Inapparent Virus Infections and their Interactions in Pupae of the Honey Bee (Apis mellifera Linnaeus) in Australia

Abstract

SUMMARYWhen honey bee pupae from seemingly healthy Australian colonies were injected with various salt solutions, inapparent infections of black queen-cell virus (BQCV), Kashmir bee virus (KBV), sacbrood virus (SBV) and, occasionally, cricket paralysis virus were activated. The activated viruses replicated to detectable concentrations after pupae were incubated at 35 °C for 3 days. Inapparent infections of SBV, but not the other viruses, were also activated merely by incubating pupae at 35 °C. The replication of activated BQCV, KBV or SBV was specifically suppressed by injecting pupae with rabbit antisera against the particles of each virus. However, a greater proportion of activated SBV infections occurred in groups of pupae in which the replication of activated KBV was suppressed than in groups of pupae in which KBV was not suppressed. In addition, a greater proportion of activated BQCV infections occurred in pupae in which the replication of both KBV and SBV was suppressed than in groups of pupae that were not injected with KBV and SBV antisera. Results from one group of pupae treated in this way indicated that about 40~ were infected with KBV, about 43~ with SBV and about 15~ with BQCV. There was no evidence of interference between the viruses in the establishment of inapparent infections of pupae, but clear evidence of interference during or after activation. These results have implications for the use of pupae for virus propagation.

Prevalence and Seasonal Variations of Six Bee Viruses in Apis mellifera L. and Varroa destructor Mite Populations in France

“…Second, the mite can also trigger virus replication by a simple mechanical effect, cuticle piercing, or by injection of external proteins into the insect hemolymph (18). The latter hypothesis is supported by several studies that demonstrated that there was reactivation of viruses already present in the insect following experimental inoculation (3,17). However, the association between parasitic mite syndrome and viruses is still controversial (21).…”

“…Two of these viruses, SBV and CBPV, produce clinical signs that are clearly identifiable by beekeepers, whereas the majority of the viruses are believed to cause persistent, usually inapparent infections in honey bees (3,6,17,20), and their associations with colony mortality remain unexplained (10,25).…”

Multiple virus infections in the honey bee and genome divergence of honey bee viruses

“…Although virus coinfections have long been recognized in plants and other animals, information on mixed virus infections in honey bees has accumulated very slowly over the last decade. Anderson and Gibbs (1988) first reported infections of KBV, SBV, and BQCV in bee colonies and demonstrated that replication of SBV and BQCV could be suppressed by activation of KBV. The genetic study of Evans (2001) showed that KBV and ABPV could infect the same bee, simultaneously.…”

“…In addition, attempts to determine the frequency of viruses in the field have been slowed by the fact that bee colonies can be attacked by more than one virus. Multiple viral infections have been reported in bees by a number of authors including Anderson (1990), Anderson and Gibbs (1988), Benjeddou et al (2001), Evans (2001), Hung et al (1996a,b), and Leat et al (2000). For many years, detection and identification of viral infection in honey bee colonies were based largely on serological methods like Ouchterlony gel diffusion, indirect fluorescent antibody (IFA) and enzyme-linked immunosorbent assay (ELISA) tests (Allen and Ball, 1995;Allen et al, 1986;Anderson, 1984).…”

A real-time PCR based survey on acute bee paralysis virus in German bee colonies

“…Bee colonies can harbour viruses without showing obvious disease symptoms (Anderson and Gibbs, 1988;Dall, 1985;Gauthier et al, 2007). Different approaches have been used to clarify the role of viruses in bee colonies.…”