RESUMO
A vaccine against bovine mastitis was developed. The vaccine was based on inactivated, highly encapsulated Staphylococcus aureus cells; a crude extract of Staph. aureus exopolysaccharides; and inactivated unencapsulated Staph. aureus and Streptococcus spp. cells. In this study, the vaccine was evaluated in 164 cows from two commercial dairies (A and B) during a 4-mo period. Two doses of the vaccine were administered subcutaneously to 82 cows in the brachiocephalicus muscle of the neck within a 4-wk interval. The results of this trial revealed significantly fewer intramammary infections caused by Staph. aureus at various levels of severity (clinical, subclinical, and latent) in cows that were vaccinated. The odds ratios of all types of intrammammary infections caused by Staph. aureus for dairies A and B, which were determined by a logistic model, were 1.84 and 1.89, respectively, for quarters of vaccinated cows and quarters of control cows. The colony counts for Staph. aureus in milk from infected quarters of vaccinated cows were significantly lower than those in milk from infected quarters of control cows. Also, the somatic cell counts per milliliter in milk from vaccinated cows were significantly decreased when the initial somatic cell count was < 500,000 cells/ml at the start of the trial. The vaccine had no observable effect on fat production in milk or on streptococcal infections.
Assuntos
Vacinas Bacterianas , Mastite Bovina/prevenção & controle , Animais , Argentina , Bovinos , Contagem de Células , Feminino , Mastite Bovina/microbiologia , Leite/citologia , Razão de Chances , Infecções Estafilocócicas/prevenção & controle , Staphylococcus aureus/imunologia , Infecções Estreptocócicas/prevenção & controle , Streptococcus/imunologiaRESUMO
The RC/79 strain of the Aujeszky's disease virus was able to induce reproductive failure of pregnant gilts intranasally inoculated at different gestation periods. Four gilts 40-46 days pregnant (group A) and 6 gilts 70-73 days pregnant (group B) were instilled with 0.2 ml x 10(5) tissue culture infectious dose 50 (TCID50/0.2 ml) of the RC/79 strain into each nostril. Two gilts 70-73 days pregnant (group C) were used as non exposed controls. The three groups were kept in separated boxes and they were observed for clinical signs of infections and samples were collected for determination of viral shedding every day. Viral isolation was attempted in Vero cells (figure 1). From the 2nd to 7th day after inoculation, groups A and B showed fever anorexia, sneezing, coughing and depression; and viral isolation from nasal swabs was possible in 7 gilts at days 4 to 11, 9 gilts developed neutralizing antibodies. The virus caused fetal reabsorption in swine during the first period of pregnancy (group A), while infection during late pregnancy resulted in still birth or normal pigs and one mummification (group B). The entire a live litter was composed of no more than 8 suckling pigs in both groups. At necropsy virus from turbinates, ovary , placenta, spleen and lung could be isolated only from 3 gilts (group B, table 1). In 5 of 35 stillbirth and alive fetuses virus could be isolated from spleen (100%), lung (80%), liver (60%) and brain (40%) indicating that the virus has the ability to cross the placental barrier thus producing lesions in porcine fetuses and causing reproductive failure in sows (table 2). Tissue specimens from these 35 fetuses were fixed in 10% formalin, included in paraffin sectioned and stained with hematoxylin and eosin. In 13 fetuses microscopic lesions i.e. necrotic foci were found in lung (60%), liver (40%) and spleen (20%), these alterations were coincident with gross lesions in most of them. Inclusion bodies were absent. The gilts organs did not present gross lesions.
