Faculty of Natural and Agricultural Sciences
School of Biological Sciences
Department of Microbiology and Plant Pathology
Selected Highlights from Research Findings
The African rabies-related viruses; Lagos bat virus (LBV), Mokola virus (MOKV) and Duvenhage virus remain among the most obscure in the Lyssavirus genus. We have succeeded with various recent isolations of MOKV and LBV from South Africa. Most recently we regularly isolated LBV from bats, but also isolated LBV for the first time from terrestrial wildlife and implicated LBV in rabies vaccine failures of dogs.
These findings re-emphasized our lack of understanding of the pathogenicity or epidemiology of lyssaviruses throughout Africa and renewed the interest in the rabies-related viruses in particular. Internationally, these aspects are closely linked to similar questions of other lyssaviruses – including the newly discovered viruses from Asia as well as the better known genotypes like the European and Australian bat lyssaviruses.
We also study the southern African mongoose rabies virus, and the origin of this unique variant of rabies virus in southern Africa. Our research explores: (1) Introduction of this virus from bats to small herpestid carnivores of southern Africa and (2) Introduction of terrestrial mongoose rabies into southern Africa before the global dissemination of cosmopolitan dog rabies.
Additionally, we have focused on the molecular epidemiology of the ongoing dog rabies epidemic in Kwazulu/Natal. For the first time we have obtained a picture of the viruses involved and their movement within and among the municipal areas of this province.
Our research indicated that, contrary to traditional belief, there have been multiple introductions of rabies virus into the province, with implication for the future control of rabies in this province and elsewhere in southern Africa. One of these introductions has been from a virus cycle associated with jackals.
Whereas the importance of dogs as rabies hosts throughout Africa is without question, the role of jackals as important hosts has to date been controversial
Contact person: Prof LH Nel.
Oral vaccination of free-roaming dogs will be a major step in the struggle to control rabies in Africa. Despite the effective use of oral vaccines to vaccinate wildlife in Europe and Northern America, current oral vaccines (designed for wildlife) are not appropriate for application in sub-Saharan Africa.
The main problems are relative instability of some vaccines, or the potential danger of others, given the very high incidence of immunodeficiency in the resident human populations, primarily through the AIDS pandemic in the subcontinent. For various related reasons, the use of these classical pox recombinants has also been met with increasing resistance in the developed world.
In this regard, a replication-deficient recombinant poxvirus expressing the relevant antigens may provide not only an effective vaccine but also a safer alternative to the currently available recombinant oral vaccines.
Several such candidate vaccines (based on recombinant LSDV and MVA) have been constructed and evaluated in murine and canine laboratory models. In addition, several combined or cross-reactive vaccines – of specific benefit to laboratory diagnosticians worldwide and to high-risk groups in those areas where rabies-related lyssaviruses, have been constructed
Contact person: Prof LH Nel.
The primary research of the plant virology program is directed at support of the South African Citrus Improvement Program (CIP) as well as the Wine Grape Certification scheme. Winetech, the wine industry research co-ordinating body, supports the grapevine research component financially, while Citrus Research International (CRI) funds the citrus component.
In both schemes virus control plays a central role, with citrus tristeza virus (CTV) being the most important virus in the citrus scheme, and Grapevine leafroll associated virus type 3 (GLRaV-3), the most important one for the wine grape scheme.
However, the differences in mode of transmission of these viruses require that the respective certification schemes employ different strategies for control of these viruses. As CTV is easily and rapidly transmissible by highly mobile aphid vectors, citrus material from which viruses have been eliminated are protected against CTV infection in the field through the pre-inoculation of planting material with mild CTV strains.
In contrast with this and because of the relative slow rate of spread of GLRaV-3, wine grape material is subjected to virus elimination techniques and then propagated under conditions to minimize re-infection
Contact person: Prof LH Nel.
The primary research of the plant virology program is directed at support of the South African Citrus Improvement Program (CIP) as well as the Wine Grape Certification scheme. Winetech, the wine industry research co-ordinating body, supports the grapevine research component financially, while Citrus Research International (CRI) funds the citrus component.
In both schemes virus control plays a central role, with citrus tristeza virus (CTV) being the most important virus in the citrus scheme, and Grapevine leafroll associated virus type 3 (GLRaV-3), the most important one for the wine grape scheme.
However, the differences in mode of transmission of these viruses require that the respective certification schemes employ different strategies for control of these viruses. As CTV is easily and rapidly transmissible by highly mobile aphid vectors, citrus material from which viruses have been eliminated are protected against CTV infection in the field through the pre-inoculation of planting material with mild CTV strains.
In contrast with this and because of the relative slow rate of spread of GLRaV-3, wine grape material is subjected to virus elimination techniques and then propagated under conditions to minimize re-infection
Contact person: Prof G Pietersen.
The primary research of the plant virology program is directed at support of the South African Citrus Improvement Program (CIP) as well as the Wine Grape Certification scheme. Winetech, the wine industry research co-ordinating body, supports the grapevine research component financially, while Citrus Research International (CRI) funds the citrus component.
In both schemes virus control plays a central role, with citrus tristeza virus (CTV) being the most important virus in the citrus scheme, and Grapevine leafroll associated virus type 3 (GLRaV-3), the most important one for the wine grape scheme.
However, the differences in mode of transmission of these viruses require that the respective certification schemes employ different strategies for control of these viruses. As CTV is easily and rapidly transmissible by highly mobile aphid vectors, citrus material from which viruses have been eliminated are protected against CTV infection in the field through the pre-inoculation of planting material with mild CTV strains.
