RESUMEN
Background: Persistent blind antibiotic treatment of patients; in resource poor nations like Nigeria; makes the prevalence of antibiotic resistance to increase sporadically. Extended spectrum beta-lactamase (ESBL) production is one of the ways by which bacteria become resistant to antibiotics. For this reason; isolation; identification; sensitivity and screening for possible resistance genes is very important before prescription; if the affected patients must receive qualitative care particularly when their condition is chronic. Materials and Methods: Four hundred suspected isolates of Klebsiella belonging to various species obtained from routine specimens such as swabs; urine; blood; and sputum from May to October 2009 were studied. The identity of all isolates obtained was biochemically analyzed. The isolates were subjected to antibiotic susceptibility testing using modified Kirby-Bauer method and ESBL production was phenotypically determined using double disc synergy test for laboratory detection and reporting of bacteria by CLSI method. Results: Ninety-eight (24.5%) isolates expressed ESBL. Majority of the ESBL producing isolates were from swab specimens 59 (14.75%) followed by blood culture 16 (4.0%); urine 13 (3.25%); and sputum 10 (2.5%). Sensitivity patterns of ESBL producing Klebsiella spp. revealed that all ware resistant to augmentin (AUG); ceftazidime (CAZ); cefotaxime (CTX); cefuroxime (CRO); cefpodoxime (CPD); and none resistant to imipenem (IMP).Conclusion: ESBL producing Klebsiella spp.; were present in University of Ilorin Teaching Hospital. They are resistant to augmentin (AUG); CAZ; CTX; and CPD. Presence of ESBL in any Klebsiella spp. has made cephalosporins which are first line antibiotics usually given non-effective; thereby reducing the treatment options. We; therefore; suggest screening and confirmation for ESBL; in other to prevent treatment failure