Multi-drug resistance profiles and the genetic features of Acinetobacter baumannii isolates from Bolivia
Multi-drug resistance profiles and the genetic features of Acinetobacter baumannii isolates from Bolivia
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DOI：
10.3855/jidc.2711
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发表时间：
2013-04-01
影响因子：
1.9
通讯作者：
Amyes, Sebastian G. B.
中科院分区：
文献类型：
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作者：
Lopes, Bruno S.;Gallego, Lucia;Amyes, Sebastian G. B.
鲍曼不动杆菌在虚弱的住院病人中是机会性的。由于以前缺乏来自一些南美国家的信息，本研究调查了2008年至2009年在玻利维亚科恰班巴的三家医院中出现的多重耐药鲍曼不雅杆菌。方法：采用多重PCR方法对15株多重耐药鲍曼不动杆菌的主要耐药基因进行鉴定。RT-PCR检测基因表达。对这些基因的遗传环境进行了PCR扩增和测序分析。测定了关键抗生素的最低抑菌浓度，有些在外排泵抑制剂1-（1-萘基甲基）哌嗪存在的情况下测定。结果：发现多重耐药菌株14株。每个菌株都含有bla（OXA-58）基因，上游有isaba3样元件，负责后者的过表达和随后的碳青霉烯类抗性。同样，bla（ADC）基因上游的ISAba1导致后者过表达和头孢菌素耐药；gyrA（Ser83 - Leu）和parC （Ser-80 - Phe）基因突变与氟喹诺酮类药物耐药相关。此外，adeA、adeB外排基因过表达。所有15株菌株至少有两种氨基糖苷类耐药基因阳性。结论：本文首次对玻利维亚鲍曼不动杆菌多重耐药谱进行了分析，发现bla（OXA-58）、bla（ADC）和外排基因的过表达、氨基糖苷修饰酶和DNA拓扑异构酶突变是导致鲍曼不动杆菌多重耐药的主要原因。
Introduction: Acinetobacter baumannii is opportunistic in debilitated hospitalised patients. Because information from some South American countries was previously lacking, this study examined the emergence of multi-resistant A. baumannii in three hospitals in Cochabamba, Bolivia, from 2008 to 2009.Methodology: Multiplex PCR was used to identify the main resistance genes in 15 multi-resistant A. baumannii isolates. RT-PCR was used to measure gene expression. The genetic environment of these genes was also analysed by PCR amplification and sequencing. Minimum inhibitory concentrations were determined for key antibiotics and some were determined in the presence of an efflux pump inhibitor, 1-(1-napthylmethyl) piperazine.Results: Fourteen strains were found to be multi-resistant. Each strain was found to have the bla(OXA-58) gene with the ISAba3-like element upstream, responsible for over-expression of the latter and subsequent carbapenem resistance. Similarly, ISAba1, upstream of the bla(ADC) gene caused over-expression of the latter and cephalosporin resistance; mutations in the gyrA(Ser83 to Leu) and parC (Ser-80 to Phe) genes were commensurate with fluoroquinolone resistance. In addition, the adeA, adeB efflux genes were over-expressed. All 15 isolates were positive for at least two aminoglycoside resistance genes.Conclusion: This is one of the first reports analyzing the multi-drug resistance profile of A. baumannii strains isolated in Bolivia and shows that the over-expression of thebla(OXA-58), bla(ADC) and efflux genes together with aminoglycoside modifying enzymes and mutations in DNA topoisomerases are responsible for the multi-resistance of the bacteria and the subsequent difficulty in treating infections caused by them.