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A pathogen-specific approach towards udder health management in dairy herds: Using culture and somatic cell counts from routine herd investigations Полный текст
2016
Petzer, Inge-Marié(University of Pretoria Department of Production Animal Studies) | Karzis, Joanne(University of Pretoria Department of Production Animal Studies) | Donkin, Edward F.(University of Pretoria Department of Animal and Wildlife Sciences) | Webb, Edward C.(University of Pretoria Department of Animal and Wildlife Sciences)
A pathogen-specific approach towards udder health management in dairy herds: Using culture and somatic cell counts from routine herd investigations Полный текст
2016
Petzer, Inge-Marié(University of Pretoria Department of Production Animal Studies) | Karzis, Joanne(University of Pretoria Department of Production Animal Studies) | Donkin, Edward F.(University of Pretoria Department of Animal and Wildlife Sciences) | Webb, Edward C.(University of Pretoria Department of Animal and Wildlife Sciences)
A dedicated udder health diagnostic programme was developed and used over a 15-year period in South Africa to analyse milk samples based on microbiological and cytological patterns within various groups and for individual cows and udder quarters in dairy herds. These pathogen-specific analyses are utilised for pro-active improvement and management of udder health in South African commercial dairy herds. The programme acts as a monitoring tool and identifies management areas at risk and individual cows with udder disease and uses both quarter and composite milk samples. Intra-mammary infection (IMI) is a dynamic situation and depending on the time a milk sample is taken, false-negative results may be obtained. A new IMI and an infection that is curing may both have low somatic cell counts (SCCs), masking the true bacterial status. SCC in individual infected udder quarters may differ greatly depending on the causative bacterial species, its pathogenicity, the host immune status and the environmental factors involved. A pathogen-specific udder health approach was followed with repeated herd tests to take account of these udder health dynamics. The results of the herd IMI investigation are applied in practice to assist veterinarians, udder health consultants and managers to make informed and specific detailed decisions at both a herd and on an individual cow basis regarding udder health.
Показать больше [+] Меньше [-]A pathogen-specific approach towards udder health management in dairy herds: Using culture and somatic cell counts from routine herd investigations Полный текст
2016
Inge-Marié Petzer | Joanne Karzis | Edward F. Donkin | Edward C. Webb
A dedicated udder health diagnostic programme was developed and used over a 15-year period in South Africa to analyse milk samples based on microbiological and cytological patterns within various groups and for individual cows and udder quarters in dairy herds. These pathogen-specific analyses are utilised for pro-active improvement and management of udder health in South African commercial dairy herds. The programme acts as a monitoring tool and identifies management areas at risk and individual cows with udder disease and uses both quarter and composite milk samples. Intra-mammary infection (IMI) is a dynamic situation and depending on the time a milk sample is taken, false-negative results may be obtained. A new IMI and an infection that is curing may both have low somatic cell counts (SCCs), masking the true bacterial status. SCC in individual infected udder quarters may differ greatly depending on the causative bacterial species, its pathogenicity, the host immune status and the environmental factors involved. A pathogen-specific udder health approach was followed with repeated herd tests to take account of these udder health dynamics. The results of the herd IMI investigation are applied in practice to assist veterinarians, udder health consultants and managers to make informed and specific detailed decisions at both a herd and on an individual cow basis regarding udder health.
