Comparative genomic analysis of Acinetobacter baumannii clinical isolates reveals extensive genomic variation and diverse antibiotic resistance determinants

BMC Genomics

Research Article

Yuying Zhu¹  Na Lu²  Fei Liu³  Baoli Zhu³  Yongfei Hu³  Yong Yi⁴ 

[1] CAS key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, China;CAS key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, China;Beijing Key Laboratory of Microbial Drug Resistance and Resistome, 100101, Beijing, China;CAS key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, China;Beijing Key Laboratory of Microbial Drug Resistance and Resistome, 100101, Beijing, China;Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, 310006, Hangzhou, China;The 306th Hospital of People’s Liberation Army, 100101, Beijing, China;

关键词: Acinetobacter baumannii;    Multidrug resistance;    Resistance island;    SNP;    Whole-genome sequencing;   

DOI  :  10.1186/1471-2164-15-1163

 received in 2014-09-19, accepted in 2014-12-16,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundAcinetobacter baumannii is an important nosocomial pathogen that poses a serious health threat to immune-compromised patients. Due to its rapid ability to develop multidrug resistance (MDR), A. baumannii has increasingly become a focus of attention worldwide. To better understand the genetic variation and antibiotic resistance mechanisms of this bacterium at the genomic level, we reported high-quality draft genome sequences of 8 clinical isolates with various sequence types and drug susceptibility profiles.ResultsWe sequenced 7 MDR and 1 drug-sensitive clinical A. baumannii isolates and performed comparative genomic analysis of these draft genomes with 16 A. baumannii complete genomes from GenBank. We found a high degree of variation in A. baumannii, including single nucleotide polymorphisms (SNPs) and large DNA fragment variations in the AbaR-like resistance island (RI) regions, the prophage and the type VI secretion system (T6SS). In addition, we found several new AbaR-like RI regions with highly variable structures in our MDR strains. Interestingly, we found a novel genomic island (designated as GIBJ4) in the drug-sensitive strain BJ4 carrying metal resistance genes instead of antibiotic resistance genes inserted into the position where AbaR-like RIs commonly reside in other A. baumannii strains. Furthermore, we showed that diverse antibiotic resistance determinants are present outside the RIs in A. baumannii, including antibiotic resistance-gene bearing integrons, the blaOXA-23-containing transposon Tn2009, and chromosomal intrinsic antibiotic resistance genes.ConclusionsOur comparative genomic analysis revealed that extensive genomic variation exists in the A. baumannii genome. Transposons, genomic islands and point mutations are the main contributors to the plasticity of the A. baumannii genome and play critical roles in facilitating the development of antibiotic resistance in the clinical isolates.

【 授权许可】

Unknown   
© Liu et al.; licensee BioMed Central. 2014. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.