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.