Показать больше [+] Меньше [-]Is a 10-sow unit economically sustainable? A profitability assessment of productivity amongst small-holder pig farmers, Mpumalanga, South Africa Полный текст
2016
Priscilla Munzhelele | James W. Oguttu | Folorunso O. Fasina
Is a 10-sow unit economically sustainable? A profitability assessment of productivity amongst small-holder pig farmers, Mpumalanga, South Africa Полный текст
2016
Priscilla Munzhelele | James W. Oguttu | Folorunso O. Fasina
The majority of small-holder pig farmers in Mpumalanga had between 1- and 10-sow herds. The main aim of this study is to evaluate the current government agricultural intervention (supply of 10 sows and a boar) in terms of technical and economic feasibilities and ascertain whether the small-scale pig value chain system alleviates poverty. Data were obtained from 220 randomly selected small-holder pig farmers using a semi-structured questionnaire. The results showed that 58% farrowed ≤ 10 piglets/born/sow/litter, 44.2% practiced no weaning method and many fed swill and leftovers alone (41.6%). Pair-wise association revealed that the feeding of commercial feeds had a relationship with pigs in relatively good to very good body condition. Pigs in poor body condition were positively correlated with the feeding of swill alone. The economic models for the 10-sow unit proved that pig farming is unprofitable if the current management and feeding systems that operate in the commercial industry are utilised. However, only through a combination of cooperative systems, benefits of economies of scale, reduction of preweaning mortalities and structured government inputs can pig production be profitable at this scale of production. Keywords: piglets; market; profit; economics; feeds
Показать больше [+] Меньше [-]Is a 10-sow unit economically sustainable? A profitability assessment of productivity amongst small-holder pig farmers, Mpumalanga, South Africa Полный текст
2016
Munzhelele, Priscilla(Nooitgedacht Research Station Department of Agriculture, Rural Development, Land and Environmental Affairs ,University of South Africa Department of Agriculture and Animal Health) | Oguttu, James W.(University of South Africa Department of Agriculture and Animal Health) | Fasina, Folorunso O.(University of Pretoria Department of production Animal Studies)
The majority of small-holder pig farmers in Mpumalanga had between 1- and 10-sow herds. The main aim of this study is to evaluate the current government agricultural intervention (supply of 10 sows and a boar) in terms of technical and economic feasibilities and ascertain whether the small-scale pig value chain system alleviates poverty. Data were obtained from 220 randomly selected small-holder pig farmers using a semi-structured questionnaire. The results showed that 58% farrowed < 10 piglets/born/sow/litter, 44.2% practiced no weaning method and many fed swill and leftovers alone (41.6%). Pair-wise association revealed that the feeding of commercial feeds had a relationship with pigs in relatively good to very good body condition. Pigs in poor body condition were positively correlated with the feeding of swill alone. The economic models for the 10-sow unit proved that pig farming is unprofitable if the current management and feeding systems that operate in the commercial industry are utilised. However, only through a combination of cooperative systems, benefits of economies of scale, reduction of preweaning mortalities and structured government inputs can pig production be profitable at this scale of production.
Показать больше [+] Меньше [-]Identification of <i>Echinococcus granulosus</i> strains using polymerase chain reaction–restriction fragment length polymorphism amongst livestock in Moroto district, Uganda Полный текст
2016
Martin Chamai | Leonard Omadang | Joseph Erume | Michael Ocaido | Peter Oba | Emmanuel Othieno | Straton Bonaventure | Annah Kitibwa
A descriptive study was conducted to identify the different strains of Echinococcus granulosus occurring in livestock in Moroto district, Uganda. Echinococcus cysts from 104 domestic animals, including cattle, sheep, goats and camels, were taken and examined by microscopy, polymerase chain reaction with restriction fragment length polymorphism and Sanger DNA sequencing. Echinococcus granulosus genotypes or strains were identified through use of Bioinformatics tools: BioEdit, BLAST and MEGA6. The major finding of this study was the existence of a limited number of E. granulosus genotypes from cattle, goats, sheep and camels. The most predominant genotype was G1 (96.05%), corresponding to the common sheep strain. To a limited extent (3.95%), the study revealed the existence of Echinococcus canadensis G6/7 in three (n = 3) of the E. granulosus–positive samples. No other strains of E. granulosus were identified. It was concluded that the common sheep strain of Echinococcus sensu stricto and G6/7 of E. canadensis were responsible for echinococcal disease in Moroto district, Uganda.
