Characterization of tuberculous lesions in naturally infected African buffalo (Syncerus caffer)
Date
2010-12
Authors
Journal Title
Journal ISSN
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Publisher
Stellenbosch : University of Stellenbosch
Abstract
ENGLISH ABSTRACT: Mycobacterium bovis has a wide host range and infects many wild and domestic animal
species as well as humans. African buffalo (Syncerus caffer) is considered to be a wildlife
reservoir of M. bovis in certain environments in South Africa, such as in the Kruger
National Park (KNP) and Hluhluwe-iMfolozi Park (HiP).
A detailed pathological study was conducted on 19 African buffalos (Syncerus caffer)
from a herd in the HiP in South Africa. The animals tested positive to the intradermal
bovine tuberculin test and were euthanazed during a test-and-cull operation to decrease
the prevalence of bovine tuberculosis (bTB) in the park. The superficial, head, thoraxic
and abdominal lymph nodes and the lungs were examined grossly for presence of
tuberculous lesions and were scored on a 1-5 scale for macroscopic changes. The gross
lesions were examined histologically and scored I-IV according to a grading system used
for bTB lesions in domestic cattle. Macroscopical lesions were limited to the
retropharyngeal, bronchial, and mediastinal lymph nodes and the lungs. The most
frequently affected lymph nodes were the bronchial (16/19) and mediastinal (11/19). All
four grades of microscopic lesions were observed, although grade II lesions were the
most frequent. Acid-fast bacilli were observed only rarely. Bovine tuberculosis was
confirmed by PCR analyses.
All animals were in good body condition and most of the lesions were in an early stage of
development, indicating an early stage of the disease. The absence of lesions in the
mesenteric lymph nodes and the high frequency of lesions in respiratory tract associated
lymph nodes suggest that the main route of M. bovis infection in African buffalo is
inhalatory rather than alimentary. This study presents a systematic evaluation and semiquantification
of the severity and stages of development of tuberculous lesions in buffalo.
The results may contribute to i) the understanding of the pathogenesis of the disease, ii)
the evaluation of experimental models of M. bovis infection in Syncerus caffer, and iii)
the interpretation of pathological data from vaccination trials.
AFRIKAANSE OPSOMMING: Mycobacterium bovis het ‘n wye reeks van gashere en dit infekteer verskeie wilde en mak dierespesies, sowel as mense. Die buffel (Syncerus caffer) word beskou as die wild reservoir van M. bovis in sekere dele van Suid Afrika, soos in die Kruger Nasionale Park (KNP) en Hluhluwe-iMfolozi Park (HiP). ‘n Breedvoerige patologiese studie is uitgevoer op 19 buffels afkomstig vanaf ‘n trop in die HiP in Suid Afrika. Die diere het almal positief getoets vir die intradermale beestuberkulin toets en is uitgesit tydens ‘n toets-en-slag operasie met die doel om die voorkoms van beestuberkulose (bTB) in die park te bekamp. Die oppervlakkige, kop, toraks en abdominale limfknope en longe is oorsigtelik ondersoek vir die teenwoordigheid van tuberkulose letsels en was ‘n punt toegeken op ‘n skaal van 1-5 vir die teenwoordigheid van makroskopiese veranderinge. Die opsigtelike letsels is histologies ondersoek en ‘n I-IV punt toegeken volgens die gradering wat gebruik word vir bTB letsels in beeste. Makroskopiese letsels was beperk tot die retrofaringeale, brongiale, en mediastinale limfknope en in die longe. Die brongiale (16/19) en mediastinale (11/19) limfknope was meestal geaffekteerd. Al vier grade van mikroskopiese letsels is gevind, alhoewel graad II letsels die volopste was. Suur-vaste basille is slegs selde waargeneem. Beestuberkulose is bevestig deur PKR analises. Al die diere was in ‘n goeie kondisie en meeste van die letsels was in ‘n vroeë stadium van ontwikkeling, wat aandui op ‘n vroeë fase van die siekte. Die afwesigheid van letsels in die mesenteriese limfknope en die hoë frekwensie van letsels in die lugweg geassosieerde limfkliere dui daarop dat the belangrikste roete van M. bovis infeksie in die buffel deur inaseming geskied eerder as deur opname in die spysverteringskanaal. Hierdie studie bied ‘n stelselmatige evaluering en semi-kwantifisering van die graad van erns en die stadia van ontwikkeling van tuberkulose letsels in buffels. Die resultate kan bydra tot i) die begrip van die patogenese van die siekte, ii) die evaluering van eksperimentele modelle van M. bovis infeksie in Syncerus caffer, en iii) die interpretasie van patologiese data van inentingsproewe.
AFRIKAANSE OPSOMMING: Mycobacterium bovis het ‘n wye reeks van gashere en dit infekteer verskeie wilde en mak dierespesies, sowel as mense. Die buffel (Syncerus caffer) word beskou as die wild reservoir van M. bovis in sekere dele van Suid Afrika, soos in die Kruger Nasionale Park (KNP) en Hluhluwe-iMfolozi Park (HiP). ‘n Breedvoerige patologiese studie is uitgevoer op 19 buffels afkomstig vanaf ‘n trop in die HiP in Suid Afrika. Die diere het almal positief getoets vir die intradermale beestuberkulin toets en is uitgesit tydens ‘n toets-en-slag operasie met die doel om die voorkoms van beestuberkulose (bTB) in die park te bekamp. Die oppervlakkige, kop, toraks en abdominale limfknope en longe is oorsigtelik ondersoek vir die teenwoordigheid van tuberkulose letsels en was ‘n punt toegeken op ‘n skaal van 1-5 vir die teenwoordigheid van makroskopiese veranderinge. Die opsigtelike letsels is histologies ondersoek en ‘n I-IV punt toegeken volgens die gradering wat gebruik word vir bTB letsels in beeste. Makroskopiese letsels was beperk tot die retrofaringeale, brongiale, en mediastinale limfknope en in die longe. Die brongiale (16/19) en mediastinale (11/19) limfknope was meestal geaffekteerd. Al vier grade van mikroskopiese letsels is gevind, alhoewel graad II letsels die volopste was. Suur-vaste basille is slegs selde waargeneem. Beestuberkulose is bevestig deur PKR analises. Al die diere was in ‘n goeie kondisie en meeste van die letsels was in ‘n vroeë stadium van ontwikkeling, wat aandui op ‘n vroeë fase van die siekte. Die afwesigheid van letsels in die mesenteriese limfknope en die hoë frekwensie van letsels in die lugweg geassosieerde limfkliere dui daarop dat the belangrikste roete van M. bovis infeksie in die buffel deur inaseming geskied eerder as deur opname in die spysverteringskanaal. Hierdie studie bied ‘n stelselmatige evaluering en semi-kwantifisering van die graad van erns en die stadia van ontwikkeling van tuberkulose letsels in buffels. Die resultate kan bydra tot i) die begrip van die patogenese van die siekte, ii) die evaluering van eksperimentele modelle van M. bovis infeksie in Syncerus caffer, en iii) die interpretasie van patologiese data van inentingsproewe.
Description
Thesis (MScMedSc (Biomedical Sciences. Medical Biochemistry))--University of Stellenbosch, 2010.
Keywords
Theses -- Medical biochemistry, Dissertations -- Medical biochemistry, Theses -- Medicine, Dissertations -- Medicine, African buffalo -- Carcasses -- Examination, Syncerus caffer