Species diversity of non-tuberculous mycobacteria isolated from humans, livestock and wildlife in the Serengeti ecosystem, Tanzania.
BACKGROUND
Non-tuberculous mycobacteria (NTM), which are ubiquitous micro-organisms occurring in humans, animals and the environment, sometimes receive public health and veterinary attention as opportunistic disease-causing agents. In Tanzania, there is limited information regarding the diversity of NTM species, particularly at the human-livestock-wildlife interface such as the Serengeti ecosystem, where potential for cross species infection or transmission may exist.


METHODS
Mycobacterial DNA was extracted from cultured isolates obtained from sputum samples of 472 suspect TB patients and 606 tissues from wildlife species and indigenous cattle. Multiplex PCR was used to differentiate NTM from Mycobacterium tuberculosis complex (MTBC) members. NTM were further identified to species level by nucleotide sequencing of the 16S rRNA gene.


RESULTS
A total of fifty five (55) NTM isolates representing 16 mycobacterial species and 5 isolates belonging to the MTBC were detected. Overall, Mycobacterium intracellulare which was isolated from human, cattle and wildlife, was the most frequently isolated species (20 isolates, 36.4%) followed by M. lentiflavum (11 isolates, 20%), M. fortuitum (4 isolates, 7.3%) and M. chelonae-abscessus group (3 isolates, 5.5%). In terms of hosts, 36 isolates were from cattle and 12 from humans, the balance being found in various wildlife species.


CONCLUSIONS
This study reveals a diversity of NTM species in the Serengeti ecosystem, some of which have potential for causing disease in animals and humans. The isolation of NTM from tuberculosis-like lesions in the absence of MTBC calls for further research to elucidate their actual role in causing disease. We are also suggesting a one health approach in identifying risk factors for and possible transmission mechanisms of the NTM in the agro-pastoral communities in the Serengeti ecosystem.
Department of Microbiology and Immunology, School of Medicine, Muhimbili University of Health and Allied Sciences (MUHAS), P.O. BOX 65001, Dar Es Salaam, Tanzania. bugwesa2002@yahoo.co.uk.|Tanzania Wildlife Research Institute (TAWIRI), P.O. BOX 661, Arusha, Tanzania. bugwesa2002@yahoo.co.uk.
Bugwesa Z
BZ
Katale
Department of Microbiology and Immunology, School of Medicine, Muhimbili University of Health and Allied Sciences (MUHAS), P.O. BOX 65001, Dar Es Salaam, Tanzania. rerasto@yahoo.com.
Erasto V
EV
Mbugi
DST/NRF Centre of Excellence for Biomedical Tuberculosis Research/MRC Centre for TB Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, Cape Town, South Africa. louisev@sun.ac.za.
Louise
L
Botha
Tanzania Wildlife Research Institute (TAWIRI), P.O. BOX 661, Arusha, Tanzania. julius.keyyu@tawiri.or.tz.
Julius D
JD
Keyyu
Centre for Emerging, Endemic and Exotic diseases, Royal Veterinary College (RVC), Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, AL9 7TA, UK. skendall@RVC.AC.UK.
Sharon
S
Kendall
Department of Immunology and infection, London School of Hygiene and Tropical Medicine (LSHTM), London, UK. Hazel.Dockrell@lshtm.ac.uk.
Hazel M
HM
Dockrell
Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria, South Africa. Anita.Michel@up.ac.za.
Anita L
AL
Michel
Department of Veterinary Medicine and Public Health, Sokoine University of Agriculture (SUA), Faculty of Veterinary Medicine, P.O. BOX 3000, Chuo Kikuu, Morogoro, Tanzania. kazwala@gmail.com.
Rudovick R
RR
Kazwala
Southern African Centre for Infectious Diseases Surveillance (SACIDS), Sokoine University of Agriculture (SUA), P.O. BOX 3297, Chuo Kikuu, Morogoro, Tanzania. mark.rweyemamu@btinternet.com.
Mark M
MM
Rweyemamu
DST/NRF Centre of Excellence for Biomedical Tuberculosis Research/MRC Centre for TB Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, Cape Town, South Africa. PVH@sun.ac.za.
Paul
P
van Helden
Department of Microbiology and Immunology, School of Medicine, Muhimbili University of Health and Allied Sciences (MUHAS), P.O. BOX 65001, Dar Es Salaam, Tanzania. mateemecky@yahoo.com.
Mecky I
MI
Matee
D000328:Adult; D000818:Animals; D000835:Animals, Wild / Q000382:microbiology; D002417:Cattle / Q000382:microbiology; D004269:DNA, Bacterial / Q000032:analysis; D017753:Ecosystem; D005260:Female; D006801:Humans; D058751:Livestock / Q000382:microbiology; D008297:Male; D009165:Mycobacterium Infections, Nontuberculous / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission; D009170:Nontuberculous Mycobacteria / Q000235:genetics / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000032:analysis; D013636:Tanzania / Q000453:epidemiology; D015047:Zoonoses
D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S