21 research outputs found

    Genetic transformation of novel isolates of chicken Lactobacillus bearing probiotic features for expression of heterologous proteins: a tool to develop live oral vaccines

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    BACKGROUND: The use of lactic acid bacteria as vehicles to delivery antigens to immunize animals is a promising issue. When genetically modified, these bacteria can induce a specific local and systemic immune response against selected pathogens. Gastric acid and bile salts tolerance, production of antagonistic substances against pathogenic microorganisms, and adhesive ability to gut epithelium are other important characteristics that make these bacteria useful for oral immunization. RESULTS: Bacteria isolated on de Man, Rogosa and Sharpe medium (MRS) from different gastrointestinal portions of broiler chicks were evaluated for their resistance to artificial gastric acid and bile salts, production of hydrogen peroxide, and cell surface hydrophobicity. Thirty-eight isolates were first typed at species level by PCR amplification of 16S-23S rRNA intergenic spacers using universal primers that anneal within 16S and 23S genes, followed by restriction digestion analyses of PCR amplicons (PCR-ARDRA). An expression cassette was assembled onto the pCR2.1-Topo vector by cloning the promoter, leader peptide, cell wall anchor and terminator sequences derived from the laminin binding S-layer protein gene of L. crispatus strain F5.7 (lbs gene). A sequence encoding the green fluorescent protein (GFP) was inserted as reporter gene, and an erythromycin resistance gene was added as selective marker. All constructs were able to express GFP in the cloning host E. coli XL1-Blue and different Lactobacillus strains as verified by FACS and laser scanning confocal microscopy. CONCLUSION: Lactobacillus isolated from gastrointestinal tract of broiler chickens and selected for probiotic characteristics can be genetically modified by introducing an expression cassette into the lbs locus. The transformed bacteria expressed on its cell wall surface different fluorescent proteins used as reporters of promoter function. It is possible then that similar bacterial model expressing pathogen antigens can be used as live oral vaccines to immunize broilers against infectious diseases

    O impacto da abstinência nos níveis séricos de leptina e no perfil nutricional de alcoolistas

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    Introduction: Alcohol use disorder (AUD) is associated with changes in metabolism and in the nutritional profile. Food-seeking behaviors and psychoactive substances share common biological pathways that activate the reward system and leptin is a modulator of this system. Objective: To measure serum leptin levels and nutritional status of individuals with before their detoxification and then 15 days later. Material and Methods: In total, 38 men diagnosed with AUD and admitted to a detoxification unit were analyzed. Serum leptin levels, Body Mass Index (BMI), Waist Circumference (WC) and body composition were assessed by Bioelectrical Impedance Analysis (BIA) within the first 48 hours of hospital admission and again 15 days after the first assessment. Results: Weight, BMI and WC increased significantly during detoxing (p<0.001), but body fat and leptin levels percentages remained similar. At admission, leptin levels were positively correlated with body fat (0.607), WC (0.696), and BMI (0.357). After 15 days, only leptin and BMI were significantly correlated (0.462). Conclusion: Our results reinforce the relationship between leptin and nutritional parameters related to body weight. It is essential to educate about nutrition and to encourage healthy eating behaviors so individuals with AUD can reduce weight gain during the recovery period.Introdu√ß√£o: O transtorno por uso de √°lcool (TUA) est√° associado a altera√ß√Ķes metab√≥licas e perfil nutricional. Comportamento de busca de alimentos e subst√Ęncias psicoativas compartilham vias biol√≥gicas comuns ativando o sistema de recompensa e a leptina modula esse sistema. Objetivo: Avaliar n√≠veis s√©ricos de leptina e estado nutricional de indiv√≠duos antes e 15 dias ap√≥s a desintoxica√ß√£o. Materiais e M√©todos: Foram analisados 38 homens com diagn√≥stico de TUA internados em unidade de desintoxica√ß√£o. N√≠veis s√©ricos de leptina, √ćndice de Massa Corporal (IMC), Circunfer√™ncia da Cintura (CC) e composi√ß√£o corporal foram avaliados por Bioimped√Ęncia El√©trica (BIA) nas primeiras 48 horas de interna√ß√£o e 15 dias ap√≥s a primeira avalia√ß√£o. Resultados: Peso, IMC e CC aumentaram significativamente durante a desintoxica√ß√£o (p<0,001), mas os percentuais de gordura corporal e n√≠veis de leptina permaneceram semelhantes. Na admiss√£o, os n√≠veis de leptina foram positivamente correlacionados com a gordura corporal (0,607), CC (0,696) e IMC (0,357). Ap√≥s 15 dias, apenas leptina e IMC foram significativamente correlacionados (0,462). Conclus√£o: Os resultados refor√ßam a rela√ß√£o entre leptina e par√Ęmetros nutricionais relacionados ao peso corporal. A educa√ß√£o nutricional e o incentivo ao comportamento alimentar saud√°vel s√£o essenciais para que indiv√≠duos com TUA reduzam o ganho de peso na desintoxica√ß√£o