Assuntos
Morte Fetal/veterinária , Doenças Fetais/veterinária , Herpesvirus Suídeo 1/isolamento & purificação , Complicações Infecciosas na Gravidez/veterinária , Pseudorraiva/transmissão , Doenças dos Suínos/transmissão , Administração Intranasal , Animais , Anticorpos Antivirais/biossíntese , Encéfalo/embriologia , Encéfalo/microbiologia , Feminino , Morte Fetal/etiologia , Morte Fetal/microbiologia , Morte Fetal/patologia , Doenças Fetais/etiologia , Doenças Fetais/microbiologia , Doenças Fetais/patologia , Reabsorção do Feto/etiologia , Reabsorção do Feto/veterinária , Herpesvirus Suídeo 1/classificação , Herpesvirus Suídeo 1/imunologia , Troca Materno-Fetal , Gravidez , Complicações Infecciosas na Gravidez/microbiologia , Pseudorraiva/microbiologia , Suínos , Doenças dos Suínos/microbiologia , Células Vero , Vísceras/embriologia , Vísceras/microbiologiaRESUMO
The RC/79 strain of the Aujeszkys disease virus was able to induce reproductive failure of pregnant gilts intranasally inoculated at different gestation periods. Four gilts 40-46 days pregnant (group A) and 6 gilts 70-73 days pregnant (group B) were instilled with 0.2 ml x 10(5) tissue culture infectious dose 50 (TCID50/0.2 ml) of the RC/79 strain into each nostril. Two gilts 70-73 days pregnant (group C) were used as non exposed controls. The three groups were kept in separated boxes and they were observed for clinical signs of infections and samples were collected for determination of viral shedding every day. Viral isolation was attempted in Vero cells (figure 1). From the 2nd to 7th day after inoculation, groups A and B showed fever anorexia, sneezing, coughing and depression; and viral isolation from nasal swabs was possible in 7 gilts at days 4 to 11, 9 gilts developed neutralizing antibodies. The virus caused fetal reabsorption in swine during the first period of pregnancy (group A), while infection during late pregnancy resulted in still birth or normal pigs and one mummification (group B). The entire a live litter was composed of no more than 8 suckling pigs in both groups. At necropsy virus from turbinates, ovary , placenta, spleen and lung could be isolated only from 3 gilts (group B, table 1). In 5 of 35 stillbirth and alive fetuses virus could be isolated from spleen (100
), lung (80
), liver (60
) and brain (40
) indicating that the virus has the ability to cross the placental barrier thus producing lesions in porcine fetuses and causing reproductive failure in sows (table 2). Tissue specimens from these 35 fetuses were fixed in 10
formalin, included in paraffin sectioned and stained with hematoxylin and eosin. In 13 fetuses microscopic lesions i.e. necrotic foci were found in lung (60
), liver (40
) and spleen (20
), these alterations were coincident with gross lesions in most of them. Inclusion bodies were absent. The gilts organs did not present gross lesions.
RESUMO
The RC/79 strain of the Aujeszkys disease virus was able to induce reproductive failure of pregnant gilts intranasally inoculated at different gestation periods. Four gilts 40-46 days pregnant (group A) and 6 gilts 70-73 days pregnant (group B) were instilled with 0.2 ml x 10(5) tissue culture infectious dose 50 (TCID50/0.2 ml) of the RC/79 strain into each nostril. Two gilts 70-73 days pregnant (group C) were used as non exposed controls. The three groups were kept in separated boxes and they were observed for clinical signs of infections and samples were collected for determination of viral shedding every day. Viral isolation was attempted in Vero cells (figure 1). From the 2nd to 7th day after inoculation, groups A and B showed fever anorexia, sneezing, coughing and depression; and viral isolation from nasal swabs was possible in 7 gilts at days 4 to 11, 9 gilts developed neutralizing antibodies. The virus caused fetal reabsorption in swine during the first period of pregnancy (group A), while infection during late pregnancy resulted in still birth or normal pigs and one mummification (group B). The entire a live litter was composed of no more than 8 suckling pigs in both groups. At necropsy virus from turbinates, ovary , placenta, spleen and lung could be isolated only from 3 gilts (group B, table 1). In 5 of 35 stillbirth and alive fetuses virus could be isolated from spleen (100
) and brain (40
) indicating that the virus has the ability to cross the placental barrier thus producing lesions in porcine fetuses and causing reproductive failure in sows (table 2). Tissue specimens from these 35 fetuses were fixed in 10
formalin, included in paraffin sectioned and stained with hematoxylin and eosin. In 13 fetuses microscopic lesions i.e. necrotic foci were found in lung (60
) and spleen (20
), these alterations were coincident with gross lesions in most of them. Inclusion bodies were absent. The gilts organs did not present gross lesions.
