Antiparasitic Action of Lactobacillus casei ATCC 393 and Lactobacillus paracasei CNCM Strains in CD-1 Mice Experimentally Infected with Trichinella britovi

Nematodes of the genus Trichinella are among the most widespread parasites of domestic and wild omnivores and predatory animals. The present study aimed to evaluate the antiparasitic effect of Lactobacillus casei ATCC 393 (original) and L. paracasei CNCM in CD-1 mice experimentally infected with Trichinella britovi. Four groups of 20 mice (10 females and 10 males/group) were used, with two control (C) groups and two experimental (E) groups, in which each animal received a daily oral dose of 100 mu L of 10(5) CFU/mL probiotics in Ringer's solution. On day 7, all mice (except the negative control group) were infected orally with Trichinella (100 larvae/animal) as well as the two probiotics. On day 9 post-infection (p.i.), 10 mice/group were euthanized, and the presence of adult parasites in the intestinal content and wall was tested. On day 32 p.i., 10 mice/group were euthanized, then trichinoscopy and artificial digestion were performed to assess the muscle infection with T. britovi. On day 9 p.i., the experimental group pretreated with L. casei ATCC 393 (6.3 +/- 3.03) showed a significantly lower number of adult parasites in the intestinal wall compared with the positive control group (24.6 +/- 4.78). Additionally, a significantly lower adult parasite count in the intestinal wall was registered in female mice pretreated with L. paracasei CNCM (7.4 +/- 4.71) compared to female mice from the positive control (29.0 +/- 5.17). No statistically relevant results were obtained concerning the male mice or the data obtained at 32 days p.i., irrespective of mice gender.