The relationship of resistance mechanism of two strains of Enterobacteriaceae resistant to carbapenems isolated from a single specimen
10.3760/cma.j.issn.0254-5101.2011.05.007
- VernacularTitle:同一标本分离的2株碳青霉烯类耐药肠杆菌科细菌耐药机制相关性分析
- Author:
Deshi SHI
;
Haifeng SHAO
;
Weiping WANG
;
Mei HUANG
;
Xiaowen ZHANG
- Publication Type:Journal Article
- Keywords:
Klebsiella pneumoniae;
Morganella morganii;
Carbapenems;
β-lactamase;
Drug resistance
- From:
Chinese Journal of Microbiology and Immunology
2011;31(5):417-420
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the relationship of resistance mechanisms of a Klebsiella pneumoniae strain and a Morganella morganii strain resistance to carbapenems isolated from a single specimen. Methods Sensibility of antimicrobial agents was detected by agar dilution method. Specific PCR and DNA sequence analysis were performed to detect resistance genes. Plasmid feature was detected by plasmid conjugation and electrophoresis analysis. Genetic environment around blaKPC was analyzed with sequencing. The changes of outer membrane permeability were analyzed with electrophoresis of outer membrane proteins. Results blaKPC-2 was detected in 2 original isolates strains and their transconjugants. Carbapenem-resistance was successfully transfered by conjugation experiments. blaKPC-2 was located on dissimilar plasmids, but genetic environment around blaKPC-2 was the same sequence. The Morganella morganii isolate showed a loss of 38 ×103 OMPs and an additional 36 ×103 OMPs appearance, while the Klebsiella pneumoniae isolate showed a loss of OMPK36. Conclusion blaKPC-2 was detected in 2 isolates. This gene encoded by two plasmids with different sizes was located on the same composite transposon. The lack of outer membrane proteins could also play an important role causing isolates to exhibite resistance to carbapenems.
