Avaliação in vitro da atividade inibitória de Lactobacillus spp., isolados do inglúvio e cecos de aves sobre Salmonella

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Detection of T lymphocytes in intestine of broiler chicks treated with Lactobacillus spp. and challenged with Salmonella enterica serovar enteritidis

The expression of immune response in the form of leukocytic infiltrate by CD3+, CD4+, and CD8+ cells in the epithelium and in the intestinal lamina propria of chicks was studied in the present work by means of immunohistochemical reaction. The chicks were treated with Lactobacillus spp. or cecal microflora (CM) and experimentally challenged or not with Salmonella enterica serovar Enteritidis. The 320 birds utilized were divided into 4 groups containing 80 chicks each and submitted to treatments with Lactobacillus reuteri, Lactobacillus salivarius, Lactobacillus acidophilus, and CM. Each group was subdivided into 4 subgroups of 20 birds each and classified into a subgroup that did not receive treatment (negative control), subgroup treated, subgroup treated and challenged with Salmonella Enteritidis, and subgroup only challenged with Salmonella Enteritidis (positive control). The results obtained show that the treatment with L. reuteri, L. salivarius, L. acidophilus, or CM and challenged or not with Salmonella Enteritidis determine immune response in the form of leukocytic infiltrate by CD3+ and CD8+ lymphocytes followed by CD4+ in the epithelium and in the lamina propria of the duodenum, jejunum, and cecum of chicks up to 12 d of age. The quantity of CD3+ lymphocytes was significantly higher (P < 0.05) in the intestine of chicks treated with L. acidophilus or CM and challenged or not with Salmonella Enteritidis; however, the higher quantity of CD8+ lymphocytes was in the intestine of chicks treated with CM and challenged with Salmonella Enteritidis. The duodenum was the segment in which the immune response by T cells (CD3+, CD4+, and CD8+) was stimulated with the greatest intensity, followed by, respectively, the jejunum and cecum. The quantity of CD3+ lymphocytes present in the duodenum, jejunum, and cecum increases with the age of chicks, independent of the stimulus determined by treatments or challenge.

Avaliação da atividade inibitória In vitro de bacteriocinas extraídas de Lactobacillus spp. isolados de aves (Gallus gallus, Linnaeus, 1758)

Pós-graduação em Medicina Veterinária - FMVZ

Detection of CD4+ and CD8+ lymphocytes in the intestine of broiler chicks treated with lactobacillus spp. and challenged with Salmonella enterica serovar enteritidis

The expression of immune response as a leukocytic infiltrate by CD4+ and CD8+ cells in the epithelium and in the intestinal lamina propria of chicks fed Lactobacillus spp or cecal microflora (CM) and experimentally challenged or not with Salmonella enterica serovar Enteritidis (SE) was studied using immunohistochemistry. Three hundred and twenty day-of-hatch broiler chicks were divided into four groups of 80 birds each and orally received L. reuteri, L. salivarius, L. acidophilus, or CM. Each group was subdivided into four subgroups of 20 birds each, classified as follows: a subgroup did not receive any oral treatment (negative control), subgroup treated with L. spp or CM, subgroup treated with L. spp or CM and challenged with SE, and subgroup only challenged with SE (positive control). The results show that the oral treatment with L. reuteri, L. salivarius, L. acidophilus, or CM and challenge or not with SE stimulated bird immune response as determined by the leukocytic infiltrate by CD8+ lymphocytes followed by CD4+ in the epithelium and in the lamina propria of the duodenum, jejunum, and cecum of chicks up to 12 days of age. CD8+ lymphocyte number was significantly higher in the intestine of chicks receiving CM and challenged with SE. The duodenum, followed by the jejunum, were the segments in which the immune response, as shown by T, CD4+ and CD8+ cells, was stimulated with the greatest intensity.

Comparação entre método bioquímico e reação em cadeia de polimerase para identificação de Lactobacillus spp., isolados de aves

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation in vitro of the antagonistic substances produced by Lactobacillus spp. isolated from chickens

To determine the inhibitory capacity of lactic acid bacteria due to the action of antagonistic substances, we tested 474 isolates of Lactobacillus from the crop and cecum of chickens against gram-positive and gram-negative indicator microorganisms by the spot-on-the-lawn and well-diffusion antagonism methods. of the 474 isolates, 265 demonstrated antimicrobial activity against the indicator microorganisms. Isolates identified as L. reuteri, L. salivarius, or Lactobacillus spp. inhibited Enterococcus faecalis, E. faecium, Listeria monocytogenes, and Salmonella spp. but not L. casei, L. delbrueckii, L. fermentum, or L. helveticus by the well-diffusion simultaneous antagonism method under anaerobic incubation conditions. The antagonistic substances produced by some of the Lactobacillus isolates were inactivated after treatment by proteolytic enzymes, which suggested that the substances could be antimicrobial peptides or bacteriocins.

