Optimisation of oat milk formulation to obtain fermented derivatives by using probiotic Lactobacillus reuteri microorganisms

Functional advantages of probiotics combined with interesting composition of oat were considered as an alternative to dairy products. In this study, fermentation of oat milk with Lactobacillus reuteri and Streptococcus thermophilus was analysed to develop a new probiotic product. Central composite design with response surface methodology was used to analyse the effect of different factors (glucose, fructose, inulin and starters) on the probiotic population in the product. Optimised formulation was characterised throughout storage time at 4 ℃ in terms of pH, acidity, β-glucan and oligosaccharides contents, colour and rheological behaviour. All formulations studied were adequate to produce fermented foods and minimum dose of each factor was considered as optimum. The selected formulation allowed starters survival above 107/cfu ml to be considered as a functional food and was maintained during the 28 days controlled. β-glucans remained in the final product with a positive effect on viscosity. Therefore, a new probiotic non-dairy milk was successfully developed in which high probiotic survivals were assured throughout the typical yoghurt-like shelf life.

Stability of probiotic Lactobacillus plantarum in dry microcapsules under accelerated storage conditions

This study investigated the stability of freeze dried and fluid bed dried alginate microcapsules coated with chitosan containing model probiotic bacteria, Lactobacillus plantarum, during storage for up to 45 days at different water activities (0.11, 0.23, 0.40 and 0.70) and temperatures (4, 30 and 37 °C). The loss in cell viability was around 0.8 log in the case of fluid bed drying and around 1.3 in the case of freeze drying, with the former method resulting in dried capsules of smaller size (~ 1 mm vs 1.3 mm), more irregular shape, and with a rougher surface. In both cases, the water activity and water content were less than 0.25 and 10% w/w, respectively, which favours high storage stability. The storage stability studies demonstrated that as the water activity and temperature decreased the survival of the dried encapsulated cells increased. Considerably better survival was observed for fluid bed dried encapsulated cells compared to freeze dried encapsulated cells and freeze dried free cells with 10% sucrose (control), and in some cases, e.g. at 4 and 30 °C at water activities of 0.11, 0.23 and 0.40, there was more than 1 log difference after 45 days, with concentrations higher than 108 CFU/g after 45 days of storage. The results indicate that fluid bed drying is an effective and efficient manufacturing method to produce probiotic containing capsules with enhanced storage stability.

Nasal immunization of mice with Lactobacillus casei expressing the Pneumococcal Surface Protein A: induction of antibodies, complement deposition and partial protection against Streptococcus pneumoniae challenge

Strategies for the development of new vaccines against Streptococcus pneumoniae infections try to overcome problems such as serotype coverage and high costs, present in currently available vaccines. Formulations based on protein candidates that can induce protection in animal models have been pointed as good alternatives. Among them, the Pneumococcal Surface Protein A (PspA) plays an important role during systemic infection at least in part through the inhibition of complement deposition on the pneumococcal surface, a mechanism of evasion from the immune system. Antigen delivery systems based on live recombinant lactic acid bacteria (LAB) represents a promising strategy for mucosal vaccination, since they are generally regarded as safe bacteria able to elicit both systemic and mucosal immune responses. In this work, the N-terminal region of clade I PspA was constitutively expressed in Lactobacillus casei and the recombinant bacteria was tested as a mucosal vaccine in mice. Nasal immunization with L. casei-PspA 1 induced anti-PspA antibodies that were able to bind to pneumococcal strains carrying both clade 1 and clade 2 PspAs and to induce complement deposition on the surface of the bacteria. In addition, an increase in survival of immunized mice after a systemic challenge with a virulent pneumococcal strain was observed. (C) 2008 Elsevier Masson SAS. All rights reserved.

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.

Cervical Lactobacillus and leukocyte infiltration in preterm premature rupture of membranes

Objectives: To evaluate the possible association between microorganisms present in the cervical secretions and amniotic fluid of pregnant women with preterm premature rupture of membranes (PPROM), and histologic chorioamnionitis. Methods: Thirty-seven pregnant women with PPROM and 21 healthy pregnant women were studied. Secretions from the cervical canal and amniotic fluid were collected to isolate microorganisms present in the genital tract. Cervical smears were Gram stained and evaluated microscopically. At delivery, chorioamniotic membranes were collected for histopathologic analysis. Results: Microscopic examination of the cervical secretion smears obtained from the PPROM group showed a low rate of Lactobacillus species, large numbers of leukocytes, and a wide diversity of microorganisms compared with the control group. The PPROM group presented an 80% rate of chorioamnionitis. Staphylococcus aureus isolation in cervical secretion was associated with intense inflammatory infiltrate in the membranes and might play a role in the pathogenesis of PPROM. Conclusions: the low colonization of cervical flora by Lactobacillus species associated with an intense leukocyte infiltrate detected in Gram-stained cervical smears can be considered a rapid method of detecting chorioamnionitis in pregnant women with PPROM. (C) 2003 International Federation of Gynecology and Obstetrics. Published by Elsevier B.V. Ireland Ltd. All rights reserved.