Показать больше [+] Меньше [-]Prevalence of virulence and antimicrobial resistance genes in <i>Salmonella</i> spp. isolated from commercial chickens and human clinical isolates from South Africa and Brazil Полный текст
2016
Oliver T. Zishiri | Nelisiwe Mkhize | Samson Mukaratirwa
Salmonellosis is a significant public health concern around the world. The injudicious use of antimicrobial agents in poultry production for treatment, growth promotion and prophylaxis has resulted in the emergence of drug resistant strains of Salmonella. The current study was conducted to investigate the prevalence of virulence and antimicrobial resistance genes from Salmonella isolated from South African and Brazilian broiler chickens as well as human clinical isolates. Out of a total of 200 chicken samples that were collected from South Africa 102 (51%) tested positive for Salmonella using the InvA gene. Of the overall 146 Salmonella positive samples that were screened for the iroB gene most of them were confirmed to be Salmonella enterica with the following prevalence rates: 85% of human clinical samples, 68.6% of South African chicken isolates and 70.8% of Brazilian chicken samples. All Salmonella isolates obtained were subjected to antimicrobial susceptibility testing with 10 antibiotics. Salmonella isolates from South African chickens exhibited resistance to almost all antimicrobial agents used, such as tetracycline (93%), trimethoprim-sulfamthoxazole (84%), trimethoprim (78.4%), kanamycin (74%), gentamicin (48%), ampicillin (47%), amoxicillin (31%), chloramphenicol (31%), erythromycin (18%) and streptomycin (12%). All samples were further subjected to PCR in order to screen some common antimicrobial and virulence genes of interest namely spiC, pipD, misL, orfL, pse-1, tet A, tet B, ant (3")-la, sul 1 and sul. All Salmonella positive isolates exhibited resistance to at least one antimicrobial agent; however, antimicrobial resistance patterns demonstrated that multiple drug resistance was prevalent. The findings provide evidence that broiler chickens are colonised by pathogenic Salmonella harbouring antimicrobial resistance genes. Therefore, it is evident that there is a need for prudent use of antimicrobial agents in poultry production systems in order to mitigate the proliferation of multiple drug resistance across species. Keywords: Salmonella; antimicrobial resistance; chicken; human; susceptibility; virulence gene
Показать больше [+] Меньше [-]Prevalence of <i>Theileria</i> and <i>Babesia</i> species in Tunisian sheep Полный текст
2016
Mohamed R. Rjeibi | Mohamed A. Darghouth | Mohamed Gharbi
In this study, the prevalence of Theileria and Babesia species in sheep was assessed with Giemsastained blood smear examination and polymerase chain reaction to identify the different piroplasms in 270 sheep from three Tunisian bioclimatic zones (north, centre, and south). The overall infection prevalence by Babesia spp. and Theileria spp. in Giemsa-stained blood smears was 2.9% (8/270) and 4.8% (13/270) respectively. The molecular results showed that sheep were more often infected by Theileria ovis than Babesia ovis with an overall prevalence of 16.3% (44/270) and 7.8% (21/270) respectively (p = 0.01). The molecular prevalence by Babesia ovis was significantly higher in females than in males (p < 0.05). According to localities B. ovis was found exclusively in sheep from the centre of Tunisia (Kairouan) whereas Theileria ovis was found in all regions. Infections with T. ovis and B. ovis were confirmed by sequencing. The sequence of T. ovis in this study (accession numbers KM924442) falls into the same clade as T. ovis deposited in GenBank. The T. ovis amplicons (KM924442) showed 99%–100% identities with GenBank sequences. Moreover, comparison of the partial sequences of 18S rRNA gene of B. ovis described in this study (KP670199) revealed 99.4% similarity with B. ovis recently reported in northern Tunisia from sheep and goats. Three nucleotides were different at positions 73 (A/T), 417 (A/T), and 420 (G/T). It also had 99% identity with B. ovis from Spain, Turkey and Iraq. The results suggest a high T. ovis prevalence in Tunisia with a decreasing north-south gradient. This could be correlated to the vector tick distribution.
Показать больше [+] Меньше [-]Health evaluation of African penguins (<i>Spheniscus demersus</i>) in southern Africa Полный текст
2016
Nola J. Parsons | Tertius A. Gous | Adam M. Schaefer | Ralph E.T. Vanstreels
The African penguin (Spheniscus demersus) is an endangered seabird that breeds along the coast of Namibia and South Africa, and disease surveillance was identified as a priority for its conservation. Aiming for the establishment of baseline data on the presence of potential pathogens in this species, a comprehensive health assessment (blood smear examination, haematology, biochemistry and serology) was conducted on samples obtained from 578 African penguins at 11 breeding colonies and a rehabilitation centre. There were 68 penguins that were seropositive for at least one of seven pathogens tested: avian encephalomyelitis virus, avian infectious bronchitis virus, avian reovirus, infectious bursal disease virus, Newcastle disease virus, Mycoplasma gallisepticum and Mycoplasma synoviae. All samples were seronegative for avian influenza virus subtypes H5 and H7 and infectious laryngotracheitis virus. The apparent prevalence of Babesia sp. and Borrelia sp. in blood smears was consistent with previous studies. Babesia-infected individuals had a regenerative response of the erythrocytic lineage, an active inflammatory response and hepatic function impairment. These findings indicate that African penguins may be exposed to conservation-significant pathogens in the wild and encourage further studies aiming for the direct detection and/or isolation of these microorganisms.
