Genetic diversity of Mycobacterium tuberculosis strains circulating in Botswana
Date
2019-05-07
Journal Title
Journal ISSN
Volume Title
Publisher
PLoS
Abstract
Background: Molecular typing of Mycobacterium tuberculosis (M.tb) isolates can inform Tuberculosis
(TB) control programs on the relative proportion of transmission driving the TB epidemic.
There is limited data on the M. tb genotypes that are circulating in Botswana. The aim of this
study was to generate baseline data on the genetic diversity of M.tb isolates circulating in
the country. Methods: A total of 461 M.tb isolates received at the Botswana National Tuberculosis Reference Laboratory between March 2012 and October 2013 were included in this study. Drug susceptibility testing was conducted using the BD BACTEC MGIT 960 System. M.tb strains were
genotyped using spoligotyping and spoligotype patterns were compared with existing patterns in the SITVIT Web database. A subset of drug resistant isolates which formed spoligo
clusters (n = 65) was additionally genotyped with 12-loci MIRU. Factors associated with
drug resistance and clustering were evaluated using logistic regression.
Results: Of the 461 isolates genotyped, 458 showed 108 distinct spoligotype patterns. The predominant M.tb lineages were Lineage 4 (81.9%), Lineage 2 (9%) and Lineage 1 (7.2%). The predominant spoligotype families within Lineage 4 were LAM (33%), S (14%), T (16%), X
(16%). Three hundred and ninety-two (86%) isolates could be grouped into 44 clusters (2–
46 isolates per cluster); giving a clustering rate of 76%. We identified 173 (37.8%) drug resistant isolates, 48 (10.5%) of these were multi-drug resistant. MIRU typing of the drug
resistant isolates allowed grouping of 46 isolates into 14 clusters, giving a clustering rate of
49.2%. There was no association between age, sex, treatment category, region and
clustering.
Conclusions: This study highlights the complexity of the TB epidemic in Botswana with multiple strains
contributing to disease and provides baseline data on the population structure of M.tb
strains in Botswana.
Description
CITATION: Mogashoa, T. et al. 2019. Genetic diversity of Mycobacterium tuberculosis strains circulating in Botswana. PLoS ONE, 14(5):e0216306, doi:10.1371/journal.pone.0216306.
The original publication is available at https://journals.plos.org/plosone
The original publication is available at https://journals.plos.org/plosone
Keywords
Mycobacterium tuberculosis, Genetic diseases, Epidemic -- TB diseases, Molecular virology
Citation
Mogashoa, T. et al. 2019. Genetic diversity of Mycobacterium tuberculosis strains circulating in Botswana. PLoS ONE, 14(5):e0216306, doi:10.1371/journal.pone.0216306.