Infection and Drug Resistance (Mar 2021)

Comparative Genome Analysis of Livestock and Human Colistin-Resistant Escherichia coli Isolates from the Same Household

  • Kawahara R,
  • Yamaguchi T,
  • Yamamoto Y

Journal volume & issue
Vol. Volume 14
pp. 841 – 847

Abstract

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Ryuji Kawahara,1 Takahiro Yamaguchi,1 Yoshimasa Yamamoto2,3 1Division of Microbiology, Osaka Institute of Public Health, Osaka, Japan; 2Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Japan; 3Life Science Research Center, Gifu University, Gifu, JapanCorrespondence: Yoshimasa YamamotoLife Science Research Center, Gifu University, 1-1 Yanagido, Gifu, 501-1194, JapanTel/Fax +81-58-230-6239Email [email protected]: Emergence and dissemination of colistin-resistant bacteria that harbor mobile colistin resistance (mcr) genes pose a dire challenge for the treatment of intractable infections caused by multidrug-resistant bacteria. Current findings on colistin-resistant bacteria in both humans and livestock of the same households highlight the need to identify the dissemination mechanisms of colistin-resistant bacteria.Methods: In this study, a comparative genome analysis of colistin-resistant Escherichia coli isolates from livestock and humans of the same household was performed to clarify the possible dissemination mechanism of mcr genes among bacteria. Pulsed-field gel electrophoresis and whole-genome sequencing followed by sequence typing of the isolates were performed for assessment of the samples.Results: The study revealed that two colistin-resistant E. coli isolates, one each from a pig and a chicken, were phylogenetically similar but not identical to the human isolates obtained from the same household. The comparative genome analysis revealed that the chicken isolate and a human isolate shared the same IncHl2 plasmid harboring the mcr transposon (mcr-1-PAP2). The pig isolate and the other human isolate retained the mcr-1 transposon on the chromosome, with the pig isolate carrying the complete mcr transposon (ISApl1-mcr-1-PAP2-ISApl1) and the human isolate carrying the incomplete mcr transposon (ISApl1-mcr-1-PAP2).Conclusion: The results of the study confirm the distribution of colistin-resistant bacteria and subsequent transmission of the resistance gene-carrying transposon between livestock and humans of the same household. To the best of our knowledge, this is the first report on genomic analysis of colistin-resistant E. coli isolates obtained from livestock and residents of the same household.Keywords: colistin-resistance, multidrug resistance, comparative genome analysis, whole-genome sequencing, mcr

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