Mycobacterium tuberculosis strain diversity and non Tuberculous Mycobacteria isolates in the West and Central Africa

• Published in: International journal of mycobacteriology Vol. 10; no. Suppl 1; p. S55
• Main Authors: Thumamo Pokam, Benjamin D., Yeboah-Manu, D., Lawson, L., Guemdjom, P. W., Teyim, P. M., Okonu, R. E., Asuquo, Anne E.
• Format: Journal Article
• Language: English
• Published: 01.01.2021
• ISSN: 2212-5531
• DOI: 10.4103/2212-5531.307106

Aims and objectives: The prevalence of pulmonary tuberculosis as well as Non Tuberculous Mycobacteria (NTM), has been on the increase worldwide. In order to improve the control of the disease, genotyping and drug susceptibility of Mycobacterium tuberculosis complex (MTBC) are important. This study sought to determine drug susceptibility and genetic diversity of MTBC as well as NTM in three West/Central African countries. Methods: A collection of 503 isolates (158 from Cameroon, 202 from Nigeria and 143 from Ghana) obtained from culture using either Lowenstein–Jensen medium, Middlebrook 7H9 Broth and/or Xpert MTB/RIF were included in the study and some isolates tested for drug susceptibility using the proportion method, BACTEC MGIT 960 or Line Probe Assay (LPA). Isolates were further subjected to IS6110 typing, large sequence polymorphisms, and spoligotyping. All IS6110-negative strains suspected as NTM were tested using hsp65 gene amplification, DNA sequencing and blast analysis. Results: The Cameroon family was the most prevalent genetic strain [128/202 (63.4%) in Nigeria, 54/150 (36%) in Cameroon and 27/119 (22.7%) in Ghana] and SIT 61 the largest cluster with 111/202 (55%) and 43/150 (27%) isolates in Nigeria and Cameroon respectively. Multidrug resistance (MDR) was observed in 29/202 (14.4%) cases in Nigeria, and HIV positivity [37/202 (18.3%) patients] was associated with rifampicin 9/37 (24.3%) resistance (p=0.012), as well as gender (p=0.009). In Cameroon, 13/147 (8.8 %) were resistant to rifampicin (RIF), with 6 (46.2%) of the 13 RIF resistant isolates associated with UgandaI sublineage (p=0.0007). Other sublineages such as Haarlem, Ghana, West African 1 were recorded in the three countries. NTMs isolates included M. colombiense, M. engbaekii, M. intracellulare strain, M. gordonae, M. fortuitum, M. paraense and Nocardia veteran. Conclusion: Neglected NTM timely diagnosis should be reinforced in the study area. Drug resistance in TB/HIV co-infected patients and its association with a sublineage calls for a surveillance strategy to curb its expansion in the west/central Africa.