Article Text

Download PDFPDF

  1. Tuelo Mogashoa1,2,
  2. Lucy Mupfumi1,2,
  3. Thato Iketleng2,3,
  4. Pinkie Melamu2,
  5. Nametso Kelentse2,
  6. Nicola Zetola4,
  7. Margaret Mokomane5,
  8. Letsibogo Letsibogo5,
  9. Elizabeth M Streicher6,
  10. Serej Ley6,
  11. Ishmael Kasvosve1,
  12. Sikhulile Moyo1,2,7,
  13. Robin Warren6,
  14. Simani Gaseitsiwe2,7
  1. 1Department of Medical Laboratory Sciences, University of Botswana, Gaborone, Botswana
  2. 2Botswana Harvard AIDS Institute Partnership, Gaborone, Botswana
  3. 3College of Health Sciences, School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Durban, South Africa
  4. 4Botswana Upenn Partnership, Gaborone Botswana
  5. 5National Tuberculosis Reference Laboratory, Ministry of Health and Wellness, Gaborone, Botswana
  6. 6DST/NRF Centre of Excellence in Biomedical Tuberculosis Research/South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
  7. 7Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA


Background The emergence and transmission of multidrug-resistant (MDR) and extensively drug-resistant (XDR) Mycobacterium tuberculosis (Mtb) strains is a serious threat to tuberculosis control in Botswana. Early detection of drug-resistant isolates is critical to ensure optimal treatment and thereby improve treatment outcomes. The objective of this study was to determine the extent of second-line drug resistance among drug-resistant Mtb-isolates from Botswana.

Methods A total of 60 drug-resistant Mtb isolates received at Botswana National Tuberculosis Reference Laboratory between 2012 and 2013 were analysed. DNA was extracted from BD Mycobacterial Growth Indicator Tubes (MGIT) using GenoLyse DNA isolation kit (Hain Lifescience). Spoligotyping was done using a commercially available spoligotyping kit (Isogen Life Science). The spoligotype patterns were compared with existing patterns in the SITVIT2 Web database. GenoType MTBDRs assay (Hain Lifescience) was used for second-line drug susceptibility testing. Fisher’s exact test was used to test for association between drug resistance patterns and HIV status, lineage and geographical location.

Results Seventeen distinct spoligotype patterns were detected amongst the 60 drug-resistant isolates. The most predominant lineages were Euro-American (58.3%), East Asian (25%) and Indo-Oceanic (15%). Fifty (83.3%) were MDR, 7 (11.7%) were resistant to fluoroquinolones (Pre-XDR) whereas 3 (5%) were resistant to both fluoroquinolones and second-line injectable drugs (XDR). Drug resistance profiles were significantly associated with Mtb lineage (p<0.001). There was no association between drug resistance profile and HIV status (p=0.057) and geographical location (p=0.372).

Conclusion This study highlights the importance of including second-line drug susceptibility testing in a testing algorithm in Botswana. The detection of XDR isolates among MDR-TB isolates highlights the ongoing evolution of resistance and the need for strengthened treatment regimens to improve treatment outcomes and to prevent the spread of these highly resistant strains. Second-line testing will be essential if the 9 month MDR regimen is used in Botswana.

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.