1
|
Lamas ZS, Krichton M, Ryabov EV, Hawthorne DJ, Evans JD. Susceptible and infectious states for both vector and host in a dynamic pathogen-vector-host system. Proc Biol Sci 2024; 291:20232293. [PMID: 38196351 PMCID: PMC10777147 DOI: 10.1098/rspb.2023.2293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 12/01/2023] [Indexed: 01/11/2024] Open
Abstract
Deformed wing virus (DWV) is a resurgent insect pathogen of honeybees that is efficiently transmitted by vectors and through host social contact. Continual transmission of DWV between hosts and vectors is required to maintain the pathogen within the population, and this vector-host-pathogen system offers unique disease transmission dynamics for pathogen maintenance between vectors and a social host. In a series of experiments, we measured vector-vector, host-host and host-vector transmission routes and show how these maintain DWV in honeybee populations. We found co-infestations on shared hosts allowed for movement of DWV from mite to mite. Additionally, two social behaviours of the honeybee, trophallaxis and cannibalization of pupae, provide routes for horizontal transmission from bee to bee. Circulation of the virus solely among hosts through communicable modes provides a reservoir of DWV for naïve Varroa to acquire and subsequently vector the pathogen. Our findings illustrate the importance of community transmission between hosts and vector transmission. We use these results to highlight the key avenues used by DWV during maintenance and infection and point to similarities with a handful of other infectious diseases of zoonotic and medical importance.
Collapse
Affiliation(s)
- Zachary S. Lamas
- Bee Research Laboratory, United States Department of Agriculture—Agricultural Research Service, Beltsville 06415, MD, USA
- Department of Entomology, University of Maryland, College Park 20742-5031, MD, USA
| | - Maiya Krichton
- Bee Research Laboratory, United States Department of Agriculture—Agricultural Research Service, Beltsville 06415, MD, USA
- Department of Entomology, University of Maryland, College Park 20742-5031, MD, USA
| | - Eugene V. Ryabov
- Bee Research Laboratory, United States Department of Agriculture—Agricultural Research Service, Beltsville 06415, MD, USA
- Department of Entomology, University of Maryland, College Park 20742-5031, MD, USA
- The James Hutton Institute, Invergowrie, Dundee, UK
| | - David J. Hawthorne
- Department of Entomology, University of Maryland, College Park 20742-5031, MD, USA
| | - Jay D. Evans
- Bee Research Laboratory, United States Department of Agriculture—Agricultural Research Service, Beltsville 06415, MD, USA
| |
Collapse
|
2
|
Doublet V, Oddie MAY, Mondet F, Forsgren E, Dahle B, Furuseth-Hansen E, Williams GR, De Smet L, Natsopoulou ME, Murray TE, Semberg E, Yañez O, de Graaf DC, Le Conte Y, Neumann P, Rimstad E, Paxton RJ, de Miranda JR. Shift in virus composition in honeybees ( Apis mellifera) following worldwide invasion by the parasitic mite and virus vector Varroa destructor. ROYAL SOCIETY OPEN SCIENCE 2024; 11:231529. [PMID: 38204792 PMCID: PMC10776227 DOI: 10.1098/rsos.231529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 12/13/2023] [Indexed: 01/12/2024]
Abstract
Invasive vectors can induce dramatic changes in disease epidemiology. While viral emergence following geographical range expansion of a vector is well known, the influence a vector can have at the level of the host's pathobiome is less well understood. Taking advantage of the formerly heterogeneous spatial distribution of the ectoparasitic mite Varroa destructor that acts as potent virus vector among honeybees Apis mellifera, we investigated the impact of its recent global spread on the viral community of honeybees in a retrospective study of historical samples. We hypothesized that the vector has had an effect on the epidemiology of several bee viruses, potentially altering their transmissibility and/or virulence, and consequently their prevalence, abundance, or both. To test this, we quantified the prevalence and loads of 14 viruses from honeybee samples collected in mite-free and mite-infested populations in four independent geographical regions. The presence of the mite dramatically increased the prevalence and load of deformed wing virus, a cause of unsustainably high colony losses. In addition, several other viruses became more prevalent or were found at higher load in mite-infested areas, including viruses not known to be actively varroa-transmitted, but which may increase opportunistically in varroa-parasitized bees.
