Infectivity and pathogenesis of iridescent virus type 22 in various insect hosts

Abstract

This paper reports the results of a series of laboratory experiments to determine the infectivity and pathogenesis of iridescent virus type 22 (IV 22) for six species of mosquitoes, phlebotomine sand flies and triatomid bugs. Following inoculation, IV 22 replicated in all of the species tested, without producing noticeable mortality within a 14 day observation period. Examination of the infected insects by immunofluorescence demonstrated large amounts of viral antigen in many different organs. Electron microscopy done on infected mosquitoes (Aedes aegypti) showed large numbers of virus particles within cells of the fat body, muscle tracheal and midgut epithelium. Virus replication in the mosquitoes was confirmed to host cell cytoplasm and was similar to that described in the natural blackfly (Simulium) host. Transovarial transmission of IV 22 could not be demonstrated in A. aegypti, and only a small percentage of mosquito larvae could be infected orally. Results of these experiments are compatible with observations of other iridescent viruses; IV 22 is highly infectious for a wide range of insects when introduced into their hemolymph, but it is not very infectious per os. These characteristics would appear to limit its value as a potential biocontrol agent for Diptera.

In vitrocultivation ofWolbachia pipientisin anAedes albopictuscell line

“…Slides were stained in a freshly prepared 1 mg/ml methanol solution of DAPI for 10 min followed by two 5 min washes in methanol and were then air dried. For the IFAT assay, acetone-®xed slides were incubated for 30 min with undiluted hybridoma culture¯uid, washed three times in PBS, and incubated for an additional 30 min in a commercial uorescein-conjugated goat anti-mouse globulin antibody (Tesh & Andreadis, 1992).…”

Iridovirus infection of cell cultures from the Diaprepes root weevil, Diaprepes abbreviatus

“…We describe methods for producing cell cultures of the Diaprepes root weevil, and on their subsequent infection with the Iridovirus, IIV-6. Previous studies support classifying IIV-6 as an entomopathogenic virus (Hall 1985, Hunter et al, 2003, Tesh and Andreadis 1992. Further evaluations of the interactions between IIV-6 and root weevils have also been reported (Hunter et al, 2003).…”

Effects of Invertebrate Iridescent Virus 6 inPhyllophaga vandineiand Its Potential as a Biocontrol Delivery System

“…Furthermore, although Iridoviridae are highly infectious when introduced to the insect hemolymph, e.g., by injection (Smith et al 1961; Kelly 1985; Anthony and Comps 1991), ingestion of virus particles typically does not result in infection (Tesh and Andreadis 1992; Williams and Hernandez 2006). Indeed, Tesh and Andreadis (1992) conclude that “these characteristics would appear to limit its value as a potential biocontrol agent”. Nonetheless, delivery systems have presented themselves in a variety of situations.…”