Characterization of a Linezolid- and Vancomycin-Resistant Streptococcus suis Isolate That Harbors optrA and vanG Operons
Characterization of a Linezolid- and Vancomycin-Resistant Streptococcus suis Isolate That Harbors optrA and vanG Operons
复制标题
具有 optrA 和 vanG 操纵子的耐利奈唑胺和万古霉素猪链球菌分离株的表征
DOI：
10.3389/fmicb.2019.02026
复制
发表时间：
2019-09-10
影响因子：
5.2
通讯作者：
Huang, Jinhu
中科院分区：
文献类型：
--
作者：
Du, Fanshu;Lv, Xi;Huang, Jinhu
Linezolid and vancomycin are among the last-resort antimicrobial agents in the treatment of multidrug-resistant Gram-positive bacterial infections. Linezolid- and vancomycin-resistant (LVR) Gram-positive bacteria may pose severe threats to public health. In this study, three optrA- and vanG-positive Streptococcus suis strains were isolated from two farms of different cities. There were only 1 and 343 single-nucleotide polymorphisms in coding region (cSNPs) of HCB4 and YSJ7 to YSJ17, respectively. Mobilome analysis revealed the presence of vanG, erm(B), tet(O/W/32/O), and aadE-apt-sat4-aphA3 cluster on an integrative and conjugative element, ICESsuYSJ17, and erm(B), aphA3, aac(6')-aph(2 ''), catpC(194), and optrA on a prophage, Phi SsuYSJ17-3. ICESsuYSJ17 exhibited a mosaic structure and belongs to a highly prevalent and transferable ICESa2603 family of Streptococcus species. Phi SsuYSJ17-3 shared conserved backbone to a transferable prophage Phi m46.1. A novel composite transposon, IS1216E-araC-optrA-hp-catpC(194)-IS1216E, which can be circulated as translocatable unit (TU) by IS1216E, was integrated on Phi SsuYSJ17-3. Vancomycin resistance phenotype and vanG transcription assays revealed that the vanG operon was inducible. The LVR strain YSJ17 exhibited moderate virulence in a zebrafish infection model. To our knowledge, this is the first report of LVR isolate, which is mediated by acquired resistance genes optrA and vanG operons in Gram-positive bacteria. Since S. suis has been recognized as an antimicrobial resistance reservoir in the spread of resistance genes to major streptococcal pathogens, the potential risks of disseminating of optrA and vanG from S. suis to other Streptococcus spp. are worrisome and routine surveillance should be strengthened.
