The effect of saprotrophic fungi on the development and hatching of Fasciola hepatica eggs.

The aim of this study was to determine the effect of 6 common soil fungi species: Alternaria alternata (Fr.) Keissl., Aspergillus candidus Link, Penicillium chrysogenum Thom, P. commune Thom, Trichothecium roseum (Pers.) Link and Ulocladium sp., on the hatching of miracidia, i.e., free living larvae of liver fluke (Fasciola hepatica). To this end, the eggs of F. hepatica were incubated in water in the presence of one of the aforementioned fungi species and in tap water (control) at a temperature of 26 degrees C. At the 15th day of incubation we determined the number of nonembryonated, embryonated and hatched eggs. We observed different degrees of antagonistic influences by the tested fungal strains on the development of F. hepatica eggs. Among the examined fungi, the strongest ovistatic effects were exhibited by Trichothecium roseum, Penicillium chrysogenum (R-3) and P. commune. The study showed no morphological damage to the shells of the F. hepatica eggs which may suggest a biochemical basis of antagonistic interactions by the fungi associated with the activity of fungal enzymes, mycotoxins and antibiotics. Low or no activity of peptide hydrolases in Penicillium chrysogenum and P. commune in the API ZYM test suggests their insignificant role in the degradation of shell proteins ofF. hepatica eggs.