Fecal IgA levels in mice inoculated with attenuated strains of Salmonella Typhimurium

The present study aimed to evaluate the immunogenic activity of three life attenuated strains of Salmonella Typhimurium isolated from guinea pig, by evaluating the excretion of faecal IgA in mice. The study was carried out with 28 four-week-old female mice of the Balb/c strain, distributed into four groups (seven mice per group): strain 1, strain 2, strain 3 and control group (PBS). Each mouse was inoculated with 109 CFU/100 mu l of the attenuated strains using an orogastric probe. Fresh stool samples were collected at days 1, 9, 15 and 21 post-immunizations. The quantification of faecal IgA was carried out by an indirect in-house ELISA test. The results indicate that the mice inoculated with strains 1 and 2 presented a higher immunogenic activity (faecal IgA) compared to the Control group.