Emergence of vancomycin- and teicoplanin-resistant Enterococcus faecium via vanD5-harbouring large genomic island
Emergence of vancomycin- and teicoplanin-resistant Enterococcus faecium via vanD5-harbouring large genomic island
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DOI：
10.1093/jac/dkaa220
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发表时间：
2020-09-01
影响因子：
5.2
通讯作者：
Yokota, Shin-ichi
中科院分区：
文献类型：
--
作者：
Sato, Toyotaka;Wada, Takayuki;Yokota, Shin-ichi
背景：VRE的治疗是临床关注的问题。虽然已分离出一定数量的Vand型VRE，但在加拿大和日本只有两株含有vanD5的粪肠球菌分离株。方法：我们报道了VanD5型粪肠球菌的分离并首次测定了全基因组序列，以探讨粪肠球菌获得vanD5基因簇的可能机制。结果：从日本一名皮肤溃疡患者的皮肤(SMVRE19)和粪便(SMVRE20)中分离到两株携带vanD5的粪便肠球菌(SMVRE19)。分离株对万古霉素和替考拉宁的MIC值为128 mg/L，而已有的携带VanD5基因的粪肠球菌只对万古霉素耐药。SMVRE19和SMVRE20是与ST18相关的克隆，ST18也见于VANA和VanB型VRE。这些分离株在DDL基因中含有插入元件ISEfm1，类似于先前描述的耐替考拉宁的VanD3型粪肠球菌。VanD5基因簇被整合到SMVRE20染色体上，作为一个大的基因组岛(约127kb)的一部分，类似于最近在荷兰传播的其他Vand变体。除了Vand基因簇周围的区域外，该基因组岛与蓝球藻基因组序列的一部分具有最大的相似性。结论：本研究报告了通过获得vanD5簇和ISEfm1插入DDL而产生对万古霉素和替考拉宁耐药的VanD5型粪肠球菌。考虑到不同VRE毒株之间的遗传相似性，目前的研究应作为对VanD5型VRE传播的警告。
Background: Treatment of VRE is of clinical concern. While certain numbers of vanD-type VRE have been isolated, only two vanD5-harbouring Enterococcus faecium isolates have been reported in Canada and Japan.Methods: We report the isolation of vanD5-type E. faecium and the first ever determination of the whole-genome sequence to investigate the possible mechanisms of the acquisition of the vanD5 gene cluster in E. faecium.Results: Two vanD5-harbouring vancomycin-resistant E. faecium were isolated from the skin (SMVRE19) and faeces (SMVRE20) of a patient with a skin ulcer in Japan. The isolates exhibited vancomycin and teicoplanin MIC values of 128 mg/L, whilst the previous isolates of vanD5-harbouring E. faecium were only resistant to vancomycin. SMVRE19 and SMVRE20 were clones related to ST18, which is also seen in vanA- and vanB-type VRE. These isolates harboured an insertion element, ISEfm1, in the ddl gene, similar to a previously described teicoplanin-resistant vanD3-type E. faecium. The vanD5 gene cluster was integrated into the SMVRE20 chromosome as a part of a large genomic island (approximately 127 kb), similar to other recently spreading vanD variants in the Netherlands. The genomic island shared the greatest similarity with a part of the Blautia coccoides genome sequence, except for the region surrounding the vanD gene cluster.Conclusions: This study reports that emergence of vancomycin- and teicoplanin-resistant vanD5-type E. faecium occurred via acquisition of the vanD5 cluster and ISEfm1 insertion into ddl. Considering the genetic similarity between the various VRE strains, the current study should serve as a warning against the spread of vanD5-type VRE.