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Barbara S Drolet - One of the best experts on this subject based on the ideXlab platform.
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impacts of infectious dose feeding behavior and age of culicoides sonorensis biting Midges on infection dynamics of vesicular stomatitis virus
Pathogenetics, 2021Co-Authors: Paula Rozolopez, Berlin Londonorenteria, Barbara S DroletAbstract:Culicoides sonorensis biting Midges are biological vectors of vesicular stomatitis virus (VSV) in the U.S. Yet, little is known regarding the amount of ingested virus required to infect Midges, nor how their feeding behavior or age affects viral replication and vector competence. We determined the minimum infectious dose of VSV-New Jersey for C. sonorensis Midges and examined the effects of multiple blood-feeding cycles and age at the time of virus acquisition on infection dynamics. A minimum dose of 3.2 logs of virus/mL of blood resulted in midgut infections, and 5.2 logs/mL resulted in a disseminated infection to salivary glands. For blood-feeding behavior studies, ingestion of one or two non-infectious blood meals (BM) after a VSV infectious blood meal (VSV-BM) resulted in higher whole-body virus titers than Midges receiving only the single infectious VSV-BM. Interestingly, this infection enhancement was not seen when a non-infectious BM preceded the infectious VSV-BM. Lastly, increased midge age at the time of infection correlated to increased whole-body virus titers. This research highlights the epidemiological implications of infectious doses, vector feeding behaviors, and vector age on VSV infection dynamics to estimate the risk of transmission by Culicoides Midges more precisely.
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venereal transmission of vesicular stomatitis virus by culicoides sonorensis Midges
Pathogenetics, 2020Co-Authors: Paula Rozolopez, Berlin Londonorenteria, Barbara S DroletAbstract:Culicoides sonorensis biting Midges are well-known agricultural pests and transmission vectors of arboviruses such as vesicular stomatitis virus (VSV). The epidemiology of VSV is complex and encompasses a broad range of vertebrate hosts, multiple routes of transmission, and diverse vector species. In temperate regions, viruses can overwinter in the absence of infected animals through unknown mechanisms, to reoccur the next year. Non-conventional routes for VSV vector transmission may help explain viral maintenance in midge populations during inter-epidemic periods and times of adverse conditions for bite transmission. In this study, we examined whether VSV could be transmitted venereally between male and female Midges. Our results showed that VSV-infected females could venereally transmit virus to uninfected naive males at a rate as high as 76.3% (RT-qPCR), 31.6% (virus isolation) during the third gonotrophic cycle. Additionally, VSV-infected males could venereally transmit virus to uninfected naive females at a rate as high as 76.6% (RT-qPCR), 49.2% (virus isolation). Immunofluorescent staining of micro-dissected reproductive organs, immunochemical staining of midge histological sections, examination of internal reproductive organ morphology, and observations of mating behaviors were used to determine relevant anatomical sites for virus location and to hypothesize the potential mechanism for VSV transmission in C. sonorensis Midges through copulation.
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Transcriptome Response of Female Culicoides sonorensis Biting Midges (Diptera: Ceratopogonidae) to Early Infection with Epizootic Hemorrhagic Disease Virus (EHDV-2)
MDPI AG, 2019Co-Authors: Dana Nayduch, Mark G Ruder, Barbara S Drolet, Mary K Mills, Vijay Shankar, Tanner Robl, Erin D. Scully, Christopher A. SaskiAbstract:Female Culicoides sonorensis biting Midges are vectors of epizootic hemorrhagic disease virus (EHDV), which causes morbidity and mortality in wild and domesticated ruminants. The aims in this study were to identify key changes in female midge transcriptome profiles occurring during early infection with EHDV-2. Midges were fed either negative control bloodmeals or bloodmeals containing EHDV-2 and transcriptomes were acquired at 36 h through deep sequencing. Reads were de novo assembled into a transcriptome comprised of 18,754 unigenes. Overall, there were 2401 differentially expressed unigenes and ~60% were downregulated in response to the virus (953 up; 1448 down). Downstream Gene Ontology enrichment, KEGG pathway mapping, and manual analyses were used to identify the effect of virus ingestion at both the gene and pathway levels. Downregulated unigenes were predominantly assigned to pathways related to cell/tissue structure and integrity (actin cytoskeleton, adherens junction, focal adhesion, hippo signaling), calcium signaling, eye morphogenesis and axon guidance. Unigenes attributed to sensory functions (especially vision), behavior, learning and memory were largely downregulated. Upregulated unigenes included those coding for innate immune processes, olfaction and photoreceptor pigments. Our results suggest that Midges respond to virus infection as soon as 36 h post-ingestion, and that EHDV-2 may have a significant phenotypic effect on sensory and neural tissues
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Physiological and immunological responses to Culicoides sonorensis blood-feeding: a murine model
