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The incursion, persistence and spread of peste des petits ruminants in Tanzania: Epidemiological patterns and predictions
2013
Kivaria, Fredrick M.(National Epidemiology Section) | Kwiatek, Olivier(CIRAD) | Kapaga, Angolwisye M.(Central Veterinary Laboratory) | Swai, Emmanuel S.(Veterinary Investigation Centre) | Libeau, Geneviève(CIRAD) | Moshy, Winford(Veterinary Investigation Centre) | Mbyuzi, Albano O.(Veterinary Investigation Centre) | Gladson, Joshua(Central Veterinary Laboratory)
Peste des petits ruminants virus, which causes a severe disease in sheep and goats, has only recently been officially declared to be present in Tanzania. An epidemiological study was carried out between September 2008 and October 2010 to investigate the incursion, persistence and spread of the virus in Tanzania. The investigation involved serosurveillance, outbreak investigation and computation of epidemiological indices such as the effective reproductive number, persistence and the threshold level for vaccination. Field and molecular epidemiological techniques were applied to isolate, characterise and trace the origin of the virus in Tanzania. A total of 2182 serum samples from goats and 1296 from sheep from 79 villages across 12 districts were investigated. Village-level prevalence of infection was variable (0.00% - 88.00%) and was higher in pastoral than in agro-pastoral villages. The overall antibody response to the virus was 22.10% (CI95% = 20.72% - 23.48%). About 68.00% and 73.00% of seropositive goats and sheep, respectively, did not show clinical signs. The proportion of seropositive animals differed significantly (p < 0.001) between age groups, sex and farming practices. Real-time polymerase chain reaction results showed that the isolated strains belong to lineage III, whose origin is in East Africa and the Middle East. This indicates that one of the northern neighbouring countries is most likely the source of infection. The computed overall effective reproductive number, the threshold level of vaccination necessary to eradicate the disease and persistence were 4.75% and 98.00%, respectively. These estimates indicate that achieving elimination of the peste des petits ruminants virus from pastoral flocks will require significant effort and development of highly effective intervention tools.
Mostrar más [+] Menos [-]Immunohistochemical studies of the enteric nervous system and interstitial cells of Cajal in the canine stomach
2013
Musara, Colin(University of Zimbabwe Department of Preclinical Veterinary Studies) | Vaillant, Camille(University of Liverpool Department of Veterinary Preclinical Studies)
The distribution of interstitial cells of Cajal (ICC), the probable pacemakers in gastrointestinal motility, was investigated using an antigenic marker of gastric ICC known as C-Kit. Antiserum raised against the general neuronal marker protein gene peptide 9.5 (PGP) as well as the nitrergic neuronal marker neuronal nitric oxide synthase (nNOS) were used to investigate the distribution of gastric nerves. Polyclonal goat anti-human C-Kit was reliable in labelling ICC in the stomach. Two classes of ICC were identified according to their distribution: ICC-MY distributed around the periphery of myenteric ganglia and ICC-IM in the circular and longitudinal muscle layers. The neuronal marker PGP was reliably consistent in revealing the density and distribution of the enteric nervous system. Density of nerve fibres was higher in circular smooth muscle than in longitudinal smooth muscle. From nNOS immunohistochemistry, it is evident that inhibitory (nitrergic) nerves constitute a substantial fraction of the enteric nervous system.
Mostrar más [+] Menos [-]Notes on the occurrence of Trypanosoma sp. (Kinetoplastida: Trypanosomatidae) in freshwater fishes from South Africa
2013
Ferreira, Maryke L(University of Johannesburg Department of Zoology) | Avenant-Oldewage, Annemariè(University of Johannesburg Department of Zoology)
A total of 257 fishes from four families, Clariidae, Cichlidae, Cyprinidae and Schilbeidae were I collected from three localities: the Sand River Dam, Swaziland; the Nylsvlei Nature Reserve, South Africa and the Vaal Dam and Vaal River Barrage, South Africa. Only fishes (n = 154) from Clariidae and Cichlidae were found to be infected with trypanosomes. A total of 221 Clarias gariepinus (Burchell 1822) were collected from the Vaal Dam and Vaal Barrage area, South Africa. Of these, 74% (89/121) were infected with trypanosomes from the Vaal Dam and 63% (63/100) from the Vaal River Barrage, with no seasonal infection pattern. A prevalence of 25% (1/4) was found in C. gariepinus from the Sand River Dam, Swaziland, and a 50% (1/2) prevalence was found in Tilapia sparrmanii from the Nylsvlei Nature Reserve, South I: Africa. Standard measurements conformed closely to the morphometric and morphological descriptions of Trypanosoma mukasai. This article provides new locality records for T. mukasai II: from the Vaal Dam, Vaal River Barrage and Nylsvlei Nature Reserve (South Africa) and the Sand River Dam (Swaziland). Tilapia sparrmanii collected in the Sand River Dam in Swaziland is also noted as a new host record.
