Emergence of a vanG-carrying and multidrug resistant ICE in zoonotic pathogen Streptococccus suis
Emergence of a vanG-carrying and multidrug resistant ICE in zoonotic pathogen Streptococccus suis
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人畜共患病病原体猪链球菌中出现了携带 vanG 且具有多重耐药性的 ICE
DOI：
10.1016/j.vetmic.2018.07.008
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发表时间：
2018-08-01
影响因子：
3.3
通讯作者：
Wang, Liping
中科院分区：
文献类型：
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作者：
Huang, Jinhu;Chen, Li;Wang, Liping
万古霉素耐药经常发生在肠球菌中，但在猪链球菌中尚未报道，猪链球菌是一种以前被忽视的新出现的人畜共患病原体。本研究对2005 - 2016年分离的256株人和猪猪链球菌进行万古霉素药敏试验，分析万古霉素耐药机制。结果发现，1株BSB6对万古霉素耐药，MIC值为4 mg/L；全基因组测序显示，ICESsuBSB6的染色体基因突变和获得性基因是抗性表型的原因。ICESsuBSB6的大小与83-kb相似，编码两个抗性基因区域ARGR1和ARGR2。ARGR1含有erm(B)、aadE-apt-sat4-aphA3簇和tet(O/W/32/O) 6个耐药基因，与猪链球菌ICESsu32457和粪肠球菌质粒pEF418的对应序列具有较高的相似性。ARGR2编码了一个vang型抗性操纵子。抗性区与粪肠球菌BM4518 vanG1相似度最高，调控区与无乳链球菌GBS-NM vanG2相似度最高。BSB6对万古霉素耐药是可诱导的。该研究首次报道了猪链球菌的vang型耐药性，强调了对其进行监测的重要性。
Vancomycin resistance occurs frequently in Enterococcus species, but has not yet been reported in Streptococcus suis, a previously neglected, newly emergent zoonotic pathogen. In this study, we tested the vancomycin susceptibility of 256 human and swine S. suis isolates from 2005 to 2016 and analyzed the mechanism of vancomycin resistance. We found that one isolate BSB6 was resistant to vancomycin with the MIC value of 4 mg/L and to another eleven kinds of tested antimicrobial agents. Whole genome sequencing showed that chromosomal gene mutations, and acquired genes in ICESsuBSB6 accounted for the resistance phenotypes. ICESsuBSB6 was similar to 83-kb in size and encoded two resistance gene regions, ARGR1 and ARGR2. ARGR1 harbored six resistance genes, namely erm(B), aadE-apt-sat4-aphA3 cluster and tet(O/W/32/O), and showed highes similarity with corresponding sequences of S. suis ICESsu32457 and Enterococcus faecalis plasmid pEF418. ARGR2 encoded a vanG-type resistance operon. The resistance region showed highest similarity to that of E. faecalis BM4518 vanG1, but the regulatory region was more similar to that of S. agalactiae GBS-NM vanG2. Vancomycin resistance in isolate BSB6 was inducible. The study is the first report of vanG-type resistance in zoonotic pathogen S. suis and highlights importance of its surveillance.