Histological parameters to evaluate intestinal health on broilers challenged with Eimeria and Clostridium perfringens with or without enramycin as growth promoter.

The maintenance of integrity of the gastrointestinal tract is an important aspect for animal productivity, since it is able to absorb nutrients more efficiently and serves as a barrier against microorganisms. To control agents detrimental to intestinal integrity, growth-promoting antibiotics (AGP) are used, which reduce the number of toxin-producing microorganisms in the intestinal lumen, acting as anti-inflammatory agents. There is a demand for restriction of use of AGP in animal feed, but there are few studies showing what parameters we should observe to search for alternative additives. The aim of this study was to establish histological parameters that explain the effect of enramycin as growth promoter on intestinal health in broilers challenged with Eimeria and Clostridium perfringens. The zootechnical performance and the histology by I See Inside (ISI) methodology were evaluated on liver and ileum samples. Chickens challenged without AGP have the worst BWG, FCR, and histological ISI score (ISI score 9) in the ileum compared to non-challenged (ISI score 5). The use of enramycin on challenged group significantly minimized the ISI score in the ileum at 21 and 28 d (ISI score 7.4 and 8.0, respectively) compared with the challenged group not fed with enramycin (ISI score 9.2 and 9.9, respectively), associated with reduced lamina propria thickness and inflammatory cell infiltration. We suggest these 2 histological parameters as a standard to compare products for gut health.

Effect of aflatoxin experimental ingestion and Eimeira vaccine challenges on intestinal histopathology and immune cellular dynamic of broilers: applying an Intestinal Health Index.

The present study evaluated the effect of aflatoxin B1 and Eimeria vaccine challenges and their interaction on intestinal morphology, applying the morphometric index "I See Inside" (ISI). Immune cellular response and broiler chicken performance were also studied. A total of 240 broiler chickens were divided in a 2 × 2 factorial arrangement with 4 treatments, T1: Control diet and no challenge (CON), T2: Aflatoxin B1 (AFLA), T3: Control diet and Eimeria challenge (COC), and T4: Aflatoxin B1 and Eimeria challenge (AFLA+COC). The mathematical morphometric index ISI was applied to evaluate macro and microscopic alterations. Samples of liver and jejunum were analyzed for macrophages, CD4+, and CD8+ cells counting by immunohistochemistry at 7, 14, and 21 d of age. Chickens challenged with Eimeria presented higher ISI of macroscopic alterations associated to Eimeria lesion at the medium small intestine, lower body weight gain (BWG) and feed intake (FI), and worse feed conversion ratio compared to non-challenged birds. Both Eimeria and aflatoxin challenges modulated the immune cells in the jejunum and liver, generally increasing the number of macrophages, CD4+, and CD8+ cells in relation to the control group. Birds from COC and COC+AFLA groups presented higher ISI histological score in the jejunum at 7 and 14 d of age compared to the CON and AFLA groups. The reduction of FI and BWG was correlated to high histological ISI and resulted in a high presence of immune cells in tissues, suggesting immune response demand. The histological ISI had statistical correlation to broiler performance.

Salmonella typhimurium vaccine to control a brazilian Salmonella heidelberg strain in broiler chickens / Vacina de Salmonella typhimurium para controlar cepa brasileira de Salmonella heidelberg em frangos de corte

Foodborne Salmonella infections in humans, which results from the consumption of contaminated poultry meat and eggs, are a major public health concern. Vaccination of animals against Salmonella is one strategy to prevent these infections and reduce the risks to public health. Live attenuated Salmonella enterica vaccines can confer protection against salmonellosis by inducing both cell-mediated and mucosal immune responses. This study assessed a live, attenuated Salmonella enterica Typhimurium (ST) vaccine in broiler chickens against a heterologous challenge with Salmonella Heidelberg (SH) by evaluating bacterial quantification, immune cells infiltration, and cytokine gene expression in the cecum. The treatments were: T1, non-vaccinated, non-challenged; T2, non-vaccinated, SH-challenged; T3, ST-vaccinated and SH-challenged. At 28 days of age, the ST-vaccinated group had significantly recovered reduction of SH in the crop (P<0,01) and cecum (P = 0,021) compared to the non-vaccinated SH-challenged group, with no significant changes (P˃0,05) in macrophages, T CD4+, or T CD8+ cells dynamics during the same period. Aerosol vaccination on the first day promoted greater interleukin-12 expression in the liver (P<0,05) and interleukin-10 expression and T CD8+ cells in the ileum 16 hours after housing. After prime-boosted oral immunization on the 13th day, the vaccinated group had greater expression of macrophages and T CD4+ cells in the liver (P<0,05) than the control group. Two doses of a live ST-attenuated vaccine promoted a partial cross-protective effect against SH strain UFPR1 challenge in broilers.(AU)

