Effect of Infectious Bursal Disease (Ibd) Vaccines on Infection of Salmonella Heidelberg in Broiler Chickens

Salmonella Heidelberg (SH) has represented a great concern to the Brazilian poultry industry in the last years. It is known that immunosuppression in poultry is a contributing factor to increase Salmonella faecal shedding and to disturb control programmes. Not only infectious bursal disease (IBD) virus but also some live vaccines have been reported to induce immunosuppression. In the present study we assessed the effects of two live vaccines against IBD on SH-infected broiler chicks. At 7 days of age, birds of three groups (vaccinated with recombinant HVT-IBD vector, with immune complex-IBD vaccine and unvaccinated) were orally challenged with 1 x 108 CFU of SH. A group of hatchmates remained unvaccinated/unchallenged to serve as negative controls. Caecal colonization and systemic invasion were evaluated by bacterial enumeration at 1, 3, 5, 7 and 14 days post-infection (Dpi) and SH faecal shedding assessed by cloacal swabs at 3, 7, 10 and 14 Dpi. The counts of SH in caecal contents were higher in birds vaccinated with immune complex-IBD than in those that received the HVT-IBD vector vaccine at 5, 7 and 14 dpi (p 0.01). There were no statistical differences in bacterial counts in liver and spleen among birds of different groups. Cloacal swabs also indicated that the birds vaccinated with immune complex-IBD shed more SH than those vaccinated with HVT-IBD vector or those unvaccinated (p 0.01). The results of the present study suggested that the immunosuppressive effect of the immune complex-IBD vaccine helped to increase the SH-faecal shedding in the infected birds.(AU)

Effect of Infectious Bursal Disease (Ibd) Vaccines on Infection of Salmonella Heidelberg in Broiler Chickens

Salmonella Heidelberg (SH) has represented a great concern to the Brazilian poultry industry in the last years. It is known that immunosuppression in poultry is a contributing factor to increase Salmonella faecal shedding and to disturb control programmes. Not only infectious bursal disease (IBD) virus but also some live vaccines have been reported to induce immunosuppression. In the present study we assessed the effects of two live vaccines against IBD on SH-infected broiler chicks. At 7 days of age, birds of three groups (vaccinated with recombinant HVT-IBD vector, with immune complex-IBD vaccine and unvaccinated) were orally challenged with 1 x 108 CFU of SH. A group of hatchmates remained unvaccinated/unchallenged to serve as negative controls. Caecal colonization and systemic invasion were evaluated by bacterial enumeration at 1, 3, 5, 7 and 14 days post-infection (Dpi) and SH faecal shedding assessed by cloacal swabs at 3, 7, 10 and 14 Dpi. The counts of SH in caecal contents were higher in birds vaccinated with immune complex-IBD than in those that received the HVT-IBD vector vaccine at 5, 7 and 14 dpi (p 0.01). There were no statistical differences in bacterial counts in liver and spleen among birds of different groups. Cloacal swabs also indicated that the birds vaccinated with immune complex-IBD shed more SH than those vaccinated with HVT-IBD vector or those unvaccinated (p 0.01). The results of the present study suggested that the immunosuppressive effect of the immune complex-IBD vaccine helped to increase the SH-faecal shedding in the infected birds.

Evaluation of propanediol and cobalamin metabolism in the intestinal colonization and systemic invasion of Salmonella Enteritidis in laying hens / [Avaliação do metabolismo do propanodiol e da cobalamina na colonização intestinal e na infecção sistêmica de Salmonella Enteritidis em poedeiras]

Embora Salmonella Enteritidis (SE) seja capaz de metabolizar 1,2-propanodiol (1,2-Pd), utilizado como fonte de carbono e de energia ao longo de uma rota dependente de vitamina B12, a importância deste composto na infeção de Gallus gallus domesticus por SE permanece desconhecida. No presente estudo, foram construídos um mutante de SE sem os genes pduCDE, que codifica a propanodiol desidratase (Pdu), e outro contendo as deleções no pduCDE e também nos genes cobS e cbiA, responsáveis pela síntese de vitamina B12. Em seguida, avaliou-se a importância do metabolismo do 1,2-Pd em SE para colonização intestinal de infecção sistêmica de poedeiras comerciais. As estirpes mutantes de SE foram capazes de colonizar o intestino, de serem excretadas nas fezes e de invadir o baço e o fígado na mesma intensidade que a estirpe selvagem, o que sugere que os produtos dos genes pduC, pduD, pduE, cobS e cbiA não são essenciais durante infecção por Salmonella Enteritidis nessa espécie.(AU)