Parasites & Vectors, 2018Co-Authors: Christopher J Lehiy, Mark G Ruder, Lindsey M. Reister-hendricks, D. Scott Mcvey, Barbara S DroletAbstract:Background Hematophagous Culicoides spp. biting Midges are of great agricultural importance as livestock, equine, and wildlife pests and as vectors of the orbiviruses bluetongue, epizootic hemorrhagic disease and African horse sickness. To obtain a blood meal, Midges deposit saliva containing allergens, proteases, and anti-hemostatic factors, into the dermis to facilitate feeding. Infected Midges deposit virus along with the myriad of salivary proteins during feeding. The extreme efficiency with which Midges are able to transmit orbiviruses is not clearly understood, as much is still unknown about the physiological trauma of the bite and immune responses to saliva deposited during feeding. Of particular interest are the first few hours and days after the bite; a critical time period for any midge-transmitted virus to quickly establish a localized infection and disseminate, while avoiding the hosts’ immune responses. Results A mouse-midge feeding model using colonized Culicoides sonorensis Midges was used to characterize innate mammalian immune responses to blood-feeding. Histological analysis of skin, and cellular and cytokine profiles of draining lymph nodes show Culicoides midge feeding elicited a potent pro-inflammatory Th-mediated cellular response with significant mast cell activation, subcutaneous hematomas, hypodermal edema and dermal capillary vasodilation, and rapid infiltration of leukocytes to the bite sites. Mast cell degranulation, triggered by bite trauma and specifically by midge saliva, was key to physiological and immunological responses and the ability of Midges to feed to repletion. Conclusions Midge feeding causes physiological and immunological responses that would be highly favorable for rapid infection and systemic dissemination orbiviruses if delivered during blood-feeding. Recruitment of leukocytic cells to bitten skin brings susceptible cell populations in proximity of deposited virus within hours of feeding. Infected cells would drain to lymph nodes, which become hyperplastic in response to saliva, and result in robust viral replication in expanding cell populations and dissemination via the lymph system. Additionally, saliva-induced vasodilation and direct breaches in dermal capillaries by biting mouthparts exposes susceptible vascular endothelial cells, thereby providing immediate sites of virus replication and a dissemination route via the circulatory system. This research provides insights into the efficiency of Culicoides Midges as orbivirus vectors.
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physiological and immunological responses to culicoides sonorensis blood feeding a murine model
Parasites & Vectors, 2018Co-Authors: Christopher J Lehiy, Mark G Ruder, Lindsey M Reisterhendricks, Scott D Mcvey, Barbara S DroletAbstract:Hematophagous Culicoides spp. biting Midges are of great agricultural importance as livestock, equine, and wildlife pests and as vectors of the orbiviruses bluetongue, epizootic hemorrhagic disease and African horse sickness. To obtain a blood meal, Midges deposit saliva containing allergens, proteases, and anti-hemostatic factors, into the dermis to facilitate feeding. Infected Midges deposit virus along with the myriad of salivary proteins during feeding. The extreme efficiency with which Midges are able to transmit orbiviruses is not clearly understood, as much is still unknown about the physiological trauma of the bite and immune responses to saliva deposited during feeding. Of particular interest are the first few hours and days after the bite; a critical time period for any midge-transmitted virus to quickly establish a localized infection and disseminate, while avoiding the hosts’ immune responses. A mouse-midge feeding model using colonized Culicoides sonorensis Midges was used to characterize innate mammalian immune responses to blood-feeding. Histological analysis of skin, and cellular and cytokine profiles of draining lymph nodes show Culicoides midge feeding elicited a potent pro-inflammatory Th-mediated cellular response with significant mast cell activation, subcutaneous hematomas, hypodermal edema and dermal capillary vasodilation, and rapid infiltration of leukocytes to the bite sites. Mast cell degranulation, triggered by bite trauma and specifically by midge saliva, was key to physiological and immunological responses and the ability of Midges to feed to repletion. Midge feeding causes physiological and immunological responses that would be highly favorable for rapid infection and systemic dissemination orbiviruses if delivered during blood-feeding. Recruitment of leukocytic cells to bitten skin brings susceptible cell populations in proximity of deposited virus within hours of feeding. Infected cells would drain to lymph nodes, which become hyperplastic in response to saliva, and result in robust viral replication in expanding cell populations and dissemination via the lymph system. Additionally, saliva-induced vasodilation and direct breaches in dermal capillaries by biting mouthparts exposes susceptible vascular endothelial cells, thereby providing immediate sites of virus replication and a dissemination route via the circulatory system. This research provides insights into the efficiency of Culicoides Midges as orbivirus vectors.
