Interrelationship between tetracycline resistance determinants, phylogenetic group affiliation and carriage of class 1 integrons in commensal Escherichia coli isolates from cattle farms.

Background: Carriage of antibiotic-resistant foodborne pathogens by food production animals is one of many contributors to treatment failure in health care settings, and it necessitates an integrated approach to investigate the carriage of resistant pathogens harboring integrons in food-producing animals.

Methods: Escherichia coli isolates with reduced susceptibility to tetracycline antibiotics (n = 92) were tested for associations between carriage of class1 integrons, phylogenetic group affiliation and tetracycline resistance determinants using the MIC method, PFGE analysis, PCR and sequencing.

Results: Phylogroups B1 and A were the most common (58.

Genetic Analysis of p17S-208 Plasmid Encoding the Colistin Resistance mcr-3 Gene in Escherichia coli Isolated from Swine in South Korea.

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.

Emergence of mcr-1 and mcr-3 variants coding for plasmid-mediated colistin resistance in Escherichia coli isolates from food- producing animals in South Korea.

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.

Characteristics of Transmissible CTX-M- and CMY-Type β-Lactamase-Producing Escherichia coli Isolates Collected from Pig and Chicken Farms in South Korea.

The rapid dissemination of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli has significantly contributed to public health hazard globally. A total of 281 strains recovered from pigs and chickens between 2009 and 2015 in South Korea were analyzed for ESBL production. ESBL phenotypes were recognized in 14 isolates; ten and three ESBLproducing isolates carried only and genes, respectively, and one isolate harbored both genes.

Occurrence of aminoglycoside-modifying enzymes among isolates of Escherichia coli exhibiting high levels of aminoglycoside resistance isolated from Korean cattle farms.

This study investigated 247 Escherichia coli isolates collected from four cattle farms to characterize aminoglycoside-modifying enzyme (AME) genes, their plasmid replicons and transferability. Out of 247 isolates a high number of isolates (total 202; 81.78%) were found to be resistant to various antibiotics by disc diffusion.

Prevalence of Antimicrobial Resistance and Transfer of Tetracycline Resistance Genes in Escherichia coli Isolates from Beef Cattle.

The aim of this study was to investigate the prevalence and transferability of resistance in tetracycline-resistant Escherichia coli isolates recovered from beef cattle in South Korea. A total of 155 E. coli isolates were collected from feces in South Korea, and 146 were confirmed to be resistant to tetracycline.