Evaluation of Disinfectants Used in Pre-Chilling water Tanks of Poultry Processing Plants

In poultry processing plants, disinfectants are often added to pre-chilling water tanks to reduce microbial contamination. The present study aimed at evaluating the effect of five disinfectants (acidified sodium chlorite, alkyl dimethyl benzyl ammonium chloride, chlorine dioxide, peracetic acid, and sodium hypochlorite) on the populations of food quality indicator microorganisms and on Salmonella Enteritidis (SE) in the presence and absence of organic matter. The results showed that chlorine dioxide and sodium hypochlorite did not reduce microbial carcass counts. On the other hand, acidified sodium chlorite, alkyl dimethyl benzyl ammonium chloride and peracetic acid reduced total and fecal coliform counts. Peracetic acid reduced the number of psychrotrophic microorganisms. All products were effective in reducing SE counts only in the absence of organic matter. Acidified sodium chlorite, alkyl dimethyl benzyl ammonium chloride and peracetic acid could be candidates for the replacement of sodium hypochlorite (commonly used in Brazil) in pre-chilling tanks.

Evaluation of Disinfectants Used in Pre-Chilling water Tanks of Poultry Processing Plants

In poultry processing plants, disinfectants are often added to pre-chilling water tanks to reduce microbial contamination. The present study aimed at evaluating the effect of five disinfectants (acidified sodium chlorite, alkyl dimethyl benzyl ammonium chloride, chlorine dioxide, peracetic acid, and sodium hypochlorite) on the populations of food quality indicator microorganisms and on Salmonella Enteritidis (SE) in the presence and absence of organic matter. The results showed that chlorine dioxide and sodium hypochlorite did not reduce microbial carcass counts. On the other hand, acidified sodium chlorite, alkyl dimethyl benzyl ammonium chloride and peracetic acid reduced total and fecal coliform counts. Peracetic acid reduced the number of psychrotrophic microorganisms. All products were effective in reducing SE counts only in the absence of organic matter. Acidified sodium chlorite, alkyl dimethyl benzyl ammonium chloride and peracetic acid could be candidates for the replacement of sodium hypochlorite (commonly used in Brazil) in pre-chilling tanks. (AU)

Salmonella serovars in laying hen flocks and commercial table eggs from a region of São Paulo state, Brazil

Salmonella spp. is the main originator of human foodborne diseases worldwide and is mainly transmitted by food containing eggs. In Brazil, as a result of the lack of studies and data collection very little is known about the prevalence of Salmonella spp. in laying hen flocks and commercial table eggs. Consequently the present study was elaborated and aimed at generating data about Salmonella spp. in part of the Brazilian egg production chain. Eight flocks of day-old chicks, eight flocks of adult laying hens (four vaccinated with bacterin against Salmonella Enteritidis and four unvaccinated) and commercial table eggs from four supermarkets were examined. Salmonella spp. was isolated in 50 % of the newly hatched chicks, 25 % of the adult flocks and 1.5 % of egg samples examined. S. enterica subsp. enterica 4,12:r:-, S. Mbandaka, S. enterica subsp. enterica 6,7: z10:-, S. Enteritidis and S. Havana were the serovars isolated in birds. In commercial table-eggs S. Mbandaka, S. enterica subsp. enterica 6,7: z10:- and S. Braenderup were isolated. These results show that Salmonella spp. is present in laying hen flocks and consequently in eggs destined for human consumption. Probably, some of the Salmonella serovars are being introduced in egg farms by vertical via.

Salmonella serovars in laying hen flocks and commercial table eggs from a region of São Paulo state, Brazil

Salmonella spp. is the main originator of human foodborne diseases worldwide and is mainly transmitted by food containing eggs. In Brazil, as a result of the lack of studies and data collection very little is known about the prevalence of Salmonella spp. in laying hen flocks and commercial table eggs. Consequently the present study was elaborated and aimed at generating data about Salmonella spp. in part of the Brazilian egg production chain. Eight flocks of day-old chicks, eight flocks of adult laying hens (four vaccinated with bacterin against Salmonella Enteritidis and four unvaccinated) and commercial table eggs from four supermarkets were examined. Salmonella spp. was isolated in 50 % of the newly hatched chicks, 25 % of the adult flocks and 1.5 % of egg samples examined. S. enterica subsp. enterica 4,12:r:-, S. Mbandaka, S. enterica subsp. enterica 6,7: z10:-, S. Enteritidis and S. Havana were the serovars isolated in birds. In commercial table-eggs S. Mbandaka, S. enterica subsp. enterica 6,7: z10:- and S. Braenderup were isolated. These results show that Salmonella spp. is present in laying hen flocks and consequently in eggs destined for human consumption. Probably, some of the Salmonella serovars are being introduced in egg farms by vertical via.(AU)

