Abstract
SummaryThis study was part of a larger cross-sectional survey that was evaluating tuberculosis (TB) infection in humans, livestock and wildlife in the Serengeti ecosystem in Tanzania. The study aimed at evaluating the genetic diversity of Mycobacterium tuberculosis isolates from TB patients attending health facilities in the Serengeti ecosystem. DNA was extracted from 214 sputum cultures obtained from consecutively enrolled newly diagnosed untreated TB patients aged ≥18 years. Spacer oligonucleotide typing (spoligotyping) and Mycobacterium Interspersed Repetitive Units and Variable Number Tandem Repeat (MIRU-VNTR) were used to genotype M. tuberculosis to establish the circulating lineages. Of the214 M. tuberculosis isolates genotyped, 55 (25.7%) belonged to the Central Asian (CAS) family, 52 (24.3%) were T family (an ill-defined family), 38 (17.8%) belonged to the Latin American Mediterranean (LAM) family, 25 (11.7%) to the East-African Indian (EAI) family, 25 (11.7%) comprised of different unassigned (‘Serengeti’) strain families, while 8 (3.7%) belonged to the Beijing family. A minority group that included Haarlem, X, U and S altogether accounted for 11 (5.2%) of all genotypes. MIRU-VNTR typing produced diverse patterns within and between families indicative of unlinked transmission chains. We conclude that, in the Serengeti ecosystem only a few successful families predominate namely CAS, T, LAM and EAI families. Other types found in lower prevalence are Beijing, Haarlem, X, S and MANU. The Haarlem, EAI_Somalia, LAM3 and S/convergent and X2 subfamilies found in this study were not reported in previous studies in Tanzania.
Highlights
We report on the genetic diversity of M. tuberculosis isolated from tuberculosis patients resident in three subdistricts of the Serengeti ecosystem
The Latin American Mediterranean (LAM) family accounted for 38 (17.8%) isolates while the East African-Indian family accounted for 25 (11.7%) isolates
Breakdown of spoligotypes by districts (Table 1) indicated 33 (60%) of the Central Asian (CAS) family overrepresented in Ngorongoro with Serengeti and Bunda districts accounting for 11 (20%) of the strain type each
Summary
The CAS family of M. tuberculosis strains are dominant in Tanzania [11e13] with little variations over time period [14,15] with some anti-tuberculosis drug resistance and multidrug resistance [15]. These previous studies have been carried in northern Tanzania (4) and Dar es Salaam (1) none has targeted the Serengeti ecosystem and the earlier studies focused largely on TB and its association with HIV/AIDS. One cannot conclude that every location in Tanzania is represented by this earlier data which provides a justification for studies in new locations, where findings might potentially provide data that could influence TB control strategies in the country
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
