Dados do Trabalho

Título

Antiparasitic activity of probiotics: Therapy with Bacillus clausii acts in Schistosoma mansoni infection

Objetivo (s)

To evaluate the effectiveness of Bacillus clausii as protection and/or treatment of schistosomiasis mansoni in vitro and in vivo.

Material e Métodos

B. clausii obtained from Enterogermina® was cultured to obtain cell-free culture supernatant (CFS) and spores. For the in vitro test, mice were infected with cercariae and, after 45 days of infection, couples of adult worms were recovered by perfusion, cultured in RPMI 1640 medium together with different concentrations of CFS, and were monitored for 5 consecutive days to evaluate the rate of mortality and changes in motility. The in vivo assay was performed for 100 days, where all animals were infected on the 30th day with 50 cercariae. Four experimental groups were formed with different therapeutic schemes: G1 - Saline solution from the 1st to the 100th day; G2 – B. clausii from the 1st to the 100th day; G3 - B. clausii from the 68th day (beginning of oviposition) to the 100th day and G4 - Praziquantel (PZQ, 50 mg/Kg) from the 75th to the 79th day. On the 100th day, the Kato-Katz test was performed in all mice. All groups received treatment by gavage daily and after 100 days of treatment, the mice were euthanized and perfused to evaluate the parasitic load (total and female worms), and their organs recovered to evaluate the load of eggs in the hepatic and intestinal tissues, and the oviposition pattern.

Resultados e Conclusão

In vitro, CFS from B. clausii did not cause mortality or change the motility of adult worms of S. mansoni. In the in vivo assay, G2 and G3 showed a significant reduction (p < 0.001) in the total worms burden of 41.4 and 30.13% and in the female worms burden of 43.06 and 38.64%, respectively, as well as a reduction (p<0.001) of 68.58 and 44.25% in the number of eggs eliminated in the feces, and the number of eggs trapped in the liver and intestine were reduced in 34.29 and 53.6% and 22.8 and 48.49%, respectively, compared to the negative control group. Furthermore, in both G2 and G3 therapeutic regimens, B. clausii increased the percentage of dead eggs in intestinal tissue. B. clausii CFS, in vitro, showed no action against S. mansoni, however treatment with spores of B. clausii favorably modulates the parasitological parameters in the experimental infection of S. mansoni.

Palavras-chave

Probiotic; Bacillus clausii; Schistosomiasis; Schistosoma mansoni.

Agradecimentos

CAPES - Code 001, FACEPE (APQ-0498-4.03/19, APQ-1181-4.03/22).