Characterization of CTX-M-Type Extended-Spectrum Beta-Lactamase-Producing Diarrheagenic Escherichia coli Isolates in the Republic of Korea During 2008-2011

Abstract

To characterize the extended-spectrum beta-lactamases (ESBLs) in diarrheagenic Escherichia coli from Korea in 2008-2011, we screened seven enterotoxigenic E. coli (ETEC) and one enteroaggregative E. coli (EAEC) that produce ESBLs from a nationwide survey. All eight isolates produced CTX-M-type ESBLs, including CTX-M-12 (n = 4), CTX-M-14 (n = 2), and CTX-M-15 (n = 2). PCR-based replicon typing indicated that the blaCTX-M-12 genes of four ETEC isolates were carried on a conjugative IncF plasmid, whereas the blaCTX-M-14 of one EAEC was located on an IncK plasmid. This is the first report of the occurrence of blaCTX-M genes in clinical isolates of EAEC in Korea. The ESBL-producing isolates were shown to be different based on pulsed-field gel electrophoresis and multilocus sequence typing, whereas the four isolates with CTX-M-12 were clonally related. These observations raise an alarm for the spread of plasmid-mediated resistance to ESBL among diarrheagenic E. coli.

Whole-Genome Sequencing-Based Characteristics in Extended-Spectrum Beta-Lactamase-Producing Escherichia coli Isolated from Retail Meats in Korea

“…In this study, 28 of 29 ESBL-EC isolates had CTX-M genotypes, just as CTX-M ESBLs have increased in occurrence worldwide since the 2000s [60]. Although genotypes of our ESBL-ECs were diverse, CTX-M group 1 (bla CTX-M-1 , bla CTX-M-3 , bla CTX-M-15 , bla CTX-M-55 ) and CTX-M group 9 (bla CTX-M-14 , bla CTX-M-27 , bla CTX-M-65 ) were prevalent types, which was consistent with the findings of previous studies in Korea [25][26][27][28]30,32,52,61,62]. The most predominant CTX-M genotype was CTX-M-55, which is a variant of globally emerging CTX-M-15, and it varies by a single amino acid substitution (Ala77→Val) that contributes to enhancing the enzymatic activity [60,63].…”

“…Since whole-genome sequencing (WGS) has become affordable and facilitates the acquisition of useful information regarding multiple AMR genes, genomic mutations, and higher-resolved microbial typing from a single assay, some countries, including the USA, have already conducted WGS-based AMR surveillance [22]. A number of studies have reported the prevalence and characteristics of ESBL-EC from humans and food-producing animals in Korea because of the importance of such ESBL-ECs from a public health perspective [23][24][25][26][27][28][29]. However, few studies have reported the prevalence and characteristics of ESBL-ECs in retail meat in Korea [30][31][32].…”

High Diversity of CTX-M Extended-Spectrum β-Lactamases in Municipal Wastewater and Urban Wetlands

“…1 and Supplementary Table S2. Most reports of these alleles have come from Asia, 24,52,58,65,66 with a few isolated accounts from Africa, 23 Europe, 8,34 Australia, 67 South America, 17 Russia, 45 and Canada. 1 Thus, it would appear that this study represents the first report of many CTX-M group 1 alleles in the United States.…”

Phenotypic Detection of Extended Spectrum Beta-lactamase Resistance of Escherichia coli from Patients Attending Selected Healthcare Facilities in Nasarawa State, Nigeria

“…Escherichia coli (E. coli) is the predominant facultative anaerobe and commensal microbiota in the mammalian gastrointestinal gut; and some strains can cause severe diarrhea illnesses in humans [1,2]. Various classes of antibiotics have been used to treat diarrhea caused by Diarrheagenic E. coli (DEC) and their continued usefulness is limited by the acquisition of resistance mechanisms in the bacteria [3].…”