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EXPERIMENTAL INFECTION OF ARCHANOBACTERIUM PYOGENES IN ONE DAY OLD CHICKS Texto completo
2012
M.Y. Al-attar | Mohammad A. Hamad | A. M. Al-Aalim
The present work aimed to study the pathogenicity of Archanobacterium pyogenes by using one day old chicks and chicken Embryonated eggs .The chicks were given the bacteria(4.2x108 CFU/ml) by orally administration and intrapertoneal injection, while the Embryonated eggs inoculated into allontoic sac at 12 days of incubation. The chicks were show dullness, decrease in food intake and nervous sings, most chicks were died after 2-3 days, and the bacteria were re-isolated from internal organs, and yolk sac. The inoculation of Embryonated chicken eggs resulting in embryonicdeath, reduce hatchery percentage and deformity of embryo. The study showed that A. pyogenesisvirulence to both chicken Embryonated eggs and one day old chicks.
Mostrar más [+] Menos [-]Molecular characterisation of Newcastle disease virus isolates from different geographical regions in Mozambique in 2005 Texto completo
2012
Raul Fringe | Anna-Mari Bosman | Karen Ebersohn | Shahn Bisschop | Celia Abolnik | Estelle Venter
Molecular characterisation of Newcastle disease virus isolates from different geographical regions in Mozambique in 2005 Texto completo
2012
Raul Fringe | Anna-Mari Bosman | Karen Ebersohn | Shahn Bisschop | Celia Abolnik | Estelle Venter
Newcastle disease (ND) is regarded as a highly contagious and economically important disease in poultry and has a worldwide distribution. Viral determinants for Newcastle disease virus (NDV) virulence are not completely understood and viruses of different pathotypes can be found at live-bird markets in different geographical areas. The prevalence of Newcastle disease in village poultry in Mozambique is not well documented and strains of NDV involved in yearly outbreaks are unknown. The fusion (F) protein is an important determinant of pathogenicity of the virus and is used commonly for phylogenetic analysis. Newcastle disease viruses from various geographical regions of Mozambique were sequenced and compared genetically to published sequences obtained from GenBank. Samples were collected in three different areas of Mozambique and NDV was isolated by infection of embryonated chicken eggs. Sequence analysis of the F-protein encoding gene was used to classify 28 isolates from Mozambique into genotypes and compare these genotypes phylogenetically with existing genotypes found in GenBank. The isolates obtained from Mozambique grouped mainly into two clades. In the first clade, 12 isolates grouped together with sequences of isolates representing genotypes from Mozambique that were previously described. In the second clade, 16 isolates group together with sequences obtained from GenBank originating from Australia, China, South Africa and the USA. Eleven of these isolates showed a high similarity with sequences from South Africa. The number of samples sequenced (<em>n</em> = 28), as well as the relatively small geographical collection area used in this study, are too small to be a representation of the circulating viruses in Mozambique in 2005. Viruses characterised in this study belonged to lineage 5b, a similar finding of a previous study 10 years ago. From this data, it merely can be concluded that no new introduction of the virus occurred from 1995 to 2005 in Mozambique.
