Carbapenemases KPC-2 and IMP-4 mediated carbapenem resistance in Enterobacteriaceae strains

• DOI: 10.3760/cma.j.issn.0254-5101.2015.06.004
• Publication Date: 2015-06-30
• Authors: Jinyun Chen; Ying Fu; Qing Yang; Keren Shi; Haiping Wang; Yanfei Wang; Zhi Ruan; Yunsong Yu
• Keywords: Ertapenem; Multilocus sequence typing; Carbapenem; Carbapenem-resistant enterobacteriaceae

Objective To investigate the mechanism of carbapenem-resistant in Enterobacteriaceae strains isolated from Fuyang First People′s Hospital and to analyze their epidemiological features.

Methods The with reduced ertapenem susceptibility were during January 2013 August 2014. K-B disk diffusion E-test performed detect antimicrobial susceptibilities those strains. The modified Hodge test, ethylenediaminetetraacetic acid (EDTA) synergy test extended-spectrum β-lactamases (ESBLs) confirmation used screen out phenotypes. PCR analysis gene sequencing drug resistance genes, genetic structures surrounding blaKPC-2 seven house-keeping genes Klebsiella pneumonia (K.pneumoniae) sequences analyzed multilocus sequence typing (MLST). Pulsed field gel electrophoresis (PFGE) was for homology within same species. S1-PFGE combination Southern blot determine location carbapenem genes.

Results A total 19 isolates screened out. Each them resistant multiple antibiotics harbored several genes. Seven including blaKPC-2, blaIMP-4, blaSHV-1, blaCTX-M-65, blaCTX-M-15, blaTEM-1 rmtB prevalent Fourteen nineteen identified as K. pneumoniae strains, mainly belonged ST11 type according results MLST. Among eleven one Escherichia coli isolate carried gene, located on plasmids varying size (95 kb, 140 200 kb 240 kb). all ISKpn8, ISKpn6-like upstream downstream. blaIMP-4 detected oxytoca isolate, a plasmid about 300 size.

Conclusion Carbapenemases KPC-2 IMP-4 closely related form Hospital. No predominant clone found isolates.

Key words: Carbapenemase; Carbapenem-resistant Enterobacteriaceae; KPC-2; IMP-4