A Study on the Molecular Genes of ESBL-Producing Enterobacteriaceae from Patients Hospitalized in the Internal Medicine Department of a Tertiary Hospital in Lagos, Nigeria

Background: Multidrug-resistant Enterobacteriaceae pose a significant global health burden. These bacteria produce extended-spectrum beta-lactamase (ESBL) enzymes, which render them resistant to many beta-lactam antibiotics. This study aimed to identify both the phenotypic traits and molecular genes associated with ESBL production in Enterobacteriaceae strains isolated from hospitalized patients in the Internal Medicine Department of Lagos University Teaching Hospital (LUTH), Idi-Araba. Materials and Methods: This cross-sectional study was carried out in the Internal Medicine Department of Lagos University Teaching Hospital, Idi-Araba. All consenting patients admitted with clinical signs of infection were enrolled. Relevant clinical samples were collected and analyzed using standard microbiological identification methods, while multiplex polymerase chain reaction (PCR) was employed to genotypic markers. Result: 300 bacterial pathogens were isolated, of which 176 belonged to the Enterobacteriaceae family. Escherichia coli was the most frequently identified pathogen, accounting for 32% of the isolates, followed by Klebsiella pneumoniae, 23.9% and Klebsiella oxytoca, 17.6%, among others. More than 60% of the Enterobacteriaceae isolates were found to produce ESBL. Among the ESBL genes detected, TEM was the most prevalent, followed by SHV and CTX-M. Conclusion: The study revealed a high prevalence of extended-spectrum beta-lactamase (ESBL) production. Plasmid-mediated resistance genes, including TEM, SHV, and CTX-M, were identified.