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A. Njeri - One of the best experts on this subject based on the ideXlab platform.
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The Rhipicephalus appendiculatus tick vector of Theileria parva is absent from cape buffalo (Syncerus Caffer) populations and associated ecosystems in northern Uganda.
Parasitology research, 2020Co-Authors: Isaiah Obara, Naftaly Githaka, Ard M. Nijhof, Jürgen Krücken, Anne Nanteza, David Odongo, D. Lubembe, P. Atimnedi, D. Mijele, A. NjeriAbstract:Rhipicephalus appendiculatus is the major tick vector of Theileria parva, an apicomplexan protozoan parasite that causes the most economically important and lethal disease of cattle in East and central Africa. The African cape buffalo (Syncerus Caffer) is the major wildlife host of T. parva from southern Uganda and Kenya to southern Africa. We show herein that R. appendiculatus appears to be absent from the two largest national parks in northern Uganda. Syncerus Caffer is common in both of these national parks, specifically Murchison falls (MFNP) and Kidepo Valley (KVNP). We re-confirmed the previously reported absence of T. parva in buffalo sampled in the two northern parks based on RLB data using a nested PCR based on the T. parva p104 gene. By contrast, T. parva-infected R. appendiculatus ticks and parasite-infected buffalo were present in Lake Mburo (LMNP) in South central Uganda. This suggests that the distribution of R. appendiculatus, which is predicted to include the higher rainfall regions of northern Uganda, may be limited by additional, as yet unknown factors.
R G Bengis - One of the best experts on this subject based on the ideXlab platform.
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BCG vaccination failed to protect yearling African buffaloes (Syncerus Caffer) against experimental intratonsilar challenge with Mycobacterium bovis.
Veterinary Immunology and Immunopathology, 2010Co-Authors: Lin-mari De Klerk, R G Bengis, N.p.j. Kriek, Anita Luise Michel, Jacques GodfroidAbstract:Vaccination has been discussed as a practical option to control bovine tuberculosis in countries where a wildlife reservoir of the disease is present. African buffaloes (Syncerus Caffer) are the main wildlife reservoir of Mycobacterium bovis in certain South African game parks and vaccination is not only the most promising but the only ethically acceptable control measure currently available. The use of Bacillus Calmette-Guerin vaccine (Pasteur strain) to vaccinate fourteen African buffalo yearlings and their reactions to subsequent intratonsilar challenge with a field strain of M. bovis are described. The BCG vaccine was administered twice intramuscularly, six weeks apart. All vaccinates and thirteen control buffaloes were euthanized and necropsies performed 9 months after the challenge. Standard sets of lymph nodes from the head, the thoracic cavity and abdomen were cultured and examined histopathologically. No significant reduction in number of lesions or severity of disease was noted, concluding that the BCG vaccine did not induce sufficient protection able to limit the shedding of organisms. The age of the buffaloes, route of vaccination and prior exposure to environmental mycobacteria are among the possible reasons for vaccination failure.
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BCG vaccination failed to protect yearling African buffaloes (Syncerus Caffer) against experimental intratonsilar challenge with Mycobacterium bovis.
Veterinary immunology and immunopathology, 2010Co-Authors: Lin-mari De Klerk, R G Bengis, N.p.j. Kriek, Anita L Michel, Jacques GodfroidAbstract:Vaccination has been discussed as a practical option to control bovine tuberculosis in countries where a wildlife reservoir of the disease is present. African buffaloes (Syncerus Caffer) are the main wildlife reservoir of Mycobacterium bovis in certain South African game parks and vaccination is not only the most promising but the only ethically acceptable control measure currently available. The use of Bacillus Calmette-Guérin vaccine (Pasteur strain) to vaccinate fourteen African buffalo yearlings and their reactions to subsequent intratonsilar challenge with a field strain of M. bovis are described. The BCG vaccine was administered twice intramuscularly, six weeks apart. All vaccinates and thirteen control buffaloes were euthanized and necropsies performed 9 months after the challenge. Standard sets of lymph nodes from the head, the thoracic cavity and abdomen were cultured and examined histopathologically. No significant reduction in number of lesions or severity of disease was noted, concluding that the BCG vaccine did not induce sufficient protection able to limit the shedding of organisms. The age of the buffaloes, route of vaccination and prior exposure to environmental mycobacteria are among the possible reasons for vaccination failure.