Troy D Anderson - One of the best experts on this subject based on the ideXlab platform.
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effect of alachlor and metolachlor on toxicity of chlorpyrifos and major detoxification enzymes in the aquatic midge chironomus tentans diptera chironomidae
Archives of Environmental Contamination and Toxicology, 2008Co-Authors: Ying Jinclark, Troy D AndersonAbstract:The toxicities of two herbicides (alachlor and metolachlor) and an organophosphate insecticide (chlorpyrifos) were evaluated individually and with either herbicide in binary mixture with chlorpyrifos in fourth-instar larvae of the aquatic midge (Chironomus tentans). Alachlor alone up to 1,000 micrograms per liter of water (μg/L) did not exhibit significant toxicity, whereas metolachlor at 1,000 μg/L affected 58% of Midges in 72-h bioassays. However, alachlor at 1,000 μg/L and metolachlor at 10, 100, and 1,000 μg/L enhanced the toxicity of chlorpyrifos to the Midges. Furthermore, alachlor and metolachlor at 1,000 μg/L reduced acetylcholinesterase (AChE) activity by 34.3% and 27.6%, respectively, in the treated Midges. Although alachlor at 1,000 μg/L did not significantly affect protein production in the treated Midges, it reduced glutathione S-transferases (GST) total activities by 1.9- to 2.1-fold. In contrast, metolachlor at 1,000 μg/L reduced protein production by 3.2-fold, which was associated with a 2.8-fold reduction of cytochrome P450 O-deethylation total activity and 1.4- to 1.7-fold reductions of GST total activities in the treated Midges. Such reduced total activities of the major detoxification enzymes in herbicide-treated Midges might impede the metabolic detoxification of chlorpyrifos and, therefore, increase the susceptibility of the Midges to chlorpyrifos. Thus, it is likely that coexistence of chlorpyrifos and these herbicides, particularly metolachlor, in surface waters may pose increased risks to Midges in aquatic environments.
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Sublethal Effects of Three Pesticides on Larval Survivorship, Growth, and Macromolecule Production in the Aquatic Midge, Chironomus tentans (Diptera: Chironomidae)
Archives of Environmental Contamination and Toxicology, 2006Co-Authors: Mamy L. Rakotondravelo, Troy D Anderson, Ralph E. CharltonAbstract:Effects of long-term exposure to each of three pesticides including atrazine, DDT, and chlorpyrifos on larval survivorship, growth, and macromolecule (total body protein and RNA) production were evaluated in the aquatic midge, Chironomus tentans , under laboratory conditions. Newly hatched larvae were exposed to atrazine at 30 and 150 μg/L, DDT at 0.01 and 0.05 μg/L, or chlorpyrifos at 0.02 and 0.10 μg/L throughout one life cycle. Larval survivorship was evaluated at 20 d and the end of the test, and larval growth at 20 d. Chlorpyrifos at 0.1 μg/L reduced the midge survivorship by 67% after 20-d exposure. However, neither atrazine nor DDT affected larval survivorship. The ash-free dry weight of midge larvae exposed to chlorpyrifos at 0.1 μg/L was 1.5-fold greater than that of the control whereas neither atrazine nor DDT showed a significant effect on the ash-free dry weight. In addition, exposures of Midges to chlorpyrifos at 0.1 μg/L increased the adult emergence rate by 81% as compared to the control although the actual number of adults that emerged from chlorpyrifos-treated larvae was significantly decreased. Both the increased ash-free dry weight of larvae and increased adult emergence rate were likely caused by reduced competition for both food and space among the survivors due to increased larval mortality. Although neither total protein nor total RNA production was significantly affected in larvae exposed to each pesticide for 20 d, a significantly higher number of males over females (ratio = 4) emerged from Midges exposed to DDT at 0.05 μg/L. Our study indicates that chronic exposure to low concentrations of chlorpyrifos and DDT results in significant mortality of midge larvae and alteration of the sex ratio of adult emergence, respectively. Because Midges are important components of the food web, our results suggest that effects elicited directly or indirectly by long-term pesticide exposures may potentially disrupt both food chains and community structure in aquatic environments.
