Organic acids and/or compound with defined microorganisms to control Salmonella enterica serovar Enteritidis experimental infection in chickens

The association of human foodborne salmonellosis with poultry products enhanced the efforts to control Salmonella Enteritidis in poultry farms. Dietary organic acid supplementation is one of the measures currently used to reduce the presence of undesirable microorganisms. Another method to control enteric Salmonella in poultry is competitive exclusion using defined or undefined microorganisms products. Organic acids and microbiological methods to accelerate the development of the intestinal microbiota can be used individually or in combination. The present study evaluated the effect of dietary supplementation of an acidifier and of a defined multi-strain microbial mixture (Biomin® PoultryStar) via drinking water in the control of the intestinal colonization of broilers by Salmonella Enteritidis. Four experiments were performed. The first experiment showed that the organic acids mixture was able to prevent Salmonella Enteritidis colonization of ceca in both inclusion rates applied (p 0.05). In the second and third experiments the probiotic either individually or in combination the acidifier, both in high and low doses reduced the incidence of Salmonella Enteritidis in the cecal contents (p 0.05). In these three experiments, birds were orally challenged. Similar results were obtained in a fourth trial, in which challenge was made by contact.

Organic acids and/or compound with defined microorganisms to control Salmonella enterica serovar Enteritidis experimental infection in chickens

The association of human foodborne salmonellosis with poultry products enhanced the efforts to control Salmonella Enteritidis in poultry farms. Dietary organic acid supplementation is one of the measures currently used to reduce the presence of undesirable microorganisms. Another method to control enteric Salmonella in poultry is competitive exclusion using defined or undefined microorganisms products. Organic acids and microbiological methods to accelerate the development of the intestinal microbiota can be used individually or in combination. The present study evaluated the effect of dietary supplementation of an acidifier and of a defined multi-strain microbial mixture (Biomin® PoultryStar) via drinking water in the control of the intestinal colonization of broilers by Salmonella Enteritidis. Four experiments were performed. The first experiment showed that the organic acids mixture was able to prevent Salmonella Enteritidis colonization of ceca in both inclusion rates applied (p 0.05). In the second and third experiments the probiotic either individually or in combination the acidifier, both in high and low doses reduced the incidence of Salmonella Enteritidis in the cecal contents (p 0.05). In these three experiments, birds were orally challenged. Similar results were obtained in a fourth trial, in which challenge was made by contact.

Isolamento de salmonella: comparação das etapas de pré- enriquecimento e enriquecimento direto de amostras de fezes armazenadas por 24 e 96 horas

ABSTRACT This work was carried out to assess the preenrichment (PE) and enrichment (DE) steps for isolating Salmonella serotypes Enteritidis (SE) and Typhimurium (STM) from chicken feces kept at 4° C for 24 and 96h. The samples were artificially contaminated and kept in 1% peptone water at 4° C for 24 or 96h. After that, part of them was incubated at 37° C/24h and part was inoculated into enrichment broth, selenite broth plus novobiocin (SN) and tetrathionate broth plus novobiocin (TN) incubated at 37°C/24h. The PE culture was inoculated in SN, TN and Rapapport-Vassiliadis novobiocin (RVN), also incubated at 37° C/24h. The enrichment broth was plated on brilliant green agar (BGA), MacConkey agar (MCA), Hektoen agar (HEA), Salmonella-Shigella agar (SSA), xylose-lysine desoxicholate agar (XLDA) and xylose-lysine tergitol 4 (XLT4), which were incubated at 37° C/24h. Salmonella-like colonies were submitted to TSI agar and LIA agar, and incubated at 37° C/24h, as well as to slide agglutination tested with poly O and poly H Salmonella antiserum. When the samples were stored for 24h there was no difference between PE and DE (p > 0.05). However after 96h the PE was superior to DE (p 0.05). For enrichment, better results were seen with RVN broth (p 0.05). The XLD yielded

RESUMO Este trabalho foi desenvolvido para avaliar comparativamente o isolamento de Salmonella sorotipos Enteritidis (SE) e Typhimurium (STM) a partir do enriquecimento direto (ED) ou processamento com pré-enriquecimento (PE) de amostras de fezes de aves adultas, armazenadas em água peptonada tamponada a 1% (APT) por 24 ou 96h a 4º C. Utilizou-se os caldos de enriquecimento Rapapport-Vassiliadis novobiocina (RVN), tetrationato-novobiocina (TN) e selenitonovobiocina (SN) e os meios para plaqueamento ágar verde brilhante (VB), ágar de MacConkey (MC), ágar de Hektoen (HE), ágar Salmonella-Shigella (SS), ágar xilose lisina desoxicolato (XLD) e ágar xilose lisina tergitol 4 (XLT4). O procedimento bacteriológico incluiu as etapas de pré-enriquecimento, enriquecimento em caldo seletivo, plaqueamento, testes bioquímicos presuntivos e confirmação sorológica com utilização de soros polivalentes anti-antígenos somáticos e anti-antígenos flagelares de Salmonella. Não houve diferença estatisticamente significativa (p > 0,05) para as amostras armazenadas por 24h submetidas tanto ao PE quanto ao ED. Entretanto, em armazenagem por 96h o número de isolamentos nas amostras submetidas ao PE foi estatisticamente superior às submetidas ao ED (p 0,05). Quanto aos caldos enriquecedores, não houve diferença estatística de número de isolamentos (p > 0,05) entre os caldos SN e TN, mas o caldo RVN mostrou-se estatisticamente superior aos demais (p 0,05). Para os meios de plaqueamento, o XLD destacou-se por promover maior número de recuperações, embora sem significado estatístico (p > 0,05) para as amostras estocadas por 24h. Entre os dois sorotipos de Salmonella (SE e STM) não houve diferença estatística no número de recuperações (p > 0,05).

Time required to protect the intestinal tract of chicks against Salmonella enterica serovar enteritidis using competitive exclusion

Competitive exclusion (CE) has been designed to accelerate the colonization of the alimentary tract of young commercial birds and it has been also used to repopulate the digestive tract after antibiotic therapy. The method has been successfully adopted as a means to prevent enteric salmonellosis. The present study was carried out to evaluate if CE is able to prevent this kind of infection. Newly hatched chicks were given a CE culture and at different intervals of time birds infected with Salmonella Enteritidis were placed together with the group of treated birds. CE culture was prepared from feces of adult laying hens incubated overnight at 37C under aerobic conditions. Birds were killed 4 and 8 days after challenge and viable counts of Salmonella Enteritidis were assessed in the cecal contents. The results showed that Salmonella infection was reduced even if CE culture administration was concomitant with the inclusion of the infected bird in the group.

Time required to protect the intestinal tract of chicks against Salmonella enterica serovar enteritidis using competitive exclusion

Competitive exclusion (CE) has been designed to accelerate the colonization of the alimentary tract of young commercial birds and it has been also used to repopulate the digestive tract after antibiotic therapy. The method has been successfully adopted as a means to prevent enteric salmonellosis. The present study was carried out to evaluate if CE is able to prevent this kind of infection. Newly hatched chicks were given a CE culture and at different intervals of time birds infected with Salmonella Enteritidis were placed together with the group of treated birds. CE culture was prepared from feces of adult laying hens incubated overnight at 37C under aerobic conditions. Birds were killed 4 and 8 days after challenge and viable counts of Salmonella Enteritidis were assessed in the cecal contents. The results showed that Salmonella infection was reduced even if CE culture administration was concomitant with the inclusion of the infected bird in the group.