Mostrar más [+] Menos [-]Vector competence of Glossina austeni and Glossina brevipalpis for Trypanosoma congolense in KwaZulu-Natal, South Africa Texto completo
2012
Motloang, Makhosazana(ARC-Onderstepoort Veterinary Institute) | Masumu, Justin(Universite Pedagogique Nationale) | Mans, Barend(ARC-Onderstepoort Veterinary Institute) | van den Bossche, Peter(Institute of Tropical Medicine) | Latif, Abdalla(ARC-Onderstepoort Veterinary Institute)
Tsetse-transmitted trypanosomosis (nagana) has been the cause of stock losses in the recent past and still presents a major problem to livestock owners in certain areas of KwaZulu-Natal, South Africa. Over 10 000 cattle mortalities were reported in the 1990 nagana outbreak. Although information on the distribution and abundance of the tsetse flies Glossina brevipalpis and Glossina austeni in KwaZulu-Natal exists, data on their vector competence are lacking. This study aimed to determine the rate of natural Trypanosoma congolense infection by field-collected as well as colony-reared flies of these species. A total of 442 field-collected G. brevipalpis and 40 G. austeni flies were dissected immediately after collection to determine their infection rates, whilst 699 G. brevipalpis and 49 G. austeni flies were fed on susceptible animals in 10 and four batches, respectively, for use in xenodiagnosis experiments. Teneral colony flies were fed on infected animals and dissected 21 days post infection to confirm their infectivity testing. Glossina austeni harboured 8% immature and mature infections. In G. brevipalpis, the infection with the immature stages was lower (1%) and no mature infections were observed. Although all four batches of G. austeni transmitted T. congolense to four susceptible animals, no transmission resulted from 10 batches of G. brevipalpis fed on susceptible cattle. Colonyderived G. austeni (534) and G. brevipalpis (882) were fed on four bovines infected with different T. congolense isolates. Both G. austeni and G. brevipalpis acquired trypanosome infection from the bovines, with immature infection ranges of 20% - 33% and 1% - 4%, respectively. Parasites, however, only matured in G. austeni (average = 4%). Glossina austeni plays a larger role in the epidemiology of animal trypanosomosis in KwaZulu-Natal than G. brevipalpis and therefore more focus should be aimed at the former when control measures are implemented.
Mostrar más [+] Menos [-]Theileriosis (Cytauxzoonosis) in Roan antelope (Hippotragus equinus): Field exposure to infection and identification of potential vectors Texto completo
2012
Steyl, Johan C.A(University of Pretoria Department of Paraclinical Sciences) | Prozesky, Leon(University of Pretoria Department of Paraclinical Sciences) | Stoltsz, Wilhelm H(University of Pretoria Department of Veterinary Tropical Diseases) | Lawrence, John A(University of Pretoria Department of Paraclinical Sciences)
Four hand-reared, naïve roan antelope, 4 months of age, were exposed to naturally infected pasture on a game farm in Mpumalanga Province, South Africa, where roan are known to die from theileriosis. Various clinical parameters were recorded during this period. The predominant ticks parasitising these animals at the time (January to February), were Rhipicephalus appendiculatus and Rhipicephalus evertsi evertsi adults. After a period of 5 weeks the animals developed signs of clinical theileriosis and were treated with buparvaquone to prevent mortality. Primary hyperplasia of the local draining lymph nodes (Lnn. anorectales) near the feeding site of adult R. evertsi evertsi indicated possible transmission of Theileria sp. (sable) by this tick species. After recovery from theileriosis, these animals were confirmed carriers of Theileria sp. (sable) by PCR (polymerase chain reaction) and DNA probe analysis. Laboratory-bred larvae and nymphs of R. evertsi evertsi and R. appendiculatus respectively, were fed on the ears of these roan antelope. Salivary glands from moulted and prefed adult ticks of each species were dissected and stained for Theileria spp., and the PCR and DNA probe applied to a representative batch of dissected glands. R. appendiculatus adults collected from grass in infected camps were also dissected after prefeeding them on rabbits. Salivary glands of both tick species showed infected acini on staining and were also positive for Theileria sp. (sable) only, on multiprotozoal PCR-screening analysis. There was no statistical significant difference between the infection rate and the intensity of infection between the two tick species. R. appendiculatus ticks collected from grass were also PCR-positive for Theileria sp. (sable)
Mostrar más [+] Menos [-]A survey of antimicrobial residues in table eggs in Khartoum State, Sudan, 2007–2008 Texto completo
2012
Mohamed M. Sirdar | Jackie Picard | Shahn Bisschop | Alexander R. Jambalang | Bruce Gummow
A survey of antimicrobial residues in table eggs in Khartoum State, Sudan, 2007–2008 Texto completo
2012
Mohamed M. Sirdar | Jackie Picard | Shahn Bisschop | Alexander R. Jambalang | Bruce Gummow
The risk to consumers of antimicrobial residues in table eggs produced in Khartoum State, Sudan, was studied. All producing layer farms (n = 175) in the state were sampled in April, June and August 2008. A total of 933 eggs from 335 layer houses were screened for antimicrobial residues by using the growth inhibition of Geobacillus stearothermophilus var. calidolactis in-house test. A high proportion of layer farms (72% in April, 61% in June and 66% in August) and layer houses (63% April, 59% in June and 61% in August) were found to have antimicrobial residues, with no significant difference in prevalence (p = 0.57) between study periods. The study showed that the consumer was at constant risk of exposure to antimicrobial residues in table eggs. The paper discusses reasons for the high prevalence of antimicrobial residues in Sudanese eggs and its implications, and makes recommendations to address this important public health problem.
