Clonal Spread of Extended-Spectrum Cephalosporin-Resistant Enterobacteriaceae Between Companion Animals and Humans in South Korea

Abstract

Extended-spectrum cephalosporin (ESC)-resistant Enterobacteriaceae is an increasingly important problem in both human and veterinary medicine. The aims of this study were to describe a comparative molecular characterization of Enterobacteriaceae carrying ESC resistance genes, encoding extended-spectrum β-lactamase (ESBL) and AmpC, isolated from human stool samples, rectal swabs from companion animals, and swabs from the environment of veterinarian hospitals in South Korea, and to examine their possible dissemination and transmission. The ESC resistance genes were identified by PCR and sequencing. Isolates with the predominant ESC resistance genes were assessed for their genetic relatedness by pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing. A total of 195 Escherichia coli and 41 Klebsiella pneumoniae isolates that exhibited ESC resistance were recovered on CHROMagar ESBL from human, companion animal, and the veterinary hospital environmental samples. In companion animals, most of the ESC resistance genes were bla CMY–2–like (26.4%), followed by bla CTX –M–55 (17.2%) and bla CTX–M–14 (16.1%), whereas bla CTX–M–15 (28.6%) was predominant in human samples. The epidemiological relatedness of isolates carrying ESC resistance genes, including 124 E. coli and 23 K. pneumoniae isolates carrying CMY-2-like, DHA-1-like, or/and CTX-M-type, were analyzed by PFGE. The pulsotypes of five E. coli isolates (three from dogs and two from humans) carrying bla CMY–2–like , which were attributed to sequence type 405, from different veterinary clinics showed >85% similarity. Our results indicate direct transmission and dissemination of ESC-resistant Enterobacteriaceae between humans and companion animals.

Molecular Characterization of Fecal Extended-Spectrum β-Lactamase- and AmpC β-Lactamase-Producing Escherichia coli From Healthy Companion Animals and Cohabiting Humans in South Korea

“…Two cases of them were occurred as interhousehold dog-dog sharing. In the remaining one case, eleven E. coli isolates (eight dogs and three humans from different households) corresponded to ST405 by MLST analysis were included in one cluster (a) by PFGE (pulsotype a1 (six dogs and two humans) with >86% clonal similarity and pulsotype a2 (two dogs and one human) with >90% clonal similarity), similar to the well-characterized E118 strain (E. coli ST405 canine isolate carrying the bla CMY−2 gene) in our previous report (Hong et al, 2019; Figure 2E).…”

“…Template DNA was prepared by the boiling method. bla CTX−M−1−like , bla CTX−M−2−like , bla CTX−M−9−like , and bla CTX−M−25−like for CTX-M-type ESBLs were amplified by PCR and direct sequencing in cefotaxime-non-susceptible E. coli isolates; bla DHA , bla ACC , bla ACT , and bla FOX for AmpCs were amplified by PCR and direct sequencing in cefoxitin-nonsusceptible E. coli isolates; IMP-, VIM-, NDM-, KPC-, GES-, and OXA-48-like for carbapenemases were amplified by PCR and direct sequencing in carbapenem-non-susceptible E. coli isolates: 1138 bp region upstream of the bla CMY−2 gene within ISEcp1 and the 116 bp spacer sequence as the predicted bla CMY−2 promoter between ISEcp1 and CMY-2 for bla CMY−2 promoter as described previously (Smet et al, 2008;Ma et al, 2011;Kurpiel and Hanson, 2012;Manageiro et al, 2015;Hong et al, 2019). The sequences were compared to published DNA sequences using BLAST 1 .…”

“…Two (E597 and E686) of the three isolates were recovered from a dog and a human in this study, respectively. The other well-characterized isolate (E118) was recovered from a dog in our previous study in 2017 (Hong et al, 2019). The bacterial DNA was extracted from the three isolates using a Wizard Genomic DNA Purification kit (Promega, Madison, WI, United States).…”

“…Our previous study targeted "diseased" companion animals (Hong et al, 2019), while this study focused on "healthy" companion animals. Namely, the significant difference between our two studies is the study population.…”

Distribution and antimicrobial resistance profiles of bacterial species in stray cats, hospital-admitted cats, and veterinary staff in South Korea

“…The ComPath study has reported a low prevalence of ESBLproducing bacteria in dogs (2.8%) and the absence of ESBL-producing bacteria in cats [26]. However, a previous Korean study has shown a higher prevalence of ESBL-producing isolates in dogs and cats (29.2% in dogs and 13.5% in cats) [33]. The differences in their prevalence may be caused by the use of an ESBL-selective agar (CHROMagar ESBL).…”