Effect of fermented milk containing probiotic bacteria in the prevention of an enteroinvasive Escherichia coli infection in mice

MEDICI, MARTA; VINDEROLA, CELSO GABRIEL; WEILL, RICARDO; PERDIGON, GABRIELA

Journal of Dairy Research

Año: 2005 vol. 72 p. 243 - 249

0022-0299

This study investigated the protective capacity of the oral administration of fermented milk containing the probiotic strains ; Lactobacillus casei, Lb. delbrueckii subsp. bulgaricus andLactobacillus casei, Lb. delbrueckii subsp. bulgaricus and Streptococcus thermophilus, against enteroinvasive Escherichia coli infection in a murine (BALB/ c mice) model. Mice were fed for 2, 5 or 7 consecutive days with fermented milk diluted to a concentration of viable Lb. casei, Lb. delbrueckii subsp. bulgaricus and Strep. thermophilus of 107 cfu/ml. Phagocytic activity of peritoneal macrophages and the number of IgA+ cells in small and large intestine were determined at the end of the feeding periods. For the preventive effect against Esch. coli, animals were fed for 5 days (selected dose). Mice were challenged with an infective dose of enteroinvasive Esch. coli of 108 cfu/mouse. The colonization of liver and spleen and the secretory IgA specific for the pathogen in the intestinal fluid were determined (ELISA test). Results showed that the unspecific immune response enhanced itself after 5 consecutive days of the administration of this fermented milk (increase in the percentage of phagocytosis and number of IgA+ cells in the small intestine). Treated animals showed less, against enteroinvasive Escherichia coli infection in a murine (BALB/ c mice) model. Mice were fed for 2, 5 or 7 consecutive days with fermented milk diluted to a concentration of viable Lb. casei, Lb. delbrueckii subsp. bulgaricus and Strep. thermophilus of 107 cfu/ml. Phagocytic activity of peritoneal macrophages and the number of IgA+ cells in small and large intestine were determined at the end of the feeding periods. For the preventive effect against Esch. coli, animals were fed for 5 days (selected dose). Mice were challenged with an infective dose of enteroinvasive Esch. coli of 108 cfu/mouse. The colonization of liver and spleen and the secretory IgA specific for the pathogen in the intestinal fluid were determined (ELISA test). Results showed that the unspecific immune response enhanced itself after 5 consecutive days of the administration of this fermented milk (increase in the percentage of phagocytosis and number of IgA+ cells in the small intestine). Treated animals showed lessLb. casei, Lb. delbrueckii subsp. bulgaricus and Strep. thermophilus of 107 cfu/ml. Phagocytic activity of peritoneal macrophages and the number of IgA+ cells in small and large intestine were determined at the end of the feeding periods. For the preventive effect against Esch. coli, animals were fed for 5 days (selected dose). Mice were challenged with an infective dose of enteroinvasive Esch. coli of 108 cfu/mouse. The colonization of liver and spleen and the secretory IgA specific for the pathogen in the intestinal fluid were determined (ELISA test). Results showed that the unspecific immune response enhanced itself after 5 consecutive days of the administration of this fermented milk (increase in the percentage of phagocytosis and number of IgA+ cells in the small intestine). Treated animals showed less7 cfu/ml. Phagocytic activity of peritoneal macrophages and the number of IgA+ cells in small and large intestine were determined at the end of the feeding periods. For the preventive effect against Esch. coli, animals were fed for 5 days (selected dose). Mice were challenged with an infective dose of enteroinvasive Esch. coli of 108 cfu/mouse. The colonization of liver and spleen and the secretory IgA specific for the pathogen in the intestinal fluid were determined (ELISA test). Results showed that the unspecific immune response enhanced itself after 5 consecutive days of the administration of this fermented milk (increase in the percentage of phagocytosis and number of IgA+ cells in the small intestine). Treated animals showed lessEsch. coli, animals were fed for 5 days (selected dose). Mice were challenged with an infective dose of enteroinvasive Esch. coli of 108 cfu/mouse. The colonization of liver and spleen and the secretory IgA specific for the pathogen in the intestinal fluid were determined (ELISA test). Results showed that the unspecific immune response enhanced itself after 5 consecutive days of the administration of this fermented milk (increase in the percentage of phagocytosis and number of IgA+ cells in the small intestine). Treated animals showed lessEsch. coli of 108 cfu/mouse. The colonization of liver and spleen and the secretory IgA specific for the pathogen in the intestinal fluid were determined (ELISA test). Results showed that the unspecific immune response enhanced itself after 5 consecutive days of the administration of this fermented milk (increase in the percentage of phagocytosis and number of IgA+ cells in the small intestine). Treated animals showed less+ cells in the small intestine). Treated animals showed less Esch. coli colonization of liver than control mice and a higher secretory anti-Esch. coli IgA in the intestinal fluids. These results suggest that the protection against enteroinvasive Esch. colicolonization of liver than control mice and a higher secretory anti-Esch. coli IgA in the intestinal fluids. These results suggest that the protection against enteroinvasive Esch. coliEsch. coli infection observed for the fermented milk containing probiotic bacteria may be associated with an enhance of the intestinal mucosa immunity.