scholarly journals Mode of Transmission Determines the Virulence of Black Queen Cell Virus in Adult Honey Bees, Posing a Future Threat to Bees and Apiculture

Viruses ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 535 ◽  
Author(s):  
Yahya Al Naggar ◽  
Robert J. Paxton
Keyword(s):  
Honey Bees ◽  
Horizontal Transmission ◽  
Well Being ◽  
Rnai Pathway ◽  
Viral Titer ◽  
Black Queen Cell Virus ◽  
Viral Pathogen ◽  
Viral Virulence ◽  
Queen Cell ◽  
Mode Of Transmission

Honey bees (Apis mellifera) can be infected by many viruses, some of which pose a major threat to their health and well-being. A critical step in the dynamics of a viral infection is its mode of transmission. Here, we compared for the first time the effect of mode of horizontal transmission of Black queen cell virus (BQCV), a ubiquitous and highly prevalent virus of A. mellifera, on viral virulence in individual adult honey bees. Hosts were exposed to BQCV either by feeding (representing direct transmission) or by injection into hemolymph (analogous to indirect or vector-mediated transmission) through a controlled laboratory experimental design. Mortality, viral titer and expression of three key innate immune-related genes were then quantified. Injecting BQCV directly into hemolymph in the hemocoel resulted in far higher mortality as well as increased viral titer and significant change in the expression of key components of the RNAi pathway compared to feeding honey bees BQCV. Our results support the hypothesis that mode of horizontal transmission determines BQCV virulence in honey bees. BQCV is currently considered a benign viral pathogen of adult honey bees, possibly because its mode of horizontal transmission is primarily direct, per os. We anticipate adverse health effects on honey bees if BQCV transmission becomes vector-mediated.

scholarly journals Direct transmission by injection affects competition among RNA viruses in honeybees

2019 ◽  
Vol 286 (1895) ◽  
pp. 20182452 ◽  
Author(s):  
Emily J. Remnant ◽  
Niklas Mather ◽  
Thomas L. Gillard ◽  
Boris Yagound ◽  
Madeleine Beekman
Keyword(s):  
Varroa Destructor ◽  
Rna Viruses ◽  
Direct Injection ◽  
Direct Transmission ◽  
Black Queen Cell Virus ◽  
Virus Inoculation ◽  
Deformed Wing Virus ◽  
Viral Virulence ◽  
Queen Cell ◽  
Mode Of Transmission

The arrival of the ectoparasitic mite Varroa destructor on the western honeybee Apis mellifera saw a change in the diversity and prevalence of honeybee RNA viruses. One virus in particular, deformed wing virus (DWV) has become closely associated with V. destructor , leading many to conclude that V. destructor has affected viral virulence by changing the mode of transmission. While DWV is normally transmitted via feeding and faeces, V. destructor transmits viruses by direct injection. This change could have resulted in higher viral prevalence causing increased damage to the bees. Here we test the effect of a change in the mode of transmission on the composition and levels of honeybee RNA viruses in the absence of V. destructor . We find a rapid increase in levels of two viruses, sacbrood virus (SBV) and black queen cell virus (BQCV) after direct injection of viral extracts into honeybee pupae. In pupae injected with high levels of DWV extracted from symptomatic adult bees, DWV levels rapidly decline in the presence of SBV and BQCV. Further, we observe high mortality in honeybee pupae when injected with SBV and BQCV, whereas injecting pupae with high levels of DWV results in near 100% survival. Our results suggest a different explanation for the observed association between V. destructor and DWV. Instead of V. destructor causing an increase in DWV virulence, we hypothesize that direct virus inoculation, such as that mediated by a vector, quickly eliminates the most virulent honeybee viruses resulting in an association with less virulent viruses such as DWV.

scholarly journals The Pathogen Profile of a Honey Bee Queen Does Not Reflect That of Her Workers