Mostrar más [+] Menos [-]A socio-economic approach to One Health policy research in southern Africa Texto completo
2012
Kim A. Kayunze | Angwara D. Kiwara | Eligius Lyamuya | Dominic M. Kambarage | Jonathan Rushton | Richard Coker | Richard Kock | Mark M. Rweyemamu
A socio-economic approach to One Health policy research in southern Africa Texto completo
2012
Kim A. Kayunze | Angwara D. Kiwara | Eligius Lyamuya | Dominic M. Kambarage | Jonathan Rushton | Richard Coker | Richard Kock | Mark M. Rweyemamu
One-health approaches have started being applied to health systems in some countries in controlling infectious diseases in order to reduce the burden of disease in humans, livestock and wild animals collaboratively. However, one wonders whether the problem of lingering and emerging zoonoses is more affected by health policies, low application of one-health approaches, or other factors. As part of efforts to answer this question, the Southern African Centre for Infectious Disease Surveillance (SACIDS) smart partnership of human health, animal health and socio-economic experts published, in April 2011, a conceptual framework to support One Health research for policy on emerging zoonoses. The main objective of this paper was to identify which factors really affect the burden of disease and how the burden could affect socio-economic well-being. Amongst other issues, the review of literature shows that the occurrence of infectious diseases in humans and animals is driven by many factors, the most important ones being the causative agents (viruses, bacteria, parasites, etc.) and the mediator conditions (social, cultural, economic or climatic) which facilitate the infection to occur and hold. Literature also shows that in many countries there is little collaboration between medical and veterinary services despite the shared underlying science and the increasing infectious disease threat. In view of these findings, a research to inform health policy must walk on two legs: a natural sciences leg and a social sciences one.
Mostrar más [+] Menos [-]A socio-economic approach to One Health policy research in southern Africa Texto completo
2012
Kayunze, Kim A.(Sokoine University of Agriculture Development Studies Institute) | Kiwara, Angwara D.(Muhimbili University of Health and Allied Sciences Institute of Development Studies) | Lyamuya, Eligius(Muhimbili University of Health and Allied Sciences) | Kambarage, Dominic M.(Sokoine University of Agriculture) | Rushton, Jonathan(Royal Veterinary College) | Coker, Richard(Mahidol University) | Kock, Richard(Royal Veterinary College) | Rweyemamu, Mark M.(Sokoine University of Agriculture)
One-health approaches have started being applied to health systems in some countries in controlling infectious diseases in order to reduce the burden of disease in humans, livestock and wild animals collaboratively. However, one wonders whether the problem of lingering and emerging zoonoses is more affected by health policies, low application of one-health approaches, or other factors. As part of efforts to answer this question, the Southern African Centre for Infectious Disease Surveillance (SACIDS) smart partnership of human health, animal health and socio-economic experts published, in April 2011, a conceptual framework to support One Health research for policy on emerging zoonoses. The main objective of this paper was to identify which factors really affect the burden of disease and how the burden could affect socio-economic well-being. Amongst other issues, the review of literature shows that the occurrence of infectious diseases in humans and animals is driven by many factors, the most important ones being the causative agents (viruses, bacteria, parasites, etc.) and the mediator conditions (social, cultural, economic or climatic) which facilitate the infection to occur and hold. Literature also shows that in many countries there is little collaboration between medical and veterinary services despite the shared underlying science and the increasing infectious disease threat. In view of these findings, a research to inform health policy must walk on two legs: a natural sciences leg and a social sciences one.
