Antibiotic Resistance Markers in Burkholderia pseudomallei Strain Bp1651 Identified by Genome Sequence Analysis
Antibiotic Resistance Markers in Burkholderia pseudomallei Strain Bp1651 Identified by Genome Sequence Analysis
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DOI：
10.1128/aac.00010-17
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发表时间：
2017-06-01
影响因子：
4.9
通讯作者：
Weigel, Linda M.
中科院分区：
文献类型：
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作者：
Bugrysheva, Julia V.;Sue, David;Weigel, Linda M.
类鼻疽伯克霍尔德杆菌 Bp1651 对通常可有效治疗类鼻疽的几类抗生素具有耐药性，包括四环素类、磺胺类和 β-内酰胺类药物，如青霉素（阿莫西林克拉维酸）、头孢菌素类（头孢他啶）和碳青霉烯类（亚胺培南和美罗培南）。我们对 Bp1651 基因组进行了测序、组装和注释，并使用易感菌株的比较基因组分析、注释的关键词搜索、公开可用的抗菌素耐药性预测工具和发表的报告来分析该序列。 Bp1651 序列中超过 100 个基因被鉴定为可能导致抗菌药物耐药性。最值得注意的是，我们在 penA 中发现了三个先前未表征的点突变，penA 编码 A 类 β-内酰胺酶，并且先前与 β-内酰胺抗生素耐药性有关。突变导致氨基酸变化 T147A、D240G 和 V261I。当单独引入选择试剂排除的类鼻疽杆菌菌株 Bp82 时，发现 D240G 有助于头孢他啶耐药性，T147A 有助于阿莫西林克拉维酸和亚胺培南耐药性。这项研究提供了第一个证据，证明 penA 突变可能会改变类鼻疽杆菌对碳青霉烯类药物的敏感性。另一个令人感兴趣的突变是影响二氢叶酸还原酶基因 folA 的点突变，这可能解释了该菌株对甲氧苄啶的耐药性。 Bp1651 对氨基糖苷类药物敏感，可能是因为 amrB 基因（AmrAB-OprA 外排泵的转运蛋白亚基）发生移码。这些发现扩大了penA的作用，包括对碳青霉烯类药物的耐药性，并可能有助于开发预测抗菌药物耐药性的分子诊断方法，并为类鼻疽的治疗提供指导。
Burkholderia pseudomallei Bp1651 is resistant to several classes of antibiotics that are usually effective for treatment of melioidosis, including tetracyclines, sulfonamides, and beta-lactams such as penicillins (amoxicillin-clavulanic acid), cephalosporins (ceftazidime), and carbapenems (imipenem and meropenem). We sequenced, assembled, and annotated the Bp1651 genome and analyzed the sequence using comparative genomic analyses with susceptible strains, keyword searches of the annotation, publicly available antimicrobial resistance prediction tools, and published reports. More than 100 genes in the Bp1651 sequence were identified as potentially contributing to antimicrobial resistance. Most notably, we identified three previously uncharacterized point mutations in penA, which codes for a class A beta-lactamase and was previously implicated in resistance to beta-lactam antibiotics. The mutations result in amino acid changes T147A, D240G, and V261I. When individually introduced into select agent-excluded B. pseudomallei strain Bp82, D240G was found to contribute to ceftazidime resistance and T147A contributed to amoxicillin-clavulanic acid and imipenem resistance. This study provides the first evidence that mutations in penA may alter susceptibility to carbapenems in B. pseudomallei. Another mutation of interest was a point mutation affecting the dihydrofolate reductase gene folA, which likely explains the trimethoprim resistance of this strain. Bp1651 was susceptible to aminoglycosides likely because of a frameshift in the amrB gene, the transporter subunit of the AmrAB-OprA efflux pump. These findings expand the role of penA to include resistance to carbapenems and may assist in the development of molecular diagnostics that predict antimicrobial resistance and provide guidance for treatment of melioidosis.