In vitro and in vivo evaluation of Bacillus clausii against Schistosoma mansoni.

Experimental studies and clinical trials have been showing that probiotics are promising in the prevention and control of parasite infections. B. clausii, obtained from Enterogermina®, was cultured to obtain cell-free culture supernatant (CFS) and spores to evaluate its schistosomicidal effect in vitro and in vivo against Schistosoma mansoni, respectively. For in vitro and in vivo analysis mice were infected with 120 and 50 cercariae, respectively. Couples of adult worms, recovered on day 45 of infection, were exposed to CFS. The in vivo assay was performed for 100 days, where all animals were infected on the 30th day. Four experimental groups were formed, as follows: G1 - Saline solution from the 1st until the 100th day; G2 - B. clausii from the 1st until the 100th day; G3 - B. clausii from the 68th day (onset of oviposition) until the 100th day and G4 - PZQ (50 mg/Kg) from the 75th until the 79th day. In vitro, CFS of B. clausii does not caused mortality nor changed the motility on S. mansoni adult worms. G2 and G3 showed reduction of the 68.58 and 44.25% in the number of eggs eliminated in the feces and 34.29 and 53.6% and 22.8 and 48.49% the number of eggs trapped in the liver and intestine, respectively. Furthermore, in both therapeutic regimens G2 and G3, B. clausii increased the percentage of dead eggs in the intestinal tissue. B. clausii CFS, in vitro, does not showed action against S. mansoni and that treatment with B. clausii spores modulates favorably the parasitological parameters in the experimental infection of S. mansoni.