Refinar búsqueda
Resultados 91-100 de 452
The diagnosis and prevalence of persistent infection with bovine viral diarrhoea virus in South African feedlot cattle
2011
Meiring, Thelma(IDEXX Laboratories ,University of Pretoria Department of Paraclinical Sciences) | Prozesky, Leon(University of Pretoria Department of Paraclinical Sciences) | du Preez, Eben R.(SD Morris Consulting Services) | Verwoerd, Dirk J.(Karan Beef Feedlot)
Bovine viral diarrhoea virus (BVDV) infection is an important viral infection affecting the cattle industry today. The prevalence of this infection in South African feedlots is unknown. Ear notch biopsies were collected from chronic poor doers and animals that appeared unthrifty upon entering feedlots, as well as animals entering the hospital pen with respiratory disease for the first time. A total of 1690 samples were collected: 1074 from the former category and 616 from the latter. A routine immunohistochemistry staining protocol showed that 49 animals tested positive, of which 43 (4%) came from the feedlot entry group and six (1%) from the hospitalised group. The prevalence of persistently infected cattle from this selected, nonrandom sample entering six large South African feedlots was found to be 2.9%, which is higher than the international rule of thumb that 0.5% of all cattle entering feedlots are persistently infected. There was no clear correlation between persistent infection and respiratory disease. Serum samples were also collected when possible and 10 positive cases were found. Results from enzyme-linked immunosorbent assays for antigen and antibody performed on these sera correlated well with those from the immunohistochemistry staining method in six cases, but in four cases the animals tested falsely positive owing to nonspecific staining. Immunohistochemistry staining on ear notch biopsies is thus a reliable diagnostic method to identify persistently infected animals with BVDV, but the pathologist should be aware of nonspecific positive staining.
Mostrar más [+] Menos [-]On the origin and diversity of Newcastle disease virus in Tanzania
2011
Yongolo, Mmeta G.(Ministry of Livestock Development Department of Virology) | Christensen, Henrik(University of Copenhagen Department of Veterinary Disease Biology) | Handberg, Kurt(University Hospital of Aarhus Department of Clinical Microbiology) | Minga, Uswege(Open University of Tanzania Faculty of Science, Technology and Environmental Studies) | Olsen, John E.(University of Copenhagen Department of Veterinary Disease Biology)
Free-range rural chickens (FRCs) dominate the poultry industry in developing countries and chickens are exposed to multi-host infections, including Newcastle disease virus (NDV). The knowledge about the characteristics of NDV from FRCs is limited. This study investigated the persistence, spread and risks of NDV from FRCs. NDV isolates (n = 21) from unvaccinated FRCs in Tanzania were characterised by conventional intracerebral pathogenicity index (ICPI) and sequence analysis of a partial region of the deduced fusion protein encompassing the cleavage site. Results showed that five isolates were screened as lentogenic, nine as mesogenic and six as velogenic. Phylogenetic analysis of the 21 isolates compared to reference sequences revealed three, four, nine and five isolates in genotypes 1, 2, 3c and 4a, respectively. Genotype 3c also included published sequences of Tanzanian isolates obtained from exotic birds and chicken isolates from Uganda. The analysis showed that NDV were persistently present among chicken populations and possibly spread through live chicken markets or migration of wild birds. Differences in amino acid sequences detected around the cleavage site separated the isolates in six types. However, cleavage site pattern could not fully differentiate mesogenic isolates from velogenic isolates.
Mostrar más [+] Menos [-]Protozoa and digestive tract parameters of the impala
2011
Booyse, Dirk G.(University of Pretoria Department of Anatomy and Physiology) | Dehority, Burk A.(Ohio State University Department of Animal Sciences)
Intestinal contents were collected from eight impala at three different localities during the winter hunting season (2005-2009), as well as from another 24 animals from a one-year trial at a game farm called Ditholo (2003-2004). Gas production, protozoa counts and several other physiological parameters were measured from both rumen and caecum or colon contents. Only higher ophryoscolecid and Isotrichidae species of protozoa were counted and identified. Ostracodinium gracile was present in all 32 impala. Eudiplodinium maggii was present in 31 animals and Eudiplodinium impalae and Epidinium (either ecaudatum or caudatum) in 30 animals. Dasytricha ruminantium was present in only 11 of the impala. Concentrations of protozoa were correlated with the season of sample collection and highly correlated with the animals living on the game farm. Gas production (mL/g of wet rumen ingesta) was weakly correlated with protozoa concentration but not with the season of collection.
