Evolution of AbaR-type genomic resistance islands in multiply antibiotic-resistant Acinetobacter baumannii
Evolution of AbaR-type genomic resistance islands in multiply antibiotic-resistant Acinetobacter baumannii
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DOI：
10.1093/jac/dkq095
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发表时间：
2010-06-01
影响因子：
5.2
通讯作者：
Hall, Ruth M.
中科院分区：
文献类型：
--
作者：
Post, Virginia;White, Peter A.;Hall, Ruth M.
为了确定来自澳大利亚的多重耐药鲍曼不动杆菌分离株中是否存在欧洲克隆谱系的成员。为了寻找Abar类型的基因组耐药岛，并确定检测到的任何Abar的遗传组织。对2002年至2007年在悉尼三家医院分离的两组多重耐药鲍曼不动杆菌进行了研究。采用多种分子生物学技术鉴定其是否属于欧洲流行克隆，并对其进行鉴定。其中一组5个分离物属于欧洲克隆I，其中存在一个以抗性基因和Tn6018为特征的Abar型岛。作图揭示了两个新的Abar构型，AbaR6和AbaR7，IS26产生的相对于AbaR5的缺失分别为29和36.2kb。第二组包括7个属于欧洲克隆II的菌株，在这些克隆中，与Abar基因组耐药岛位于同一染色体位置的转座子不同。澳大利亚医院发现了属于欧洲流行克隆系I和II的多重耐药鲍曼不动杆菌，表明这些克隆是全球分布的。在检测的菌株中，只有克隆I菌株含有Abar型耐药岛，并鉴定出两种新类型，即只携带4个抗生素耐药基因的AbaR6和AbaR7。因此，Abar不断进化，而IS26在这一过程中发挥着关键作用。
To determine if members of the European clonal lineages are present amongst multiply antibiotic-resistant Acinetobacter baumannii isolates from Australia. To search for AbaR-type genomic antibiotic resistance islands and determine the genetic organization of any AbaR detected.Two groups of multiply antibiotic-resistant A. baumannii strains isolated between 2002 and 2007 at three Sydney hospitals were studied. Various molecular techniques were used to determine whether they belong to European epidemic clones and to detect and characterize the AbaR.One group of five isolates belonged to European clone I. In these, an AbaR-type island, characterized by the presence of resistance genes and Tn6018, was present. Mapping revealed two novel AbaR configurations, AbaR6 and AbaR7, with IS26-generated deletions of 29 and 36.2 kb, respectively, relative to AbaR5. The second group contained seven isolates belonging to European clone II and, in these, a different transposon was present in the same chromosomal location as the AbaR genomic resistance islands.Multiply antibiotic-resistant A. baumannii strains belonging to both European epidemic clonal lineages I and II are found in Australian hospitals, indicating that these clones are globally distributed. Amongst the isolates examined, only the clone I strains harboured an AbaR-type resistance island, and two novel types, AbaR6 and AbaR7, carrying only four antibiotic resistance genes were identified. Hence, AbaR are continuously evolving and IS26 plays a key role in this process.