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A Pleuropneumonia Contagiosa Bovina (PPCB) é uma enfermidade respiratória grave, causada pelo Mycoplasma mycoides subsp mycoides Small Colony (MmmSC), sendo de primeira ordem no quadro nosológico em Angola, com alta prevalência e grandes repercussões econômicas na pecuária angolana. Objetivando caracterizar os achados anatomopatológicos e a resposta inflamatória na ocorrência natural da PPCB, realizou-se a coleta de amostras de pulmão e linfonodos regionais em 50 bovinos com lesões macroscópicas compatíveis com a doença e abatidos na cidade de Huambo, Angola. As amostras teciduais foram fixadas em formol 10% e incluídas em parafina para avaliação histopatológica, pela técnica de hematoxilina-eosina, e detecção do agente infeccioso por PCR a partir do DNA total extraído do tecido pulmonar parafinado. A caracterização da resposta inflamatória foi avaliada por imunohistoquímica, utilizando-se o método de detecção por polímero para os marcadores de linfócitos T (CD3) e B (Pax5), assim como as interleucinas (IL)-1β e 4. Após avaliação molecular, 7 amostras foram excluídas por não apresentarem DNA viável e 16/43 (37,2%) animais foram positivos para o MmmSC pelo PCR. Dos animais positivos, a lesão macroscópica mais frequente foi a aderência (7/16, 43,8%); enquanto a lesão microscópica mais frequente foi a hiperplasia linfoide (9/16, 56,2%). Houve associação significativa entre a positividade dos animais e a presença da alteração nas lesões de aderência (p=0,047), pulmão marmoreado (p=0,012), sequestro (p=0,001) e fibrose pulmonares (p<0,05). O pulmão esquerdo e lobo diafragmático esquerdo foram frequentemente afetados na doença, porém sem diferença significativa. Os resultados imunohistoquímicos demonstraram marcação focal para linfócitos B e T, assim como imunoexpressão de IL-1β e IL-4 em intensidade fraca a moderada na maioria dos casos analisados. Os resultados demostraram que a PPCB está presente em bovinos na região estudada, porém com lesões anatomopatológicas e resposta inflamatória inespecíficas. Estes resultados ressaltam a importância da avaliação integrada de dados epidemiológicos, anatomopatológicos, imunológicos e moleculares para estabelecer um diagnóstico preciso e definitivo da PPCB nestes animais. / Bovine Contagious Pleuropneumonia (PPCB) is a serious respiratory disease caused by Mycoplasma mycoides subsp mycoides Small Colony (MmmSC) , being of first order in the nosological framework in Angola, with high prevalence and great economic repercussions in Angolan livestock. Aiming to characterize the anatomopathological findings and the inflammatory response in the natural occurrence of PPCB, samples of lung and regional lymph nodes were collected in 50 cattle with macroscopic lesions compatible with the disease and slaughtered in the city of Huambo, Angola. Tissue samples were fixed in 10% formalin and embedded in paraffin for histopathological evaluation by the hematoxylin-eosin technique and detection of the infectious agent by PCR from the total DNA extracted from the paraffin-shaped lung tissue. The characterization of the inflammatory response was evaluated by immunohistochemistry, using the polymer detection method for T (CD3) and B (Pax5) lymphocytes, as well as interleukins (IL) -1β and 4. After molecular evaluation, 7 samples were excluded because they did not present viable DNA and 16/43 (37.2%) animals were positive for MmmSC by PCR. Of the positive animals, the most frequent macroscopic lesion was adhesion (7/16, 43.8%); while the most frequent microscopic lesion was lymphoid hyperplasia (9/16, 56.2%). There was a significant association between the positivity of the animals and the presence of changes in adhesion lesions (p = 0.047), marbled lung (p = 0.012), pulmonary sequestra (p = 0.001) and fibrosis (p <0.05). The left lung and left diaphragmatic lobe were frequently affected in the disease, but without significant difference. Immunohistochemical results demonstrated focal labeling for B and T lymphocytes as well as weak to moderate intensity of IL-1β and IL-4 immunoexpression in most of the analyzed cases. The results showed that CPBP is present in cattle in the studied region, but with nonspecific anatomopathological lesions and inflammatory response. These results highlight the importance of the integrated evaluation of epidemiological, anatomopathological, immunological and molecular data to establish an accurate and definitive diagnosis of CBPP in these animals.

