Spread of the bla(OXA-23)-Containing Tn2008 in Carbapenem-Resistant Acinetobacter baumannii Isolates Grouped in CC92 from China.
Spread of the bla(OXA-23)-Containing Tn2008 in Carbapenem-Resistant Acinetobacter baumannii Isolates Grouped in CC92 from China.
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DOI：
10.3389/fmicb.2017.00163
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发表时间：
2017
影响因子：
5.2
通讯作者：
Ying C
中科院分区：
文献类型：
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作者：
Chen Y;Gao J;Zhang H;Ying C
耐碳青霉烯类鲍曼不动杆菌 (CRAB) 临床分离株的快速扩张是一个大问题。我们对中国上海两家医院收集的鲍曼不动杆菌的抗生素敏感性、分子流行病学和耐药基因进行了调查。此外，还进行了基于鲍曼不动杆菌PCR的复制子分型方法（AB-PBRT），根据复制酶基因将质粒分类为同质组。大多数 CRAB 分离株对几乎所有抗生素均表现出高水平耐药性，但仍对粘菌素和替加环素保持敏感性。共有101个分离株携带blaOXA-51样基因。测序鉴定出 CRAB 分离株中存在 blaOXA-66。在所有 CRAB 分离株中均发现了 blaOXA-23 基因。每个 CRAB 分离株包含 19 个不同的质粒复制酶 (rep) 基因同源组 (GR) 中的 1-3 个，并且 GR6 (repAci6) 无处不在。通过多位点序列分型 (MLST) 进行的基因分型显示了七种定义的 MLST 模式，并发现了三种新的 ST。 eBURST 分析表明，它们均被分组为 CC92 (GCII)，其中 ST208 最为常见 (50%)。发现了两个带有 blaOXA-23 的转座子：Tn2006 和 Tn2008。在 54 个分离株 (96.4%) 中检测到 Tn2008，在其余两个分离株中检测到 Tn2006。 blaOXA-23碳青霉烯基因与属于CC92克隆组的repAci6质粒密切相关。我们的调查显示鲍曼不动杆菌分离株存在严重的耐药性。含有 Tn2008 的 CC92 鲍曼不动杆菌是地方性的，这可能促进了 blaoxa23 的传播。
The rapid expansion of carbapenem-resistant Acinetobacter baumannii (CRAB) clinical isolates is a big issue. We investigated the antibiotic susceptibility, molecular epidemiology and resistance gene of A. baumannii collected at two hospitals in Shanghai, China. Besides, the A. baumannii PCR-based replicon typing method (AB-PBRT) was conducted to categorize the plasmids into homogeneous groups on the basis of replicase genes. Most CRAB isolates showed high-level resistance to almost all antibiotics but retain susceptibility to colistin and tigecycline. A total of 101 isolates carried blaOXA-51-like gene. Sequencing identified the presence of blaOXA-66 for CRAB isolates. blaOXA–23 gene were discovered in all CRAB isolates. Each CRAB isolate contained 1–3 of 19 different plasmid replicase (rep) gene homology groups (GRs) and the GR6 (repAci6) was ubiquitous. Genotyping by Multilocus Sequence Typing (MLST) showed seven defined MLST patterns and three novel STs were found. eBURST analysis indicated they were all grouped in CC92 (GCII) with the most frequent ST208 (50%). Two blaOXA–23-bearing transposons were found: Tn2006 and Tn2008. Tn2008 were detected in 54 (96.4%) isolates and Tn2006 in two remaining isolates. The blaOXA–23 carbapenem gene was vitally associated with repAci6 plasmid belong to CC92 clonal group. Our survey revealed severe drug resistance in A. baumannii isolates. Tn2008-containing CC92 A. baumannii were endemic, which may facilitate the blaoxa23 dissemination.