Genotypic Diversity of Mycobacterium Tuberculosis Complex from the Southern Half of the Volta Region, Ghana

Abstract

Tuberculosis (TB) still remains a major global health problem particularly in resource-limited settings despite the availability of treatment regimen for decades. Although two pathogens, Mycobacterium tuberculosis sensu stricto (MTBss) and Mycobacterium africanum (Maf) are responsible for TB incidence in humans, more research attention has been accorded MTBss to the neglect of Maf, which is reported to be geographically restricted to West Africa and its immigrants. This thesis sought to determine the phylogenetic population structure of Mycobacterium tuberculosis complex (MTBC) isolates from the southern half of Volta region, which has never been done. Sputum samples were cultured and the obtained mycobacterial isolates confirmed as MTBC by PCR amplification of insertion sequence, IS6110. Non-MTBCs were characterized by amplifying mycobacterial heat shock protein 65 (hsp65). The MTBCs were then genotyped by spoligotyping and their drug susceptibility profiles determined based on line probe assay using GenoTypeMTBDRplus. The MTBC lineage associations were assessed. Of the 270 sputum samples collected, acid fast bacilli (AFB) positivity recorded was 183 (67.8%) and mycobacterial isolation positivity recorded was 125 (68.3%) out of the 183 AFB positive confirmed samples. In all, 117 isolates were characterized as members of the MTBC with 8 as non-tuberculous mycobacteria (NTMs). The odds of finding a multi-drug resistant (MDR) MTBss infection was relatively higher than finding an MDR Maf infection (OR=1.54, CI=0.07-33.13). This study thus, confirms the importance of M. africanum lineages in Ghana and should be considered in the development of new diagnostics, drugs, and vaccines.