Efeito da microbiota cecal e do Lactobacillus salivarius inoculados in ovo em aves desafiadas com Salmonella enterica sorovar Enteritidis

Ovos embrionados provenientes de matrizes pesadas foram inoculados na câmara de ar com microbiota cecal total, microbiota cecal diluída e cultura de Lactobacillus salivarius, no 18º dia de incubação. Dois dias após o nascimento, as aves foram desafiadas com Salmonella enterica sorovar Enteritidis (SE) e, cinco dias após o desafio, avaliou-se a presença da bactéria no fígado e ceco. O efeito de exclusão competitiva, após o desafio com SE, somente foi observado pela ausência da bactéria no fígado das aves tratadas in ovo com L. salivarius. A inoculação in ovo de microbiota cecal indefinida ou diluída não reduziu a colonização de SE no fígado e no ceco das aves, incluindo, neste último, também o tratamento com L. salivarius. Nenhum dos tratamentos in ovo determinou índice de eclodibilidade superior a 65%.

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)

Immunological evaluation of the intestinal mucosa of broiler chicks treated with Lactobacillus Spp. and challenged with Salmonella Enteritidis

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

Transference in vitro of the resistance to the antimicrobials between Escherichia coli, Lactobacillus spp. and Salmonella enteritidis isolated from chickens

O objetivo deste trabalho foi verificar a possibilidade de transferência de resistência aos antimicrobianos entre bactérias normais da microbiota de frangos e Salmonella Enteritidis. Utilizamos amostras de Lactobacillus spp. (L. spp.), Salmonella Enteritidis (SE) e Escherichia coli (E. coli) previamente isolados de frangos, selecionados após prova de sensibilidade antimicrobiana in vitro conforme metodologia padrão (Comitê Nacional para Padrões Clínicos de Laboratório). Utilizamos aqueles com resistência e sensibilidade aos antimicrobianos indutores, chamados de bactérias doadoras e receptoras, respectivamente. Os antimicrobianos indutores foram utilizados para estimular a transferência de resistência aos antimicrobianos entre as bactérias. A possibilidade de transferência foi verificada da E. coli resistente para a SE e L. spp. Também foi verificada a transferência de uma amostra de L. spp resistente aos antimicrobianos indutores para a SE. Só foi possível verificar a transferência da resistência aos antimicrobianos indutores quando a bactéria doadora foi a E. coli e a bactéria receptora foi a SE. No presente estudo concluímos que a transferência de resistência aos antimicrobianos entre bactérias é possível, mas nem todas as bactérias participam desse evento, não transmitindo e nem adquirindo esta resistência.

Evaluation of in vitro and in vivo adhesion and immunomodulatory effect of Lactobacillus species strains isolated from chickens

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

First Autochthonous Case of Canine Visceral Leishmaniasis in the Center of Rio Grande do Sul State, Brazil

Background: Leishmaniasis is one of the most important vector-borne diseases of humans. This parasitic disease can be caused by many species of Leishmania. In humans, different species of the parasite are associated with different forms of the disease, cutaneous and visceral. Among domesticated animals, dogs are the most important species in the epidemiology of this disease. Leishmania chagasi, an important zoonosis, is well established as the agent of visceral leishmaniasis in Brazil. The disease is endemic in north, northeast, midwest and southeast, and is transmitted to mammals by hematophagous insects such as the Lutzomyia longipalpis. In 2008, our research group has diagnosed a case of canine leishmaniasis in the municipality of Uruguaiana and subsequently there were several cases in the city and the neighbor municipality of Sao Borja. Most Brazilian states are endemic for leishmaniasis, with the exception of Rio Grande do Sul. In southern Brazil, the reports of humans and dogs infected by Leishmania spp. are the source of endemic area in the country. Therefore, the aim of this study is register the first clinical case of canine visceral leishmaniasis in the municipality of Santa Maria, RS.Case: In october 2010, a veterinary clinic of Santa Maria received a canine, female, Doberman, with two years of age. The animal had severe skin lesions on the head and limbs, pale mucous membranes, and enlarged lymph nodes. According to the owner, the animal showed progressive weight loss and anorexia for more than five days. During the clinical examination the blood was collected for hemogram and cytology of lymph nodes was performed by puncture aspiration with a fine needle. In the erythrogram, it was observed a decrease in the total number of erythrocytes (2.8 x 10(6)/mu L), hematocrit (21%), hemoglobin (6.8 g/dL) and platelets (98 x 10(3)/mu L). In the leucogram, any alteration was observed. The cytology of lymph nodes showed amastigotes forms, suggestive of the Leishmania spp. Based on this finding; we performed the blood collection for PCR, to confirm parasitism and to determine the species of Leishmania. At the molecular test was used PCR-specific for L. chagasi, and the result was positive.Discussion: This is the first autochthonous clinical case in the central region of the RS, non-endemic area for leishmaniasis. In serological studies of visceral leishmaniasis it was diagnosed in five asymptomatic dogs in the municipalities of Santa Maria, Julio de Castilhos and Itaara, however not confirmed by molecular analysis. In the municipalities of Cruz Alta and Uruguaiana cases of L. chagasi have been reported in dogs which previously resided in Leishmania sp. endemic areas. The municipality of Sao Borja had the first record of L. longipalpis in the RS during the leishmaniasis outbreak in 2008-2009. In the central region of the RS vector has not been found, but because in this first autochthonous case dog in Santa Maria believe that the parasite is present and/or doing other insect transmission of leishmaniasis. Clinical signs associated with hematologic and coagulation disorders observed in the canine are commonly described in symptomatic dogs in endemic regions. This case of autochthonous leishmaniasis reinforces the idea of the vector presence in Santa Maria, center of the RS. We believe that canine leishmaniasis is an emerging disease in the southern region of Brazil.