Genetic diversities of Mycobacterium tuberculosis complex species in Western Kenya

Background. Tuberculosis (TB) remains a high burden infectious disease worldwide. Mycobacterium tuberculosiscomplex (MTBC) is the etiological agent of TB. Research Gap. TB burden is majorly linked to development of drug resistant strains. Thus, there is urgent need for close surveillance of MTBC circulating in a given region like Western Kenya for treatment of TB. Aim. To determine the proportion of MTBC species, strains and genetic diversities in circulation in an HIV/AIDS prevalent regions especially in Western Kenya. The clinical MTBC isolates were collected from Moi Teaching and Referral Hospital (MTRH) at Eldoret-Kenya during 2013-14. All clinical MTBC isolates were confirmed by the gold standard method (i.e. Lowenstein-Jensen medium culture) before inclusion in the investigation. Methodology. A 12-loci of Mycobacterium Interspersed Repetitive Units-Variable Number Tandem Repeats (MIRU-VNTR) genotyping was performed to determine the circulating species/strains of MTBC using www. MIRU-VNTRplus web platform. Allelic diversity was calculated using the Hunters-Gaston Diversity Index (HGDI). Results. The species M. tuberculosis, M. bovis, M. africanum, M. pinnipedii, M. microti, M. caprae and M. canettiwere identified in the MTBC population. These strains were found in the Beijing, Latin American Mediterranean, Uganda 1/2, East African Indian, Ilama, West African 1/2, Harlem, URAL, Ghana, Seal, Cameroon and Vole etc. regions of Western Kenya. Notably, some isolates had unknown (new/unassigned) species. The strains were grouped into nine clusters with a clustering rate of 31.18% and a high allelic diversity index of 0.53 was observed. Conclusion. The present findings suggest that there is an urgent need for more awareness among healthcare and stakeholders on the existence of foreign MTBC species/strains in Kenya. Furthermore, 12-loci MIRU-VNTR may not be suitable for the surveillance of MTBC strains in the circulation in Kenya. Thus, high-resolution techniques i.e., Whole Genome Sequencing needs to be adopted to resolve the genetic diversity to establish evolutionary trends for future and archived samples. This knowledge will be crucial in restraining TB, giving insights into new drug development, and prevention, control, and treatment strategies of TB.