Показать больше [+] Меньше [-]Feline panleukopaenia virus in captive non-domestic felids in South Africa Полный текст
2016
Emily P. Lane | Helene Brettschneider | Peter Caldwell | Almero Oosthuizen | Desiré L. Dalton | Liza du Plessis | Johan Steyl | Antoinette Kotze
Feline panleukopaenia virus in captive non-domestic felids in South Africa Полный текст
2016
Emily P. Lane | Helene Brettschneider | Peter Caldwell | Almero Oosthuizen | Desiré L. Dalton | Liza du Plessis | Johan Steyl | Antoinette Kotze
An outbreak of feline panleukopaenia virus (FPLV) infection was diagnosed by pathology, electron microscopy and polymerase chain reaction (PCR) in vaccinated captive-bred subadult cheetahs in South Africa. Subsequent to this disease outbreak, 12 cases of FPLV diagnosed on histology were confirmed by PCR in captive African black-footed cat, caracal, cheetah, lion, ocelot and serval. Phylogenetic analyses of the viral capsid protein gene on PCR-positive samples, vaccine and National Center for Biotechnology Information (NCBI) reference strains identified a previously unknown strain of FPLV, present since at least 2006, that differs from both the inactivated and the modified live vaccine strains. A previously described South African strain from domestic cats and cheetahs was identified in a serval. Surveys of FPLV strains in South African felids are needed to determine the geographical and host species distribution of this virus. Since non-domestic species may be reservoirs of parvoviruses, and since these viruses readily change host specificity, the risks of FPLV transmission between captive-bred and free-ranging carnivores and domestic cats and dogs warrant further research. Keywords: feline panleukopaenia; parvovirus; felid; cheetah; vaccination
Показать больше [+] Меньше [-]Feline panleukopaenia virus in captive non-domestic felids in South Africa Полный текст
2016
Lane, Emily P.(National Zoological Gardens of South Africa Department of Research and Scientific Services) | Brettschneider, Helene(National Zoological Gardens of South Africa Department of Research and Scientific Services) | Caldwell, Peter(Old Chapel Veterinary Clinic) | Oosthuizen, Almero(National Zoological Gardens of South Africa Department of Research and Scientific Services) | Dalton, Desiré L.(National Zoological Gardens of South Africa Department of Research and Scientific Services ,University of the Free State Department of Genetics) | du Plessis, Liza(IDEXX Laboratories (Pty) Ltd.) | Steyl, Johan(University of Pretoria Department of Paraclinical Science) | Kotze, Antoinette(National Zoological Gardens of South Africa Department of Research and Scientific Services ,University of the Free State Department of Genetics)
An outbreak of feline panleukopaenia virus (FPLV) infection was diagnosed by pathology, electron microscopy and polymerase chain reaction (PCR) in vaccinated captive-bred subadult cheetahs in South Africa. Subsequent to this disease outbreak, 12 cases of FPLV diagnosed on histology were confirmed by PCR in captive African black-footed cat, caracal, cheetah, lion, ocelot and serval. Phylogenetic analyses of the viral capsid protein gene on PCR-positive samples, vaccine and National Center for Biotechnology Information (NCBI) reference strains identified a previously unknown strain of FPLV, present since at least 2006, that differs from both the inactivated and the modified live vaccine strains. A previously described South African strain from domestic cats and cheetahs was identified in a serval. Surveys of FPLV strains in South African felids are needed to determine the geographical and host species distribution of this virus. Since non-domestic species may be reservoirs of parvoviruses, and since these viruses readily change host specificity, the risks of FPLV transmission between captive-bred and free-ranging carnivores and domestic cats and dogs warrant further research.
