Susceptibility and molecular mechanism of carbapenem -resistant Acinetobacter baumannii
- VernacularTitle:耐碳青霉烯类抗生素鲍曼不动杆菌的药物敏感性及其分子特征
- Author:
Wei-Bu CHEN
1
;
Wei-Yuan WU
Author Information
1. 暨南大学 第二临床医学院/深圳市人民医院 检验科/深圳市病原微生物及细菌耐药监控重点实验室
- Keywords:
Acinetobacter baumannii;
carbapenemase;
pulsed field gel electrophoresis;
molecular epidemiology
- From:
The Chinese Journal of Clinical Pharmacology
2014;(4):332-336
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the susceptibility of antimicrobial agents, carbapenemase genotypes and clonal relatedness among carbap-enem-resistant Acinetobacter baumannii ( CRAB) isolated from intensive care unit ( ICU) in Shenzhen People′s Hospital.Methods Forty-eight non-duplicated CRAB isolates were collected from ICU in this hospital in 2010.The minimum inhibitory concentrations ( MICs) of fifteen anti-microbial agents against CRAB were detected by agar dilution method.Polymerase chain reaction ( PCR) and DNA sequencing were used to in-vestigate the carbapenemase genotype among CRAB.All isolates were typed by pulse field gel electrophoresis ( PFGE ).Results Polymixin B showed the highest activity against forty-eight CRAB isolates ( suscepti-bility of 100%) , with the MIC50/MIC90 of 1 μg· mL -1 , followed by mi-nocycline (susceptibility of 95.8%), with the MIC50/MIC90 of 4 μg· mL -1, and tigecycline (intermediate of 89.6%), with the MIC50/MIC90 of 4 μg· mL-1 , respectively.Approximately ninety percent (43/48 ) of CRAB isolates harbored blaOXA-23-like , which showed high resistance to imipenem and meropenem , with the main distribution of MICs ranging from 16 to 64 μg · mL-1.Three and two CRAB isolates harbored blaOXA-58-like and ISAba1-blaOXA-51-like, respectively.Both of them exhibited intermediate resistance against imipenem and meropenem, with the main distribution of MICs ranging from 8 to 16 μg· mL-1.blaOXA-24-like, blaOXA-143-like, metallo-β-lactamase and KPC genes were not detected in any of isolates.Four distinct PFGE patterns were observed among forty-eight isolates of CRAB.All of type A isolates harbored blaOXA-23-like , accounting for 87.5%(42/48) of CRAB.Conclusion The spread of CRAB clone harboring blaOXA-23-like occurred in ICU of our hospital during 2010.
