Prevalence of Mobile Colistin Resistance Gene-positive Enterobacteriaceae and Carbapenem-resistant Enterobacteriaceae in Swine and Broiler Chicken in Okinawa

Infectious diseases caused by carbapenem-resistant Enterobacteriaceae (CRE) and mobile colistin resistance gene-positive Enterobacteriaceae have attracted attention in the medical and animal husbandry fields. In this study, we investigated the prevalence of CRE and mobile colistin resistance gene-positive Enterobacteriaceae in swine and broiler chicken in Okinawa as an indicator of resistant bacterial control. Although CRE was not detected, mobile colistin resistance genes mcr-1 , mcr-3 , and mcr-5 in Enterobacteriaceae such as Escherichia coli , Escherichia fergusonii , Escherichia albertii , and Klebsiella pneumoniae were found in 38.1% (137/360) and 41.8% (141/346) of the healthy swine and diseased broiler chickens, respectively. Because bacterial strains were isolated using SuperPolymyxin medium, a selection medium for colistin-resistant strains, the positive rate might be higher than those previously reported. Colistin resistance gene-positive Enterobacteriaceae are wide-ly found in Okinawa; therefore, it is essential to monitor their prevalence.