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sublethal effects of three pesticides on activities of selected target and detoxification enzymes in the aquatic midge chironomus tentans diptera chironomidae
Archives of Environmental Contamination and Toxicology, 2006Co-Authors: Troy D Anderson, Mamy L. Rakotondravelo, Ralph E. Charlton, Kun Yan ZhuAbstract:Sublethal effects of three pesticides including atrazine (triazine herbicide), DDT (organochlorinated insecticide), and chlorpyrifos (organophosphate insecticide) on acetylcholinesterase (AChE), general esterase (GE), glutathione S-transferase (GST), and cytochrome P450 monooxygenase (P450) activities were evaluated in the aquatic midge Chironomus tentans. Exposures of Midges to atrazine at 30 and 150 micrograms per liter (μg/L) for 20 d (i.e., from the first- to fourth-instar larvae) enhanced P450 O-deethylation activity by 12.5- and 15.5-fold, respectively, but did not significantly change AChE, GST, and GE activities. Similar exposures to DDT at 0.01 and 0.05 μg/L did not significantly affect AChE, GE, and P450 activities; however, DDT at 0.05 μg/L enhanced GST activity toward the substrate 1-chloro-2, 4-dinitrobenzene by 33.6%. Exposures of Midges to chlorpyrifos at 0.10 μg/L for 20 d reduced AChE activity by 59.8%, and GE activities toward the substrates α-naphthyl acetate and β-naphthyl acetate by 30.7 and 48.8%, respectively. The reduced GE activities appear to be due to the inhibition of several esterases, particularly the one with a slow migration, by chlorpyrifos as demonstrated by non-denaturing polyacrylamide gel electrophoresis. Furthermore, exposure of Midges to chlorpyrifos at 0.10 μg/L for 20 d enhanced the P450 O-deethylation activity by 3.3-fold although no significant effect was observed at 0.02 μg/L for the same enzyme. These results provide insights into the sublethal effects of these commonly detected pesticides in aquatic environments on important enzymes in aquatic Midges.
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synergistic and antagonistic effects of atrazine on the toxicity of organophosphorodithioate and organophosphorothioate insecticides to chironomus tentans diptera chironomidae
Pesticide Biochemistry and Physiology, 2004Co-Authors: Troy D AndersonAbstract:Abstract The acute toxicities of two organophosphorodithioate (dimethoate and disulfoton) and two organophosphorothioate (omethoate and demeton-S-methyl) insecticides were evaluated individually and in binary combination with the herbicide atrazine using fourth-instar larvae of the aquatic midge, Chironomus tentans. Atrazine alone up to 1000 μg/L did not show significant toxicity to the Midges in a 48-h bioassay. However, atrazine concentrations as low as 1 μg/L in combination with dimethoate at EC25 (concentration to affect 25% of tested Midges), 100 μg/L in combination with disulfoton (EC25), and 10 μg/L in combination with demeton-S-methyl (EC25) significantly enhanced the toxicity of each organophosphate insecticide. In contrast, atrazine concentrations of 10 μg/L and above in combination with omethoate (EC25) significantly decreased the toxicity of the insecticide. Biochemical analysis indicated that increased toxicity of dimethoate, disulfoton, and demeton-S-methyl in binary combination with atrazine correlated to the increased inhibition of acetylcholinesterase. Furthermore, cytochrome P450-dependent O-deethylation activity in the Midges exposed to atrazine at 1000 μg/L was 1.5-fold higher than that in the control Midges. Thus, atrazine appeared to induce cytochrome P450 monooxygenases in the Midges. Elevated cytochrome P450 monooxygenase activity may increase the toxicities of dimethoate, disulfoton, and demeton-S-methyl by enhancing the oxidative activation of dimethoate into omethoate, and disulfoton and demeton-S-methyl into their sulfoxide analogs with increased anticholinesterase activity. In contrast, atrazine reduced the toxicity of omethoate possibly by enhancing the oxidative metabolic detoxification since omethoate does not require oxidative activation.
Mark G Ruder - One of the best experts on this subject based on the ideXlab platform.