A Pleuropneumonia Contagiosa Bovina (PPCB) é uma enfermidade respiratória grave, causada pelo Mycoplasma mycoides subsp mycoides Small Colony (MmmSC), sendo de primeira ordem no quadro nosológico em Angola, com alta prevalência e grandes repercussões econômicas na pecuária angolana. Objetivando caracterizar os achados anatomopatológicos e a resposta inflamatória na ocorrência natural da PPCB, realizou-se a coleta de amostras de pulmão e linfonodos regionais em 50 bovinos com lesões macroscópicas compatíveis com a doença e abatidos na cidade de Huambo, Angola. As amostras teciduais foram fixadas em formol 10% e incluídas em parafina para avaliação histopatológica, pela técnica de hematoxilina-eosina, e detecção do agente infeccioso por PCR a partir do DNA total extraído do tecido pulmonar parafinado. A caracterização da resposta inflamatória foi avaliada por imunohistoquímica, utilizando-se o método de detecção por polímero para os marcadores de linfócitos T (CD3) e B (Pax5), assim como as interleucinas (IL)-1β e 4. Após avaliação molecular, 7 amostras foram excluídas por não apresentarem DNA viável e 16/43 (37,2%) animais foram positivos para o MmmSC pelo PCR. Dos animais positivos, a lesão macroscópica mais frequente foi a aderência (7/16, 43,8%); enquanto a lesão microscópica mais frequente foi a hiperplasia linfoide (9/16, 56,2%). Houve associação significativa entre a positividade dos animais e a presença da alteração nas lesões de aderência (p=0,047), pulmão marmoreado (p=0,012), sequestro (p=0,001) e fibrose pulmonares (p<0,05). O pulmão esquerdo e lobo diafragmático esquerdo foram frequentemente afetados na doença, porém sem diferença significativa. Os resultados imunohistoquímicos demonstraram marcação focal para linfócitos B e T, assim como imunoexpressão de IL-1β e IL-4 em intensidade fraca a moderada na maioria dos casos analisados. Os resultados demostraram que a PPCB está presente em bovinos na região estudada, porém com lesões anatomopatológicas e resposta inflamatória inespecíficas. Estes resultados ressaltam a importância da avaliação integrada de dados epidemiológicos, anatomopatológicos, imunológicos e moleculares para estabelecer um diagnóstico preciso e definitivo da PPCB nestes animais. / Bovine Contagious Pleuropneumonia (PPCB) is a serious respiratory disease caused by Mycoplasma mycoides subsp mycoides Small Colony (MmmSC) , being of first order in the nosological framework in Angola, with high prevalence and great economic repercussions in Angolan livestock. Aiming to characterize the anatomopathological findings and the inflammatory response in the natural occurrence of PPCB, samples of lung and regional lymph nodes were collected in 50 cattle with macroscopic lesions compatible with the disease and slaughtered in the city of Huambo, Angola. Tissue samples were fixed in 10% formalin and embedded in paraffin for histopathological evaluation by the hematoxylin-eosin technique and detection of the infectious agent by PCR from the total DNA extracted from the paraffin-shaped lung tissue. The characterization of the inflammatory response was evaluated by immunohistochemistry, using the polymer detection method for T (CD3) and B (Pax5) lymphocytes, as well as interleukins (IL) -1β and 4. After molecular evaluation, 7 samples were excluded because they did not present viable DNA and 16/43 (37.2%) animals were positive for MmmSC by PCR. Of the positive animals, the most frequent macroscopic lesion was adhesion (7/16, 43.8%); while the most frequent microscopic lesion was lymphoid hyperplasia (9/16, 56.2%). There was a significant association between the positivity of the animals and the presence of changes in adhesion lesions (p = 0.047), marbled lung (p = 0.012), pulmonary sequestra (p = 0.001) and fibrosis (p <0.05). The left lung and left diaphragmatic lobe were frequently affected in the disease, but without significant difference. Immunohistochemical results demonstrated focal labeling for B and T lymphocytes as well as weak to moderate intensity of IL-1β and IL-4 immunoexpression in most of the analyzed cases. The results showed that CPBP is present in cattle in the studied region, but with nonspecific anatomopathological lesions and inflammatory response. These results highlight the importance of the integrated evaluation of epidemiological, anatomopathological, immunological and molecular data to establish an accurate and definitive diagnosis of CBPP in these animals.

