Zingali Tiziana, Chapman Toni A, Webster John, Roy Chowdhury Piklu, Djordjevic Steven P
The ithree Institute, University of Technology Sydney, City Campus, Ultimo, NSW 2007, Australia.
Australian Centre for Genomic Epidemiological Microbiology, University of Technology Sydney, P.O. Box 123, Broadway, NSW 2007, Australia.
Microorganisms. 2020 Jun 14;8(6):896. doi: 10.3390/microorganisms8060896.
Antibiotic resistance genes (ARGs) including those from the family and that encode resistance to extended spectrum β-lactams and colistin, respectively, have been linked with IncHI2 plasmids isolated from swine production facilities globally but not in IncHI2 plasmids from Australia. Here we describe the first complete sequence of a multiple drug resistance Australian IncHI2-ST4 plasmid, pTZ41_1P, from a commensal from a healthy piglet. pTZ41_1P carries genes conferring resistance to heavy-metals (copper, silver, tellurium and arsenic), β-lactams, aminoglycosides and sulphonamides. The ARGs reside within a complex resistance locus (CRL) that shows considerable sequence identity to a CRL in pSDE_SvHI2, an IncHI2:ST3 plasmid from an enterotoxigenic with serotype O157:H19 of porcine origin that caused substantial losses to swine production operations in Australia in 2007. pTZ41_1P is closely related to IncHI2 plasmids found in and from porcine, avian and human sources in Europe and China but it does not carry genes encoding resistance to clinically-important antibiotics. We identified regions of IncHI2 plasmids that contribute to the genetic plasticity of this group of plasmids and highlight how they may readily acquire new resistance gene cargo. Genomic surveillance should be improved to monitor IncHI2 plasmids.
抗生素抗性基因（ARGs），包括分别来自某个家族且编码对超广谱β-内酰胺和粘菌素抗性的那些基因，已与全球养猪场分离出的IncHI2质粒相关联，但澳大利亚的IncHI2质粒中未发现此类基因。在此，我们描述了来自一只健康仔猪共生菌的多药抗性澳大利亚IncHI2-ST4质粒pTZ41_1P的首个完整序列。pTZ41_1P携带赋予对重金属（铜、银、碲和砷）、β-内酰胺、氨基糖苷类和磺胺类药物抗性的基因。这些ARGs位于一个复杂抗性位点（CRL）内，该位点与pSDE_SvHI2中的一个CRL具有相当高的序列同一性，pSDE_SvHI2是一种来自猪源产肠毒素大肠杆菌（血清型为O157:H19）的IncHI2:ST3质粒，在2007年给澳大利亚的养猪生产造成了重大损失。pTZ41_1P与欧洲和中国猪、禽及人类来源的大肠杆菌中发现的IncHI2质粒密切相关，但它不携带编码对临床重要抗生素抗性的基因。我们确定了IncHI2质粒中有助于该组质粒遗传可塑性的区域，并强调了它们如何能够轻易获得新的抗性基因负载。应加强基因组监测以监控IncHI2质粒。