    Protective Effect of Lactobacillus diolivorans 1Z, Isolated From Brazilian Kefir, Against Salmonella enterica Serovar Typhimurium in Experimental Murine Models

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    Kefir is a beverage obtained by fermentation of milk or sugar solution by lactic acid bacteria and yeasts, and several health benefits have been attributed to its ingestion, part of them being attributed to Lactobacillus species. The objective of the present study was to evaluate, in vivo, the probiotic potential of Lactobacillus diolivorans 1Z, isolated from Brazilian kefir grains. Initially, conventional mice were orally treated daily or not during 10 days with a suspension of L. diolivorans 1Z, and then orally challenged with Salmonella enterica serovar Typhimurium. Treatment with L. diolivorans 1Z resulted in higher survival (70%) of animals after the challenge with the pathogen than for not treated mice (0%). When germ-free mice were monoassociated (GN-PS group) or not (GN-CS group) with L. diolivorans 1Z and challenged after 7 days with S. Typhimurium, Salmonella fecal counts were significantly lower (P &lt; 0.05) for the GN-PS group when compared to the GN-CS group. Histopathological analysis revealed less damage to the ileum mucosa, as demonstrated by smallest perimeter of major lesions for mice of the GN-PS group in comparison to the group GN-CS (P &lt; 0.05). These findings were accompanied by a lower expression of IFN-ő≥ and TNF-őĪ in the intestinal tissue of GN-PS mice. Additionally, translocation of S. Typhimurium to liver was significantly lower in GN-PS than in GN-CS mice (P &lt; 0.05), and IgA levels in intestinal content and number of Kupffer cells in liver were higher. No difference was observed for hepatic cellularity between GN-PS and GN-CS groups (P &gt; 0.05), but the pattern of inflammatory cells present in the liver was predominantly of polymorphonuclear in GN-CS group and of mononuclear in the GN-PS group, and a higher hepatic expression of IL-10 and TGF-ő≤ was observed in GN-PS group. Concluding, L. diolivorans 1Z showed to be a potential probiotic strain that protected mice from death after challenge with S. Typhimurium, apparently by immunological modulation

    La Passion matricielle ou la Passion de l’origine

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    Boissonnas Sylvina, Nicoli Elisabeth, Fouque Antoinette. La Passion matricielle ou la Passion de l‚Äôorigine. In: Dipl√īm√©es, n¬į274-275, 2020. Passion(s) pp. 31-42

    Antoinette Fouque ¬ęLa force d‚Äô√™tre des femmes¬Ľ

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    Nicoli Elisabeth, Boissonnas Sylvina, Idels Mich√®le. Antoinette Fouque ¬ęLa force d‚Äô√™tre des femmes¬Ľ. In: Dipl√īm√©es, n¬į270-271, 2020. Les Pionni√®res. pp. 253-266

    Malaise et mutation dans l’espèce

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    Boissonnas Sylvina, Guyot Catherine, Nicoli Elisabeth, Villeneuve Christine. Malaise et mutation dans l‚Äôesp√®ce. In: Dipl√īm√©es, n¬į280-281, 2022. Futurs possibles. pp. 205-211

    52 ans de libération des femmes, égalité et différence

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    Boissonnas Sylvina, Guyot Catherine, Nicoli Elisabeth, Villeneuve Christine. 52 ans de lib√©ration des femmes, √©galit√© et diff√©rence. In: Dipl√īm√©es, n¬į272-273, 2020. Les Pionni√®res. pp. 93-105

    Identification to the species level of <it>Lactobacillus </it>isolated in probiotic prospecting studies of human, animal or food origin by 16S-23S rRNA restriction profiling