Insects ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 382 ◽  
Author(s):  
Jessica L. Kevill ◽  
Katie Lee ◽  
Michael Goblirsch ◽  
Erin McDermott ◽  
David R. Tarpy ◽  
...  
Keyword(s):  
Honey Bee ◽  
Horizontal Transmission ◽  
Pathogen Transmission ◽  
Black Queen Cell Virus ◽  
Deformed Wing Virus ◽  
Israeli Acute Paralysis Virus ◽  
Queen Cell ◽  
Honey Bee Queen ◽  
Acute Bee Paralysis Virus ◽  
Paralysis Virus

Throughout a honey bee queen’s lifetime, she is tended to by her worker daughters, who feed and groom her. Such interactions provide possible horizontal transmission routes for pathogens from the workers to the queen, and as such a queen’s pathogen profile may be representative of the workers within a colony. To explore this further, we investigated known honey bee pathogen co-occurrence, as well as pathogen transmission from workers to queens. Queens from 42 colonies were removed from their source hives and exchanged into a second, unrelated foster colony. Worker samples were taken from the source colony on the day of queen exchange and the queens were collected 24 days after introduction. All samples were screened for Nosema spp., Trypanosome spp., acute bee paralysis virus (ABPV), black queen cell virus (BQCV), chronic bee paralysis virus (CBPV), Israeli acute paralysis virus (IAPV), Lake Sinai virus (LSV), and deformed wing virus master variants (DWV-A, B, and C) using RT-qPCR. The data show that LSV, Nosema, and DWV-B were the most abundant pathogens in colonies. All workers (n = 42) were LSV-positive, 88% were Nosema-positive, whilst pathogen loads were low (<1 × 106 genome equivalents per pooled worker sample). All queens (n = 39) were negative for both LSV and Nosema. We found no evidence of DWV transmission occurring from worker to queen when comparing queens to foster colonies, despite DWV being present in both queens and workers. Honey bee pathogen presence and diversity in queens cannot be revealed from screening workers, nor were pathogens successfully transmitted to the queen.

scholarly journals Brain transcriptomes of honey bees ( Apis mellifera ) experimentally infected by two pathogens: Black queen cell virus and Nosema ceranae

Genomics Data ◽  
2016 ◽  
Vol 10 ◽  
pp. 79-82 ◽  
Author(s):  
Vincent Doublet ◽  
Robert J. Paxton ◽  
Cynthia M. McDonnell ◽  
Emeric Dubois ◽  
Sabine Nidelet ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Honey Bees ◽  
Nosema Ceranae ◽  
Black Queen Cell Virus ◽  
Queen Cell

scholarly journals Feral and managed honey bees, Apis mellifera (Hymenoptera: Apidae), in southern California have similar levels of viral pathogens

2021 ◽  
Author(s):  
Amy C Geffre ◽  
Dillon Travis ◽  
Joshua Kohn ◽  
James Nieh
Keyword(s):  
Apis Mellifera ◽  
Honey Bees ◽  
Southern California ◽  
Multiple Stressors ◽  
Pollination Services ◽  
Viral Pathogens ◽  
Viral Pathogen ◽  
Deformed Wing Virus ◽  
Native Bee ◽  
Queen Cell

Bees provide critical pollination services but are threatened by multiple stressors, including viral pathogens. Most studies of pollinator health focus on managed honey bees (Apis mellifera Linnaeus) (MHB) or native bee species, but a third player, the feral honey bee (FHB), requires further study. Spillover and spillback of viral pathogens between these managed, feral, and native bees is generating increasing interest. In this case study, we provide evidence suggesting that FHB colonies play an important role in viral pathogen dynamics of southern California pollinator communities because they act as reservoirs, of viral pathogens such as acute bee paralysis virus (ABPV), black queen cell virus (BQCV), and deformed wing virus (DWV). Surprisingly, even though FHB are not treated for diseases or parasites, they harbor similar pathogen loads to MHB, which are usually highly treated, suggesting the need for future studies to determine if FHB resist or are more resilient to viruses.