Mostrar más [+] Menos [-]Comparing effects of freezing at -196 °C and -20 °C on the viability of mastitis pathogens Texto completo
2012
Inge-Marie Petzer | Joanne Karzis | Theodorus J. van der Schans | Johanna C. Watermeyer | Norman Mitchell-Innes | Stephanie Eloff | Geoffrey T. Fosgate
Comparing effects of freezing at -196 °C and -20 °C on the viability of mastitis pathogens Texto completo
2012
Inge-Marie Petzer | Joanne Karzis | Theodorus J. van der Schans | Johanna C. Watermeyer | Norman Mitchell-Innes | Stephanie Eloff | Geoffrey T. Fosgate
The aim of this study was to compare the effects of cryopreservation at approximately -196 °C in liquid nitrogen (N) and freezing at approximately -20 °C in a freezer, on the viability and survival of eight different mastitogenic bacteria inoculated in milk. Bacteria were frozen at approximately -20 °C in a freezer and cryopreserved at approximately -196 °C in liquid nitrogen. An effective preservation method was needed for follow-up samples from cows identified in the South African National Milk Recording Scheme (NMRS) with somatic cell counts above 250 000 cells/mL milk. The organisation responsible for sample collection of the NMRS milk samples also provides producers with liquid nitrogen for their semen flasks at the collection sites. This existing mode of storage and transport could therefore be utilised. Ten samples of each organism were thawed and cultured bi-weekly until week 18 for both temperature treatments. An additional sampling was performed at week 30 for samples frozen at approximately -20 °C. Freezing and cryopreservation did not impair subsequent isolation of Streptococcus dysgalactiae, Streptococcus uberis, Enterococcus faecalis, Staphylococcus aureus (STH) (phage type lytic group III) or Sta. aureus (STA) (phage typed, other than lytic group III). Survival was indicated by the isolation of bacteria from samples, and viability by the strength of growth of the bacteria isolated. The survival of Streptococcus agalactiae decreased after week 12 and Escherichia coli after week 16 of freezing, but both organisms survived under cryogenic preservation until week 18. Coagulase-negative staphylococci survived until week 18 for both freezing and cryogenic preservation. Both storage methods could thus contribute to the improvement of a pro-active approach towards udder health management in South African dairy herds.
Mostrar más [+] Menos [-]The African buffalo: A villain for inter-species spread of infectious diseases in southern Africa Texto completo
2012
Anita L. Michel | Roy G. Bengis
The African buffalo: A villain for inter-species spread of infectious diseases in southern Africa Texto completo
2012
Anita L. Michel | Roy G. Bengis
The African buffalo (Syncerus caffer) is a large wild bovid which until recently ranged across all but the driest parts of sub-Saharan Africa, and their local range being limited to about 20 km from surface water. They are of high ecological value due to their important role as bulk feeders in the grazing hierarchy. They also have high economic value, because they are one of the sought after ‘Big Five’ in the eco-tourism industry. In Africa, buffaloes have been recognised for some time as an important role player in the maintenance and transmission of a variety of economically important livestock diseases at the wildlife and/or livestock interface. These include African strains of foot-and-mouth disease (FMD), Corridor disease (theileriosis), bovine tuberculosis and bovine brucellosis. For a number of other diseases of veterinary importance, African buffaloes may also serve as amplifier or incidental host, whereby infection with the causative pathogens may cause severe clinical signs such as death or abortion as in the case of anthrax and Rift Valley fever, or remain mild or subclinical for example heartwater. The long term health implications of most of those infections on the buffalo at a population level is usually limited, and they do not pose a threat on the population’s survival. Because of their ability to harbour and transmit important diseases to livestock, their sustainable future in ecotourism, trade and transfrontier conservation projects become complex and costly and reliable diagnostic tools are required to monitor these infections in buffalo populations.
