Study on the molecular mechanism of carbapenem-resistant Escherichia coli
10.3760/cma.j.issn.0254-5101.2010.09.010
- VernacularTitle:大肠埃希菌对碳青霉烯类药物的耐药机制研究
- Author:
Shougang KUAI
;
Haifeng SHAO
;
Weiping WANG
;
Ming FAN
;
Mei HUANG
- Publication Type:Journal Article
- Keywords:
Escherichia coli;
Carbapenems;
β-lactamase;
Enterobacteriaceae;
Drug resistance
- From:
Chinese Journal of Microbiology and Immunology
2010;30(9):829-833
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the molecular epidemiology and mechanism of carbapenem resistance of Escherichia coli collected from intensive care units(ICUs)of general surgery.Methods Agardilution were carried out to confirmed the drug-susceptibility,pulsed-field gel electrophoresis(PFGE)were performed to analyze the molecular epidcmiology of carbapenem-resistance isolates.Specific PCR,DNA sequencing,conjugation experiments,plasmids extraction,plasmid transformation assays and SDS-PAGE of outer membrane proteins(OMPs)were carried to confirm genotype of carbapenemase and its transmission mechanism.Results PFGE showed the isolates belonged to 10 clonotype,and all the clinical isolates were resistant to β-lactams including imipenem and meropenem,but uncertain to aminoglycosides,specific PCR and DNA sequencing revealed that all isolates encoded carbapenem-hydrolyzing enzyme gene,KPC-2.Plasmid DNA extraction and plasmid transformation assays from some isolates comfirmed that KPC-2 encoded on a 56 kb plasmid.SDS-PAGE analysis confirmed that there are alterations in OMPs of Escherichia coli.Conclusion Escherichia coli isolates with carbapenem resistance are collected from our hospital,production of KPC-2 carbapenemase mainly contributed to reduced susceptibility of carbapenem in Escherichia coli,the alterations in OMPs may as a cofactor in high-level drug-resistance in Escherichia coli.