Показать больше [+] Меньше [-]Salmonella contamination, serovars and antimicrobial resistance profiles of cattle slaughtered in South Africa Полный текст
2016
Madoroba, Evelyn(Agricultural Research Council-Onderstepoort Veterinary Institute ,University of South Africa College of Agriculture and Environmental Sciences) | Kapeta, Daniel(University of South Africa College of Agriculture and Environmental Sciences) | Gelaw, Awoke K.(Agricultural Research Council-Onderstepoort Veterinary Institute)
Antimicrobial resistant Salmonella are among the leading causes of foodborne infections. Our aim was to determine Salmonella contamination during cattle slaughter in South African rural abattoirs (n = 23) and environmental samples. Furthermore, antimicrobial resistance patterns of the Salmonella isolates were determined. Samples of cattle faeces (n = 400), carcass sponges (n = 100), intestinal contents (n = 62), hides (n = 67), and water from the abattoirs (n = 75) were investigated for Salmonella species using microbiological techniques and species-specific polymerase chain reaction targeting the invA gene. In total 92 Salmonella species isolates were recovered. The Salmonella mean frequency of occurrence on hides, carcasses, and intestinal contents was 35.37% (n = 81). Eleven faecal samples (2.75%) tested positive for Salmonella. The predominant serovar was Salmonella Enteritidis. Diverse serovars that were identified on carcasses were not necessarily found on the hides and intestinal contents. The inconsistent occurrence of the diverse Salmonella serovars on hides, carcasses, and intestinal contents implies that in addition to carriage on hides and in intestinal contents, other external factors also play an important role regarding carcass contamination. The 92 Salmonella were serotyped and tested for susceptibility towards the following antimicrobials: ampicillin, cefotaxime, enrofloxacin, kanamycin, and oxytetracycline using the disk diffusion method. Most Salmonella (n = 66; 71.7%) isolates were resistant to at least one antimicrobial with highest resistance observed towards oxytetracycline (51.90%), which highlights the need for strict hygiene during slaughter and prudent antimicrobial use during animal production. In conclusion, cattle slaughtered in South African rural abattoirs harbour diverse Salmonella serovars that are resistant to antimicrobials, which could be a public health risk. The findings should assist policymakers with improving implementation of hygienic slaughter of cattle in rural abattoirs, which is paramount from socioeconomic, public health, and epidemiological standpoints.
Показать больше [+] Меньше [-]Identification of latent neosporosis in sheep in Tehran, Iran by polymerase chain reaction using primers specific for the Nc-5 gene Полный текст
2016
Arbabi, Mohsen(Kashan University of Medical Sciences Department of Parasitology) | Abdoli, Amir(Kashan University of Medical Sciences Department of Parasitology) | Dalimi, Abdolhossein(Tarbiat Modares University Department of Parasitology) | Pirestani, Majid(Tarbiat Modares University Department of Parasitology)
Little is known about latent infection and molecular characterisation of Neospora caninum in sheep (Ovis aries). In this study, 330 sheep samples (180 hearts and 150 brains) were analysed for N. caninum DNA by nested polymerase chain reaction (PCR) targeting the Nc-5 gene. Neospora caninum DNA was detected in 3.9% (13/330) of sheep samples. The parasite's DNA was detected in 6.7% of heart samples (12/180) and 0.7% (1/150) of brain samples. No clinical signs were recorded from infected or uninfected animals. Sequencing of the genomic DNA revealed 96% - 99% similarity with each other and 95.15% - 100% similarity with N. caninum sequences deposited in GenBank. To our knowledge, this is the first report on the use of PCR to identify latent neosporosis in sheep in Iran. The results of this study have the potential to contribute to our understanding of the role of N. caninum-infected sheep in the epidemiology of neosporosis.
Показать больше [+] Меньше [-]Enhanced expression of recombinant beta toxin of Clostridium perfringens type B using a commercially available Escherichia coli strain Полный текст
2016
Bakhshi, Fatemeh(Islamic Azad University Department of Biology) | Langroudi, Reza Pilehchian(Education and Extension Organization Razi Vaccine and Serum Research Institute) | Eimani, Bahram Golestani(Islamic Azad University Department of Biology)
Clostridium perfringens beta toxin is only produced by types B and C and plays an important role in many human and animal diseases, causing fatal conditions that originate in the intestines. We compared the expression of C. perfringens type B vaccine strain recombinant beta toxin gene in theEscherichia coli strains RosettaTM(DE3) and BL21(DE3). The beta toxin gene was extracted from pJETβ and ligated with pET22b(+). pET22β was transformed into E. coli strains BL21(DE3) and RosettaTM(DE3). Recombinant protein was expressed as a soluble protein after isopropyl β-D-1-thiogalactopyranoside (IPTG) induction in strain RosettaTM(DE3) but not in BL21(DE3). Expression was optimised by growing recombinant cells at 37 °C and at an induction of 0.5 mM, 1 mM, 1.5 mM IPTG. Expression was evaluated using sodium dodecyl sulfate Polyacrylamide gel electrophoresis (SDS-PAGE). The recombinant protein was purified via Ni-NTA and was analysed using western blot. We concluded that E. coli strain RosettaTM(DE3) can enhance the expression of C. perfringens recombinant beta toxin.
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