Mostrar más [+] Menos [-]Descriptions of diplostomid metacercariae (Digenea: Diplostomidae) from freshwater fishes in the Tshwane area
2013
Moema, Esmey B.E.(University of Limpopo) | King, Pieter H.(University of Limpopo) | Rakgole, Johnny N.(University of Limpopo) | Baker, Chantélle(University of Limpopo)
The metacercarial (larval) stages of diplostomid digeneans are known to inhabit freshwater fish, causing tissue damage in the process. Due to their widespread diversity, little is known about their life cycle. The classification of these parasitic stages to the species level using only the morphology is very challenging due to the lack of genitalia; they are regarded to be the most important structures in the identification of these organisms. In this study, additional morphological information through light and scanning electron microscopy is given for two different diplostomids found in the cranial cavity of Clarias gariepinus and the vitreous chambers of Tilapia sparrmanii and Pseudocrenilabrus philander. The diplostomid metacercaria inhabiting the cranial cavity of Clarias gariepinus was morphologically identified as Diplostomulum (Tylodelphys) mashonense and an unknown metacercaria of the genus Diplostomum was found in the vitreous chambers of Pseudocrenilabrus philander and Tilapia sparrmanii. Both parasitic species' 28S recombinant deoxyribonucleic acid genomic regions were successfully amplified using Dig 125/1500R primer pairs. The assay yielded a product of approximately 1300 base pairs as seen on the gel images. There were 14 nucleotide differences over the entire analysed sequences resulting in a 1.1% (14/1273) nucleotide difference. In line with the morphological characteristics of these parasites, there seemed to be a slight difference in their genetic makeup. The application of molecular techniques on digenetic trematodes seems very promising and may yield great potential in future descriptions of morphologically similar parasitic species.
Mostrar más [+] Menos [-]A review of the epidemiology and control of gastrointestinal nematode infections in cattle in Zimbabwe
2013
Pfukenyi, Davies M(University of KwaZulu-Natal) | Mukaratirwa, Samson(University of KwaZulu-Natal)
In this review, the main gastrointestinal nematodes infecting cattle in Zimbabwe and the epidemiological factors influencing their occurrence are reviewed and discussed. Nineteen gastrointestinal nematode species that belong to seven families have been found to occur in cattle in Zimbabwe. The main genera reported to date are Cooperia, Haemonchus, Trichostrongylus and Oesophagostomum and the dominant species are Cooperia pectinata, Cooperia punctata, Haemonchus placei and Trichostrongylus axei. The mixed infection by several species from the genera is the cause of parasitic gastroenteritis in cattle in Zimbabwe. Production and husbandry practices, season, host age and environment are considered to be the main factors that influence gastrointestinal nematode infection in cattle. The geographical distribution of the gastrointestinal nematodes is also reviewed in relation to the climatic conditions of the country. Various control options are discussed and how they are applicable to the Zimbabwean situation. Based on reports and existing data on the epidemiological features of the gastrointestinal nematode infection in cattle, practical control measures are critically reviewed and recommendations are made for a national control programme.
Mostrar más [+] Menos [-]Alternatively activated M2 macrophages increase in early stages of experimental autoimmune myocarditis in Lewis rats
2013
Oh, H., Jeju National University, Jeju, Republic of Korea | Ahn, M., Jeju National University, Jeju, Republic of Korea | Matsumoto, Y., Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan | Shin, T., Jeju National University, Jeju, Republic of Korea
To better understand the role of macrophages in early stages of experimental autoimmune myocarditis (EAM), we compared the expression of inducible nitric oxide synthase (iNOS) and arginase-1, markers for classically activated M1 and alternatively activated M2 macrophages, respectively, in the hearts of EAM-affected and control rats. Immunohistochemical evidence revealed that both iNOS-positive and arginase 1-positive macrophages were found in EAM lesions, while some cells were co-localized with both markers. This finding suggests that the increased level of arginase-1, which is partly from M2 macrophages, contributes to the modulation of EAM, possibly through the reduction of nitric oxide in the lesion.
Mostrar más [+] Menos [-]Attraction effect against Lycorma delicatula, antioxidant activity and local irritation test of Ailanthus altissima extract
2013
Lee, S.J., Kyungpook National University, Daegu, Republic of Korea | Park, S.C., Kyungpook National University, Daegu, Republic of Korea
This study aimed to assess the attraction effect against Lycorma delicatula and antioxidant activity of hexane, chloroform, butanol and water fraction obtained from Ailanthus altissima methanol extract. The attraction effect of chloroform fraction showed the highest activity (47%) as compared to that of other fractions. In the DPPH radical scavenging activity, methanol and butanol fraction showed higher antioxidant activity than other solvent fractions. From the above results, the potential chloroform fraction was further performed by local irritation test in New Zealand white rabbits. In eye irritation test, chloroform fraction showed moderate irritant at high concentration 0.5 g/site/mL, but there was no eye irritation at low concentration (0.05 g/site/mL). In accordance with the Draize evaluation of skin irritation, the primary irritation index was calculated to 3.3 and 0.68 at high (0.5 g/site/mL) and low concentration (0.05 g/site/ mL) causing moderate and mild irritation, respectively. On the basis of this study, Ailanthus altissima chloroform fraction could be safely considered to be a candidate of attractant against Lycorma delicatula.
