Distribution and molecular profiling of class 1 integrons in MDR Acinetobacter baumannii isolates and whole genome-based analysis of antibiotic resistance mechanisms in a representative strain

Yuying Zhu; Yong Yi; Fei Liu; Na Lv; Xi Yang; Jing Li; Yongfei Hu; Baoli Zhu

doi:10.1016/j.micres.2014.04.002

Distribution and molecular profiling of class 1 integrons in MDR Acinetobacter baumannii isolates and whole genome-based analysis of antibiotic resistance mechanisms in a representative strain

Microbiol Res. 2014 Nov;169(11):811-6. doi: 10.1016/j.micres.2014.04.002. Epub 2014 Apr 18.

Authors

Yuying Zhu¹, Yong Yi², Fei Liu¹, Na Lv¹, Xi Yang¹, Jing Li¹, Yongfei Hu³, Baoli Zhu⁴

Affiliations

¹ Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Beijing Key Laboratory of Microbial Drug Resistance and Resistome, Beijing 100101, China.
² The 306th Hospital of People's Liberation Army, Beijing 100101, China.
³ Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Beijing Key Laboratory of Microbial Drug Resistance and Resistome, Beijing 100101, China. Electronic address: huyf@im.ac.cn.
⁴ Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Beijing Key Laboratory of Microbial Drug Resistance and Resistome, Beijing 100101, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310006, China. Electronic address: zhubaoli@im.ac.cn.

PMID: 24809232
DOI: 10.1016/j.micres.2014.04.002

Abstract

The class 1 integron is an important driver of the nosocomial dissemination of multidrug-resistant (MDR) bacteria, such as Acinetobacters. In this study, we characterized the gene cassette arrays of class 1 integrons in Acinetobacter baumannii, where the detailed structure of these integrons for 38 clinical strains was analyzed. The results showed that there are three types of gene cassette arrays that are carried by different class 1 integrons, among them the aac(6')-IId-catB8-aadA1 array was the most prevalent. For detailed analysis of the integron structure, whole genome sequencing was carried out on strain AB16, and it was found that a single integron on its chromosome has a partial Tn21 transposon in its 5' flanking region and two complete copies of the insertion element IS26 in both the 5' and 3' flanking regions, indicating that the integron could be acquired by horizontal gene transfer. Furthermore, there is one resistance island AbaR22, one bla gene containing a transposon, four intrinsic resistant genes and one efflux pump that together confer six types of antibiotic resistance.

Keywords: Acinetobacter baumannii; Class 1 integron; Gene cassettes; Multidrug resistance.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Acinetobacter Infections / microbiology
Acinetobacter baumannii / drug effects
Acinetobacter baumannii / genetics*
Acinetobacter baumannii / isolation & purification
Anti-Bacterial Agents / pharmacology*
Cross Infection / microbiology
Drug Resistance, Bacterial*
Genome, Bacterial
Integrons*
Microbial Sensitivity Tests

Substances

Anti-Bacterial Agents