Mostrar más [+] Menos [-]Parasites of South African wildlife: XIX. The prevalence of helminths in some common antelopes, warthogs and a bushpig in the Limpopo province, South Africa
2011
van Wyk, Ilana C.(University of Pretoria Department of Veterinary Tropical Diseases) | Boomker, Joop(University of Pretoria Department of Veterinary Tropical Diseases)
Little work has been conducted on the helminth parasites of artiodactylids in the northern and western parts of the Limpopo province, which is considerably drier than the rest of the province. The aim of this study was to determine the kinds and numbers of helminth that occur in different wildlife hosts in the area as well as whether any zoonotic helminths were present. Ten impalas (Aepyceros melampus), eight kudus (Tragelaphus strepsiceros), four blue wildebeest (Connochaetes taurinus), two black wildebeest (Connochaetes gnou), three gemsbok (Oryx gazella), one nyala (Tragelaphus angasii), one bushbuck (Tragelaphus scriptus), one waterbuck (Kobus ellipsiprymnus), six warthogs (Phacochoerus aethiopicus) and a single bushpig (Potamochoerus porcus) were sampled from various localities in the semi-arid northern and western areas of the Limpopo province. New host-parasite associations included Trichostrongylus deflexus from blue wildebeest, Agriostomum gorgonis from black wildebeest, Stilesia globipunctata from the waterbuck and Fasciola hepatica in a kudu. The mean helminth burden, including extra-gastrointestinal helminths, was 592 in impalas, 407 in kudus and blue wildebeest, 588 in black wildebeest, 184 in gemsbok, and 2150 in the waterbuck. Excluding Probstmayria vivipara, the mean helminth burden in warthogs was 2228 and the total nematode burden in the bushpig was 80. The total burdens and species richness of the helminths in this study were consistently low when compared with similar studies on the same species in areas with higher rainfall. This has practical implications when animals are translocated to areas with higher rainfall and higher prevalence of helminths.
Mostrar más [+] Menos [-]Ticks infesting cattle in the Central Equatoria region of South Sudan
2011
Marcellino, Wani L.(Ministry of Animal Resources and Fisheries) | Julla, Ibrahim I.(University of Bahr el Ghazal College of Veterinary Science) | Salih, Diaeldin A.(Central Veterinary Research Laboratories) | El Hussein, Abdel R.M.(Central Veterinary Research Laboratories)
Ticks infesting cattle represent a serious problem for improvement of cattle productivity in South Sudan. There has been limited information on ticks and tick-borne diseases in southern Sudan. This study was initiated to update the current distribution of ticks infesting cattle in the Central Equatoria region of South Sudan. The surveys for the present study were conducted at various cattle camps in Juba, Mangalla and Terekeka between December 2004 and June 2005. A total of 2322 ticks were collected from the bodies of 88 randomly selected cattle. Ticks were preserved in 70%ethanol for later identification. Seven ixodid tick species were found to infest cattle in Juba whilst six species were recorded in Mangalla and only four species in Terekeka. Amblyomma variegatum was the most common and widely distributed species found on cattle across all the study locations. Amblyomma lepidum was not found during this study. Based on these findings, it would be advisable to preempt the situation and institute containment procedures before possible East Coast fever outbreaks occur.