Infecções por Salmonella transmitidas por alimentos como consumo de carne de frango e ovos contaminados em seres humanos constituem um importante problema de saúde pública. A vacinação de animais contra Salmonella é uma estratégia para prevenir essas infecções e reduzir o risco para a saúde pública. As vacinas vivas atenuadas de Salmonella enterica podem conferir proteção contra a salmonelose, induzindo respostas imunológicas mediadas por células e em mucosas. Este estudo avaliou uma vacina viva e atenuada de Salmonella enterica Typhimurium (ST) em frangos de corte contra um desafio heterólogo com Salmonella Heidelberg (SH), avaliando a quantificação de Salmonella, infiltração de células imunes e a expressão de genes de citocinas no ceco. Os tratamentos foram: T1, não vacinado, não desafiado; T2, não vacinado, desafiado com SH; T3, ST-vacinado, desafiado com SH. Aos 28 dias de idade, o grupo vacinado com ST apresentou significativa redução de SH no papo (P<0,01) e no ceco (P = 0,021) comparado ao grupo T2-não vacinado SH-desafiado, sem alterações significativas na dinâmica celular de macrófagos, T CD4+ ou T CD8+ (P˃0,05) durante o mesmo período. A vacinação por aerossol no primeiro dia promoveu maior expressão de IL-12 no fígado (P<0,05), maior expressão de IL-10 e células T CD8+ no íleo, 16 horas após o alojamento. Após o reforço de imunização oral ao 13º dia, o grupo vacinado apresentou maior expressão de macrófagos e células T CD4+ no fígado (P<0,05) do que o grupo controle. Duas doses de uma vacina viva atenuada de ST promoveram um efeito de proteção cruzada parcial contra o desafio da cepa de Salmonella Heidelberg cepa UFPR1 em frangos de corte.(AU)

Salmonella typhimurium vaccine to control a brazilian Salmonella heidelberg strain in broiler chickens / Vacina de Salmonella typhimurium para controlar cepa brasileira de Salmonella heidelberg em frangos de corte

Foodborne Salmonella infections in humans, which results from the consumption of contaminated poultry meat and eggs, are a major public health concern. Vaccination of animals against Salmonella is one strategy to prevent these infections and reduce the risks to public health. Live attenuated Salmonella enterica vaccines can confer protection against salmonellosis by inducing both cell-mediated and mucosal immune responses. This study assessed a live, attenuated Salmonella enterica Typhimurium (ST) vaccine in broiler chickens against a heterologous challenge with Salmonella Heidelberg (SH) by evaluating bacterial quantification, immune cells infiltration, and cytokine gene expression in the cecum. The treatments were: T1, non-vaccinated, non-challenged; T2, non-vaccinated, SH-challenged; T3, ST-vaccinated and SH-challenged. At 28 days of age, the ST-vaccinated group had significantly recovered reduction of SH in the crop (P<0,01) and cecum (P = 0,021) compared to the non-vaccinated SH-challenged group, with no significant changes (P˃0,05) in macrophages, T CD4+, or T CD8+ cells dynamics during the same period. Aerosol vaccination on the first day promoted greater interleukin-12 expression in the liver (P<0,05) and interleukin-10 expression and T CD8+ cells in the ileum 16 hours after housing. After prime-boosted oral immunization on the 13th day, the vaccinated group had greater expression of macrophages and T CD4+ cells in the liver (P<0,05) than the control group. Two doses of a live ST-attenuated vaccine promoted a partial cross-protective effect against SH strain UFPR1 challenge in broilers.

Infecções por Salmonella transmitidas por alimentos como consumo de carne de frango e ovos contaminados em seres humanos constituem um importante problema de saúde pública. A vacinação de animais contra Salmonella é uma estratégia para prevenir essas infecções e reduzir o risco para a saúde pública. As vacinas vivas atenuadas de Salmonella enterica podem conferir proteção contra a salmonelose, induzindo respostas imunológicas mediadas por células e em mucosas. Este estudo avaliou uma vacina viva e atenuada de Salmonella enterica Typhimurium (ST) em frangos de corte contra um desafio heterólogo com Salmonella Heidelberg (SH), avaliando a quantificação de Salmonella, infiltração de células imunes e a expressão de genes de citocinas no ceco. Os tratamentos foram: T1, não vacinado, não desafiado; T2, não vacinado, desafiado com SH; T3, ST-vacinado, desafiado com SH. Aos 28 dias de idade, o grupo vacinado com ST apresentou significativa redução de SH no papo (P<0,01) e no ceco (P = 0,021) comparado ao grupo T2-não vacinado SH-desafiado, sem alterações significativas na dinâmica celular de macrófagos, T CD4+ ou T CD8+ (P˃0,05) durante o mesmo período. A vacinação por aerossol no primeiro dia promoveu maior expressão de IL-12 no fígado (P<0,05), maior expressão de IL-10 e células T CD8+ no íleo, 16 horas após o alojamento. Após o reforço de imunização oral ao 13º dia, o grupo vacinado apresentou maior expressão de macrófagos e células T CD4+ no fígado (P<0,05) do que o grupo controle. Duas doses de uma vacina viva atenuada de ST promoveram um efeito de proteção cruzada parcial contra o desafio da cepa de Salmonella Heidelberg cepa UFPR1 em frangos de corte.

SALMONELLA TYPHIMURIUM VACCINE TO CONTROL A BRAZILIAN SALMONELLA HEIDELBERG STRAIN IN BROILER CHICKENS

Foodborne Salmonella infections in humans, which results from the consumption of contaminated poultry meat and eggs, are a major public health concern. Vaccination of animals against Salmonella is one strategy to prevent these infections and reduce the risks to public health. Live attenuated Salmonella enterica vaccines can confer protection against salmonellosis by inducing both cell-mediated and mucosal immune responses. This study assessed a live, attenuated Salmonella enterica Typhimurium (ST) vaccine in broiler chickens against a heterologous challenge with Salmonella Heidelberg (SH) by evaluating bacterial quantification, immune cells infiltration, and cytokine gene expression in the cecum. The treatments were: T1, non-vaccinated, non-challenged; T2, non-vaccinated, SH-challenged; T3, ST-vaccinated and SH-challenged. At 28 days of age, the ST-vaccinated group had significantly recovered reduction of SH in the crop (P