Collapse
Affiliation(s)
- Vincent Doublet
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany
- Institute for Biology, Martin Luther University Halle-Wittenberg, Halle (Saale) 061200, Germany
| | - Melissa A. Y. Oddie
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala 750 07, Sweden
- Norwegian Beekeepers Association, Kløfta 2040, Norway
| | - Fanny Mondet
- INRAE, UR 406 Abeilles et Environnement, Avignon 84914, France
| | - Eva Forsgren
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala 750 07, Sweden
| | - Bjørn Dahle
- Norwegian Beekeepers Association, Kløfta 2040, Norway
| | - Elisabeth Furuseth-Hansen
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Ås 1432, Norway
| | - Geoffrey R. Williams
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, Bern 3097, Switzerland
- Entomology & Plant Pathology, Auburn University, Auburn, AL 36832, USA
| | - Lina De Smet
- Department of Biochemistry and Microbiology, Ghent University, Ghent 9000, Belgium
| | - Myrsini E. Natsopoulou
- Institute for Biology, Martin Luther University Halle-Wittenberg, Halle (Saale) 061200, Germany
| | - Tomás E. Murray
- Institute for Biology, Martin Luther University Halle-Wittenberg, Halle (Saale) 061200, Germany
| | - Emilia Semberg
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala 750 07, Sweden
| | - Orlando Yañez
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, Bern 3097, Switzerland
| | - Dirk C. de Graaf
- Department of Biochemistry and Microbiology, Ghent University, Ghent 9000, Belgium
| | - Yves Le Conte
- INRAE, UR 406 Abeilles et Environnement, Avignon 84914, France
| | - Peter Neumann
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, Bern 3097, Switzerland
| | - Espen Rimstad
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Ås 1432, Norway
| | - Robert J. Paxton
- Institute for Biology, Martin Luther University Halle-Wittenberg, Halle (Saale) 061200, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, 04103, Germany
| | - Joachim R. de Miranda
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala 750 07, Sweden
| |
Collapse
|
3
|
Smeele ZE, Baty JW, Lester PJ. Effects of Deformed Wing Virus-Targeting dsRNA on Viral Loads in Bees Parasitised and Non-Parasitised by Varroa destructor. Viruses 2023; 15:2259. [PMID: 38005935 PMCID: PMC10674661 DOI: 10.3390/v15112259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 11/09/2023] [Accepted: 11/09/2023] [Indexed: 11/26/2023] Open
Abstract
The Varroa destructor mite is a devastating parasite of honey bees; however the negative effects of varroa parasitism are exacerbated by its role as an efficient vector of the honey bee pathogen, Deformed wing virus (DWV). While no direct treatment for DWV infection is available for beekeepers to use on their hives, RNA interference (RNAi) has been widely explored as a possible biopesticide approach for a range of pests and pathogens. This study tested the effectiveness of three DWV-specific dsRNA sequences to lower DWV loads and symptoms in honey bees reared from larvae in laboratory mini-hives containing bees and varroa. The effects of DWV-dsRNA treatment on bees parasitised and non-parasitised by varroa mites during development were investigated. Additionally, the impact of DWV-dsRNA on viral loads and gene expression in brood-parasitising mites was assessed using RNA-sequencing. Bees parasitised during development had significantly higher DWV levels compared to non-parasitised bees. However, DWV-dsRNA did not significantly reduce DWV loads or symptoms in mini-hive reared bees, possibly due to sequence divergence between the DWV variants present in bees and varroa and the specific DWV-dsRNA sequences used. Varroa mites from DWV-dsRNA treated mini-hives did not show evidence of an elevated RNAi response or significant difference in DWV levels. Overall, our findings show that RNAi is not always successful, and multiple factors including pathogen diversity and transmission route may impact its efficiency.
Collapse
Affiliation(s)
- Zoe E. Smeele
- School of Biological Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6140, New Zealand; (J.W.B.); (P.J.L.)
| | | | | |
Collapse
|