Identificação e avaliação in vitro da atividade inibitória de Lactobacillus spp isolados do ingúvio e cecos de aves (Gallus gallus, Linneaus, 1758), em relação a sorotipos de Salmonella

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Detecção de línfócitos T no intestino de frangos de corte tratados com lactobacillus spp. e desafiados com Salmonella enteritidis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Utilização de bacteriófagos em associação com Lactobacillus no controle de Salmonella enterica subs. enterica sorotipo typhimurium antibiótico-resitente em frangos de corte (Gallus gallus domesticus - Linnaes, 1758)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Immunomodulatory activity and control of Salmonella Enteritidis colonization in the intestinal tract of chickens by Lactobacillus based probiotic

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Inibição do crescimento de Escherichia coli isolada de Queijo Minas Frescal por Lactobacillus acidophilus

Escherichia coli faz parte da microbiota anaeróbica facultativa normal, sendo também considerada um dos maiores patógenos entéricos predominantes no cólon dos animais e homem. Neste trabalho, realizaram-se ensaios in vitro para avaliar o grau de atividade antagonista de cinco cepas de Lactobacillus acidophilus, com capacidade probiótica sobre Escherichia coli BIA 26 (STEC) isolada de queijo Minas Frescal. Para tanto, foi utilizado o teste de inibição através do método de dupla camada em triplicata para avaliar zonas de inibição de crescimento. Todas as cepas de Lactobacillus mostraram-se capazes de inibir a E. coli, com zonas de inibição variando de 12 a 15mm de diâmetro, sendo que a maioria apresentou 14mm de diâmetro, consideradas como fortes halos de inibição.

Óxido de cálcio e Lactobacillus buchneri NCIMB 40788 na ensilagem de cana-de-açúcar in natura ou queimada

Objetivou-se avaliar os efeitos da inclusão de óxido de cálcio (CaO) e/ou L. buchneri (LB) sobre as perdas e alterações químicas de silagens de cana-de-açúcar in natura ou queimada. Foram avaliadas silagens de cana-de-açúcar in natura ou queimada produzidas sem aditivo; com Lactobacillus buchneri; com óxido de cálcio equivalente 1% da matéria natural; ou com a associação do L. buchneri e do óxido de cálcio. O delineamento experimental utilizado foi o inteiramente casualizado em esquema fatorial (2 × 4), considerando fatores a queima (presença ou ausência) e o uso de aditivos (L. buchneri, óxido de cálcio e sua associação), cada um avaliado com três repetições. O óxido de cálcio foi mais eficiente em reduzir a variação no teor de matéria seca tanto nas silagens de cana-de-açúcar in natura quanto na queimada. Nas silagens de cana-de-açúcar sem aditivos, maiores recuperações de matéria seca foram observadas quando a ensilagem foi feita com cana in natura (63,5%) em comparação à cana queimada (46,8%). Todavia, quando utilizados aditivos, não houve diferenças entre as silagens de cana-de-açúcar in natura e queimada. A presença de óxido de cálcio foi o fator que promoveu maior diferença entre as silagens. O óxido de cálcio é eficiente em reduzir as perdas e as alterações químicas na ensilagem de cana-de-açúcar, tanto in natura quanto queimada. O L. buchneri atua eficientemente em silagens de cana-de-açúcar queimada. Silagens de cana-de-açúcar queimada são mais propensas às perdas que as de cana-de-açúcar in natura.

Fermentation and aerobic stability of high-moisture corn silages inoculated with different levels of Lactobacillus buchneri

Fermentation and aerobic stability were evaluated in high-moisture corn (HMC) silage inoculated with different levels of Lactobacillus buchneri. The HMC composed of 654 g/kg dry matter (DM) was ensiled in quadruplicate laboratory silos (7 L) per treatment. L. buchneri 40788 was applied at 5 × 10(4); 1 × 10(5); 5 × 10(5); and 1 × 10(6) cfu/g to the ground corn. Silages with no additive were used as controls. After 140 d of ensiling, the silages were subjected to an aerobic stability evaluation for 12 days in which the chemical parameters, microbiological parameters and silage temperature were measured to determine the aerobic deterioration. The lactic acid, acetic acid and propionic acid concentrations did not differ between silages. The fermentation parameters of HMC were not affected by L. buchneri. The HMC containing L. buchneri had a low number of yeast and mould colonies and a more stable pH until in the eighth measurement, which improved the aerobic stability without affecting gas loss. Doses of L. buchneri greater than or equal to 5 × 10(5) cfu/g applied to the HMC were the most efficient in control of aerobic deterioration.

Fermentation and aerobic stability of corn silage inoculated with Lactobacillus buchneri

The characteristics of fermentation and aerobic stability were evaluated in corn silage inoculated with different doses of Lactobacillus buchneri. The whole corn plant (300 g/kg DM) was ensiled in quadruplicate laboratory silos (7L). L. buchneri 40788 was applied at 5×10(4), 1×10(5), 5×10(5) and 1×10(6) cfu/g of fresh forage. Silages with no additive were used as controls. After 130 d of ensiling, the silages were subjected to an aerobic stability evaluation for 12 days, in which chemical and microbiological parameters as well as the temperature of the silage were measured to determine the aerobic deterioration. The addition of L. buchneri resulted in increased acetic acid concentrations. The number of yeast colonies was low in all treated silages. The pH, lactic and propionic acid concentrations did not differ between silages. Under aerobic conditions, all the treated silages showed a low number of yeasts and a great aerobic stability. Therefore, L. buchneri is effective against yeasts and improves the aerobic stability of corn silage in laboratory silos. However, doses equal or superior to 1×10(5) cfu/g of fresh forage were more efficient in the control of aerobic spoilage.

A soy-based product fermented by Enterococcus faecium and Lactobacillus helveticus inhibits the development of murine breast adenocarcinoma

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)