RESUMO
Streptococcus uberis has become one of the most important environmental pathogens associated with clinical and subclinical bovine mastitis. Biofilm confers to bacteria more resistance to physical and chemical agents as well as to different mechanisms of the innate immune system. The aim of this work was to evaluate the ability of in vitro biofilm production in 32 S. uberis isolates from bovine mastitis and identified by biochemical tests and milk subsequently confirmed by the amplification of the pauA gene. The isolates were cultivated in TMP broth and TMP broth with the addition of 0.5% glucose, 1% sucrose, 1% lactose or 0.5% skim milk in microtiter plates stained with crystal violet. We demonstrated that S. uberis isolated from bovine mastitis are able to produce biofilms in TMP broth and, also that biofilm formation by S. uberis can be significantly enhanced by the addition of 0.5% glucose or 1% sucrose to TMP broth. This may suggest that the carbohydrates in milk or within the ruminant gut might affect the growth mode of S. uberis. In addition, our results showed that in vitro biofilm production under different conditions of supplementation displays variation among the isolates and that each isolate shows a particular profile of biofilm production. This phenotypic heterogeneity in biofilm production exhibited by S. uberis could at least partly explain why this bacterium has the ability to adapt to different niches facilitating survival to diverse and stressful conditions.
Streptococcus uberis es uno de los más importantes patógenos medioambientales asociados a la mastitis bovina clínica y subclínica. El biofilm confiere a las bacterias resistencia a agentes físicos y químicos, como así también a diferentes mecanismos del sistema inmune innato. El objetivo del presente estudio fue evaluar la habilidad de producción de biofilm in vitro de 32 aislamientos de S. uberis recuperados de mastitis bovina, previamente identificados por pruebas bioquímicas y confirmados por la amplificación del gen pauA. Los aislamientos fueron cultivados en caldo TMP sin carbohidratos, y además en caldo TMP con la adición de 0,5% de glucosa, 1% de sacarosa, 1% de lactosa o 0,5% de leche descremada, en placas de microtitulación tenidas con cristal violeta. Se demostró que dichos aislamientos son capaces de producir biofilm en caldo TMP, y además se observó un incremento significativo en la producción de biofilm en caldo TMP suplementado con 0,5% de glucosa o con 1% de sacarosa. Así, los carbohidratos de la leche o los presentes dentro del intestino de los rumiantes podrían afectar el modo de crecimiento de S. uberis. Además, nuestros hallazgos mostraron que la producción de biofilm in vitro en diferentes condiciones de suplementación presenta variabilidad entre los aislamientos de S. uberis y que cada aislamiento muestra un perfil particular de producción de biofilm. Esta heterogeneidad fenotípica en la producción de biofilm de S. uberis podría explicar, al menos en parte, por qué esta bacteria tiene la habilidad de adaptarse a diferentes nichos, lo que le facilita la supervivencia frente a condiciones diversas y estresantes.
Assuntos
Animais , Bovinos , Feminino , Infecções Estreptocócicas , Biofilmes , Leite , Mastite Bovina , Infecções Estreptocócicas/veterinária , Streptococcus , Carboidratos , Leite/microbiologia , Mastite Bovina/microbiologiaRESUMO
Streptococcus uberis has become one of the most important environmental pathogens associated with clinical and subclinical bovine mastitis. Biofilm confers to bacteria more resistance to physical and chemical agents as well as to different mechanisms of the innate immune system. The aim of this work was to evaluate the ability of in vitro biofilm production in 32 S. uberis isolates from bovine mastitis and identified by biochemical tests and subsequently confirmed by the amplification of the pauA gene. The isolates were cultivated in TMP broth and TMP broth with the addition of 0.5% glucose, 1% sucrose, 1% lactose or 0.5% skim milk in microtiter plates stained with crystal violet. We demonstrated that S. uberis isolated from bovine mastitis are able to produce biofilms in TMP broth and, also that biofilm formation by S. uberis can be significantly enhanced by the addition of 0.5% glucose or 1% sucrose to TMP broth. This may suggest that the carbohydrates in milk or within the ruminant gut might affect the growth mode of S. uberis. In addition, our results showed that in vitro biofilm production under different conditions of supplementation displays variation among the isolates and that each isolate shows a particular profile of biofilm production. This phenotypic heterogeneity in biofilm production exhibited by S. uberis could at least partly explain why this bacterium has the ability to adapt to different niches facilitating survival to diverse and stressful conditions.
Assuntos
Biofilmes , Mastite Bovina , Leite , Infecções Estreptocócicas , Animais , Carboidratos , Bovinos , Feminino , Mastite Bovina/microbiologia , Leite/microbiologia , Infecções Estreptocócicas/veterinária , StreptococcusRESUMO
Introducción: dos factores importantes han sido descritos como contribuyentes en la aparición de fatiga durante el ejercicio físico: la disminución de las reservas de glucógeno muscular y la pérdida de agua con electrolitos a través del sudor, que favorecen la deshidratación. Debido a esto, la reposición de líquidos y electrolitos posterior al ejercicio físico se transforma en la prioridad para restablecer la homeostasis corporal alterada durante el ejercicio físico. Por su composición nutricional, la leche parece ser una buena alternativa natural como bebida rehidratante posterior al ejercicio físico. Objetivo: comparar la efectividad como bebida de rehidratación de la leche descremada chocolatada contra una bebida deportiva artificial en militares, a partir de la hipótesis de que la leche descremada chocolatada tiene iguales o mejores efectos sobre la hidratación post ejercicio, que una bebida deportiva artificial. Método: 30 militares (23,0 ± 3,2 años) se dividieron en 2 grupos: 1) rehidratación con bebida deportiva con 6 pòr ciento de carbohidratos y relación de Na/K 2:1 (grupo ISO). Rehidratación con leche descremada chocolatada (grupo LECHE). Se evaluó la retención de fluidos a través del peso corporal y la gravedad específica de la orina (GEO) antes y después del ejercicio físico y posterior a las 2 horas de rehidratación. Resultados: se encontraron diferencias significativas (p< 0,05) en la retención de fluidos en el grupo LECHE comparado con el grupo ISO. No hubo diferencias significativas entre la GEO de ambos grupos. Conclusión: Los resultados muestran que la rehidratación con leche descremada es más efectiva en la retención de fluidos y recuperación del peso previo al ejercicio que la bebida deportiva(AU)
ntroduction: Two important factors have been described as contributing to the onset of fatigue during physical exercise: Decreased muscle glycogen stores and the loss of water with electrolytes through sweating, favoring dehydration. Because of this, fluid and electrolyte replacement after physical exercise becomes the priority to restore altered body homeostasis during physical exercise. Due to its nutritional composition, milk appears to be a good natural alternative as a rehydration beverage after exercise. Objective: To compare the effectiveness chocolate skim milk as pots-exercise rehydration beverage with an artificial sports drink in the military, based on the hypothesis that chocolate skim milk has equal or better effects on post-exercise hydration than an artificial sports drink. Method: 30 soldiers (23.0 ± 3.2 years) were divided into 2 groups: 1) rehydration with sports drink with 6 percent carbohydrates and ratio of Na / K 2: 1 (ISO group). Rehydration with chocolate skim milk (LECHE group). Fluid retention was assessed through body weight and the specific gravity of urine (GEO) before and after physical exercise and after 2 hours of rehydration. Results: significant differences were found (p < 0.05) in fluid retention in the LECHE group compared to the ISO group. There were no significant differences between the GEO of both groups. Conclusion: The results show that rehydration with skim milk is more effective in fluid retention and weight recovery prior to exercise than sports drink(AU)