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    Abstract Background The accurate identification of Lactobacillus and other co-isolated bacteria during microbial ecological studies of ecosystems such as the human or animal intestinal tracts and food products is a hard task by phenotypic methods requiring additional tests such as protein and/or lipids profiling. Results Bacteria isolated in different probiotic prospecting studies, using de Man, Rogosa and Sharpe medium (MRS), were typed at species level by PCR amplification of 16S-23S rRNA intergenic spacers using universal primers that anneal within 16S and 23S genes, followed by restriction digestion analyses of PCR products. The set of enzymes chosen differentiates most species of Lactobacillus genus and also co-isolated bacteria such as Enterococcus, Streptococcus, Weissella, Staphylococcus, and Escherichia species. The in silico predictions of restriction patterns generated by the Lactobacillus shorter spacers digested with 11 restriction enzymes with 6 bp specificities allowed us to distinguish almost all isolates at the species level but not at the subspecies one. Simultaneous theoretical digestions of the three spacers (long, medium and short) with the same set of enzymes provided more complex patterns and allowed us to distinguish the species without purifying and cloning of PCR products. Conclusion Lactobacillus isolates and several other strains of bacteria co-isolated on MRS medium from gastrointestinal ecosystem and fermented food products could be identified using DNA fingerprints generated by restriction endonucleases. The methodology based on amplified ribosomal DNA restriction analysis (ARDRA) is easier, faster and more accurate than the current methodologies based on fermentation profiles, used in most laboratories for the purpose of identification of these bacteria in different prospecting studies.</p

    Biological activity of the non-microbial fraction of kefir: Antagonism against intestinal pathogens

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    Kefir is a fermented milk obtained by the activity of kefir grains which are composed of lactic and acetic acid bacteria, and yeasts. Many beneficial health effects have been associated with kefir consumption such as stimulation of the immune system and inhibition of pathogenic microorganisms. The biological activity of kefir may be attributed to the presence of a complex microbiota as well as the microbial metabolites that are released during fermentation. The aim of this work was to characterise the non-microbial fraction of kefir and to study its antagonism against Escherichia coli, Salmonella spp. and Bacillus cereus. During milk fermentation there was a production of organic acids, mainly lactic and acetic acid, with a consequent decrease in pH and lactose content. The non-microbial fraction of kefir added to nutrient broth at concentrations above 75% v/v induced a complete inhibition of pathogenic growth that could be ascribed to the presence of un-dissociated lactic acid. In vitro assays using an intestinal epithelial cell model indicated that pre-incubation of cells with the non-microbial fraction of kefir did not modify the association/invasion of Salmonella whereas pre-incubation of Salmonella with this fraction under conditions that did not affect their viability significantly decreased the pathogen's ability to invade epithelial cells. Lactate exerted a protective effect against Salmonella in a mouse model, demonstrating the relevance of metabolites present in the non-microbial fraction of kefir produced during milk fermentation.Fil: Iraporda, Carolina. Provincia de Buenos Aires. Gobernaci√≥n. Comisi√≥n de Investigaciones Cient√≠ficas. Centro de Investigaci√≥n y Desarrollo en Criotecnolog√≠a de Alimentos. Consejo Nacional de Investigaciones Cient√≠ficas y T√©cnicas. Centro Cient√≠fico Tecnol√≥gico Conicet - La Plata. Centro de Investigaci√≥n y Desarrollo en Criotecnolog√≠a de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigaci√≥n y Desarrollo en Criotecnolog√≠a de Alimentos; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ingenieria Olavarria. Departamento de Ingenieria Quimica; ArgentinaFil: Abatemarco J√ļnior, M√°rio. Universidade Federal de Minas Gerais; BrasilFil: Neumann, Elisabeth. Universidade Federal de Minas Gerais; BrasilFil: Nunes, √Ālvaro Cantini. Universidade Federal de Minas Gerais; BrasilFil: Nicoli, Jacques R.. Universidade Federal de Minas Gerais; BrasilFil: Abraham, Analia Graciela. Provincia de Buenos Aires. Gobernaci√≥n. Comisi√≥n de Investigaciones Cient√≠ficas. Centro de Investigaci√≥n y Desarrollo en Criotecnolog√≠a de Alimentos. Consejo Nacional de Investigaciones Cient√≠ficas y T√©cnicas. Centro Cient√≠fico Tecnol√≥gico Conicet - La Plata. Centro de Investigaci√≥n y Desarrollo en Criotecnolog√≠a de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigaci√≥n y Desarrollo en Criotecnolog√≠a de Alimentos; ArgentinaFil: Garrote, Graciela Liliana. Provincia de Buenos Aires. Gobernaci√≥n. Comisi√≥n de Investigaciones Cient√≠ficas. Centro de Investigaci√≥n y Desarrollo en Criotecnolog√≠a de Alimentos. Consejo Nacional de Investigaciones Cient√≠ficas y T√©cnicas. Centro Cient√≠fico Tecnol√≥gico Conicet - La Plata. Centro de Investigaci√≥n y Desarrollo en Criotecnolog√≠a de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigaci√≥n y Desarrollo en Criotecnolog√≠a de Alimentos; Argentin
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