Mostrar más [+] Menos [-]Pathologic studies in lymph nodes of pigs infected with porcine circovirus type 2, porcine reproductive and respiratory syndrome virus
2013
Jung, J.Y., Jeju National University, Jeju, Republic of Korea | Kim, J.H., Jeju National University, Jeju, Republic of Korea
Porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) have been suspected to have immunosuppressive effects on pigs. To investigate the correlation between these virus infection and the lesions of lymph nodes including sub-mandibular and inguinal lymph node, 44 pigs (PCV2 single, n = 14; PRRSV single, n = 10; PCV2/PRRSV, n = 14; negative control, n = 6) were examined by histopathology and immunohistochemistry. Histopathologically, granulomatous lymphadenitis characterized by lymphoid depletion with histiocytic cells infiltration was observed in PCV-2 single and PCV-2/PRRSV group. Immunohistochemically, there were significant reduction of B and T lymphocytes in lymph nodes of these groups, while the number of macrophages was increased. In only PRRSV infected group, germinal center hypertrophy and lymphoid necrosis were observed. Immunohistochemically, the number of CD3+ T lymphocytes was slightly increased. Severe lymphocytic depletion in PCV-2 infection-related lymph nodes might be associated with producing immunocompromised state in pig. Comparing with PCV-2 infected group, PRRSV produced minor effects on the changes in immune cell population in the lymph nodes of pigs. PRRSV may increase susceptibility of the disease in pigs by disruption of the first defense lines in target organs, such as the alveolar macrophages in lungs.
Mostrar más [+] Menos [-]Classification of acute clinical mastitis on the base of vital signs and complete blood count test in dairy cows
2013
Hur, T.Y., Rural Development Administration (RDA), Cheonan, Republic of Korea | Kang, S.J., Rural Development Administration (RDA), Cheonan, Republic of Korea | Jung, Y.H., Rural Development Administration (RDA), Cheonan, Republic of Korea | Lee, H.J., Rural Development Administration (RDA), Cheonan, Republic of Korea | Ki, K.S., Rural Development Administration (RDA), Cheonan, Republic of Korea | Choe, C.Y., Rural Development Administration (RDA), Cheonan, Republic of Korea | Suh, G.H., Chonnam National University, Gwangju, Republic of Korea
This study was carried out to evaluate the diagnosis of acute clinical mastitis (ACM) which was based on the vital signs and complete blood count (CBC) tests in dairy cows. Twenty eight dairy cows diagnosed with ACM, were selected for the study between Jan 2003 and July 2006 in the National Institute of Animal Science. Based on their vital signs (rectal temperature, depression, rumen contraction and, dehydration status), ACM was divided into three different classes; mild, moderate and severe forms. In addition, ACM cows were subjected to CBC tests for further diagnosis of ACM. Of the 27 dairy cows diagnosed with ACM, 3 cows were determined to have a mild form, while moderate and sever forms were each observed in twelve cows. Among of them, 4 cows died, 5 cows were culled and 18 cows were recovered. In the mild form, all haematological parameters were comparable with normal values. However, leukopenia, due to neutropenia and lymphocytopenia, appeared characteristically in the moderate and severe forms. Using the observation of vital signs in conjunction with CBC tests, the diagnosis of ACM is more accurate, and is helpful in making decisions of whether treatment or culling of dairy cows infected with ACM is most appropriate.
Mostrar más [+] Menos [-]Application of SYBR Green real-time PCR assay for the specific detection of Salmonella spp
2013
Shin, S.W., Seoul National University, Seoul, Republic of Korea | Cha, S.B., Plant and Fisheries Quarantine and Inspection Agency, Anyang, Republic of Korea | Lee, W.J., Seoul National University, Seoul, Republic of Korea | Shin, M.K., Seoul National University, Seoul, Republic of Korea | Jung, M., Seoul National University, Seoul, Republic of Korea | Yoo, A., Seoul National University, Seoul, Republic of Korea | Jung, B.Y., Seoul National University, Seoul, Republic of Korea | Yoo, H.S., Seoul National University, Seoul, Republic of Korea
The aim of this study was to applicate and evaluate a SYBR Green real-time PCR for the specific detection of Salmonella spp. Specificity of the PCR method was confirmed with 48 Salmonella spp. and 5 non-Salmonella strains using invA gene primer. The average threshold cycle (CT) of Salmonella spp. was 11.83 ± 0.78 while non-Salmonella spp. was 30.86 ± 1.19. Correlation coefficients of standard curves constructed using CT versus copy number of Salmonella Enteritidis ATCC 13076 showed good linearity (R2 = 0.993; slope = 3.563). Minimum level of detection with the method was 102 colony forming units (CFU)/mL. These results suggested that the SYBR Green real-time PCR might be applicable for the specific detection of Salmonella spp. isolates.
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