title: Prevalence of Genes of OXA-23 Carbapenemase and AdeABC Efflux Pump Associated with Multidrug Resistance of Acinetobacter baumannii Isolates in the ICU of a Comprehensive Hospital of Northwestern China.
abstract: The objective of this study was to explore the molecular epidemiology and the genetic support of clinical multidrug resistant (MDR) Acinetobacter baumannii (A. baumannii) isolates in an ICU ward of a comprehensive hospital. A total of 102 non-duplicate drug-resistant A. baumannii isolates were identified and 93 (91.1%) of them were MDR strains. Molecular analysis demonstrated that carbapenemase genes blaOXA-23 and blaOXA-51 were presented in all 93 MDR isolates (100%), but other carbapenemase genes, including blaOXA-24, blaOXA-58, blaIMP-1, blaIMP-4, blaSIM, and blaVIM genes were completely absent in all isolates. In addition, genes of AdeABC efflux system were detected in 88.2% (90/102) isolates. Interestingly, an addition to efflux pump inhibitor, reserpine could significantly enhance the susceptibility of MDR isolates to moxifloxacin, cefotaxime, and imipenem (p < 0.01). Clonal relationship analysis further grouped these clinical drug-resistant isolates into nine clusters, and the MDR strains were mainly in clusters A, B, C, and D, which include 16, 13, 25, and 15 isolates, respectively. This study demonstrated that clinical isolates carrying carbapenemase-encoding genes blaOXA-23 and AdeABC efflux pump genes are the main prevalent MDR A. baumannii, and the co-expression of oxacillinase and efflux pump proteins are thus considered to be the important reason for the prevalence of this organism in the ICU of this hospital.
authors: Ningxia Key laboratory of Clinical and Pathogenic Microbiology, Yinchuan, Ningxia 750004, China. zhy34@163.com.|Center of Laboratory Medicine, the General Hospital of Ningxia Medical University, Yinchuan, Ningxia 750004, China. zhy34@163.com.
authors: Wei
authors: W
authors: Jia
authors: Ningxia Key laboratory of Clinical and Pathogenic Microbiology, Yinchuan, Ningxia 750004, China. lcy77720150427777@163.com.|The Graduate school, Ningxia Medical University, Yinchuan, Ningxia 750004, China. lcy77720150427777@163.com.
authors: Caiyun
authors: C
authors: Li
authors: Center of Laboratory Medicine, the General Hospital of Ningxia Medical University, Yinchuan, Ningxia 750004, China. zhy34@163.com.|The First People's Hospital of Mudanjiang City, Mudanjiang, Heilongjiang 157011, China. zhy34@163.com.
authors: Haiyun
authors: H
authors: Zhang
authors: Ningxia Key laboratory of Clinical and Pathogenic Microbiology, Yinchuan, Ningxia 750004, China. zhy34@163.com.|Center of Laboratory Medicine, the General Hospital of Ningxia Medical University, Yinchuan, Ningxia 750004, China. zhy34@163.com.
authors: Gang
authors: G
authors: Li
authors: Ningxia Key laboratory of Clinical and Pathogenic Microbiology, Yinchuan, Ningxia 750004, China. liuxiaoming@nxmu.edu.cn.
authors: Xiaoming
authors: X
authors: Liu
authors: Ningxia Key laboratory of Clinical and Pathogenic Microbiology, Yinchuan, Ningxia 750004, China. weijun@nxmu.edu.cn.|Center of Laboratory Medicine, the General Hospital of Ningxia Medical University, Yinchuan, Ningxia 750004, China. weijun@nxmu.edu.cn.
authors: Jun
authors: J
authors: Wei
mesh_terms: D000151:Acinetobacter Infections / Q000453:epidemiology* / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000187:drug effects* / Q000235:genetics* / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002681:China / Q000453:epidemiology; D024901:Drug Resistance, Multiple, Bacterial; D019450:Genes, MDR / Q000187:drug effects*; D007362:Intensive Care Units; D015995:Prevalence; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D001618:beta-Lactamases; C000599728:beta-lactamase OXA-23, Acinetobacter baumannii; C063912:carbapenemase
keywords: Acinetobacter baumannii; efflux pump; multidrug resistance; nosocomial infections; oxacillinase