title: Non-tuberculous Mycobacteria in South African Wildlife: Neglected Pathogens and Potential Impediments for Bovine Tuberculosis Diagnosis.
abstract: Non-tuberculous mycobacteria (NTM) are not only emerging and opportunistic pathogens of both humans and animals, but from a veterinary point of view some species induce cross-reactive immune responses that hamper the diagnosis of bovine tuberculosis (bTB) in both livestock and wildlife. Little information is available about NTM species circulating in wildlife species of South Africa. In this study, we determined the diversity of NTM isolated from wildlife species from South Africa as well as Botswana. Thirty known NTM species and subspecies, as well as unidentified NTM, and NTM closely related toMycobacterium goodii/Mycobacterium smegmatiswere identified from 102 isolates cultured between the years 1998 and 2010, using a combination of molecular assays viz PCR and sequencing of different Mycobacterial house-keeping genes as well as single nucleotide polymorphism (SNP) analysis. The NTM identified in this study include the following species which were isolated from tissue with tuberculosis- like lesions in the absence ofMycobacterium tuberculosiscomplex (MTBC) implying their potential role as pathogens of animals:Mycobacterium abscessussubsp.bolletii, Mycobacterium gastri, Mycobacteriumspecies closely related toMycobacterium goodii/Mycobacterium smegmatis, Mycobacterium brasiliensis, Mycobacterium sinenseJMD 601,Mycobacterium aviumsubsp.avium, Mycobacteriumsp. GR-2007,Mycobacterium bouchedurhonense, andMycobacterium septicum/M. peregrinum. Mycobaterium brasiliensis, Mycobacterium gastri, Mycobacteriumsp. GR-2007, and a potential novelMycobacteriumspecies closely related toMycobacterium goodiiwere found for the first time in this study to be potential pathogens of animals.Mycobacterium simiaewas isolated from a sample originating from a tuberculin skin test positive reactor, demonstrating its potential to elicit inappropriate immune responses in animals that may interfere with diagnosis of tuberculosis by immunology.Mycobacterium abscessussubsp.bollettiwas the most frequently detected NTM identified in 37 of the 102 isolates. Other NTM species were also isolated from animals not showing any pathological changes. Knowledge gained in this study contribute to the understanding of NTM species circulating in wild animals in South Africa and the pathogenic potential of certain species, whose role in disease causation need to be examined, as well as to a certain extent the potential ofM. simiaeto hamper the diagnosis of bTB.
authors.affiliation: Tuberculosis Laboratory, Onderstepoort Veterinary Institute, Zoonotic Diseases, Agricultural Research Council Onderstepoort, South Africa.
authors.forename: Nomakorinte
authors.initials: N
authors.lastname: Gcebe
authors.affiliation: Tuberculosis Laboratory, Onderstepoort Veterinary Institute, Zoonotic Diseases, Agricultural Research Council Onderstepoort, South Africa.
authors.forename: Tiny M
authors.initials: TM
authors.lastname: Hlokwe
mesh_terms: D000818:Animals; D000835:Animals, Wild; D001902:Botswana / Q000453:epidemiology; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D020043:Genes, Essential; D009165:Mycobacterium Infections, Nontuberculous / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D009170:Nontuberculous Mycobacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D017422:Sequence Analysis, DNA; D013019:South Africa / Q000453:epidemiology
chemical_list: D004269:DNA, Bacterial
keywords: 16S rDNA sequencing; South African wildlife; bovine tuberculosis; immune responses; non-tuberculous mycobacteria; potential pathogens