Multidrug resistant Escherichia coli Harboring Extendedspectrum β-Lactamase-encoding genes isolated from clinically healthy pigs
A total of 292 E. coli isolates obtained from fecal samples from pigs in Central (n = 103) and Northeastern (n = 189) provinces of Thailand were included in this study. Eighty-six E. coli isolates were phenotypically confirmed to be β- lactamases producers and screened for the presence of β-lactamase genes. The CTX-M family was most frequently identified (90.7%). The blaCTX-M-15 gene belonging to CTX-M group I (59.3%) was the most predominantly identified CTX-M genotype followed by blaCTX-M-14 (31.4%) and blaCTX-M-4 (25.6%). The blaTEM-1 gene was prevalent (75.6%). The blaCTX-M-4 and blaCTX-M-14 genes were located on conjugative plasmid. The results highlighted healthy pigs as reservoirs of ESBL-producing E. coli carrying ESBL genes that could be horizontally transferred.