Antibiogram and Molecular Characterization of Extended-Spectrum Beta-Lactamase-Producing Klebsiella pneumoniae in a Nigerian Teaching Hospital

Background: Klebsiella pneumoniae is a gram-negative bacterium responsible for infections like urinary tract infections (UTIs) and is a leading cause of nosocomial infections in immunocompromised patients. Data on resistance profiles in Nigeria is limited. This study investigated the antibiogram and molecular characteristics of ESBL-producing Klebsiella pneumoniae at the University of Medical Sciences Teaching Hospital, Ondo State. Methods: A cross-sectional study analyzed 300 samples from urine, sputum, and wound infections. Isolates were cultured on MacConkey agar, followed by biochemical tests. The Kirby-Bauer method assessed resistance, and the double-disk synergy test confirmed ESBL production. PCR identified blaTEM, blaSHV, and blaCTX-M genes. SPSS was used for statistical analysis (P < 0.05). Results: Of 300 samples, 185 showed bacterial growth, with 54 confirmed as Klebsiella pneumoniae. Among these, 22 were multidrug-resistant (MDR), and 8 (14.8%) were ESBL producers. The blaTEM gene was present in all ESBL isolates, and the blaSHV gene in 7 of 8 (87.5%). Resistance to β-lactam antibiotics and aminoglycosides was high. Older patients and prolonged hospital stays correlated with higher MDR rates. A slight female predominance was noted. Conclusions: The high prevalence of MDR Klebsiella pneumoniae highlights the need for enhanced surveillance and deeper understanding of resistance patterns in the region.