43 research outputs found

    Detection of Babesia species in domestic and wild Southern African felids by means of DNA probes

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    Feline babesiosis, first described in domestic cats in South Africa in 1937, is regarded to be of great importance in the coastal regions although isolated cases also occur on the eastern highlands of Mpumalanga Province. Babesia felis (described from domestic cats) and B. leo (described from lions) are the two best characterised Babesia species in felids. These two parasites are morphologically similar when examined under a light microscope, but are serologically and genetically distinct. In this study the prevalence of these two Babesia species in various wild and domestic felid species was determined. A total of 358 samples were tested using the reverse line blot hybridization (RLB) assay. This assay makes it possible to simultaneously detect and differentiate between blood parasites using DNA probes. The RLB consists of three basic steps, the first being amplification of the variable region (V4) in the 18S rRNA gene using genus-specific primers where one is labelled with biotin. This is followed by a blotting step, where the amplicons are hybridized to oligonucleotides bound to a nitrocellulose membrane. The third and last step is the detection of the hybridized amplicons by using chemiluminescence reagents. This assay is a screening tool utilizing the variable (V4) region in the 18S rRNA gene to detect and differentiate between blood parasites. A new B. felis-specific DNA probe was developed to use in the RLB assay. Results demonstrated that these two parasites not only occur in the felid species from which they have been described, but also in other felid species. Babesia microti was also detected in various felid species, while B. rossi was detected in 1 of the lion samples. Two hundred and twelve samples tested positive for Babesia spp., of which only 54.24% of the samples reacted with the genus-specific probe. This indicates the presence of a novel Babesia or Theileria species or variant of a species.Dissertation (MSc)--University of Pretoria, 2010.Veterinary Tropical Diseasesunrestricte

    Occurrence of Babesia felis and Babesia leo in various wild felid species and domestic cats in Southern Africa, based on reverse line blot analysis

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    Reverse line blot (RLB) is a hybridization assay that can be used to detect various blood parasites and differentiate between them. Results, using the RLB, showed that Babesia felis and Babesia leo occurred as single or mixed infections in various felid species, but most frequently in domestic cats and lions, respectively. Prevalence of infection in free-ranging cheetahs in Namibia was low (7, 5%), whereas 50% of free-ranging lions in South Africa and Swaziland were infected. A large number (52, 9%) of samples tested positive only for Babesia, neither B. felis nor B. leo. This could be an indication of at least one further, as yet undescribed, Babesia species in felids.Mrs. Gerty Pretorius (Clinical Pathology Section, Department of Companion Animal Clinical Studies), and Prof. Moritz van Vuuren (Department of Veterinary Tropical Diseases) submitted blood specimens. This report emanates from project 36-5-613 which was approved by the Research Committee of the Faculty of Veterinary Science and the Animal Use and Care Committee of the University of Pretoria

    Transmembrane proteins - mining the cattle tick transcriptome

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    Managing the spread and load of pathogen-transmitting ticks is an important task worldwide. The cattletick, Rhipicephalus microplus, not only impacts the economy through losses in dairy and meat pro-duction, but also raises concerns for human health in regards to the potential of certain transmittedpathogens becoming zoonotic. However, novel strategies to control R. microplus are hindered by lack ofunderstanding tick biology and the discovery of suitable vaccine or acaricide targets. The importance oftransmembrane proteins as vaccine targets are well known, as is the case in tick vaccines with Bm86 asantigen. In this study, we describe the localization and functional annotation of 878 putative transmem-brane proteins. Thirty proteins could be confirmed in the R. microplus gut using LC-MS/MS analysis andtheir roles in tick biology are discussed. To the best of our knowledge, 19 targets have not been reportedbefore in any proteomics study in various tick species and the possibility of using the identified proteins astargets for tick control are discussed. Although tissue expression of identified putative proteins throughexpansive proteomics is necessary, this study demonstrates the possibility of using bioinformatics forthe identification of targets for further evaluation in tick control strategies.Red Meat Research Development Trust, the University of Pretoria Research Development Programme and the Technology and Human Resources for Industry Programme.http://www.elsevier.com/locate/ttbdis2016-09-30hb201

    Bacteria profile and antibiogram of the bacteria isolated from the exposed pulp of dog canine teeth