Mostrar más [+] Menos [-]The African buffalo: A villain for inter-species spread of infectious diseases in southern Africa Texto completo
2012
Michel, Anita L.(University of Pretoria Department of Veterinary Tropical Diseases) | Bengis, Roy G(Directorate Veterinary Services)
The African buffalo (Syncerus caffer) is a large wild bovid which until recently ranged across all but the driest parts of sub-Saharan Africa, and their local range being limited to about 20 km from surface water. They are of high ecological value due to their important role as bulk feeders in the grazing hierarchy. They also have high economic value, because they are one of the sought after 'Big Five' in the eco-tourism industry. In Africa, buffaloes have been recognised for some time as an important role player in the maintenance and transmission of a variety of economically important livestock diseases at the wildlife and/or livestock interface. These include African strains of foot-and-mouth disease (FMD), Corridor disease (theileriosis), bovine tuberculosis and bovine brucellosis. For a number of other diseases of veterinary importance, African buffaloes may also serve as amplifier or incidental host, whereby infection with the causative pathogens may cause severe clinical signs such as death or abortion as in the case of anthrax and Rift Valley fever, or remain mild or subclinical for example heartwater. The long term health implications of most of those infections on the buffalo at a population level is usually limited, and they do not pose a threat on the population's survival. Because of their ability to harbour and transmit important diseases to livestock, their sustainable future in ecotourism, trade and transfrontier conservation projects become complex and costly and reliable diagnostic tools are required to monitor these infections in buffalo populations.
Mostrar más [+] Menos [-]A questionnaire survey of poultry layer farmers in Khartoum State, Sudan, to study their antimicrobial awareness and usage patterns Texto completo
2012
Mohamed M. Sirdar | Jackie Picard | Shahn Bisschop | Bruce Gummow
A questionnaire survey of poultry layer farmers in Khartoum State, Sudan, to study their antimicrobial awareness and usage patterns Texto completo
2012
Mohamed M. Sirdar | Jackie Picard | Shahn Bisschop | Bruce Gummow
An initial census of layer farms in Khartoum State, Sudan, was carried out in late 2007 and early 2008 and found that there were 252 layer farms with a total population of 2 221 800 birds. This paper reports the findings of the census. Based on this information, a structured questionnaire survey of 92 farms was then conducted in the state in April 2008 to collect data on antibiotic usage, demographic data and public health awareness. Ninety-eight per cent of participating farms comprised open-sided houses. It was found that 49% of the farms surveyed were on antibiotic treatment when the survey was conducted, whilst 59% of the farms had used antibiotics within the last 3 months. The study found that farmers and producers had a lack of knowledge about antimicrobial residues, their withdrawal periods and the risk posed by the consumption of these residues. The study also concluded that traditional farming systems in Sudan relied heavily on antimicrobial medication to control disease and almost half of the farms surveyed were treating their flocks with antimicrobials. In addition to this, there was a lack of disease control programmes which probably resulted in a massive use of antibiotics to control endemic diseases. This was further compounded by the absence of governmental supervision and control on the use of drugs.
Mostrar más [+] Menos [-]Evaluation of factors associated with the risk of infection with Cryptosporidium parvum in dairy calves Texto completo
2012
Szonyi, Barbara | Chang, Yung-Fu | Wade, Susan E. | Mohammed, Hussni O.
Objective-To identify risk factors associated with Cryptosporidium parvum infection in dairy calves. Animals-108 case animals and 283 control animals. Procedures-Case animals were calves infected with C parvum, and controls were infected with Cryptosporidium bovis (n = 67) or calves not infected with Cryptosporidium spp. Fecal samples were tested via the flotation concentration method for Cryptosporidium spp. Samples were genotyped by sequencing of the 18s rRNA gene. Associations between host, management, geographic, and meteorologic factors and Cryptosporidium genotype were assessed. Results-Younger calves and calves housed in a cow barn were more likely to be infected with both genotypes. Herd size and hay bedding were associated with an increased risk of infection with C parvum, and Jersey breed was a risk factor for C bovis infection. Compared with a flat surface, a steeper slope was significantly associated with a decreased likelihood of infection with both genotypes, and precipitation influenced the risk of C parvum infection only. Conclusions and Clinical Relevance-Risk factors for calf infection with C parvum differed from those for infection with C bovis. Results may be useful to help design measures that reduce animal exposure and decrease public health risk and economic losses associated with C parvum infection in cattle.
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