-producing <italic>E. coli</italic> genomes, with clonal complex ST10 being detected in 2 out of 5 genomes. The predominant phylogroup detected was group A (<italic>n</italic> = 4/5). The <italic>bla</italic><sub>TEM1B</sub> (<italic>n</italic> = 5/5) was the most predominant extended-spectrum beta-lactamase (ESBL) gene, followed by different alleles of <italic>bla</italic><sub>CTX-M</sub> (<italic>bla</italic><sub>CTX-M</sub> -55,-65,-123; <italic>n</italic> = 3/5). Multiple plasmid replicons were detected, with IncX being the most common. One <italic>E. coli</italic> strain was classified as enteropathogenic <italic>E. coli</italic>. The genomes of all five isolates harbored five primary and four secondary function genes related to H<sub>2</sub>S production. These findings suggest the potential of these isolates to cause disease and spread antibiotic resistance. Therefore, such atypical <italic>E. coli</italic> forms should be included in differential diagnosis to understand the pathogenicity, antimicrobial resistance and evolution of H<sub>2</sub>S-producing <italic>E. coli.</italic></p>