title: Characterization of carbapenem-resistant Acinetobacter baumannii isolates in a Chinese teaching hospital.
abstract: Carbapenem-resistant Acinetobacter baumannii (CRAB) presents a serious therapeutic and infection control challenge. In this study, we investigated the epidemiological and molecular differences of CRAB and the threatening factors for contributing to increased CRAB infections at a hospital in western China. A total of 110 clinical isolates of A. baumannii, collected in a recent 2-year period, were tested for carbapenem antibiotic susceptibility, followed by a molecular analysis of carbapenemase genes. Genetic relatedness of the isolates was characterized by multilocus sequence typing. Sixty-seven of the 110 isolates (60.9%) were resistant to carbapenems, 80.60% (54/67) of which carried the bla OXA-23 gene. Most of these CRAB isolates (77.62%) were classified as clone complex 92 (CC92), and sequence type (ST) 92 was the most prevalent STs, followed by ST195, ST136, ST843, and ST75. One CRAB isolate of ST195 harbored plasmid pAB52 from a Chinese patient without travel history. This plasmid contains toxin-antitoxin elements related to adaptation for growth, which might have emerged as a common vehicle indirectly mediating the spread of OXA-23 in CRAB. Thus, CC92 A. baumannii carrying OXA-23 is a major drug-resistant strain spreading in China. Our findings indicate that rational application of antibiotics is indispensable for minimizing widespread of drug resistance.
authors.affiliation: Small Molecule Drugs Sichuan Key Laboratory, Institute of Materia Medica, Chengdu Medical College Chengdu, China.
authors.forename: Yaowen
authors.initials: Y
authors.lastname: Chang
authors.affiliation: Non-coding RNA and Drug Discovery Laboratory, Chengdu Medical College Chengdu, China.
authors.forename: Guangxin
authors.initials: G
authors.lastname: Luan
authors.affiliation: Clinical Laboratory, The First Affiliated Hospital, Chengdu Medical College Chengdu, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Non-coding RNA and Drug Discovery Laboratory, Chengdu Medical College Chengdu, China.
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Non-coding RNA and Drug Discovery Laboratory, Chengdu Medical College Chengdu, China.
authors.forename: Min
authors.initials: M
authors.lastname: Shen
authors.affiliation: Small Molecule Drugs Sichuan Key Laboratory, Institute of Materia Medica, Chengdu Medical College Chengdu, China.
authors.forename: Chi
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Small Molecule Drugs Sichuan Key Laboratory, Institute of Materia Medica, Chengdu Medical College Chengdu, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zheng
authors.affiliation: Institute of Antibiotics, The Fifth Affiliated Hospital, Wenzhou Medical University Lishui, China.
authors.forename: Jinwei
authors.initials: J
authors.lastname: Huang
authors.affiliation: Non-coding RNA and Drug Discovery Laboratory, Chengdu Medical College Chengdu, China.
authors.forename: Jingni
authors.initials: J
authors.lastname: Yang
authors.affiliation: Non-coding RNA and Drug Discovery Laboratory, Chengdu Medical College Chengdu, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Jia
authors.affiliation: Small Molecule Drugs Sichuan Key Laboratory, Institute of Materia Medica, Chengdu Medical College Chengdu, China.
authors.forename: Baodong
authors.initials: B
authors.lastname: Ling
keywords: Acinetobacter baumannii; CC92; OXA-23; carbapenem resistance; plasmid