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Transcriptome Response of Female Culicoides sonorensis Biting Midges (Diptera: Ceratopogonidae) to Early Infection with Epizootic Hemorrhagic Disease Virus (EHDV-2)
MDPI AG, 2019Co-Authors: Dana Nayduch, Mark G Ruder, Barbara S Drolet, Mary K Mills, Vijay Shankar, Tanner Robl, Erin D. Scully, Christopher A. SaskiAbstract:Female Culicoides sonorensis biting Midges are vectors of epizootic hemorrhagic disease virus (EHDV), which causes morbidity and mortality in wild and domesticated ruminants. The aims in this study were to identify key changes in female midge transcriptome profiles occurring during early infection with EHDV-2. Midges were fed either negative control bloodmeals or bloodmeals containing EHDV-2 and transcriptomes were acquired at 36 h through deep sequencing. Reads were de novo assembled into a transcriptome comprised of 18,754 unigenes. Overall, there were 2401 differentially expressed unigenes and ~60% were downregulated in response to the virus (953 up; 1448 down). Downstream Gene Ontology enrichment, KEGG pathway mapping, and manual analyses were used to identify the effect of virus ingestion at both the gene and pathway levels. Downregulated unigenes were predominantly assigned to pathways related to cell/tissue structure and integrity (actin cytoskeleton, adherens junction, focal adhesion, hippo signaling), calcium signaling, eye morphogenesis and axon guidance. Unigenes attributed to sensory functions (especially vision), behavior, learning and memory were largely downregulated. Upregulated unigenes included those coding for innate immune processes, olfaction and photoreceptor pigments. Our results suggest that Midges respond to virus infection as soon as 36 h post-ingestion, and that EHDV-2 may have a significant phenotypic effect on sensory and neural tissues
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Physiological and immunological responses to Culicoides sonorensis blood-feeding: a murine model
Parasites & Vectors, 2018Co-Authors: Christopher J Lehiy, Mark G Ruder, Lindsey M. Reister-hendricks, D. Scott Mcvey, Barbara S DroletAbstract:Background Hematophagous Culicoides spp. biting Midges are of great agricultural importance as livestock, equine, and wildlife pests and as vectors of the orbiviruses bluetongue, epizootic hemorrhagic disease and African horse sickness. To obtain a blood meal, Midges deposit saliva containing allergens, proteases, and anti-hemostatic factors, into the dermis to facilitate feeding. Infected Midges deposit virus along with the myriad of salivary proteins during feeding. The extreme efficiency with which Midges are able to transmit orbiviruses is not clearly understood, as much is still unknown about the physiological trauma of the bite and immune responses to saliva deposited during feeding. Of particular interest are the first few hours and days after the bite; a critical time period for any midge-transmitted virus to quickly establish a localized infection and disseminate, while avoiding the hosts’ immune responses. Results A mouse-midge feeding model using colonized Culicoides sonorensis Midges was used to characterize innate mammalian immune responses to blood-feeding. Histological analysis of skin, and cellular and cytokine profiles of draining lymph nodes show Culicoides midge feeding elicited a potent pro-inflammatory Th-mediated cellular response with significant mast cell activation, subcutaneous hematomas, hypodermal edema and dermal capillary vasodilation, and rapid infiltration of leukocytes to the bite sites. Mast cell degranulation, triggered by bite trauma and specifically by midge saliva, was key to physiological and immunological responses and the ability of Midges to feed to repletion. Conclusions Midge feeding causes physiological and immunological responses that would be highly favorable for rapid infection and systemic dissemination orbiviruses if delivered during blood-feeding. Recruitment of leukocytic cells to bitten skin brings susceptible cell populations in proximity of deposited virus within hours of feeding. Infected cells would drain to lymph nodes, which become hyperplastic in response to saliva, and result in robust viral replication in expanding cell populations and dissemination via the lymph system. Additionally, saliva-induced vasodilation and direct breaches in dermal capillaries by biting mouthparts exposes susceptible vascular endothelial cells, thereby providing immediate sites of virus replication and a dissemination route via the circulatory system. This research provides insights into the efficiency of Culicoides Midges as orbivirus vectors.
