Clonal Endemicity of Clinical Isolates of Carbapenem Resistant Klebsiella pneumoniae from a Tertiary Care Hospital in North India

Abstract

Background: Dissemination of carbapenem resistant Klebsiella pneumoniae (CRKP) harbouring multiple resistance determinants constitute significant threat to hospital ecology. Aims: This study analysed susceptibility of carbapenem non-susceptible K. pneumoniae (CNSKP) to tigecycline and colistin and the prevalence of CRPK and clonal diversity among clinical isolates of K. pneumoniae. Study Design: Investigative. Place and Duration of Study: The study was performed in the Microbiology Department, Institute of Medical Science, in association with Sir Sunderlal hospital, Banaras Hindu University Varanasi, during January 2012 to May 2015. Methodology: Multidrug-resistance and non-susceptibility to carbapenem was determined by disk diffusion test. Further susceptibility of the CNSKP to ceftriaxone, cefoperazone, ceftazidime, carbapenems, tigecycline, and colistin was performed by agar dilution test and CRKP screened by standard protocol. Multiplex PCR amplification for blaNDM-1 and blaOXA-48 was performed on the CRKP using primers specific for each gene, while methyltransferase activity was determined on brain-heart infusion agar supplemented with gentamicin and amikacin. PCR amplification for methyltransferase genes (rmtF and rmtG) was determined using specific primers and typing was done by enterobacterial repetitive intergenic consensus (ERIC) PCR. Results: Of the 238 K. pneumoniae isolates, 173 were MDRKP, 113 CNSKP and 75 CRKP. Susceptibility spectrum of CNSPK to doripenem, tigecycline and colistin was 40.4%, 56.0% and 84.1% respectively, while blaNDM-1, blaOXA-48 and methyltransferase activity among CRKP was 53.3%, 38.7% and 70.7% respectively. rmtF and rmtG occurrence among the methyltransferase positive isolates was 37.7% and 13.2% respectively. Thirty six profiles of single strain each and nine clonal types of CRKP were observed. Conclusion: Declining efficacy of antibiotic and dissemination of clones harbouring several resistant determinants was observed, hence an urgent need for implementation of workable infection control policy in order to limit spread of MDR K. pneumoniae within the hospital.