Jiang Xinlei, Liu Xuan, Law Carmen O K, Wang Ya, Lo Wai U, Weng Xing, Chan Ting Fung, Ho P L, Lau Terrence C K
Department of Biomedical Sciences, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region.
Department of Microbiology, University of Hong Kong, Hong Kong, Hong Kong Special Administrative Region.
FEMS Microbiol Ecol. 2017 Jul 1;93(7). doi: 10.1093/femsec/fix090.
The dissemination of extended-spectrum β-lactamases (ESBLs) genes among bacteria is commonly achieved by plasmid conjugation. In the last decade, the CTX-M type enzyme was the most widespread and prevalent ESBLs in the world. In Hong Kong and mainland China, among the commonly found CTX-M-carrying plasmids were pHK01 and pHK01-like plasmids, which belong to incompatibility group FII (IncFII). In this work, we studied the physiological effect caused by the pHK01 plasmid in bacterial host Escherichia coli J53. The plasmid did not affect cell growth of the host but reduced their motility. The reduction of host motility was attributed to downregulation of genes that encode the flagellar system. We also identified several plasmid-encoded sRNAs, and showed that the overexpression of one of them, AS-traI, in the presence of pHK01 plasmid shortened the lag phase of host growth. In addition to the study of pHK01 in bacteria, we also developed a fast and incompatibility group-specific curing method using countertranscribed RNA, which could be of general usage for studying plasmid-host interaction in clinical aspects.
超广谱β-内酰胺酶（ESBLs）基因在细菌间的传播通常是通过质粒接合实现的。在过去十年中，CTX-M型酶是世界上分布最广、最为常见的ESBLs。在香港和中国大陆，常见的携带CTX-M的质粒中，pHK01及类似pHK01的质粒属于不相容群FII（IncFII）。在本研究中，我们探究了pHK01质粒对细菌宿主大肠杆菌J53的生理影响。该质粒不影响宿主细胞的生长，但降低了其运动性。宿主运动性的降低归因于编码鞭毛系统的基因表达下调。我们还鉴定了几种质粒编码的小RNA，并表明在pHK01质粒存在的情况下，其中一种小RNA（AS-traI）的过表达缩短了宿主生长的延迟期。除了对细菌中的pHK01进行研究外，我们还开发了一种使用反转录RNA的快速且具有不相容群特异性的消除方法，该方法在临床研究质粒-宿主相互作用方面具有广泛的应用前景。