scholarly journals Analysis of the complete genome sequence of black queen-cell virus, a picorna-like virus of honey bees

2000 ◽  
Vol 81 (8) ◽  
pp. 2111-2119 ◽  
Author(s):  
Neil Leat ◽  
Brenda Ball ◽  
Vandana Govan ◽  
Sean Davison
Keyword(s):  
South African ◽  
Honey Bees ◽  
Untranslated Region ◽  
Rhopalosiphum Padi ◽  
Amino Acid Sequences ◽  
Nucleotide Sequence Analysis ◽  
Black Queen Cell Virus ◽  
Queen Cell ◽  
African Honey Bees ◽  
Plautia Stali

A virus with picorna-like biophysical properties was isolated from South African honey bees. On the basis of serology, it was identified as an isolate of black queen-cell virus (BQCV). Nucleotide sequence analysis revealed an 8550 nt polyadenylated genome containing two large ORFs. The 5′-proximal ORF (ORF 1) represented 4968 nt while the 3′-proximal ORF (ORF 2) represented 2562 nt. The ORFs were separated by a 208 nt intergenic region and were flanked by a 657 nt 5′-untranslated region and a 155 nt 3′-untranslated region. Deduced amino acid sequences for ORF 1 and ORF 2 were most similar to the non-structural and structural proteins, respectively, of Drosophila C virus (DCV), Rhopalosiphum padi virus (RhPV), Himetobi P virus (HiPV) and Plautia stali intestine virus (PSIV). It is proposed that BQCV belongs to the group of picorna-like, insect-infecting RNA viruses constituted by DCV, RhPV, HiPV and PSIV.

scholarly journals Tolerance of Honey Bees to Varroa Mite in the Absence of Deformed Wing Virus

Viruses ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 575 ◽  
Author(s):  
John M. K. Roberts ◽  
Nelson Simbiken ◽  
Chris Dale ◽  
Joel Armstrong ◽  
Denis L. Anderson
Keyword(s):  
Honey Bee ◽  
Honey Bees ◽  
High Throughput Sequencing ◽  
Solomon Islands ◽  
Host Shift ◽  
Colony Losses ◽  
Viral Pathogen ◽  
Deformed Wing Virus ◽  
Bee Health ◽  
Queen Cell

The global spread of the parasitic mite Varroa destructor has emphasized the significance of viruses as pathogens of honey bee (Apis mellifera) populations. In particular, the association of deformed wing virus (DWV) with V. destructor and its devastating effect on honey bee colonies has led to that virus now becoming one of the most well-studied insect viruses. However, there has been no opportunity to examine the effects of Varroa mites without the influence of DWV. In Papua New Guinea (PNG), the sister species, V. jacobsoni, has emerged through a host-shift to reproduce on the local A. mellifera population. After initial colony losses, beekeepers have maintained colonies without chemicals for more than a decade, suggesting that this bee population has an unknown mite tolerance mechanism. Using high throughput sequencing (HTS) and target PCR detection, we investigated whether the viral landscape of the PNG honey bee population is the underlying factor responsible for mite tolerance. We found A. mellifera and A. cerana from PNG and nearby Solomon Islands were predominantly infected by sacbrood virus (SBV), black queen cell virus (BQCV) and Lake Sinai viruses (LSV), with no evidence for any DWV strains. V. jacobsoni was infected by several viral homologs to recently discovered V. destructor viruses, but Varroa jacobsoni rhabdovirus-1 (ARV-1 homolog) was the only virus detected in both mites and honey bees. We conclude from these findings that A. mellifera in PNG may tolerate V. jacobsoni because the damage from parasitism is significantly reduced without DWV. This study also provides further evidence that DWV does not exist as a covert infection in all honey bee populations, and remaining free of this serious viral pathogen can have important implications for bee health outcomes in the face of Varroa.

scholarly journals Home sick: impacts of migratory beekeeping on honey bee (Apis mellifera) pests, pathogens, and colony size