Mostrar más [+] Menos [-]Contamination status of groundwater used as livestock drinking in beef and dairy cattle farms, Korea
2011
Jang, Y.H., Konkuk University, Seoul, Republic of Korea | Lee, S.J., Konkuk University, Seoul, Republic of Korea | Kim, H.B., Konkuk University, Seoul, Republic of Korea | Lee, J.H., Seoul Research Institute of Public Health and Environment, Seoul, Republic of Korea | Lee, M.H., Seoul Research Institute of Public Health and Environment, Seoul, Republic of Korea | Gil, H.K., Seoul Research Institute of Public Health and Environment, Seoul, Republic of Korea | Choe, N.H., Konkuk University, Seoul, Republic of Korea
In Korea, groundwater is main water source in livestock farms. Most dairy and cattle farms have constructed their own wells for human drinking and livestock farming. However, these private residential wells have not been controlled by government and also there was scant study about livestock drinking water quality. Therefore this study was to monitor of the livestock farms' groundwater quality in Korea. Water samples were collected at 123 dairy and cattle farms and were analysed forty six substances with quality standard for drinking water approved by the Minister of Environment. Seventy eight (63.4%) of 123 samples failed to drinking water stand a test. The most frequent contaminants were nitrate-nitrogen and microbial. 22.8% (n = 28) of samples showed nitrate-N concentration of higher than 10 mg/L meant that can't be used drinking water for human and the Nitrate-N concentration analysed in the range of 0.2 to 61.2 mg/L. All of 78 failed to drinking samples had microbial problems, especially 5.7% (n = 7) of samples indicated water could be contaminated by feces. Other contaminants detected were zinc and evaporation residue. Especially detected zinc concentration (32 mg/L) was about ten times higher than standard of zinc (3 mg/L). Regression analysis indicated that groundwater pH did not influence to nitrate-N concentration but the hardness and chloride could affect to nitrate-N concentration in the groundwater. Most livestock farms were adjacent to crop farmland in Korea. This could cause contamination of groundwater with nitrate-N and pesticide that could accumulate livestock product. Moreover Heavy metal such as zinc and copper could be released from a corrosive plated water pipe in livestock farm. Put together, Korea livestock system is indoor, not pasture-based, hence livestock could be exposed to potential contaminated water consistently. Therefore on the basis of these data, appropriate livestock drinking water quality standards should be prepared to keep livestock healthy and their product safe. Further, livestock drinking water quality should be monitored continuously in suitable livestock drinking water standards.
Mostrar más [+] Menos [-]Changes of colonic endocrine cells in trinitrobenzene sulfonic acid (TNBS)-induced rat colitis
2011
Back, Y.D., Oriental Hospital, Gyeongsan, Republic of Korea | Lee, H.S., Daegu Haany University, Gyeongsan, Republic of Korea | Chung, I.K., Daegu Haany University, Gyeongsan, Republic of Korea | Cheon, W.H., Daegu Haany University, Gyeongsan, Republic of Korea | Ku, S.K., Daegu Haany University, Gyeongsan, Republic of Korea
In this study, immunohistochemistry was used to examine the changes in the density of colonic endocrine cells - argyrophil and argentaffin cells, chromogranin A (CGA), serotonin, somatostatin and glucagon-containing cells in trinitrobenzene sulfonic acid (TNBS)-induced rat colitis. Ulcerative colitis was induced by the instillation of 10 mg of TNBS into the colonic lumen through the anus. To confirm the inducement of ulcerative colitis, the macroscopic and microscopic scores as well as the colonic myeloperoxidase (MPO) activities were monitored for 8 days after TNBS instillation in the colonic lumens. In addition, the number of argyrophil and argentaffin cells, CGA, serotonin, somatostatin and glucagon-immunoreactive cells were counted in the colonic mucosa, respectively. After TNBS instillation into the lumen of the colon from the anus in rats, increases in macroscopic and microscopic scores in the colon tissues were observed along with increases in the colonic MPO activities. Therefore, ulcerative colitis was relatively well induced by the TNBS instillations. Marked decreases in the number of colonic endocrine cells were detected in the TNBS-treated animal compared to the sham control. These results suggest that colonic endocrine cells were also disrupted by TNBS-induced ulcerative colitis.