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physiological and immunological responses to culicoides sonorensis blood feeding a murine model
Parasites & Vectors, 2018Co-Authors: Christopher J Lehiy, Mark G Ruder, Lindsey M Reisterhendricks, Scott D Mcvey, Barbara S DroletAbstract:Hematophagous Culicoides spp. biting Midges are of great agricultural importance as livestock, equine, and wildlife pests and as vectors of the orbiviruses bluetongue, epizootic hemorrhagic disease and African horse sickness. To obtain a blood meal, Midges deposit saliva containing allergens, proteases, and anti-hemostatic factors, into the dermis to facilitate feeding. Infected Midges deposit virus along with the myriad of salivary proteins during feeding. The extreme efficiency with which Midges are able to transmit orbiviruses is not clearly understood, as much is still unknown about the physiological trauma of the bite and immune responses to saliva deposited during feeding. Of particular interest are the first few hours and days after the bite; a critical time period for any midge-transmitted virus to quickly establish a localized infection and disseminate, while avoiding the hosts’ immune responses. A mouse-midge feeding model using colonized Culicoides sonorensis Midges was used to characterize innate mammalian immune responses to blood-feeding. Histological analysis of skin, and cellular and cytokine profiles of draining lymph nodes show Culicoides midge feeding elicited a potent pro-inflammatory Th-mediated cellular response with significant mast cell activation, subcutaneous hematomas, hypodermal edema and dermal capillary vasodilation, and rapid infiltration of leukocytes to the bite sites. Mast cell degranulation, triggered by bite trauma and specifically by midge saliva, was key to physiological and immunological responses and the ability of Midges to feed to repletion. Midge feeding causes physiological and immunological responses that would be highly favorable for rapid infection and systemic dissemination orbiviruses if delivered during blood-feeding. Recruitment of leukocytic cells to bitten skin brings susceptible cell populations in proximity of deposited virus within hours of feeding. Infected cells would drain to lymph nodes, which become hyperplastic in response to saliva, and result in robust viral replication in expanding cell populations and dissemination via the lymph system. Additionally, saliva-induced vasodilation and direct breaches in dermal capillaries by biting mouthparts exposes susceptible vascular endothelial cells, thereby providing immediate sites of virus replication and a dissemination route via the circulatory system. This research provides insights into the efficiency of Culicoides Midges as orbivirus vectors.
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dynamics of epizootic hemorrhagic disease virus infection within the vector culicoides sonorensis diptera ceratopogonidae
PLOS ONE, 2017Co-Authors: Mary K Mills, Mark G Ruder, Dana Nayduch, Kristin Michel, Barbara S DroletAbstract:Culicoides sonorensis biting Midges are confirmed vectors of epizootic hemorrhagic disease virus (EHDV), which causes mortality in white-tailed deer and ruminant populations. Currently, of the seven EHDV serotypes, only 1, 2, and 6 are detected in the USA, and very few studies have focused on the infection time course of these serotypes within the midge. The objective of this current research was to characterize EHDV-2 infection within the midge by measuring infection prevalence, virus dissemination, and viral load over the course of infection. Midges were fed a blood meal containing 106.9 PFU/ml EHDV-2, collected every 12 h from 0–2 days post feeding (dpf) and daily from 3–10 dpf, and cohorts of 20 C. sonorensis were processed using techniques that assessed EHDV infection and dissemination. Cytopathic effect assays and quantitative (q)PCR were used to determine infection prevalence, revealing a 50% infection rate by 10 dpf using both methods. Using immunohistochemistry, EHDV-2 infection was detectable at 5 dpf, and shown to disseminate from the midgut to other tissues, including fat body, eyes, and salivary glands by 5 dpf. Stain intensity increased from 5–8 dpf, indicating replication of EHDV-2 in secondary infection sites after dissemination. This finding is also supported by trends in viral load over time as determined by plaque assays and qPCR. An increase in titer between 4–5 dpf correlated with viral replication in the midgut as seen with staining at day 5, while the subsequent gradual increase in viral load from 8–10 dpf suggested viral replication in Midges with disseminated infection. Overall, the data presented herein suggest that EHDV-2 disseminates via the hemolymph to secondary infection sites throughout the midge and demonstrate a high potential for transmission at five days at 25°C after an infective blood-meal.
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vector competence of culicoides sonorensis diptera ceratopogonidae to epizootic hemorrhagic disease virus serotype 7
Parasites & Vectors, 2012Co-Authors: Mark G Ruder, David E Stallknecht, Elizabeth W Howerth, Eyal Klement, Deborah L Carter, Andrew B Allison, Barbara S Drolet, Daniel G MeadAbstract:Culicoides sonorensis (Diptera: Ceratopogonidae) is a vector of epizootic hemorrhagic disease virus (EHDV) serotypes 1 and 2 in North America, where these viruses are well-known pathogens of white-tailed deer (WTD) and other wild ruminants. Although historically rare, reports of clinical EHDV infection in cattle have increased in some parts of the world over the past decade. In 2006, an EHDV-7 epizootic in cattle resulted in economic loss for the Israeli dairy industry. White-tailed deer are susceptible to EHDV-7 infection and disease; however, this serotype is exotic to the US and the susceptibility of C. sonorensis to this cattle-virulent EHDV is not known. The objective of the study was to determine if C. sonorensis is susceptible to EHDV-7 infection and is a competent vector. To evaluate the susceptibility of C. sonorensis, Midges were fed on EHDV-7 infected WTD, held at 22 ± 1°C, and processed individually for virus isolation and titration on 4–16 days post feeding (dpf). Midges with a virus titer of ≥102.7 median tissue culture infective doses (TCID50)/midge were considered potentially competent. To determine if infected C. sonorensis were capable of transmitting EHDV-7 to a host, a susceptible WTD was then fed on by a group of 14–16 dpf Midges. From 4–16 dpf, 45% (156/350) of Midges that fed on WTD with high titer viremia (>107 TCID50/ml) were virus isolation-positive, and starting from 10–16 dpf, 32% (35/109) of these virus isolation-positive Midges were potentially competent (≥102.7 TCID50/midge). Midges that fed on infected deer transmitted the virus to a susceptible WTD at 14–16 dpf. The WTD developed viremia and severe clinical disease. This study demonstrates that C. sonorensis is susceptible to EHDV-7 infection and can transmit the virus to susceptible WTD, thus, C. sonorensis should be considered a potential vector of EHDV-7. Together with previous work, this study demonstrates that North America has a susceptible ruminant and vector host for this exotic, cattle-virulent strain of EHDV-7.