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5812 ◽  
Author(s):  
Samantha A. Alger ◽  
P. Alexander Burnham ◽  
Zachary S. Lamas ◽  
Alison K. Brody ◽  
Leif L. Richardson
Keyword(s):  
Honey Bee ◽  
Pesticide Exposure ◽  
Floral Resources ◽  
Black Queen Cell Virus ◽  
Manipulative Experiment ◽  
Viral Pathogen ◽  
Deformed Wing Virus ◽  
Single Location ◽  
Queen Cell ◽  
Bee Colonies

Honey bees are important pollinators of agricultural crops and the dramatic losses of honey bee colonies have risen to a level of international concern. Potential contributors to such losses include pesticide exposure, lack of floral resources and parasites and pathogens. The damaging effects of all of these may be exacerbated by apicultural practices. To meet the pollination demand of US crops, bees are transported to areas of high pollination demand throughout the year. Compared to stationary colonies, risk of parasitism and infectious disease may be greater for migratory bees than those that remain in a single location, although this has not been experimentally established. Here, we conducted a manipulative experiment to test whether viral pathogen and parasite loads increase as a result of colonies being transported for pollination of a major US crop, California almonds. We also tested if they subsequently transmit those diseases to stationary colonies upon return to their home apiaries. Colonies started with equivalent numbers of bees, however migratory colonies returned with fewer bees compared to stationary colonies and this difference remained one month later. Migratory colonies returned with higher black queen cell virus loads than stationary colonies, but loads were similar between groups one month later. Colonies exposed to migratory bees experienced a greater increase of deformed wing virus prevalence and load compared to the isolated group. The three groups had similar infestations of Varroa mites upon return of the migratory colonies. However, one month later, mite loads in migratory colonies were significantly lower compared to the other groups, possibly because of lower number of host bees. Our study demonstrates that migratory pollination practices has varying health effects for honey bee colonies. Further research is necessary to clarify how migratory pollination practices influence the disease dynamics of honey bee diseases we describe here.

scholarly journals Vector-mediated viral transmission favours less virulent viruses

2018 ◽  
Author(s):  
Emily J. Remnant ◽  
Niklas Mather ◽  
Thomas L. Gillard ◽  
Boris Yagound ◽  
Madeleine Beekman
Keyword(s):  
Alternative Explanation ◽  
Rna Viruses ◽  
Black Queen Cell Virus ◽  
Viral Titre ◽  
Exact Role ◽  
Deformed Wing Virus ◽  
Route Of Transmission ◽  
Queen Cell ◽  
Mode Of Transmission ◽  
Honeybee Health

AbstractWhile it is well-established that the ectoparasitic mite Varroa destructor is largely responsible for the widely-reported decline of populations of the Western honeybee Apis mellifera, the exact role the mite plays in honeybee health remains unclear. The last few years have seen a surge in studies associating RNA viruses vectored by the mite with the death of honeybee colonies. Varroa facilitates the spread of RNA viruses because it feeds on developing bee brood and transfers haemolymph from bee-to-bee. Such a change in transmission, from horizontal and vertical to vector-based, is predicted to lead to an increase in virulence of RNA viruses, thus potentially providing an explanation for the observed association between Varroa and certain viruses. Here we document the effect of changing the route of transmission of honeybee viruses contained in the haemolymph of honeybee pupae. We find that a change in mode of transmission rapidly increases viral titres of two honeybee viruses, Sacbrood virus (SBV) and Black queen cell virus (BQCV). This increase in viral titre is accompanied by an increase in virulence. In contrast, the virus most often associated with Varroa, Deformed wing virus (DWV), shows a reduction in viral titre in the presence of SBV and BQCV. In addition, DWV does not cause mortality to honeybee pupae in isolation. Most likely a change in mode of transmission due to the arrival of a vector quickly eliminates the most virulent honeybee viruses resulting in an association between Varroa and less virulent viruses such as DWV. Our work therefore provides empirical evidence for an alternative explanation for the widely-observed association between Varroa and DWV.

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