Co-production of carbapenem-hydrolyzing enzyme KPC-2 and ArmA 16S rRNA methylase in pandrugs resistant Enterobacter cloacae
10.3760/cma.j.issn.0254-5101.2011.10.007
- VernacularTitle:同时产ArmA型16S rRNA甲基化酶及KPC-2型β-内酰胺酶泛耐药阴沟肠杆菌的研究
- Author:
Qiong WU
;
Yuxing NI
;
Lizhong HAN
;
Jingyong SUN
;
Qingzhong LIU
;
Yanqun JIANG
;
Feng GAO
- Publication Type:Journal Article
- Keywords:
Enterobacter cloacae;
Carbapenemase;
16S rRNA methylase
- From:
Chinese Journal of Microbiology and Immunology
2011;31(10):888-892
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the production of carbapenemase and 16S rRNA methylase in five isolates of pan-drugs resistant E.cloacae recovered in Ruijin hospital.Methods MICs of the five isolates to 10 antibiotics were determined by E test.Six kinds of 16S rRNA methylase genes and a series of β- lactamase genes were amplified by PCR.Shotgun cloning was performed to detect carbapenem resistance determinant.The conjugal transfer of carbapenemase gene and 16S rRNA methylase gene was performed in broth culture with E.coli J53 as the recipient.Pulsed-field gel electrophoresis (PFGE) was carried out to analyse the genotyping.IEF was performed to detect β-1actamases.Southern blot was performed to determine the location of carbapenem resistance determinant.Results The MICs of 10 antibiotics were ＞32 mg/L.Four β-1actamases with pIs of 5.4 ( TEM-1 ),6.7 ( KPC-2 ),8.2 ( SHV-12 ),8.4 (CTX-M-14) were determined.The insertion sequence in the recombinant plasmid was blaKPC-2 flanked by a transposon.blaKPC-2 was located on a large non-conjugative plasmid whereas armA was located on an other conjugative plasmid.PFGE patterns of 5 isolates were identical.Conclusion KPC-2 was responsible for carbapenem resistance in pandrugs resistant Enterobacter cloacae.There was no relationship between blaKPC-2 and armA.Although pandrug resistant Enterobacteriaceae remain rare,the emergence of this group of organism merits monitoring.