Christie E Mayo - One of the best experts on this subject based on the ideXlab platform.
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lack of evidence for laboratory and natural vertical transmission of bluetongue virus in culicoides sonorensis diptera ceratopogonidae
Journal of Medical Entomology, 2015Co-Authors: C J Osborne, Alec C. Gerry, Christie E Mayo, Bradley A Mullens, Emily G Mcdermott, William K Reisen, Nigel J MaclachlanAbstract:Culicoides sonorensis (Wirth & Jones) is the principal North American vector of bluetongue virus (BTV). BTV infection of livestock is distinctly seasonal (late summer and fall) in temperate regions of the world such as California, which has led to speculation regarding vertical transmission of the virus within the midge vector as a potential mechanism for interseasonal maintenance ("overwintering") of the virus. To evaluate potential vertical transmission of BTV in its midge vector, we fed adult Midges BTV-spiked blood and used a BTV-specific quantitative reverse transcriptase polymerase chain reaction assay to evaluate parent, egg, and progeny stages of laboratory-reared C. sonorensis for the presence of viral nucleic acid. Whereas BTV nucleic acid was weakly detected in egg batches of virus-fed female Midges, virus was never detected in subsequent progeny stages (larvae, pupae, and F1 generation adults). Similarly, BTV was not detected in pools of larvae collected from the waste-water lagoon of a BTV-endemic dairy farm in northern California during the seasonal period of virus transmission. Collectively, these results indicate that BTV is not readily transmitted vertically in C. sonorensis, and that persistence of the virus in long-lived parous female Midges is a more likely mechanism for overwintering of BTV in temperate regions.
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estimating culicoides sonorensis biting midge abundance using digital image analysis
Medical and Veterinary Entomology, 2014Co-Authors: C J Osborne, Christie E Mayo, Bradley A Mullens, Nigel J MaclachlanAbstract:ImageJ is an open-source software tool used for a variety of scientific objectives including cell counting, shape analysis and image correction. This technology has previously been used to estimate mosquito abundance in surveillance efforts. However, the utility of this application for estimating abundance or parity in the surveillance of Culicoides spp. (Diptera: Ceratopogonidae) has not yet been tested. Culicoides sonorensis (Wirth and Jones), a biting midge often measuring 2.0-2.5 mm in length, is an economically important vector of ruminant arboviruses in California. Current surveillance methods use visual sorting for the characteristics of Midges and are very time-intensive for large studies. This project tested the utility of ImageJ as a tool to assist in gross trap enumeration as well as in parity analysis of C. sonorensis in comparison with traditional visual methods of enumeration using a dissecting microscope. Results confirmed that automated counting of Midges is a reliable means of approximating midge numbers under certain conditions. Further evaluation confirmed accurate and time-efficient parity analysis in comparison with hand sorting. The ImageJ software shows promise as a tool that can assist and expedite C. sonorensis surveillance. Further, these methods may be useful in other insect surveillance activities.
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potential strategies for control of bluetongue a globally emerging culicoides transmitted viral disease of ruminant livestock and wildlife
Antiviral Research, 2013Co-Authors: James N Maclachlan, Christie E MayoAbstract:Abstract Bluetongue (BT) is a non-zoonotic arboviral disease of certain wild and domestic species of cloven-hoofed ungulates. The causative agent, bluetongue virus (BTV), is spread through temperate and tropical regions of the world by biting Culicoides Midges. Control of BTV infection is complicated by the plurality of virus serotypes and the ubiquity and opportunistic feeding behavior of its midge vector. The global distribution of BTV infection has recently altered, perhaps driven in part by climatic influences on midge species resident in different regions. The goal of this review is to evaluate realistic strategies that might be utilized to control or prevent future outbreaks of BT and other Culicoides-transmitted diseases. Importantly, optimal control of emerging, rapidly evolving arbovirus diseases such as BT will require integrated countermeasures that mitigate all aspects of the virus’s transmission cycle. This will best be accomplished using preventative, rather than purely reactive strategies.
