Molecular characterization and antimicrobial resistance profiles of Mycobacterium tuberculosis complex in environmental substrates from three dairy farms in Eastern Cape, South Africa

ABSTRACT

This study analysed 330 environmental substrates from three dairy farms for the occurrence, drug resistance and the genetic mutations of MTBC (Mycobacterium tuberculosis complex) in Eastern Cape, South Africa using PCR, while the Genotype MTBDRplus assay was used for drug susceptibility and genetic mutations analyses. About 17% (55/330) of the samples were positive for MTBC at 16.7% (water), 13.3% (soil) and 20% (hayfeed). Isoniazid resistance was detected in 47.3% (26/55) of the samples while 16.4% (9/55) were multidrug-resistant. Genetic mutations were detected on the rpoB gene (resistance to rifampicin) with frequencies ranging from 53.6% (D516V) to 21.4% (H526D), while mutations on the katG and inhA genes (resistance to isoniazid) ranged between 14.3% and 80%. Incidents of diverse genetic mutations in the environmental matrices suggest possible resistance to other anti-TB drugs not assayed in this study and emphasizes the need for continuous monitoring of drug resistance patterns for timely detection and control of new clonal groups of MTBC.

KEYWORDS:

• MTBC
• environment
• multidrug resistance
• mutations
• anti-TB drugs

Acknowledgments

Our sincere appreciation goes to the National Research Foundation (NRF) for providing Ntloko A. with an MSc research bursary. We also thank the Govan Mbeki Research and Development Centre (GMRDC), University of Fort Hare for partly funding this project.

Supplementary material

Supplemental data for this article can be accessed here.

Additional information

Funding

This work was supported by the National Research Foundation (NRF);Govan Mbeki Research and Development Centre (GMRDC), University of Fort Hare.