Objective: Klebsiella pneumoniae is highly prevalent in hospitals and causes many nosocomial infections. The study sought to determine prevalence rates of extended spectrum β-lactamases (ESBLs) in clinical isolates of K. pneumoniae from Cairo, Egypt and to detect the ESBL-encoding genes in the isolates.Methods: K. pneumoniae isolates were collected through two-year period (2011-2012). Identification of K. pneumoniae was carried out using automated Microscan and standard biochemical tests. ESBL pattern and minimum inhibitory concentrations (MICs) were detected using Clinical and Laboratory Standards Institute guidelines and confirmatory tests. Multiplex polymerase chain reaction for ESBL-encoding genes and plasmid profiling were performed.Results: In the present work; 112 isolates, 75 of them from cancer patients, were characterized. High proportion (52 of 112, 46 %â€) of ESBLs among the isolates were detected. Highest prevalence of ESBLs was seen among cancer patients, 39 isolates of 75 (52%). Plasmid profile for ESBL-producing K. pneumoniae isolates showed different sizes and numbers of plasmids in all isolates. MICs for all ESBL-producing isolates revealed high resistance rates with tetracycline (100%), cefepime (96%), gentamycin (90%) and ciprofloxacin (79%). Whereas, only two isolates (4%) were resistant to both carbapenem drugs tested, imipenem and meropenem. blaTEM, blaSHV, and bla CTX-M were performed for all ESBL-producing isolates. Five patterns of ESBL-encoding genes were detected. The most prevalent ESBL-encoding gene was blaTEM;alone in 40% and with other ESBL-encoding gene(s) in 48% of the isolates.Conclusion: High prevalence of ESBL (46%) in our isolates suggesting the need for continuous monitoring of emergence of this pattern in our region.Â
