Mixed infections of Corynebacterium pseudotuberculosis and non-tuberculous mycobacteria in South African antelopes presenting with tuberculosis-like lesions.
Routine meat inspection of antelope carcasses from a South African game reserve revealed a high prevalence of tuberculosis-like lesions. This study aimed to identify the causative agent of this disease and to describe its pathological features. In total, 139 antelopes were randomly harvested from the game reserve and subjected to meat inspection. Of these animals, 46 (33%) showed gross visible, tuberculosis-like lesions. Histopathological examination revealed the presence of encapsulated necrogranulomas in organs and/or lymph nodes of 22 of 27 animals tested. Tissue samples from lesions were processed for both non-selective bacterial culture and mycobacterial culture following decontamination. In non-selective cultures of lesions from 25 of 31 animals tested, Corynebacterium pseudotuberculosis was detected. Isolation of C. pseudotuberculosis was closely associated with the presence of necrogranulomas. In mycobacterial cultures of lesions from 9 of 41 animals tested, different species of non-tuberculous mycobacteria (NTMs) were detected. In 5 instances, depending on the culture procedure that was applied, either C. pseudotuberculosis or NTMs were isolated from the same tissue sample. Our results suggest that the disease has been caused by infections with C. pseudotuberculosis. In sub-Saharan Africa, the role of pathogens other than Mycobacterium bovis may be underestimated in causing tuberculosis-like lesions. In cases where potentially pathogenic NTMs are isolated from mycobacterial cultures of tuberculosis-like lesions, the non-use of additional non-selective culture techniques could lead to misinterpretations of the diagnostic test results.
Müller
Borna
B
DST/NRF Centre of Excellence for Biomedical Tuberculosis Research/MRC Centre for Molecular and Cellular Biology, Division of Molecular Biology and Human Genetics, Stellenbosch University, Francie van Zyl Avenue, Tygerberg 7505, Cape Town, South Africa. bmuller@sun.ac.za
de Klerk-Lorist
Lin-Mari
LM
Henton
Marijke M
MM
Lane
Emily
E
Parsons
Sven
S
Gey van Pittius
Nicolaas C
NC
Kotze
Antoinette
A
van Helden
Paul D
PD
Tanner
Manfred
M
D000818:Animals; D000866:Antelopes; D003354:Corynebacterium Infections / Q000473:pathology / Q000662:veterinary*; D016925:Corynebacterium pseudotuberculosis / Q000302:isolation & purification / Q000502:physiology*; D009161:Mycobacterium / Q000302:isolation & purification / Q000502:physiology*; D009164:Mycobacterium Infections / Q000473:pathology / Q000662:veterinary*; D013019:South Africa; D014376:Tuberculosis / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*