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    Twenty-seven microbiological samples were taken from root canals (RC) of the canine teeth of 20 dogs where the pulps were non-vital and exposed due to complicated crown fractures. These pulps were cultured for aerobic/anaerobic bacteria. Antimicrobial susceptibility of isolates was determined using the Kirby-Bauer diffusion test. A total of 49 cultivable isolates, belonging to 27 different microbial species and 18 different genera, were recovered from the 27 RCs sampled. Twenty (40.81 per cent) of the cultivable isolates were Gram positive while 29 (59.19 per cent) were Gram negative. Facultative anaerobes were the most common bacteria (77.56 per cent). Aerobic isolates represented 18.36 per cent, and strict anaerobes 4.08 per cent. The antimicrobials with the highest in vitro efficacy were gentamicin (100 per cent) and enrofloxacin (93.32 per cent).http://veterinaryrecord.bmj.comhj2018Companion Animal Clinical StudiesVeterinary Tropical Disease

    Molecular characterisation of Mycoplasma species isolated from the genital tract of Dorper sheep in South Africa

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    Biochemical and molecular analysis were conducted on 34 strains of Mycoplasma species isolated between 2003 and 2009 from the genital tract of clinically healthy Dorper sheep and sheep with ulcerative vulvitis and balanitis. Earlier publications identified the causative agent as Mycoplasma mycoides mycoides large colony (MmmLC) and Arcanobacterium pyogenes. The aims of the study were to characterise Mycoplasma species isolated from the genital tract of Dorper sheep with polymerase chain reaction assay, cloning and gene sequencing. Basic Local Alignment Search Tool (BLAST) results revealed six predominant Mycoplasma species: Mycoplasma arginini, Mycoplasma bovigenitalium, Arcanobacterium laidlawii, MmmLC, Mycoplasma sp. ovine/caprine serogroup II and M. canadense. Sequencing of the 34 isolates were analysed using phylogenetic methods, and 18 (50%) were identified as M. arginini with 99% – 100% similarity to M. arginini from England and Sweden. Six isolates showed 99% similarity to M. bovigenitalium strains from Turkey and Germany. Two isolates had 99% similarity to an M. sp. ovine/caprine sero group II from the United Kingdom. BLAST for two isolates revealed 99% similarity to Acholeplasma laidlawii from India, another two were 99% similar to MmmLC strain from Sweden, two showed 98% similarity to Mycoplasma sp. Usp 120 from Brazil, and two isolates have a 97% – 99% similarity to M. mm. Jcv1 strain from the United States of America. Finally, one isolate showed similarity of 99% to Mycoplasma canadense strain from Italy. The findings support the hypothesis that ulcerative vulvitis and balanitis of Dorper sheep in South Africa (SA) is a multifactorial disease with involvement of different Mycoplasma species.http://www.jsava.co.zaam201

    Tick-borne blood parasites in nyala (Tragelaphus angasii, Gray 1849) from KwaZulu-Natal, South Africa

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    A total of 97 blood samples of nyala (Tragelaphus angasii, Gray 1849) from South Africa were tested for the presence of tick-borne haemoparasites by means of polymerase chain reaction (PCR) and reverse line blot (RLB) hybridisation. The majority of blood samples contained several different haemoparasites, often in combination. Prevalent haemoparasites were Theileria sp. (kudu), T. buffeli, T. sp. (sable), T. bicornis, Ehrlichia sp. Omatjenne, Anaplasma marginale and A. bovis. This serves as the first report of T. sp. (kudu), T. buffeli, T. bicornis, Ehrlichia sp.Omatjenne, A. marginale and A. bovis in nyala, who seem to carry multiple haemoparasites without ill effect.This study (V009/08) was approved by the Research Committee of the Faculty of Veterinary Science and the Animal Use and Care Committee of the University of Pretoria. The senior author received a postgraduate bursary from the University of Pretoria. Financial support from the National Research Foundation Grant (GUN 44403) to B.L. Penzhorn is acknowledged.http://www.elsevier.com/locate/vetpa

    The classification of seven serotypes of equine encephalosis virus and the prevalence of homologous antibody in horses in South Africa

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    Selected isolates of equine encephalosis virus were shown to have comparable viral protein profiles and to represent seven distinct serotypes, based on cross-neutralization tests. Serotype-specific virus-neutralizing antibody in serum samples from horses confirmed the widespread occurrence of infection. The distribution and prevalence of individual serotypes however, varied considerably. Localised foci with an increased seasonal seroconversion in groups of horses to a specific serotype and the detection of an ongoing low level of infection from other serotypes within the population, confirmed the independent persistence of the viruses in a maintenance cycle. The identification of donors with antibody resulting from infection with multiple serotypes indicated a low level of cross protection in horses to natural reinfection.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat v.9 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.Equine Research Centre, Faculty of Veterinary Science, University of Pretoria.mn201

    Sensitivity and specificity of a nested polymerase chain reaction for detection of lentivirus infection in lions (Panthera leo)