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Clinical Demodicosis in African Buffalo (Syncerus Caffer) in the Kruger National Park
Journal of wildlife diseases, 2009Co-Authors: Julie Wolhuter, R G Bengis, Brian K. Reilly, Paul C. CrossAbstract:We investigated the relationship between prevalence and severity of clinical signs of Demodex Cafferi infection in free-ranging African buffalo (Syncerus Caffer) and other factors such as age, sex, pregnancy status, and concomitant infections with bovine tuberculosis (BTB), Rift Valley fever (RVF), and brucellosis (BA). Approximately half of 203 buffalo examined in this study had clinical signs of demodicosis (cutaneous nodules); younger age classes had the highest prevalence and severity of lesions (χ2=21.4, df=6, P=0.0015). Nodules were generally limited to the head and neck region, but in severe cases were present over the entire animal. We found no significant association between clinical severity of the Demodex infection and gender, pregnancy status, or infection with BTB, RVF, or BA.
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An experimental intratonsilar infection model for bovine tuberculosis in African buffaloes, Syncerus Caffer.
The Onderstepoort journal of veterinary research, 2006Co-Authors: L.-m. De Klerk, R G Bengis, N.p.j. Kriek, Anita Luise Michel, Douw Grobler, R. Mitchell Bush, Markus Hofmeyr, J. F. T. Griffin, C. G. MackintoshAbstract:An infection model for Mycobacterium bovis in African buffaloes, Syncerus Caffer, was developed, using the intratonsilar route of inoculation. Two groups of 11 buffaloes each, aged approximately 18 months, were infected with either 3.2 x 102 cfu (low dose) or 3 x 104 cfu (high dose) of M. bovis strain isolated from a buffalo. A control group of six buffaloes received saline via the same route. The infection status was monitored in vivo using the comparative intradermal tuberculin test, and in vitro by the modified interferon-gamma assay. All buffaloes were euthanazed 22 weeks post infection and lesion development was assessed by macroscopic examination, culture and histopathology. It was found that the high dose caused macroscopic lesions in nine out of 11 buffaloes. Mycobacterium bovis was isolated from all buffaloes in the high-dose group and from six out of 11 in the low-dose group.
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an outbreak of bovine tuberculosis in a free living african buffalo Syncerus Caffer sparrman population in the kruger national park a preliminary report
Onderstepoort Journal of Veterinary Research, 1996Co-Authors: R G Bengis, D.f. Keet, N.p.j. Kriek, J P Raath, H F A K HuchzermeyerAbstract:: Bovine tuberculosis was diagnosed for the first time in an African buffalo (Syncerus Caffer) in the Kruger National Park (KNP). The index case was a 2-year-old, emaciated bull which had been found recumbent and obviously ill, near the south-western boundary of the KNP, in July 1990. During a follow-up random sampling of 57 buffalo, from two herds in close proximity to this initial case, nine more suspect cases were found. Mycobacterium bovis was isolated from a lung and thoracic lymph node, respectively, of two of these cases. Histopathologically, all nine of these animals had granulomatous lesions compatible with a diagnosis of mycobacteriosis, but acid-fast organisms could be demonstrated in only one animal.
Isaiah Obara - One of the best experts on this subject based on the ideXlab platform.
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The Rhipicephalus appendiculatus tick vector of Theileria parva is absent from cape buffalo (Syncerus Caffer) populations and associated ecosystems in northern Uganda.
Parasitology research, 2020Co-Authors: Isaiah Obara, Naftaly Githaka, Ard M. Nijhof, Jürgen Krücken, Anne Nanteza, David Odongo, D. Lubembe, P. Atimnedi, D. Mijele, A. NjeriAbstract:Rhipicephalus appendiculatus is the major tick vector of Theileria parva, an apicomplexan protozoan parasite that causes the most economically important and lethal disease of cattle in East and central Africa. The African cape buffalo (Syncerus Caffer) is the major wildlife host of T. parva from southern Uganda and Kenya to southern Africa. We show herein that R. appendiculatus appears to be absent from the two largest national parks in northern Uganda. Syncerus Caffer is common in both of these national parks, specifically Murchison falls (MFNP) and Kidepo Valley (KVNP). We re-confirmed the previously reported absence of T. parva in buffalo sampled in the two northern parks based on RLB data using a nested PCR based on the T. parva p104 gene. By contrast, T. parva-infected R. appendiculatus ticks and parasite-infected buffalo were present in Lake Mburo (LMNP) in South central Uganda. This suggests that the distribution of R. appendiculatus, which is predicted to include the higher rainfall regions of northern Uganda, may be limited by additional, as yet unknown factors.
