Isolation and molecular characterization of Non-Tuberculous Mycobacteria of Public Health significance from Humans and water in Namwala Districts of Zambia

Abstract

Globally, opportunistic infections due to environmental Non-tuberculous Mycobacteria are increasingly becoming a public health threat due to the Human Immunodeficiency Virus and Acquired Immunodeficiency Syndrome pandemic. In Zambia, Non tuberculous Mycobacteria are gaining recognition as pathogens of public health significance. However, there is scanty information on the isolation and speciation of these organisms for better patient management, which could consequentially reduce the burden of these infections. Given the above information, the thrust of this study was to isolate and characterize NTM of public health significance from humans and water in Namwala district of Zambia. The study was a cross-sectional study were 306 sputum samples from adult human patients with suspected Tuberculosis were collected from four health centres in Namwala district. Additionally, 149 water samples were collected from different water drinking sources such as Tap water, Borehole water, rivers, wells and streams. Standard TB culture methods were employed to isolate Nontuberculous Mycobacteria. The isolates were then characterized using the 16S-23S internal transcribed spacer region Sequencing. One hundred and fifty three (153) individuals with suspected TB were sampled and 7(4.6%) were found to have NTM with M. arupense (3, 2%) being the most common organism. Out of the 149 water samples collected, (23, 15%) NTM were isolated with the common species being Mycobacterium gordonae (5, 3%), Mycobacterium senegalense (3, 2%), Mycobacterium peregrinum (3, 2%) and Mycobacterium fortuitum (3, 2%). Mycobacterium avium and Mycobacterium fortuitum were both isolated from humans and water.