Alabi, O. S.Adeleke, O. E.Adegoke, O. A.Gbadeyan, O. F.Ejilude, O.2025-12-1920150189-8434ui_art_alabi_multidrug_2015Nigerian Journal of Pharmaceutical Research 1, pp. 40-45https://repository.ui.edu.ng/handle/123456789/11505Background: Multidrug resistant (MDR) and extended-spectrum beta-lactamase (ESBL) producing Gram-negative bacteria pose great threat to antibiotic treatment of life threatening infections worldwide. Objectives: This study investigated the occurrence and distribution of MDR and ESBL producing Proteus mirabilis among clinical isolates collected from tertiary hospitals in four states in Southwest Nigeria. Materials and Methods: One hundred and eight (108) none-duplicated P. mirabilis collected from microbiology units of tertiary hospitals in four states in Southwest Nigeria namely; Oyo, Osun, Ogun and Lagos state, after authentication with standard bacteriological method, were subjected to antibiotic susceptibility test against ten selected antibiotics using disc-diffusion method. Presumptive production of ESBL was determined by double disc synergy test among isolates with MDR phenotype that showed resistance to any of the third generation cephalosporin antibiotics. Results: Of the 108 clinical isolates of P. mirabilis collected from Oyo (39.8%), Osun (25.9%), Ogun (21.3%) and Lagos (13%) states, 60 (55.6%) showed MDR phenotype. Among the 60 MDR isolates collected in Oyo (50%), Lagos (10%), Ogun (21.7%) and Osun (18.3%), 66.7%, 66.7%, 30.8% and 9.1% of the isolates produced ESBL, respectively. Conclusion: This study recorded the occurrence of ESBL and MDR P. mirabilis in all the four states but higher percentage of ESBL-production among MDR P. mirabilis in two of the states, Oyo and Lagos. Hence, there is need for adequate monitoring of antibiotic use to prevent increased rate of ESBL-positive MDR P. mirabilis in these states and others in the nearest future.enExtended-spectrum beta-lactamaseMultidrug resistant Proteus mirabilisPhenotypic screeningTertiary hospitalArticle