Study of Extended spectrum beta-lactamases (ESBLs) producing Klebsiella species in various clinical specimens: A preliminary report

Objective The present study has been undertaken to detect the presence of ESBLs producing Klebsiella species in various clinical specimens and their antibiotic susceptibility pattern. Materials and methods The study consists of 60 clinical isolates of Klebsiella species from various clinical specimens submitted to the microbiology laboratory, Kasturba Medical College Teaching Hospital Mangalore over a period of one year, between 1st January 2007 to 31st December, 2007. All isolates were identified morphologically and biochemically by standard procedures and ESBLs production was detected by re-arranging routine discs in a novel predictor disc approximation method. Antimicrobial susceptibility was performed using Kirby-Bauer disc-diffusion method where Imipenem disc, an inducer was placed in center and on either side of it at 15mm distance were placed ceftazidime and cefotaxime (indicator of induction). In addition, another inducer cefoxitin was placed 15mm from cefotaxime (indicator). This was placed opposite to that of ceftazidime + clavulanic acid to avoid any affect of inducible beta-lactamase on the zone of inhibition of the latter. Results A total of 16 out of 60 Klebsiella isolates (26.66%) were found to be ESBL producers. Conclusions Imipenem was found to be the most effective antibiotic (46.66%) followed by Cefoxitin (31.66%) and Cefotaxime (30.00%). Key words: Klebsiella species; clinical specimens; ESBLs DOI: 10.3126/jcmsn.v6i3.4070 Journal of College of Medical Sciences-Nepal , 2010, Vol. 6, No. 3 pp.19-23