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    Feline immunodeficiency virus (FIV) is a lentivirus in the Retroviridae family that causes lifelong infection in domestic cats. The lentivirus of African lions (Panthera leo), referred to as FIVple, is endemic in certain lion populations in eastern and southern Africa. Lentivirus infection leads to immunologic dysfunction and immunosuppressive disease in domestic cats; however, little is known about the pathogenic effects of infection in lions, nor about the epidemiologic impact on free-ranging and captive populations. Whole blood and serum samples were collected opportunistically from free-ranging lions in Kruger National Park, Republic of South Africa (RSA). Whole blood and serum samples were also collected from captive wild lions in the RSA. A nested polymerase chain reaction (PCR) assay for detection of FIV was performed on all whole blood samples. In addition, serum samples were tested for cross-reactive antibodies to domestic feline lentivirus antigens and puma lentivirus synthetic envelope peptide antigen. The PCR assay successfully amplified the lion lentivirus from African lions. The relative sensitivity and relative specificity were 79% and 100%, respectively, and the positive and negative predictive values were 100% and 67%, respectively. This research represents the first study to compare genetic material with antibody-based methods of lentivirus detection on lions in RSA. Using PCR as an additional diagnostic test for FIV in lions will increase screening sensitivity and will allow viral characterization among circulating isolates and monitoring of changes in the viral epidemiology within geographic regions and populations over time

    Effects of probiotic (Saccharomyces cerevisiae) and ascorbic acid on oxidative gene damage biomarker, heat shock protein 70 and interleukin 10 in broiler chickens exposed to heat stress

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    Heat stress is a prominent factor responsible for losses economically in poultry meat industry due to adverse effects on the general performance of broiler chickens. In this study, we evaluated the effects of probiotic (Saccharomyces cerevisiae) and ascorbic acid on oxidative gene damage biomarker, heat shock protein 70 (HSP70) and interleukin 10 (IL-10) in broiler chickens exposed to heat stress under natural conditions. Fifty-six broiler chickens served as the subjects, they were divided into 4 groups of 14 as follows: group I (control), group II (probiotic S. cerevisiae at 1 g/kg of feed), group III (ascorbic acid at 200 mg/kg of feed) and group IV (probiotic + ascorbic acid at 1 g/kg and 200 mg/kg of feed, respectively). The treatments were administered via feed for 35 days (D1 to D35). Enzyme-linked immunosorbent assay (ELISA) and one step real time reverse transcription polymerase chain reaction (RT-PCR) was utilised to study the effects of heat stress on the expression levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG), HSP70 and IL-10 respectively, in broiler chickens raised during the hot summer season. The level of 8-OHdG gene was significantly lower in the probiotic administered group. The expression level of HSP70 was lowest in the ascorbic acid group while, IL-10 level of expression was highest in the probiotic + ascorbic acid group. The administered antioxidants were efficient in exhibiting anti-stress effects at the level of gene expression. We conclude that probiotic, ascorbic acid and probiotic + ascorbic acid reduced oxidative gene damage, affected the expression of HSP70 and increased the level of IL-10 gene respectively, in broiler chickens exposed to heat stressThe University of Pretoria Doctoral Research Bursary, Department of Anatomy and Physiology and Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, South Africa.https://www.sciencedirect.com/journal/animal-geneAnatomy and PhysiologyParaclinical SciencesVeterinary Tropical Disease

    Detection and characterisation of papillomavirus in skin lesions of giraffe and sable antelope in South Africa

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    Papillomavirus was detected electron microscopically in cutaneous fibropapillomas of a giraffe (Giraffa camelopardalis) and a sable antelope (Hippotragus niger). The virus particles measured 45 nm in diameter. Histopathologically, the lesions showed histopathological features similar to those of equine sarcoid as well as positive immunoperoxidase-staining of tissue sections for papillomavirus antigen. Polymerase chain reaction (PCR) detected bovine papillomavirus (BPV) DNA. Bovine papillomavirus-1 was characterised by real-time PCR in the sable and giraffe, and cloning and sequencing of the PCR product revealed a similarity to BPV-1. As in the 1st giraffe, the lesions from a 2nd giraffe revealed locally malignant pleomorphism, possibly indicating the lesional end-point of papilloma infection. Neither virus particles nor positively staining papillomavirus antigen could be demonstrated in the 2nd giraffe but papillomavirus DNA was detected by real-time PCR which corresponded with BPV-1 and BPV-2.Grants from the South African Veterinary Foundation, the Research and Development Fund of the University of Pretoria, and the Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria.http://www.journals.co.za/ej/ejour_savet.htm
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