Lyophilized Symbiotic Mitigates Mucositis Induced by 5-Fluorouracil.

Mucositis is an adverse effect of cancer chemotherapies using 5-Fluorouracil (5-FU). It is characterized by mucosal inflammation, pain, diarrhea, and weight loss. Some studies reported promising healing effects of probiotic strains, when associated with prebiotics, as adjuvant treatment of mucositis. We developed a lyophilized symbiotic product, containing skimmed milk, supplemented with whey protein isolate (WPI) and with fructooligosaccharides (FOS), and fermented by Lactobacillus casei BL23, Lactiplantibacillus plantarum B7, and Lacticaseibacillus rhamnosus B1. In a mice 5-FU mucositis model, this symbiotic lyophilized formulation was able to reduce weight loss and intestinal permeability. This last was determined in vivo by quantifying blood radioactivity after oral administration of 99mTc-DTPA. Finally, histological damages caused by 5-FU-induced mucositis were monitored. Consumption of the symbiotic formulation caused a reduced score of inflammation in the duodenum, ileum, and colon. In addition, it decreased levels of pro-inflammatory cytokines IL-1ß, IL-6, IL-17, and TNF-α in the mice ileum. The symbiotic product developed in this work thus represents a promising adjuvant treatment of mucositis.

Differential Immune Response of Lactobacillus plantarum 286 Against Salmonella Typhimurium Infection in Conventional and Germ-Free Mice.

We aimed at evaluating in vivo the probiotic potential of Lactobacillus plantarum 286 against Salmonella enterica serov. Typhimurium. Colonization capacity and antagonistic activity were determined in feces of gnotobiotic mice. Survival to infection, translocation, histopathology, IgA and cytokine levels (IL-10, IL-6, IFN-γ, TNF-α, TGF-ß) were determined both in conventional and germ-free mice followed L. plantarum 286 administration and Salmonella infection. L. plantarum 286 colonized the intestine of gnotobiotic mice, where it produced antagonistic substances against S. Typhimurium. In conventional animals, the administration of this strain increased intestinal IgA levels and reduced the inflammatory response and the tissue damage caused by S. Typhimurium. Reduction of tissue damage in the intestine and liver of germ-free animals was also observed, however the immune response elicited was different in either model. L. plantarum 286 showed in vivo probiotic properties in both murine models. Probiotic capacity results may depend on the animal model chosen.

Milk Fermented by Lactobacillus paracasei NCC 2461 (ST11) Modulates the Immune Response and Microbiota to Exert its Protective Effects Against Salmonella typhimurium Infection in Mice.

Probiotics form a promising strategy to maintain intestinal health. Milks fermented with probiotic strains, such as the Lactobacillus paracasei ST11, are largely commercialized in Brazil and form a low-cost alternative to probiotic pharmaceutical formulations. In this study, we assessed the probiotic effects of milk fermented by L. paracasei ST11 (administered through fermented milk) in a Salmonella typhimurium infection model in BALB/c mice. We observed in this murine model that the applied probiotic conferred protective effects against S. typhimurium infection, since its administration reduced mortality, weight loss, translocation to target organs (liver and spleen) and ileum injury. Moreover, a reduction in the mRNA expression of pro-inflammatory cytokines such as IFN-γ, IL-6, TNF-α and IL-17 in animals that received the probiotic before challenge was observed. Additionally, the ileum microbiota was better preserved in these animals. The present study highlights a multifactorial protective aspect of this commercial probiotic strain against a common gastrointestinal pathogen.

In vivo probiotic and antimicrobial photodynamic therapy as alternative therapies against cryptococcosis are ineffective.

Cryptococcosis, an invasive fungal infection distributed worldwide that affects both domestic and wild animals, has incredible rates regarding treatment failure, leading to the necessity of the development of new therapies. In this way, we aimed to evaluate the probiotic (Saccharomyces boulardii, Lactobacillus paracasei ST-11, and Lactobacillus rhamnosus GG) and antimicrobial photodynamic alternative therapies against Cryptococcus gattii in a murine model. Although previous studies suggest that these therapies can be promising against cryptococcosis, our experimental conditions for both probiotic and antimicrobial photodynamic therapies (aPDT) were not able to improve the survival of mice with cryptococcosis, even with the treatment combined with fluconazole. Our results may help other researchers to find the best protocol to test alternative therapies against Cryptococcus gattii.

Detecção de genes toxigênicos, susceptibilidade antimicrobiana e antagonismo in vitro de Staphylococcus spp. isolados de queijos artesanais / Detection of toxigenic genes, susceptibility antimicrobial and in vitro antagonism of Staphylococcus spp. isolated from artisanal cheeses

Cepas de Staphylococcus spp. molecularmente identificadas foram submetidas à Reação em Cadeia da Polimerase (PCR), utilizando-se iniciadores específicos para a detecção de genes codificadores de enterotoxinas clássicas (SEA, SEB, SEC, SED, SEE) e da Toxina-1 da Síndrome do Choque Tóxico (TSST-1). Foi realizada PCR-Multiplex para detecção dos genes sea, sec, sed e see. Para seb e tst, foram realizadas PCR-Uniplex. Além disso, foi analisado o perfil de susceptibilidade das cepas a antimicrobianos de diferentes classes e foi verificado antagonismo in vitro entre Lactobacillus spp. e as cepas estudadas. Genes codificadores de enteroxinas clássicas, assim como de TSST-1, não foram encontrados. Em relação ao antibiograma, Sulfonamida, Penicilina, Ceftazidima e Oxacilina apresentaram os maiores percentuais de resistência (100, 80, 60 e 40%, respectivamente). Os demais antimicrobianos foram eficientes em percentuais acima de 70%. Lactobacillus spp. foram capazes de inibir o desenvolvimento in vitro de Staphylococcus spp. Conclui-se que as cepas estudadas não possuem genes codificadores da produção de enterotoxinas clássicas e TSST-1, são sensíveis à maioria dos antimicrobianos e são inibidos por bactérias do gênero Lactobacillus.