Abundance of Colistin-Resistance Genes in Retail Meats in Vietnam.

The degree of contamination of retail meat with colistin-resistant bacteria and its potential contribution to dissemination within communities remains to be determined. Thus, we aimed to elucidate the contamination status of colistin-resistance genes, indicative of colistin-resistant bacteria, in retail meats in Vietnam. In total, 46 chicken and 49 pork meats from stores in Vietnam and Japan were examined. Multiplex real-time polymerase chain reaction with TaqMan probes was performed for detecting , , and . Colistin-resistant bacteria in meats were isolated using selective media. The minimum inhibitory concentrations of colistin were determined using the broth microdilution method. The results showed that 70.7% of chicken meats in Vietnam were contaminated with both and . Meanwhile, and were detected in 15.9% and 40.9% of pork meat, respectively. Only was detected in 40% of chicken in Japan. In addition, -harboring and -harboring were isolated from chicken meats in Vietnam. Some of these isolates showed colistin resistance. These results showed that most retail meats were highly contaminated with colistin-resistance genes. Notably, our results suggest that is more prevalent in the contaminated samples compared with .