Replication of an Iridovirus in a nematode (Mermithidae).

An iridovirus was observed with the electron microscope in the tissues of a mermithid nematode parasitic in the isopods Porcellio scaber and Armadillidium vulgare. Virus particles were seen associated with virogenic areas in the cytoplasm along with viral stages suggestive of particle maturation. Extracts of portions of the same nematodes used for transmission electron microscopy appeared positive in serologically specific electron microscopy with antisera prepared against iridescent virus from the isopod hosts. These same extracts in 21 of 40 isopods produced infections when fed to P. scaber. This is the first report of a known virus replicating in a nematode and extends the host range of iridoviruses to the phylum Nematoda.