Isolation of Mycobacterium tuberculosis from Sputum Samples at Chest Clinic, University College Hospital Ibadan

Tuberculosis continues to impose a substantial disease burden on Nigeria, with accurate laboratory diagnosis critical to effective case management. This study isolates and characterises Mycobacterium tuberculosis from sputum samples of presumptive TB patients attending the Chest Clinic of University College Hospital (UCH), Ibadan, Oyo State, South West Nigeria. Early morning sputum samples were collected from 150 presumptive TB patients. Samples were processed by N-acetyl-L-cysteine-sodium hydroxide decontamination and subjected to Ziehl-Neelsen staining, Lowenstein-Jensen culture, and GeneXpert MTB/RIF assay. Culture positivity was 38 percent, while GeneXpert detected 44 percent positivity overall, confirming its higher sensitivity. Rifampicin resistance was detected in 11 percent of positive cases, indicating potential multidrug-resistant TB. Smear-negative but culture-positive cases constituted 19 percent of confirmed TB, underscoring the limitation of smear microscopy alone. HIV co-infection was present in 28 percent of confirmed TB cases. The study underlines the diagnostic superiority of GeneXpert over smear microscopy and highlights the MDR-TB burden at UCH. Recommendations include universal GeneXpert access, contact tracing intensification, and integrated TB/HIV services at UCH Ibadan. Keywords: Mycobacterium tuberculosis, GeneXpert, MDR-TB, UCH Ibadan, sputum culture