In vitro antibiotic effects of drug combinations against colistin-heteroresistant Acinetobacter baumannii
10.3760/cma.j.issn.0254-5101.2018.08.006
- VernacularTitle: 体外联合用药对黏菌素异质性耐药鲍曼不动杆菌的抗菌活性研究
- Author:
Siqin ZHANG
1
;
Hong LU
2
;
Jianming CAO
3
;
Chunquan XU
1
;
Xiaoya ZHANG
3
;
Xiangkuo ZHENG
3
;
Guofeng DONG
3
;
Tieli ZHOU
1
Author Information
1. Laboratory Medicine Center, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China
2. Department of Clinical Laboratory, Peace Hospital Affiliated to Changzhi Medical College, Changzhi 046000, China
3. School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou 325000, China
- Publication Type:Journal Article
- Keywords:
Colistin;
Heteroresistance;
Acinetobacter baumannii;
Drug combination
- From:
Chinese Journal of Microbiology and Immunology
2018;38(8):593-598
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To evaluate the in vitro antibiotic effects of colistin combined with meropenem, levofloxacin or fosfomycin against colistin-heteroresistant Acinetobacter baumannii (A.baumannii).
Methods:A total of 576 A. baumannii clinical isolates were collected from the First Affiliated Hospital of Wenzhou Medical University from 2014 to 2015. Minimal inhibitory concentrations (MICs) of colistin against A. baumannii were detected by broth dilution method. Colistin-heteroresistant A. baumannii isolates were screened using population analysis profiles (PAPs). MICs of colistin combined with meropenem, levofloxacin or fosfomycin, and the four drugs used alone against colistin-heteroresistant A. baumannii were detected by checkerboard method and broth dilution method. Fractional inhibitory concentration index (FICI) was calculated to evaluate antibiotic effects.
Results:None of the 576 A. baumannii isolates was resistant to colistin as indicated by the broth dilution method. Nine colistin-heteroresistant A. baumannii isolates were identified using PAPs. Compared with the MICs of colistin used alone, the MICs of colistin used in combination with meropenem, levofloxacin or fosfomycin against colistin-heteroresistant isolates were all decreased. Colistin-meropenem combination showed synergistic (55.6%), additive (33.3%) and indifferent effects (11.1%), but no antagonistic effect. Colistin-levofloxacin combination showed synergistic (55.6%), additive (22.2%) and indifferent effects (22.2%), but no antagonistic effect. Colistin-fosfomycin combination showed synergistic (77.8%) and additive (22.2%) effects, but no indifferent or antagonistic effect.
Conclusion:In vitro use of colistin in combination with meropenem, levofloxacin or fosfomycin has synergistic and additive antibacterial effects against colistin-heteroresistant A. baumannii. Combinations of colistin-meropenem and colistin-levofloxacin have fewer indifferent effects and no antagonistic effect.
