Molecular Identification of Chronic Bee Paralysis Virus Infection in Apis mellifera Colonies in Japan

Tomomi Morimoto,Bu Yang,Mikio Yoshiyama,Yuriko Kojima,Tatsuhiko Kadowaki,Kiyoshi Kimura

doi:10.3390/v4071093

Abstract

Chronic bee paralysis virus (CBPV) infection causes chronic paralysis and loss of workers in honey bee colonies around the world. Although CBPV shows a worldwide distribution, it had not been molecularly detected in Japan. Our investigation of Apis mellifera and Apis cerana japonica colonies with RT-PCR has revealed CBPV infection in A. mellifera but not A. c. japonica colonies in Japan. The prevalence of CBPV is low compared with that of other viruses: deformed wing virus (DWV), black queen cell virus (BQCV), Israel acute paralysis virus (IAPV), and sac brood virus (SBV), previously reported in Japan. Because of its low prevalence (5.6%) in A. mellifera colonies, the incidence of colony losses by CBPV infection must be sporadic in Japan. The presence of the (−) strand RNA in dying workers suggests that CBPV infection and replication may contribute to their symptoms. Phylogenetic analysis demonstrates a geographic separation of Japanese isolates from European, Uruguayan, and mainland US isolates. The lack of major exchange of honey bees between Europe/mainland US and Japan for the recent 26 years (1985–2010) may have resulted in the geographic separation of Japanese CBPV isolates.

Highlights

Chronic bee paralysis virus (CBPV) causes chronic paralysis, an infectious disease of adult honey bees
Our current investigation has revealed a lower prevalence of CBPV in Japan, relative to other viruses, including deformed wing virus (DWV), black queen cell virus (BQCV), Israel acute paralysis virus (IAPV), and sac brood virus (SBV) [6], this prevalence could be underestimated because one primer set we used for primary screening may fail to detect more divergent strains of CBPV
Our investigation of A. mellifera and A. c. japonica colonies with RT-PCR has revealed CBPV

Summary

Introduction

Chronic bee paralysis virus (CBPV) causes chronic paralysis, an infectious disease of adult honey bees. The symptoms of this disease include severe trembling of the wings and bodies, and diseased bees often crawl on the ground. Diseased bees die within a few days [1,2]. CBPV can persist as an unapparent infection but may multiply to high levels in honey bee colonies [3], causing significant losses [4]. CBPV shares several characteristics with the Nodaviridae and Tombusviridae virus families, CBPV is considered a new family of positive single-stranded RNA viruses. The sizes of the two major CBPV RNAs were determined to be 3674 bases for RNA 1 and 2305 bases for RNA 2 [5]

Results

Discussion

Conclusion