Klebsiella pneumoniae complex harboring mcr‐1, mcr‐7, and mcr‐8 isolates from slaughtered pigs in thailand

Abstract

Dissemination of the mobile colistin resistance gene mcr in Enterobacterales among hu-mans, animals, and the environment is a public health issue. We characterized mcr genes in the Klebsiella pneumoniae complex (KpnC) isolated from slaughtered pigs in Thailand. The 280 KpnCs consisted of K. pneumoniae (85%), Klebsiella quasipneumoniae (8.21%), and Klebsiella variicola (6.79%). mcr genes were detected in 6.79% (19/280) of KpnC isolates, consisting of mcr‐8 (n = 9; 3.21%), mcr‐7 (n = 7; 2.50%), mcr‐7 + mcr‐8 (n = 2; 0.71%), and mcr‐1 + mcr‐7 (n = 1; 0.36%). K. pneumoniae predomi-nantly carried the mcr‐7 and mcr‐8 genes, while K. variicola and K. quasipneumoniae harbored mcr‐7 and mcr‐8, respectively. Six of the nineteen mcr‐harboring KpnC isolates exhibited colistin re-sistance, and five had mcr‐1 or mcr‐8 transferable to an Escherichia coli recipient. Antimicrobial susceptibility analysis revealed that all mcr‐carrying KpnC isolates were susceptible to carbapenems, cefotaxime, cefepime, amoxicillin/clavulanic acid, piperacillin/tazobactam, amikacin, and fosfomy-cin, and had high resistance to azithromycin. Multilocus sequence analysis demonstrated that the mcr‐harboring KpnC isolates were genetically diverse. A ‘One‐Health’ approach is useful to combat antimicrobial‐resistant bacteria through coordinating the human, animal, and environmental sec-tors. Hence, continuous monitoring and surveillance of mcr‐carrying KpnCs throughout the pork supply chain is crucial for ensuring public health.