RESUMO
The RC/79 strain of the Aujeszkys disease virus was able to induce reproductive failure of pregnant gilts intranasally inoculated at different gestation periods. Four gilts 40-46 days pregnant (group A) and 6 gilts 70-73 days pregnant (group B) were instilled with 0.2 ml x 10(5) tissue culture infectious dose 50 (TCID50/0.2 ml) of the RC/79 strain into each nostril. Two gilts 70-73 days pregnant (group C) were used as non exposed controls. The three groups were kept in separated boxes and they were observed for clinical signs of infections and samples were collected for determination of viral shedding every day. Viral isolation was attempted in Vero cells (figure 1). From the 2nd to 7th day after inoculation, groups A and B showed fever anorexia, sneezing, coughing and depression; and viral isolation from nasal swabs was possible in 7 gilts at days 4 to 11, 9 gilts developed neutralizing antibodies. The virus caused fetal reabsorption in swine during the first period of pregnancy (group A), while infection during late pregnancy resulted in still birth or normal pigs and one mummification (group B). The entire a live litter was composed of no more than 8 suckling pigs in both groups. At necropsy virus from turbinates, ovary , placenta, spleen and lung could be isolated only from 3 gilts (group B, table 1). In 5 of 35 stillbirth and alive fetuses virus could be isolated from spleen (100
) and brain (40
) indicating that the virus has the ability to cross the placental barrier thus producing lesions in porcine fetuses and causing reproductive failure in sows (table 2). Tissue specimens from these 35 fetuses were fixed in 10
formalin, included in paraffin sectioned and stained with hematoxylin and eosin. In 13 fetuses microscopic lesions i.e. necrotic foci were found in lung (60
) and spleen (20
), these alterations were coincident with gross lesions in most of them. Inclusion bodies were absent. The gilts organs did not present gross lesions.
RESUMO
The RC/79 strain of the Aujeszkys disease virus was able to induce reproductive failure of pregnant gilts intranasally inoculated at different gestation periods. Four gilts 40-46 days pregnant (group A) and 6 gilts 70-73 days pregnant (group B) were instilled with 0.2 ml x 10(5) tissue culture infectious dose 50 (TCID50/0.2 ml) of the RC/79 strain into each nostril. Two gilts 70-73 days pregnant (group C) were used as non exposed controls. The three groups were kept in separated boxes and they were observed for clinical signs of infections and samples were collected for determination of viral shedding every day. Viral isolation was attempted in Vero cells (figure 1). From the 2nd to 7th day after inoculation, groups A and B showed fever anorexia, sneezing, coughing and depression; and viral isolation from nasal swabs was possible in 7 gilts at days 4 to 11, 9 gilts developed neutralizing antibodies. The virus caused fetal reabsorption in swine during the first period of pregnancy (group A), while infection during late pregnancy resulted in still birth or normal pigs and one mummification (group B). The entire a live litter was composed of no more than 8 suckling pigs in both groups. At necropsy virus from turbinates, ovary , placenta, spleen and lung could be isolated only from 3 gilts (group B, table 1). In 5 of 35 stillbirth and alive fetuses virus could be isolated from spleen (100
), lung (80
), liver (60
) and brain (40
) indicating that the virus has the ability to cross the placental barrier thus producing lesions in porcine fetuses and causing reproductive failure in sows (table 2). Tissue specimens from these 35 fetuses were fixed in 10
formalin, included in paraffin sectioned and stained with hematoxylin and eosin. In 13 fetuses microscopic lesions i.e. necrotic foci were found in lung (60
), liver (40
) and spleen (20
), these alterations were coincident with gross lesions in most of them. Inclusion bodies were absent. The gilts organs did not present gross lesions.