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Prevalence and Distribution of Non‐Tuberculous Mycobacteria ( NTM ) in Cattle, African Buffaloes ( S yncerus caffer ) and their Environments in South Africa
Author(s) -
Gcebe N.,
Rutten V.,
Gey van Pittius N. C.,
Michel A.
Publication year - 2013
Publication title -
transboundary and emerging diseases
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.392
H-Index - 63
eISSN - 1865-1682
pISSN - 1865-1674
DOI - 10.1111/tbed.12133
Subject(s) - mycobacterium bovis , biology , mycobacterium , veterinary medicine , livestock , tuberculosis , mycobacterium tuberculosis complex , bovine tuberculosis , nontuberculous mycobacteria , microbiology and biotechnology , mycobacterium tuberculosis , medicine , bacteria , ecology , pathology , genetics
Summary It has been hypothesized that a variety of non‐tuberculous mycobacteria ( NTM ) species to which livestock and wildlife species are naturally exposed induce broadly cross‐reactive anti‐mycobacterial immune responses which interfere with current standard diagnostic assays. Non‐tuberculous mycobacteria have also been implicated in M ycobacterium bovis ‐specific immune responsiveness, hence potentially the development of tuberculosis. Cattle and African buffaloes are both maintenance hosts of bovine tuberculosis ( BTB ) in S outh A frica, yet the effective diagnosis and control in these species may be hampered by adverse effects of NTM . As part of an investigation of the role of NTM in the immune responsiveness of cattle and A frican buffaloes to NTM , we conducted a countrywide survey to establish the prevalent NTM species and their distribution in the natural environments of these animals. A total of 1123 samples (water, soil, nasal and pharyngeal swabs) were collected for mycobacterium isolation. In addition, NTM isolated from tissue samples between 1991 and 2011 were included in the analysis. Mycobacteria were isolated from 56% of the samples from the countrywide survey. A total of 420 NTM isolates from soil, water, animal tissues and animal‐derived swab samples were genotyped with the following results: 302 belonged to 40 known NTM species, 79 were found to be closely related to 23 known NTM species, and 38 isolates were found to be potentially novel species that are not currently listed in the RIDOM and NCBI BLAST databases. The four NTM species or closely related groups most frequently isolated in this survey included M ycobacterium terrae (11.2% of isolates) , a group of mycobacteria closely related to M ycobacterium moriokaense (referred to as M . moriokaense‐ like) (8.1% of isolates), M ycobacterium nonchromogenicum (7.4% of isolates) and M ycobacterium vaccae/M. vanbaalenii (5.2% of isolates). The phylogenetic analysis of the M . moriokaense‐ like isolates, based on the 16S rRNA sequences, revealed at least eight clusters, possibly associated with eight different NTM species. Our findings provide account of NTM species diversity and associated prevalences in cattle and A frican buffaloes and their environments in S outh A frica. The identification of the most prevalent NTM species in this study will allow for a targeted investigation of their effects on host immune responses.