Control of Salmonella enterica serovar Enteritidis in laying hens by inactivated Salmonella Enteritidis vaccines / "Controle de Salmonella enterica sorovar Enteritidis em poedeiras comerciais com a utilização de vacinas inativadas"

Salmonella Enteritidis is one of the agents that is responsible for outbreaks of human foodborne salmonellosis caused by Salmonella Enteritidis and is generally associated with the consumption of poultry products. Inactivated Salmonella Enteritidis cell vaccine is one of the available methods to control Salmonella Enteritidis in breeders and laying hens, however results in terms of efficacy vary. This vaccine has never been tested in Brazil, therefore, the present work was carried out to assess three commercial inactivated Salmonella Enteritidis vaccines allowed in Brazil. Four hundred white light variety commercial laying hens were obtained at one-day-of age. At eight weeks old, the birds were divided into four groups with one hundred animals each. Birds from three groups (V1, V2 and V3) received different intramuscular vaccines, followed by a booster dose at 16 weeks of age. Birds from another group (CG) were not vaccinated. When the laying hens were 20, 25 and 31 weeks old, 13 from each group were transferred to another room and were challenged by inoculating 2 mL neat culture of Salmonella Enteritidis. On the second day after each challenge, the caecal contents, spleen, liver and ovary of three birds from each group were analyzed for the presence of Salmonella Enteritidis. Twice a week a cloacal swab of each bird was taken and all eggs laid were examined for the presence of Salmonella Enteritidis. After four consecutive negative cloacal swabs in all the groups, the birds were sacrificed so as to examine the liver, caecal contents and ovaries. Overall, the inactivated vaccine used in group V3 reduced Salmonella Enteritidis in the feces and eggs. A very small amount of Salmonella was found in the spleen, liver, ovary and caeca of the birds in the four groups during the whole experiment. In general, inactivated Salmonella Enteritidis vaccines was able to decrease the presence of Salmonella Enteritidis in the birds and in the eggs as...

Salmonella Enteritidis é um dos agentes responsáveis por toxinfecção alimentar em humanos e tem sido associada a alimentos de origem avícola. Entre os métodos disponíveis para o seu controle está a vacinação de poedeiras e matrizes com vacinas inativadas (bacterinas). Os resultados a respeito da proteção das bacterinas contra Salmonella Enteritidis em aves são variados. Face à inexistência de dados referentes ao uso dessas vacinas no Brasil, realizou-se o presente trabalho. Foram utilizadas 400 pintinhas de uma linhagem de postura leve. Na 8º semana de idade, as aves foram divididas em quatro grupos (V1, V2, V3 e CG). Três diferentes bacterinas comerciais foram administradas às aves do V1, V2 e V3 em duas doses, na 8º e 16º semanas de vida; as do CG não receberam vacina. Treze aves por grupo foram infectadas com Salmonella Enteritidis nas 20º, 25º e 31º semanas. No 2º dia após cada desafio foram sacrificadas três aves por grupo, para contagem de Salmonella Enteritidis em fígado, baço, conteúdo cecal e pesquisa do microrganismo no ovário. Suabes de cloaca foram realizados dois dias pós-infecção (dpi) e duas vezes por semana. Todos os ovos foram examinados. Após a ausência de Salmonella Enteritidis em quatro suabes de cloaca consecutivos, esse microrganismo foi pesquisado em fígado, conteúdo cecal e ovário. Não houve diferença da contagem de Salmonella Enteritidis nos órgãos. O conteúdo cecal das aves do V1 teve menos Salmonella que as do CG. As aves do V3 excretaram menos Salmonella em fezes e ovos. Conforme os resultados observados no V3, é possível reduzir excreção de Salmonella Enteritidis com o uso de bacterinas; contudo, deve ser utilizado de forma complementar a boas práticas de manejo, limpeza e desinfecção.

Control of Salmonella enterica serovar Enteritidis in laying hens by inactivated Salmonella Enteritidis vaccines.

Salmonella Enteritidis is one of the agents that is responsible for outbreaks of human foodborne salmonellosis caused by Salmonella Enteritidis and is generally associated with the consumption of poultry products. Inactivated Salmonella Enteritidis cell vaccine is one of the available methods to control Salmonella Enteritidis in breeders and laying hens, however results in terms of efficacy vary. This vaccine has never been tested in Brazil, therefore, the present work was carried out to assess three commercial inactivated Salmonella Enteritidis vaccines allowed in Brazil. Four hundred white light variety commercial laying hens were obtained at one-day-of age. At eight weeks old, the birds were divided into four groups with one hundred animals each. Birds from three groups (V1, V2 and V3) received different intramuscular vaccines, followed by a booster dose at 16 weeks of age. Birds from another group (CG) were not vaccinated. When the laying hens were 20, 25 and 31 weeks old, 13 from each group were transferred to another room and were challenged by inoculating 2 mL neat culture of Salmonella Enteritidis. On the second day after each challenge, the caecal contents, spleen, liver and ovary of three birds from each group were analyzed for the presence of Salmonella Enteritidis. Twice a week a cloacal swab of each bird was taken and all eggs laid were examined for the presence of Salmonella Enteritidis. After four consecutive negative cloacal swabs in all the groups, the birds were sacrificed so as to examine the liver, caecal contents and ovaries. Overall, the inactivated vaccine used in group V3 reduced Salmonella Enteritidis in the feces and eggs. A very small amount of Salmonella was found in the spleen, liver, ovary and caeca of the birds in the four groups during the whole experiment. In general, inactivated Salmonella Enteritidis vaccines was able to decrease the presence of Salmonella Enteritidis in the birds and in the eggs as well. Nevertheless, they must be associated with general hygiene and disinfection practices in poultry husbandry.