Contagious bovine pleuropneumonia (CBPP) is a bovine bacterial disease of major economic importance in sub-Saharan Africa. Vaccination has been recommended to control the disease in endemic areas such as the Maasai ecosystems of Kenya and Tanzania; however, the currently used live attenuated vaccine has been reported to have poor vaccine safety and efficacy. To compare standard (current) and an improved (buffered) version of the live CBPP-vaccine, several epidemiological studies were carried out in Maasai cattle in Kenya between 2006 and 2008. Specifically, the aims were to estimate CBPP seroprevalence at herd and animal level; to identify risk factors for seroprevalence at both levels; to investigate the spatial distribution of seroprevalence; to compare post vaccination adverse events in cattle vaccinated with a standard and a buffered vaccine, and finally to compare efficacy of the two vaccines to induce seroconversion and to prevent development of clinical signs suggestive of CBPP. A cross-sectional study was carried out in 6872 cattle in 175 randomly selected herds from Loita and Mara divisions. A competitive ELISA revealed that 85% of the herds in the area had at least one seropositive animal and that seropositive herds were harbouring 11% seropositive cattle. A complement fixation test revealed that 46% of the herds had at least one seropositive animal and that seropositive herds were harbouring 4% seropositive cattle. A multivariable logistic regression analysis of the seroprevalence indicated that previous vaccination against CBPP, a history of CBPP outbreaks in the herd, animal age and the location of the herd in the division of Mara were positively correlated to seroprevalence. To investigate the observed difference in herd seroprevalence between the two divisions further, a spatial analysis was conducted. A SatScan test revealed clusters in Mara in areas identified by veterinary personnel as CBPP ‘hot spots’. A logistic regression using spatial information identified that location in the midland agro-ecological zone or close to a river and vaccination were positively associated with seroprevalence. To compare safety and efficacy of a standard and a buffered vaccine, two cohorts of approximately 40,000 cattle were used. The study showed that within 100 days post vaccination, 6.2 cattle per 1000 vaccinates developed adverse events, 4.1 of which were specifically attributable to vaccination and ranging from swelling of the tail to the tail sloughing off. This study revealed a slightly higher incidence of adverse events in cattle vaccinated with the buffered vaccine compared to the standard vaccine. A comparison of the efficacy of the two vaccines revealed that cattle vaccinated with the buffered vaccine had higher odds of seroconversion and lower odds of developing symptoms of CBPP, three and twelve months post vaccination respectively. The epidemiological studies conducted clearly show wide spread seroprevalence in the Maasai cattle. Given the (spatial) heterogeneity observed, control measures should probably be targeted in areas of increased risk (clusters). However, positive association of vaccination and seropositivity call for better diagnostics tests that can differentiate vaccinated from infected animals. Vaccination with buffered vaccine resulted in increased seroconversion, decreased clinical signs indicative of CBPP post vaccination and low seroprevalence post ‘outbreak’. Nevertheless, the increase in adverse events related to the buffered vaccine calls for further research into safer CBPP vaccines.

No description available.

Each of two affinity isolation methods, the first based on biotinylated porcine transferrin plus streptavidin-agarose, and the second on Sepharose-coupled porcine transferrin, followed by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE), allowed the isolation and identification of two potential porcine-transferrin-binding polypeptides (∼64 kDa and 99 kDa) from total membranes of Actinobacillus pleuropneumoniae grown under iron-restricted conditions. Both polypeptides were iron-repressible and were identified as potential receptor candidates as they were not isolated when biotinylated human transferrin was used instead of biotinylated porcine transferrin. The 64 kDa polypeptide was the more easily removed from Sepharose-coupled porcine transferrin and only the 99 kDa polypeptide appeared to be an outer membrane protein. These results suggest that the 99 kDa polypeptide represents the porcine transferrin receptor of A. pleuropneumoniae, and that the 64 kDa polypeptide represents an associated protein serving an accessory role. Fe+3 uptake studies using plate assays and attempted isolation of a putative lactoferrin receptor using biotinylated porcine lactoferrin plus streptavidin-agarose, followed by SDS-PAGE, showed that A. pleuropneumoniae lacks a mechanism for the use of porcine lactoferrin as an iron source.

Thesis (M. Sc. Vet. Sc.)--Faculty of Veterinary Science, University of Sydney, 2005. / Bibliography: leaves 165-172.

Thesis (MMedVet (Production Animal Studies)--University of Pretoria, 2007. / Includes bibliographical references.

Thesis (M. Sc. Vet. Sc.)--University of Sydney, 2005. / Title from title screen (viewed 27 May 2008). Submitted in fulfilment of the requirements for the degree of Master of Science in Veterinary Science to the Faculty of Veterinary Science. Includes bibliographical references. Also available in print form.

No description available.