Vermial virucidal activity: Implications for management of pathogenic biological wastes on land

The earthworm Eisenia fetida, known to contain bactericidal enzymes, was tested for virucidal activity using Cowpea mosaic virus (CPMV) and Tobacco mosaic virus (TMV) as model agents. Earthworms were fed cellulose saturated with a virus suspension and their excreted castings were analyzed for structurally intact virus protein using enzyme-linked immunosorbant assay (ELISA) and virus infectivity by local lesion assays. Observations of the feeding experiments indicated a considerable reduction in the infectivity of both viruses. Virucidal activity was also observed when virus suspensions were incubated with the earthworm enzyme extract and analyzed by local lesion assay. The observed reductions in the infectivity of both viruses suggest that E. fetida may possess a virucidal enzyme system and, accordingly, may contribute to the inactivation of pathogenic viruses potentially associated with land application of sewage sludges and livestock manures.