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Antibes, France

De Miranda J.R.,Swedish University of Agricultural Sciences | Bailey L.,Rothamsted Research | Ball B.V.,Rothamsted Research | Blanchard P.,Bee Diseases Unit | And 10 more authors.
Journal of Apicultural Research | Year: 2013

Honey bee virus research is an enormously broad area, ranging from subcellular molecular biology through physiology and behaviour, to individual and colony-level symptoms, transmission and epidemiology. The research methods used in virology are therefore equally diverse. This article covers those methods that are very particular to virological research in bees, with numerous cross-referrals to other BEEBOOK papers on more general methods, used in virology as well as other research. At the root of these methods is the realization that viruses at their most primary level inhabit a molecular, subcellular world, which they manipulate and interact with, to produce all higher order phenomena associated with virus infection and disease. Secondly, that viruses operate in an exponential world, while the host operates in a linear world and that much of the understanding and management of viruses hinges on reconciling these fundamental mathematical differences between virus and host. The article concentrates heavily on virus propagation and methods for detection, with minor excursions into surveying, sampling management and background information on the many viruses found in bees. © IBRA 2013.

Chevin A.,Bee Diseases Unit | Coutard B.,Aix - Marseille University | Blanchard P.,Bee Diseases Unit | Dabert-Gay A.-S.,French National Center for Scientific Research | And 2 more authors.
Viruses | Year: 2015

Chronic bee paralysis virus (CBPV) is the etiological agent of chronic paralysis, an infectious and contagious disease in adult honeybees. CBPV is a positive single-stranded RNA virus which contains two major viral RNA fragments. RNA 1 (3674 nt) and RNA 2 (2305 nt) encode three and four putative open reading frames (ORFs), respectively. RNA 1 is thought to encode the viral RNA-dependent RNA polymerase (RdRp) since the amino acid sequence derived from ORF 3 shares similarities with the RdRP of families Nodaviridae and Tombusviridae. The genomic organization of CBPV and in silico analyses have suggested that RNA 1 encodes non-structural proteins, while RNA 2 encodes structural proteins, which are probably encoded by ORFs 2 and 3. In this study, purified CBPV particles were used to characterize virion proteins by mass spectrometry. Several polypeptides corresponding to proteins encoded by ORF 2 and 3 on RNA 2 were detected. Their role in the formation of the viral capsid is discussed. © 2015 by the authors; licensee MDPI, Basel, Switzerland.

Carletto J.,Bee Diseases Unit | Blanchard P.,Bee Diseases Unit | Gauthier A.,Bee Diseases Unit | Schurr F.,Bee Diseases Unit | And 3 more authors.
Journal of Invertebrate Pathology | Year: 2013

Nosema apis and Nosema ceranae are the causative agents of nosemosis, a contagious honeybee disease that weakens bee colonies. The species are discriminated through several PCR-based methods including a multiplex PCR recommended by the World Organization for Animal Health (OIE). In this study, the OIE protocol was compared to two other PCR protocols using different PCR kits with the same primer pairs as described in OIE. The results showed that the three PCR protocols have similar sensitivity but only the kit dedicated to multiplex PCR could detect small quantities of one Nosema species when greater quantities of the other were also present. However, singleplex PCR methods are currently the most sensitive methods for discerning each species. These results have important implications for epidemiology and the understanding of the disease. © 2013 Elsevier Inc.

Chevin A.,Bee Diseases Unit | Schurr F.,Bee Diseases Unit | Blanchard P.,Bee Diseases Unit | Thiery R.,Bee Diseases Unit | Ribiere M.,Bee Diseases Unit
Virus Research | Year: 2012

Chronic paralysis is an infectious and contagious disease of the honeybee (Apis mellifera L.) and is caused by the chronic bee paralysis virus (CBPV). This disease leads to death in adult bees and is therefore a serious threat for colony health. CBPV is a positive single-stranded RNA virus and its genome is composed of two RNA segments, RNA 1 and RNA 2, 3674nt and 2305nt, respectively. Although CBPV shares some characteristics with viruses classified into families Nodaviridae and Tombusviridae, it has not been assigned to any viral taxa yet. The characterisation of CBPV proteins and their functions are needed to better understand the mechanisms of CBPV infection. However, since honeybee cell lines are not yet available, experimental infection of adult bees is the only method currently available to propagate the virus. With the objective of studying CBPV proteins using the viral genome, we used experimental infection in adult bees to evaluate the infectivity of naked CBPV RNAs by direct inoculation. Our results demonstrated that an injection of naked RNAs, ranging from 10 9 to 10 10 CBPV copies, caused chronic paralysis. Bees inoculated with naked RNA showed chronic paralysis signs 5 days after inoculation. Moreover, injected RNAs replicated and generated viral particles. We therefore provide an in vivo experimental model that will be useful tool for further studies by using a reverse genetics system. © 2012 Elsevier B.V.

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