Emergence of an Australian-like pstS -null vancomycin resistant Enterococcus faecium clone in Scotland
Emergence of an Australian-like pstS -null vancomycin resistant Enterococcus faecium clone in Scotland
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苏格兰出现类似澳大利亚 pstS 的万古霉素抗性屎肠球菌克隆
DOI：
10.1101/236786
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Lemonidis K
中科院分区：
文献类型：
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作者：
Lemonidis K
多位点测序分型（MLST）被广泛用于监测微生物暴发的发生。然而，最近在澳大利亚出现了几种缺失MLST基因座（pstS）的万古霉素耐药屎肠球菌（VREfm）菌株，英国也报告了一些病例。在这里，我们发现了在苏格兰两家邻近医院传播的类似的不同菌株。对从这些医院分离的五种VREfm菌株进行全基因组测序，在这两家医院发现了四种pstS无效菌株，而第五种是多位点序列型（ST）262，这是英国首次记录。所有5个苏格兰分离株在tetM基因中有一个插入，这与四环素类药物敏感性增加有关，前提是不存在其他四环素耐药基因。在所有检测的vanA-型pepstS-无效VREfm菌株（5个英国菌株和68个澳大利亚菌株）中另外鉴定了这种插入，其包括adfrG基因和两个目前未表征的基因。与其他VREfm基因组的系统发育比较表明，在这项研究中测序的fourpstS-null苏格兰菌株更密切相关的topstS-null菌株来自澳大利亚，而不是EnglishpstS-null菌株。考虑到这种pstS无效菌株在澳大利亚的扩张速度，这种克隆在苏格兰的出现引起了人们对潜在疫情的担忧。
Multi-locus sequencing typing (MLST) is widely used to monitor the phylogeny of microbial outbreaks. However, several strains of vancomycin-resistantEnterococcus faecium(VREfm) with a missing MLST locus (pstS) have recently emerged in Australia, with a few cases also reported in England. Here, we identified similarly distinct strains circulating in two neighbouring hospitals in Scotland. Whole genome sequencing of five VREfm strains isolated from these hospitals identified fourpstS-null strains in both hospitals, while the fifth was multi-locus sequence type (ST) 262, which is the first documented in the UK. All five Scottish isolates had an insertion in thetetMgene, which is associated with increased susceptibility to tetracyclines, providing no other tetracycline-resistant gene is present. Such an insertion, which encompasses adfrGgene and two currently uncharacterised genes, was additionally identified in all testedvanA-typepstS-null VREfm strains (5 English and 68 Australian). Phylogenetic comparison with other VREfm genomes indicates that the fourpstS-null Scottish isolates sequenced in this study are more closely related topstS-null strains from Australia rather than the EnglishpstS-null isolates. Given how rapidly suchpstS-null strains have expanded in Australia, the emergence of this clone in Scotland raises concerns for a potential outbreak.