Mobile genetic elements facilitate the transmission of antibiotic resistance genes in multidrug-resistant Enterobacteriaceae from duck farms
Xiner Zheng, Dingting Xu, Jinchang Yan, Min Qian, Peng Wang, Davood Zaeim, Jianzhong Han, Daofeng Qu
Abstract
Multidrug-resistant (MDR) <i>Enterobacteriaceae</i> critically threaten duck farming and public health. The phenotypes, genotypes, and associated mobile genetic elements (MGEs) of MDR <i>Enterobacteriaceae</i> isolated from six duck farms in Zhejiang province, China, were investigated. A total of 215 isolates were identified as <i>Escherichia coli</i> (64.65%), <i>Klebsiella pneumoniae</i> (12.09%), <i>Proteus mirabilis</i> (10.23%), <i>Salmonella</i> (8.84%), and <i>Enterobacter cloacae</i> (4.19%). Meanwhile, all isolates were resistant to at least two antibiotics. Most isolates carried <i>tet</i>(A) (85.12%), <i>bla</i><sub>TEM</sub> (78.60%) and <i>sul1</i> (67.44%) resistance genes. Gene co-occurrence analysis showed that the resistance genes were associated with IS<i>26</i> and integrons. A conjugative IncFII plasmid pSDM004 containing all the above MGEs was detected in <i>Proteus mirabilis</i> isolate SDM004. This isolate was resistant to 18 antibiotics and carried the <i>bla</i><sub>NDM-5</sub> gene. MGEs, especially plasmids, are the primary antibiotic resistance gene (ARG) transmission route in duck farms. These findings provide a theoretical basis for the rational use of antibiotics in farms which are substantial for evaluating public health and food safety.