Identification of deformed wing virus (DWV) in honeybee pupae by RT-PCR

The virus is widely distributed and prevalent in colonies infested by the mite. Using RT-PCR based assays, the virus infections in honey bees can be detected and quantified in a rapid and accurate manner. Infected honeybees from colonies suffering with symptoms of depopulation, sudden collapse, paralysis, and varroa infestation, used in this study, originated from 23 provinces of Iran. Bee samples were collected between July - September 2011 and 2012. Altogether, samples from 156 apiaries were collected and submitted for virus screening. From each apiary, 100-500 adult worker bees were sampled. RNA extraction and RT-PCR were performed with QIAGEN kits. The primers lead to a fragment of 434 bp. The PCR products were electrophoresed in a 1.2 % agarose gel (stained with ethidium bromide). Following the RT-PCR reaction with the specific primers, out of the 156 apiaries examined, 34 (21.8 %) were infected with DWV. This is the first study of DWV detection in Iranian apiaries. We have looked into the occurrence of the DWV and identified differences in the distribution of the virus in the collected samples from different geographic regions of Iran. The spread of V. destructor has been implicated in a dramatic increase in the prevalence of DWV and it is likely that this virus will become predominant in infested areas. The role of V. destructor in DWV transmission and the appearance of wing deformities in newly emerged bees also deserve more intensive investigation.