ABSTRACT
We screened, for the first time, plasmid-mediated colistin resistance mcr-3 genes among 636 Escherichia coli isolates collected from swine in South Korea. Whole-genome sequencing showed that the E. coli strain harbored the mcr-3 gene in a p17S-208 plasmid with an IncHI2-ST3 plasmid type and a size of 260,399 base pairs. The deduced amino acid sequences revealed that persistent evolution in the bacterial genome has resulted in mcr gene variants. There is a need for extensive surveillance to prevent the dissemination of colistin resistance mcr genes from animal to human.
Subject(s)
Colistin/pharmacology , Drug Resistance, Bacterial/genetics , Escherichia coli Proteins/genetics , Escherichia coli/genetics , Escherichia coli/isolation & purification , Plasmids/genetics , Transferases (Other Substituted Phosphate Groups)/genetics , Animals , Anti-Bacterial Agents/pharmacology , Escherichia coli/drug effects , Escherichia coli Infections/drug therapy , Escherichia coli Infections/microbiology , Genome, Bacterial/genetics , Microbial Sensitivity Tests/methods , Republic of Korea , SwineABSTRACT
We hereby report the first characterization of mcr-3 gene from healthy animals in South Korea. Out of 636 E. coli isolates, collected between 2014- 2017, nine colistin resistant isolates were screened for the presence of mcr-1 and mcr-3 genes. Nine (1.4%) isolates had shown resistance for colistin and among them three and two isolates were mcr-1 harboring and mcr-3 harboring strains, respectively. All the colistin-resistant isolates were multidrug-resistant. mcr-1 and mcr-3 genes were confirmed to be transferred to a recipient E. coli J53 AZR.
Subject(s)
Anti-Bacterial Agents/pharmacology , Colistin/pharmacology , Drug Resistance, Bacterial/drug effects , Escherichia coli Infections/veterinary , Escherichia coli Proteins/genetics , Escherichia coli/drug effects , Livestock/microbiology , Animals , Drug Resistance, Bacterial/genetics , Escherichia coli/genetics , Escherichia coli/isolation & purification , Escherichia coli Infections/drug therapy , Escherichia coli Infections/microbiology , Microbial Sensitivity Tests , Plasmids , Poultry/microbiology , Republic of KoreaABSTRACT
The rapid dissemination of extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli has significantly contributed to public health hazard globally. A total of 281 E. coli strains recovered from pigs and chickens between 2009 and 2015 in South Korea were analyzed for ESBL production. ESBL phenotypes were recognized in 14 E. coli isolates; ten and three ESBLproducing isolates carried only blaCTX-M and blaCMY genes, respectively, and one isolate harbored both genes. The predominant CTX-M and CMY types were CTX-M-15 (n = 8) and CMY-2 (n = 3). We also detected ESBL-producing isolates harboring blaCTX-M-65, blaCTX-M-14, blaCMY-6, blaDHA-1, and blaTEM-1 genes. All ESBL-producing isolates showed resistance to the extent of the fourth generation cephalosporins, along with multidrug resistance. CTX-M-15- producing isolates showed higher MIC values than CTX-M-14- and CTX-M-65-producing isolates. The blaCTX-M and blaCMY genes have the potential to be transferable. The spreading of blaCMY and blaCTX-M genes was arbitrated mainly v ia F rep a nd I ncI1 plasmids. Our i solates showed clonal diversity in PFGE analysis. This is the first report of E. coli isolates carrying blaCMY-6 in chicken from South Korea. The emergence of CMY-6 ESBLs in a population of poultry suggests that extensive screening with long-term surveillance is necessary to prevent the dissemination of ESBL from chicken to human.
