In several regions of Russia, broad distribution of RNA-containing bee viruses was found at apiaries of honey bee Apis mellifera using RT-PCR. Detected RNA-containing bee viruses are transferred simultaneously with invasion of mite Varroa destructor and lead to mass bee mortality that results in economic losses in bee breeding. In samples of Varroa destructor, bee viruses DWV and ABPV were found. High degree of RNA-containing virus (BQCV, DWV SBV, ABPV, CBPV and KBV) infection was revealed: in the average, at least 50% for bee families with mite infection. In the bee families studied in this work, mixed infection with 2-6 viruses simultaneously was detected. Amplified fragments of viruses BQCV, DWV and SBV obtained using RT-PCR were sequenced and registered in Genbank.
Apis mellifera filamentous virus (AmFV) is a large double stranded DNA virus of honey bees, but its relationship with other parasites and prevalence are poorly known. We analyzed individual honey bees from three colonies at different times post emergence in order to monitor the dynamics of the AmFV gut colonization under natural conditions. Prevalence and loads of microsporidia and trypanosomes were also recorded, as well as five common honey bee RNA viruses. The results show that a high proportion of bees get infected with AmFV during the first week post-emergence (75%) and that AmFV DNA levels remained constant. A similar pattern was observed for microsporidia while trypanosomes seem to require more time to colonize the gut. No significant associations between these three infections were found, but significant positive correlations were observed between AmFV and RNA viruses. In parallel, the prevalence of AmFV in France and Sweden was assessed from pooled honey bee workers. The data indicate that AmFV is almost ubiquitous, and does not seem to follow seasonal patterns, although higher viral loads were significantly detected in spring. A high prevalence of AmFV was also found in winter bees, without obvious impact on overwintering of the colonies.
Cites: Adv Virus Res. 2007;70:33-8017765703
Cites: Environ Microbiol. 2015 Nov;17(11):4322-3125728008
Honey bee virus prevalence data are an essential prerequisite for managing epidemic events in a population. A survey study was carried out for seven viruses in colonies representing a healthy Danish honey bee population. In addition, colonies from apiaries with high level Varroa infestation or high level of winter mortality were also surveyed. Results from RT-qPCR showed a considerable difference of virus levels between healthy and sick colonies. In the group of healthy colonies, no virus was detected in 36% of cases, while at least one virus was found in each of the sick colonies. Virus titers varied among the samples, and multiple virus infections were common in both groups with a high prevalence of Sacbrood virus (SBV), Black queen cell virus (BQCV) and Deformed wing virus (DWV). Based on the distribution of virus titers, we established four categories of infection: samples free of virus (C = 0), samples with low virus titer (estimated number of virus copies 0
Cites: Proc Natl Acad Sci U S A. 2005 May 24;102(21):7470-515897457