RESUMO
Antimicrobial resistance is an important health concern globally, and probiotics are considered an alternative to minimize it. The present study examined the in vitro probiotic characteristics and in vivo immunomodulatory potential of Bacillus sp. 62A - an extremophile bacterium. Bacillus sp. 62A was evaluated in vitro for its cytotoxicity, hemolytic activity, antibiotic susceptibility, and resistance to gastrointestinal conditions (bile salts, low pH, and intestinal adherence). Additionally, the immunomodulatory effect of Bacillus sp. 62A was studied in mice. The animals were supplemented daily with phosphate-buffered saline (control) and Bacillus sp. 62A at 1 × 108 colony forming units (CFU). Samples were taken on days 5 and 10. Isolated splenocytes were challenged with Escherichia coli for immunological analyses and immune-related gene expression. Serum and feces were collected for IgA and IgG determination. Bacillus sp. 62A did not show cytotoxicity, hemolytic activity, or resistance to antibiotics. Furthermore, the bacterium has autoaggregation and intestinal adhesion capacities and grows in the presence of bile salts and low pH. Bacillus supplementation in mice improved respiratory burst activity, nitric oxide production, and IL-1ß and IL-6 gene expressions, mainly at 10 days. After E. coli challenge, Bacillus supplementation in mice induced an anti-inflammatory response through a decrease in immunological parameters and an increase in IL-10 gene expression. Moreover, serum IgA and IgG and fecal IgG augmented in supplemented mice. In conclusion, Bacillus sp. 62A has biosafe and immunomodulatory probiotic potential.
RESUMO
KEY MESSAGE: A plant-based multiepitopic protein (LTBentero) containing epitopes from ETEC, S. typhimurium, and V. parahaemolyticus was produced in plants cells and triggered systemic and intestinal humoral responses in immunized mice. Around 200 million people suffer gastroenteritis daily and more than 2 million people die annually in developing countries due to such pathologies. Vaccination is an alternative to control this global health issue, however new low-cost vaccines are needed to ensure proper vaccine coverage. In this context, plants are attractive hosts for the synthesis and delivery of subunit vaccines. Therefore, in this study a plant-made multiepitopic protein named LTBentero containing epitopes from antigens of enterotoxigenic E. coli, S. typhimurium, and V. parahaemolyticus was produced and found immunogenic in mice. The LTBentero protein was expressed in tobacco plants at up to 5.29 µg g-1 fresh leaf tissue and was deemed immunogenic when administered to BALB/c mice either orally or subcutaneously. The plant-made LTBentero antigen induced specific IgG (systemic) and IgA (mucosal) responses against LTB, ST, and LptD epitopes. In conclusion, multiepitopic LTBentero was functionally produced in plant cells, being capable to trigger systemic and intestinal humoral responses and thus it constitutes a promising oral immunogen candidate in the fight against enteric diseases.
Assuntos
Toxinas Bacterianas/imunologia , Epitopos/imunologia , Imunização , Proteínas de Plantas/imunologia , Proteínas Recombinantes/imunologia , Vacinas de Plantas Comestíveis/imunologia , Animais , Anticorpos Antibacterianos/imunologia , Toxinas Bacterianas/genética , Vacinas Bacterianas/imunologia , Escherichia coli Enterotoxigênica/genética , Escherichia coli Enterotoxigênica/imunologia , Epitopos/genética , Feminino , Regulação da Expressão Gênica de Plantas , Imunoglobulina A , Imunoglobulina G , Camundongos , Camundongos Endogâmicos BALB C , Mucosa/imunologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/imunologia , Plantas Geneticamente Modificadas/metabolismo , Proteínas Recombinantes/metabolismo , Nicotiana/genética , Vacinação , Vacinas de Plantas Comestíveis/genéticaRESUMO
Este trabajo tiene como proposito, contribuir en la tecnica de la medicion de flujos de gas producidos dentro una planta, es decir introducir un sistema estandar de medicion, ya que su utilizacion sera amplia, por las caracteristicas que presentan los yacimientos descubiertos ultimamente por nuestro pais. Con el criterio de tener una idea cabal del proceso que sufre el gas: La primera parte, consiste de una descripcion del sistema de separacion, haciendo incapie principalmente en la determinacion de las capacidades de los diferentes tipos de separadores mediante los metodos analitico y grafico. Luego se introduce el tema en si, para lo cual se realiza un estudio profundo del fundamento teorico, y los principios en que se basan los medidores de gas, como tambien de los diferentes tipos de registradores y sus respectivas partes componentes, ademas de su efectiva utilizacion, para obtener calculos de flujos de gas con bastante precision, para tal efecto se emplea la formula basica de orificio, que se basa en ecuaciones de mecanica de fluidos, como ser la ecuacion de Bernoulli y complementadas por las leyes de Boyle, Charles y otras; posteriormente se tiene una serie de tablas para los diferentes factores de los que esta formada la ecuacion de orificio, esto con la finalidad de simplificar los calculos, para un mejor y rapido empleo en las diferentes plantas de gas.