Hezron Nonga - One of the best experts on this subject based on the ideXlab platform.
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Detection of Theileria parva antibodies in the African buffalo (Syncerus Caffer) in the livestock-wildlife interface areas of Zambia.
Veterinary parasitology, 2009Co-Authors: Hetron Mweemba Munang'andu, Victor M Siamudaala, Musso Munyeme, Wigganson Matandiko, Andrew Nambota, Misheck Mulumba, Stephen Mutoloki, Hezron NongaAbstract:A serolocigical survey was conducted for the detection of Theileria parva antibodies in 176 African buffaloes (Syncerus Caffer) sampled between 1996 and 2005 in livestock-wildlife interface areas of Zambia. Rhipicephalus appendiculatus, Rhipicephalus species, and Amblyomma variegatum were the most abundant tick species identified on buffaloes. T. parva sero-positives were reported in buffaloes sampled from game management areas at Mlanga and Nanzhila bordering the Kafue National Parks and in the Lochnivar National Park while buffaloes sampled from Lower Zambezi National Park were sero-negative. Given that Game Management Areas serve as interface areas that permit the co-existence of livestock and wildlife in similar ecological habitats our findings suggest that buffaloes could play a significant role in the epidemiology of theileriosis in livestock-wildlife interface areas. Thus far, the disease has only been reported in livestock and is herein being reported in the African buffalo for the first time in Zambia.
Anita Luise Michel - One of the best experts on this subject based on the ideXlab platform.
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infection of african buffalo Syncerus Caffer by oryx bacillus a rare member of the antelope clade of the mycobacterium tuberculosis complex
Journal of Wildlife Diseases, 2012Co-Authors: Nicolaas Gey C Van Pittius, D.f. Keet, Keith D Perrett, Anita Luise Michel, Tiny Motlatso Hlokwe, E M Streicher, Robin M Warren, Paul D. Van HeldenAbstract:Mycobacterium tuberculosis complex species cause tuberculosis disease in animals and humans. Although they share 99.9% similarity at the nucleotide level, several host-adapted ecotypes of the tubercule bacilli have been identified. In the wildlife setting, probably the most well-known member of this complex is Mycobacterium bovis, the causative agent of bovine tuberculosis. The recently described oryx bacillus is an extremely rare slow-growing member of the antelope clade of the M. tuberculosis complex and is closely related to the dassie bacillus, Mycobacterium africanum and Mycobacterium microti. The antelope clade is a group of strains apparently host adapted to antelopes, as most described infections were associated with deer and antelope, most specifically the Arabian oryx (Oryx leucoryx). In this study, oryx bacillus was isolated from a free-ranging adult female African buffalo (Syncerus Caffer), in good physical condition, which tested strongly positive on three consecutive comparative intradermal ...
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approaches towards optimising the gamma interferon assay for diagnosing mycobacterium bovis infection in african buffalo Syncerus Caffer
Preventive Veterinary Medicine, 2011Co-Authors: Anita Luise Michel, David Cooper, L.-m. De Klerk, J Jooste, Anna E. JollesAbstract:The application of diagnostic tests for bovine tuberculosis in wildlife poses formidable technical difficulties and the use of the gamma interferon assay offers a simplified approach to testing wild animal species. We compared the performance of the gamma interferon assay in African buffalo (Syncerus Caffer) under the recommended guidelines for interpretation of test results and found a high sensitivity (92.1%) at the cost of a greatly reduced specificity (68.3%). The optimised cut-off value for positive test results under local conditions was identified at an optical density of 0.385 at wavelength 450 nm as the preferred compromise between sensitivity and specificity. Additional optimisation approaches to improve test performance were examined and showed that the application of ‘a priori exclusions’ of test results on the basis of reactivity to fortuitum PPD (sensitin produced from Mycobacterium fortuitum) and to a lesser degree, avian PPD, increased specificity without losing sensitivity. The implications of these findings on a modified testing protocol adjusted to include measurement of immune responsiveness to fortuitum PPD and other interpretation schemes are discussed. © 2010 Elsevier B.V. All rights reserved.
