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.

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 Presence and Prevalence of Viruses in Local and Migratory Honeybees (Apis mellifera) in Massachusetts

2009 ◽  
Vol 75 (24) ◽  
pp. 7862-7865 ◽  
Author(s):  
Anna Welch ◽  
Francis Drummond ◽  
Sunil Tewari ◽  
Anne Averill ◽  
John P. Burand
Keyword(s):  
Apis Mellifera ◽  
Black Queen Cell Virus ◽  
Deformed Wing Virus ◽  
Sacbrood Virus ◽  
Queen Cell ◽  
The Impact

ABSTRACT Migratory and local bees in Massachusetts were analyzed for seven viruses. Three were detected: black queen cell virus (BQCV), deformed wing virus (DWV), and sacbrood virus (SBV). DWV was most common, followed closely by BQCV and then by SBV. BQCV and SBV were present at significantly higher rates in the migratory bees assayed, bringing into question the impact that these bees have on the health of local bee populations.

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 Phylogenetic analysis of black queen cell virus and deformed wing virus in honeybee colonies infected by mites in Van, Eastern Turkey

2018 ◽  
Vol 74 (1) ◽  
pp. 5990-2018 ◽  
Author(s):  
ZEYNEP KARAPINAR ◽  
BEKİR OĞUZ ◽  
ENDER DİNÇER ◽  
CİHAT ÖZTÜRK
Keyword(s):  
Phylogenetic Analysis ◽  
Analysis Data ◽  
Parasitic Infections ◽  
Black Queen Cell Virus ◽  
Deformed Wing Virus ◽  
Eastern Turkey ◽  
Geographical Regions ◽  
Queen Cell ◽  
Colony Loss ◽  
Paralysis Virus

This study aimed to determine the presence and prevalence of viral and parasitic infections causing high rates of colony loss in honey bee colonies in Van province, eastern Turkey. Twenty-six different apiaries were collected from five counties in Van province. These samples were tested by Reverse-Transcriptase PCR (RT-PCR) for acute bee paralysis virus (ABPV), chronic bee paralysis virus (CBPV), black queen cell virus (BQCV) and deformed wing virus (DWV). Selected positives were sequenced, phylogenetically analyzed and investigated in terms of Varroa. DWV and BQCV were identified in 69.23% (18/26) and 88.46% (23/26) of the bees respectively whereas ABPV and CBPV were not detected in the sampled apiaries. Results of the phylogenetic analysis of DWV and BQCV sequences showed 94–100% similarity to DWV and BQCV isolates obtained from Genbank. Prevalence of varroasis was 89% (23/26) in Van. The obtained samples were identified as V. Varroa destructor by morphological investigation. The study showed that viral and parasitic agents commonly infect honeybees in Van province, with high prevalence rates for BQCV and DWV. There was also a high degree of conservation of DWV and BQCV sequences distinct from DWV and BQCV isolates from other geographical regions. These findings, including current prevalence and phylogenetic analysis data for DWV, BQCV and varroazis in honeybees, are useful for future studies. .

scholarly journals Parasites and RNA viruses in wild and laboratory reared bumble bees Bombus pauloensis (Hymenoptera: Apidae) from Uruguay

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249842
Author(s):  
Sheena Salvarrey ◽  
Karina Antúnez ◽  
Daniela Arredondo ◽  
Santiago Plischuk ◽  
Pablo Revainera ◽  
...  
Keyword(s):  
Native Species ◽  
Rna Viruses ◽  
Mite Species ◽  
Bumble Bees ◽  
Natural Ecosystems ◽  
Deformed Wing Virus ◽  
Internal Parasites ◽  
Queen Cell ◽  
Field Workers ◽  
Paralysis Virus

Bumble bees (Bombus spp.) are important pollinators insects involved in the maintenance of natural ecosystems and food production. Bombus pauloensis is a widely distributed species in South America, that recently began to be managed and commercialized in this region. The movement of colonies within or between countries may favor the dissemination of parasites and pathogens, putting into risk while populations of B. pauloensis and other native species. In this study, wild B. pauloensis queens and workers, and laboratory reared workers were screened for the presence of phoretic mites, internal parasites (microsporidia, protists, nematodes and parasitoids) and RNA viruses (Black queen cell virus (BQCV), Deformed wing virus (DWV), Acute paralysis virus (ABCV) and Sacbrood virus (SBV)). Bumble bee queens showed the highest number of mite species, and it was the only group where Conopidae and S. bombi were detected. In the case of microsporidia, a higher prevalence of N. ceranae was detected in field workers. Finally, the bumble bees presented the four RNA viruses studied for A. mellifera, in proportions similar to those previously reported in this species. Those results highlight the risks of spillover among the different species of pollinators.

Occurrence, detection, and quantification of economically important viruses in healthy and unhealthy honey bee (Hymenoptera: Apidae) colonies in Canada

2015 ◽  
Vol 148 (1) ◽  
pp. 22-35 ◽  
Author(s):  
Suresh D. Desai ◽  
Santosh Kumar ◽  
Robert W. Currie
Keyword(s):  
Polymerase Chain Reaction ◽  
Honey Bee ◽  
Multiple Infections ◽  
Black Queen Cell Virus ◽  
Chain Reaction ◽  
Deformed Wing Virus ◽  
Sacbrood Virus ◽  
Queen Cell ◽  
Polymerase Chain ◽  
Paralysis Virus

AbstractThe occurrence, quantification, and distribution patterns of deformed wing virus (DWV) and sacbrood virus (SBV), (family Iflaviridae); black queen cell virus (BQCV), Israeli acute paralysis virus (IAPV), Kashmir bee virus (KBV), and acute bee paralysis virus (ABPV) (family Dicistroviridae), and chronic bee paralysis virus (CBPV) (unclassified), were characterised in 80 “healthy” honey bee (Apis mellifera Linnaeus; Hymenoptera: Apidae) colonies and 23 “unhealthy” colonies by employing reverse transcription polymerase chain reaction (RT-PCR) for virus identification and quantitative real-time polymerase chain reaction (qPCR) for quantification. All seven viruses were common but the most prevalent viruses were DWV, followed by BQCV and IAPV. For most viruses, prevalence in surviving but unhealthy colonies in spring did not differ from that of healthy baseline colony levels in fall suggesting spring prevalence level would not be a useful metric for diagnosis of factors contributing to colony loss. Sacbrood virus was the only virus that was more prevalent in unhealthy colonies from Manitoba, Canada than in healthy from colonies across Canada but did not differ from healthy colonies within Manitoba. Multiple infections were ubiquitous with a few colonies having simultaneous infection with as many as five viruses. Among the three viruses quantified by qPCR, DWV had the highest relative concentrations in pooled samples of worker bees. Deformed wing virus was the only virus within healthy colonies that differed in fall concentration among provinces and was at high levels in unhealthy colonies. Black queen cell virus was positively correlated with IAPV across all samples. Our study provides the first major baseline study of viruses in Canadian honey bees.

Sign in / Sign up

Export Citation Format

Share Document