Mostrar más [+] Menos [-]Resistance of Cryptosporidium parvum oocysts following commercial bleach treatment
2011
Surl, C.G., National Veterinary Research and Quarantine Service, Anyang, Republic of Korea | Jung, B.D., Kangwon National University, Chuncheon, Republic of Korea | Park, B.K., Chungnam National University, Daejeon, Republic of Korea | Kim, H.C., Kangwon National University, Chuncheon, Republic of Korea
We investigate the resistance of Cryptosporidium (C.) parvum oocysts to commercial bleach treatment. The viability and infectivity of C. parvum oocysts suspended in 100, 50, 25, 12.5, 6.3 or 3.2% aqueous commercial bleach for 10, 30, 60, 120 or 180 min at room temperature were assessed by nucleic acid Syto-9 staining, histologic examination of ileum and infectivity to immunosuppressed neonatal C57BL/6N mice. Although the viability was decreased compared with normal oocysts, all oocysts in contact with serially diluted commercial bleach for 180 min were alive by nucleic acid dye Syto-9 staining. And, microscopic examination of ileum sections revealed developmental stages of C. parvum in all mice. The oocyst shedding patterns between mice infected with oocysts contacted with commercial bleach and normal control mice were not significantly different each other. Although commercial bleach is widely used as a bacterial and viral disinfectant, the present findings indicate that it is not an effective disinfectant for C. parvum oocysts under practical conditions. Authors conclude that, therefore, it is undesirable to recommend commercial bleach as a disinfectant for C. parvum oocysts.
Mostrar más [+] Menos [-]Comparison of tuberculin skin test with Interferon-γ assay for the diagnosis of bovine tuberculosis in Korean cattle
2011
Shin, S.W., Seoul National University, Seoul, Republic of Korea | Shin, M.K., Seoul National University, Seoul, Republic of Korea | Cha, S.B., Seoul National University, Seoul, Republic of Korea | Woo, J.T., Gyeonggido Veterinary Service, Suwon, Republic of Korea | Lee, S.M., Incheon Metropolitan City Institute of Health and Environment, Incheon, Republic of Korea | Ku, B.K., Animal, Plant and Fisheries Quarantine and Inspection Agency, Anyang, Republic of Korea | Cho, Y.S., Animal, Plant and Fisheries Quarantine and Inspection Agency, Anyang, Republic of Korea | Jung, S.C., Animal, Plant and Fisheries Quarantine and Inspection Agency, Anyang, Republic of Korea | Yoo, H.S., Seoul National University, Seoul, Republic of Korea
Bovine tuberculosis (bTB), caused primarily by Mycobacterium bovis, continues to exert an economic loss, even in countries with active control measures, and is one of zoonotic diseases enable to be transmitted to human. The control and eradication of bTB are mainly based on a test and slaughter policy and/or abattoir surveillance. Various factors including limitation of diagnostic tests have been considered as major constraints to eradication. Single intradermal test (SIT) is the official diagnostic test. New diagnostic methods are needed to be developed, because of limitations of the test. In the present study SIT was compared with single intradermal comparative cervical test (SICCT) and interferon (IFN)-γ assay. There was very low correlation between SIT and SICCT. However, high correlation was shown between SIT and IFN-γ assay while no correlation was observed between SICCT and IFN-γ assay. Therefore, our results suggest the possibility of replacement of SIT with IFN-γ assay for the diagnosis of bovine tuberculosis.
Mostrar más [+] Menos [-]Oral contrast media for computed tomography of canine pancreas
2011
Choi, J.H., Chonnam National University, Gwangju, Republic of Korea | Chang, J.H., Seoul National University, Seoul, Republic of Korea | Oh, S.K., Seoul National University, Seoul, Republic of Korea | Yoon, J.H., Seoul National University, Seoul, Republic of Korea
Barium suspension, oral iodine contrast medium and water were applied in eight dogs to evaluate (1) distension of gastrointestinal tract, (2) the effect of the oral contrast media on the identification of the pancreas from surrounding organs, and (3) image quality and the presence of artifacts in canine pancreas computed tomography (CT) images. Oral iodine contrast medium, gastrografin, produced significant artifacts that deteriorated the CT images of the pancreas. The use of water did not provide the fullness of the gastrointestinal lumens. Barium suspension was effective for the identification of the pancreas from the surrounding gastrointestinal tract, without significantly increasing image noise. Barium suspension can be used as an optimal contrast medium that will not cause an adverse effect on the pancreatic density and image quality.
Mostrar más [+] Menos [-]