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approaches towards optimising the gamma interferon assay for diagnosing mycobacterium bovis infection in african buffalo Syncerus Caffer
Preventive Veterinary Medicine, 2011Co-Authors: Anita Luise Michel, David Cooper, L.-m. De Klerk, J Jooste, Anna E. JollesAbstract:The application of diagnostic tests for bovine tuberculosis in wildlife poses formidable technical difficulties and the use of the gamma interferon assay offers a simplified approach to testing wild animal species. We compared the performance of the gamma interferon assay in African buffalo (Syncerus Caffer) under the recommended guidelines for interpretation of test results and found a high sensitivity (92.1%) at the cost of a greatly reduced specificity (68.3%). The optimised cut-off value for positive test results under local conditions was identified at an optical density of 0.385 at wavelength 450 nm as the preferred compromise between sensitivity and specificity. Additional optimisation approaches to improve test performance were examined and showed that the application of ‘a priori exclusions’ of test results on the basis of reactivity to fortuitum PPD (sensitin produced from Mycobacterium fortuitum) and to a lesser degree, avian PPD, increased specificity without losing sensitivity. The implications of these findings on a modified testing protocol adjusted to include measurement of immune responsiveness to fortuitum PPD and other interpretation schemes are discussed. © 2010 Elsevier B.V. All rights reserved.
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BCG vaccination failed to protect yearling African buffaloes (Syncerus Caffer) against experimental intratonsilar challenge with Mycobacterium bovis.
Veterinary Immunology and Immunopathology, 2010Co-Authors: Lin-mari De Klerk, R G Bengis, N.p.j. Kriek, Anita Luise Michel, Jacques GodfroidAbstract:Vaccination has been discussed as a practical option to control bovine tuberculosis in countries where a wildlife reservoir of the disease is present. African buffaloes (Syncerus Caffer) are the main wildlife reservoir of Mycobacterium bovis in certain South African game parks and vaccination is not only the most promising but the only ethically acceptable control measure currently available. The use of Bacillus Calmette-Guerin vaccine (Pasteur strain) to vaccinate fourteen African buffalo yearlings and their reactions to subsequent intratonsilar challenge with a field strain of M. bovis are described. The BCG vaccine was administered twice intramuscularly, six weeks apart. All vaccinates and thirteen control buffaloes were euthanized and necropsies performed 9 months after the challenge. Standard sets of lymph nodes from the head, the thoracic cavity and abdomen were cultured and examined histopathologically. No significant reduction in number of lesions or severity of disease was noted, concluding that the BCG vaccine did not induce sufficient protection able to limit the shedding of organisms. The age of the buffaloes, route of vaccination and prior exposure to environmental mycobacteria are among the possible reasons for vaccination failure.
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An experimental intratonsilar infection model for bovine tuberculosis in African buffaloes, Syncerus Caffer.
The Onderstepoort journal of veterinary research, 2006Co-Authors: L.-m. De Klerk, R G Bengis, N.p.j. Kriek, Anita Luise Michel, Douw Grobler, R. Mitchell Bush, Markus Hofmeyr, J. F. T. Griffin, C. G. MackintoshAbstract:An infection model for Mycobacterium bovis in African buffaloes, Syncerus Caffer, was developed, using the intratonsilar route of inoculation. Two groups of 11 buffaloes each, aged approximately 18 months, were infected with either 3.2 x 102 cfu (low dose) or 3 x 104 cfu (high dose) of M. bovis strain isolated from a buffalo. A control group of six buffaloes received saline via the same route. The infection status was monitored in vivo using the comparative intradermal tuberculin test, and in vitro by the modified interferon-gamma assay. All buffaloes were euthanazed 22 weeks post infection and lesion development was assessed by macroscopic examination, culture and histopathology. It was found that the high dose caused macroscopic lesions in nine out of 11 buffaloes. Mycobacterium bovis was isolated from all buffaloes in the high-dose group and from six out of 11 in the low-dose group.