In contrast with this and because of the relative slow rate of spread of GLRaV-3, wine grape material is subjected to virus elimination techniques and then propagated under conditions to minimize re-infection
Contact person: Mej W Markotter.
Oral vaccination of free-roaming dogs will be a major step in the struggle to control rabies in Africa. Despite the effective use of oral vaccines to vaccinate wildlife in Europe and Northern America, current oral vaccines (designed for wildlife) are not appropriate for application in sub-Saharan Africa.
The main problems are relative instability of some vaccines, or the potential danger of others, given the very high incidence of immunodeficiency in the resident human populations, primarily through the AIDS pandemic in the subcontinent. For various related reasons, the use of these classical pox recombinants has also been met with increasing resistance in the developed world.
In this regard, a replication-deficient recombinant poxvirus expressing the relevant antigens may provide not only an effective vaccine but also a safer alternative to the currently available recombinant oral vaccines.
Several such candidate vaccines (based on recombinant LSDV and MVA) have been constructed and evaluated in murine and canine laboratory models. In addition, several combined or cross-reactive vaccines – of specific benefit to laboratory diagnosticians worldwide and to high-risk groups in those areas where rabies-related lyssaviruses, have been constructed
Contact person: Mej W Markotter.
Oral vaccination of free-roaming dogs will be a major step in the struggle to control rabies in Africa. Despite the effective use of oral vaccines to vaccinate wildlife in Europe and Northern America, current oral vaccines (designed for wildlife) are not appropriate for application in sub-Saharan Africa.
The main problems are relative instability of some vaccines, or the potential danger of others, given the very high incidence of immunodeficiency in the resident human populations, primarily through the AIDS pandemic in the subcontinent. For various related reasons, the use of these classical pox recombinants has also been met with increasing resistance in the developed world.
In this regard, a replication-deficient recombinant poxvirus expressing the relevant antigens may provide not only an effective vaccine but also a safer alternative to the currently available recombinant oral vaccines.
Several such candidate vaccines (based on recombinant LSDV and MVA) have been constructed and evaluated in murine and canine laboratory models. In addition, several combined or cross-reactive vaccines – of specific benefit to laboratory diagnosticians worldwide and to high-risk groups in those areas where rabies-related lyssaviruses, have been constructed
Contact person: Prof G Pietersen.
The African rabies-related viruses; Lagos bat virus (LBV), Mokola virus (MOKV) and Duvenhage virus remain among the most obscure in the Lyssavirus genus. We have succeeded with various recent isolations of MOKV and LBV from South Africa. Most recently we regularly isolated LBV from bats, but also isolated LBV for the first time from terrestrial wildlife and implicated LBV in rabies vaccine failures of dogs.
These findings re-emphasized our lack of understanding of the pathogenicity or epidemiology of lyssaviruses throughout Africa and renewed the interest in the rabies-related viruses in particular. Internationally, these aspects are closely linked to similar questions of other lyssaviruses – including the newly discovered viruses from Asia as well as the better known genotypes like the European and Australian bat lyssaviruses.
We also study the southern African mongoose rabies virus, and the origin of this unique variant of rabies virus in southern Africa. Our research explores: (1) Introduction of this virus from bats to small herpestid carnivores of southern Africa and (2) Introduction of terrestrial mongoose rabies into southern Africa before the global dissemination of cosmopolitan dog rabies.
Additionally, we have focused on the molecular epidemiology of the ongoing dog rabies epidemic in Kwazulu/Natal. For the first time we have obtained a picture of the viruses involved and their movement within and among the municipal areas of this province.
Our research indicated that, contrary to traditional belief, there have been multiple introductions of rabies virus into the province, with implication for the future control of rabies in this province and elsewhere in southern Africa. One of these introductions has been from a virus cycle associated with jackals.
Whereas the importance of dogs as rabies hosts throughout Africa is without question, the role of jackals as important hosts has to date been controversial
Contact person: Prof G Pietersen.
The African rabies-related viruses; Lagos bat virus (LBV), Mokola virus (MOKV) and Duvenhage virus remain among the most obscure in the Lyssavirus genus. We have succeeded with various recent isolations of MOKV and LBV from South Africa. Most recently we regularly isolated LBV from bats, but also isolated LBV for the first time from terrestrial wildlife and implicated LBV in rabies vaccine failures of dogs.
These findings re-emphasized our lack of understanding of the pathogenicity or epidemiology of lyssaviruses throughout Africa and renewed the interest in the rabies-related viruses in particular. Internationally, these aspects are closely linked to similar questions of other lyssaviruses – including the newly discovered viruses from Asia as well as the better known genotypes like the European and Australian bat lyssaviruses.
We also study the southern African mongoose rabies virus, and the origin of this unique variant of rabies virus in southern Africa. Our research explores: (1) Introduction of this virus from bats to small herpestid carnivores of southern Africa and (2) Introduction of terrestrial mongoose rabies into southern Africa before the global dissemination of cosmopolitan dog rabies.
Additionally, we have focused on the molecular epidemiology of the ongoing dog rabies epidemic in Kwazulu/Natal. For the first time we have obtained a picture of the viruses involved and their movement within and among the municipal areas of this province.
Our research indicated that, contrary to traditional belief, there have been multiple introductions of rabies virus into the province, with implication for the future control of rabies in this province and elsewhere in southern Africa. One of these introductions has been from a virus cycle associated with jackals.
Whereas the importance of dogs as rabies hosts throughout Africa is without question, the role of jackals as important hosts has to date been controversial
Contact person: Mej W Markotter.
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