Phenotypic Detection and Susceptibility Pattern for the Detection of Extended Spectrum β-Lactamase-Producing Klebsiella pneumonia Isolates in Nairobi, Kenya*

Abstract

Klebsiella pneumoniae is an opportunistic pathogen that is an important cause of nosocomial infections. Detection of ESBL producers' poses a special challenge for clinical microbiology laboratories, although ESBL producing pathogens are able to hydrolyze extended-spectrum penicillins, cephalosporins, and aztreonam, the minimum inhibitory concentrations (MIC) of some and perhaps even all of these agents may be within the susceptible range. The third generation cephalosporins have the reputation for being useful against a broad range of bacterial infections. However, resistance to these agents is something that must still be considered and creates obstacles for their clinical use. A total of 80 multi drug resistant clinical isolates of Klebsiella pneumoniae were obtained from a study on anaerobes associated with Pel-vic Inflammatory disease (P.I.D), KEMRI S.S.C No.495. The isolates were identified by standard microbiological procedures. Antimicrobial susceptibility testing was carried out by Kirby-Bauer method. Upon identification, the anti-biogram profiles of the isolates were determined and those resistant to third-generation cephalosporins were tested for production of ESBL. ESBL production among the multi drug resistant isolates was detected using the phenotypic con-firmatory disc diffusion test (PCDDT) and double disk synergy test (DDST). While using standard double disk synergy test (DDST) as screening method for identifying potential ESBL producers, ceftriaxone was the most efficient antim-icrobial in screening isolates as potential ESBL producers followed by cefotaxime.