RESUMEN
The effect of the intraperitoneal (ip) administration of Lactobacillus casei Shirota strain (LcS) in CD1 mice on the establishment of Trichinella spiralis adult worms (TSAW), and on the generation of intestinal IgA anti-T. spiralis after challenge (AC) were evaluated. One hundred and twenty mice were allocated at random into two groups of 60 mice each: Treated group (T) and Non-treated group (NT). Each mouse in T group was inoculated with LcS at days -21, -14, and -7. On day 0 each mouse was challenged with 200 larvae of T. spiralis. At days 3, 5, 7, 10, 12, 14, 17, 19, 21, and 28 AC, six mice from each group were sacrificed to obtain TSAW. At days 7, 14, 21, and 28 IgA-s anti-T. spiralis levels in intestinal washings were evaluated by ELISA. From day five on AC, mice in LcS group showed significantly less TSAW (P<0.05) than animals from NT group. At days 7, 14, 21, and 28 AC IgA anti-T. spiralis levels were higher in mice from T group (P<0.05) than in the NT group. The results indicate that LcS inoculated into mice induces protection against T. spiralis and an increase in the production of IgA anti-T. spiralis.