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the combination of abundance and infection rates of culicoides sonorensis estimates risk of subsequent bluetongue virus infection of sentinel cattle on california dairy farms
Veterinary Parasitology, 2012Co-Authors: Christie E Mayo, Alec C. Gerry, Bradley A Mullens, Alan John Guthrie, Ian A Gardner, Peter P C Mertens, Christopher M Barker, Sushila Maan, Narender S Maan, James N MaclachlanAbstract:Abstract Bluetongue (BT) is an important viral disease of ruminants that is transmitted by hematophagous Culicoides Midges. We examined the seasonal patterns of abundance and infection of Culicoides sonorensis at four dairy farms in the northern Central Valley of California to develop estimates of risk for bluetongue virus (BTV) transmission to cattle at each farm. These four farms were selected because of their similar meteorological conditions but varying levels of vector abundance and BTV infection of cattle. C. sonorensis Midges were collected weekly at each farm during the seasonal transmission period, using three different trapping methods: traps baited with either carbon dioxide (CO 2 ) alone or traps with CO 2 and UV light, and by direct aspiration of Midges from sentinel cattle. Analysis of BTV-infected Midges using group and serotype-specific quantitative reverse-transcriptase polymerase chain reaction (RT-qPCR) assays confirmed that BTV serotypes 10, 11, 13 and 17 are all present in the region, but that midge infection rates and the number of BTV serotypes circulating differed markedly among the individual farms. Furthermore, more serotypes of BTV were present in Midges than in sentinel cattle at individual farms where BTV circulated, and the virus was detected at each farm in Midges prior to detection in cattle. BTV infection rates were remarkably lower among female C. sonorensis Midges collected by CO 2 traps with UV light than among Midges collected by either animal-baited aspirations or in CO 2 traps without light. A subsample of female Midges examined from each collection method showed no overall differences in the proportion of female Midges that had previously fed on a host. Findings from this study confirm the importance of using sensitive surveillance methods for both midge collection and virus detection in epidemiological studies of BTV infection, which is especially critical if the data are to be used for development of mathematical models to predict the occurrence of BTV infection of livestock.
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interactions among the predatory midge aphidoletes aphidimyza diptera cecidomyiidae the fungal pathogen metarhizium brunneum ascomycota hypocreales and maize infesting aphids in greenhouse mesocosms
Insects, 2017Co-Authors: Ana Gorete Campos De Azevedo, Bernhardt M Steinwender, Jørgen Eilenberg, Lene SigsgaardAbstract:The generalist entomopathogenic fungus, Metarhizium brunneum, has proved to have great potential as a versatile biological pest control agent. The gall midge Aphidoletes aphidimyza is a specialist predator that occurs naturally in Europe and has been successfully used for aphid suppression. However, the interaction between these two biological control organisms and how it may affect the biological control of aphids awaits further investigation. As part of the EU-supported project INBIOSOIL, this study was conducted in greenhouse conditions to assess the possible effects of combining both biological control agents. In a randomized complete block design, sweet corn (Zea mays var. saccharata) plants were grown in large pots filled with natural soil or natural soil inoculated with M. brunneum. At the third leaf stage, before being individually caged, plants were infested with Rhopalosiphum padi and A. aphidimyza pupae were introduced in the soil. Aphidoletes aphidimyza midge emergence, number of living Midges and number of aphids were recorded daily. The presence of conidia in the soil and on leaves was assessed during the experiment. At the conclusion of the experiment, the number of live aphids and their developmental stage, consumed aphids, and A. aphidimyza eggs was assessed under stereomicroscope. This study’s findings showed that the presence of M. brunneum did not affect A. aphidimyza midge emergence. However, longevity was significantly affected. As the study progressed, significantly fewer predatory Midges were found in cages treated with M. brunneum compared to untreated cages. Furthermore, by the end of the study, the number of predatory Midges found in the Metarhizium-treated cages was four times lower than in the untreated cages. Both daily and final count of aphids were significantly affected by treatment. Aphidoletes aphidimyza applied alone suppressed the aphid population more effectively than M. brunneum applied alone. Additionally, the aphid population was most suppressed when both agents were combined, though the suppression was less than additive.