Salmonella spp. in meat-type quails (Coturnix coturnix coturnix) in the State of São Paulo, Brazil

In the present study Salmonella spp. was surveyed in four flocks of meat-type quails reared in a farm that also had processing plant on site, located in the region of Bastos, state of São Paulo, Brazil. Meconium samples of one-day-old quail chicks were collected from transport cardboard boxes. Cecal content was collected on days 7, 14, 21, 28 and 35 of rearing. At 36 days of age, birds were slaughtered in the farm's processing plant, where two samples of water from the scalding and the chilling tanks and four carcasses per flock were collected. All samples were examined for Salmonella spp. using traditional bacteriological methods. Salmonella spp. was present in meconium samples of three flocks and in cecal feces of the four flocks. This bacterium was also isolated in the chiller water and in the carcasses of three of the evaluated flocks and in the scalding water of one flock. In this study, S. enterica subspecies enterica 4, 5, 12; S. Corvalis; S. Give; S. Lexington; S. Minnesota; S. Schwarzengrund; S. Rissen and S. Typhimurium were the eight serovars identified.

Experimental infection of commercial layers with wild or attenuated Salmonella Gallinarum mutant strains: anatomic pathology, total blood cell count and serum protein levels

The aim of the present study was to comparatively evaluate hemogram, blood serum components and anatomopathologic alterations in commercial layers experimentally challenged with an attenuated vaccine candidate strain (SG∆cobS∆cbiA) and other two pathogenic strains (SGDcobS and SGNalr) of Gallinarum (SG). In total, 280 commercial layers were randomly divided into 4 groups (G1, G2, G3 and G4). At five days of age, birds from groups G1 received approximately 107 colony forming units (CFU) of SGDcobS; meanwhile birds from group G2 and G3 received the same dose of SGNalr and SG∆cobS∆cbiA, respectively. Birds from G4 were not infected. At 24 hours before (DBI) and 24 hours after (1 DAI), and three (3 DAI), five (5 DAI), seven (7 DAI) ten (10 DAI), and fifteen (15 DAI) days after the infection, 10 birds of each group were humanely killed and blood samples collected to hematological and serum tests. Samples of liver, spleen, thymus, bursa of Fabricius, kidney and heart were also collected for the histological examination. Birds inoculated with SGDcobS and SGNalr showed similar alterations in hemogram, blood serum components and anatomopathologic exams. On the other hand, the exams of birds inoculated with SG∆cobS∆cbiA strain were similar to those of the uninfected birds. However, changes could be noticed in levels of uric acid and cholesterol during the course of the infection of birds from G3. Decrease in levels of light IgG 3 DAI was also observed in birds from this group. Pyknosis in kidney cells was a microscopic alteration found in birds from G3. Further studies must be done to verify if these alterations will not interfere in the performance of the vaccinate birds with SG∆cobS∆cbiA strain.(AU)

Salmonella spp. in meat-type quails (Coturnix coturnix coturnix) in the State of São Paulo, Brazil

In the present study Salmonella spp. was surveyed in four flocks of meat-type quails reared in a farm that also had processing plant on site, located in the region of Bastos, state of São Paulo, Brazil. Meconium samples of one-day-old quail chicks were collected from transport cardboard boxes. Cecal content was collected on days 7, 14, 21, 28 and 35 of rearing. At 36 days of age, birds were slaughtered in the farm's processing plant, where two samples of water from the scalding and the chilling tanks and four carcasses per flock were collected. All samples were examined for Salmonella spp. using traditional bacteriological methods. Salmonella spp. was present in meconium samples of three flocks and in cecal feces of the four flocks. This bacterium was also isolated in the chiller water and in the carcasses of three of the evaluated flocks and in the scalding water of one flock. In this study, S. enterica subspecies enterica 4, 5, 12; S. Corvalis; S. Give; S. Lexington; S. Minnesota; S. Schwarzengrund; S. Rissen and S. Typhimurium were the eight serovars identified.(AU)