| the effect of salinity on oviposition and egg hatching in culicoides variipennis sonorensis (diptera: ceratopogonidae). | the preferences of culicoides variipennis sonorensis females for oviposition on different salinities were tested in experiments using small wells in a 4 x 4 latin square array. the mean numbers of eggs deposited on wet surfaces on salinites of 0.0, 9.9, 19.0 and 34.0o/oo, were 1212, 659, 287, and 0, respectively. within a higher range, salinites of 19.0, 23.0, 28.0 and 34.0o/oo yielded mean numbers laid of 110, 3, 6 and 0, respectively. the overall relationship could be reasonably well described ... | 1986 | 3507474 |
| flight activity and response to carbon dioxide of culicoides variipennis sonorensis (diptera: ceratopogonidae) in southern california. | adult culicoides variipennis sonorensis wirth & jones were collected using miniature suction traps during 12 nights in october and november at a southern california dairy. traps were baited with carbon dioxide at a constant release rate of 300, 1,000, or 3,000 ml/min or with 1.3 kg of dry ice. the release rate of co2 from the dry ice in the laboratory declined from 1,486 ml/min during the first 2 h to 303 ml/min after 10-12 h. nulliparous and parous females responded in a similar and positive ma ... | 1995 | 7616522 |
| rubidium in female culicoides variipennis sonorensis (diptera: ceratopogonidae) after engorgement on a rubidium-treated host. | a rabbit given an intraperitoneal injection of 500 mg/kg of rubidium chloride retained elevated blood levels of rb+ for at least 30 d with no overt effects. all culicoides variipennis sonorensis (wirth & jones) females that fed on the rabbit 1, 4, 7, and 14 d after injection were marked with rb+ when engorged (day 1), and 95% were marked when gravid (day 3). at 7 d, 79% of flies were marked, and 16% exhibited elevated levels after 14 d. eggs laid 3-4 d after feeding contained elevated rb+ levels ... | 1995 | 7616533 |
| fluorescence as a tool for age determination in culicoides variipennis sonorensis (diptera: ceratopogonidae). | adult culicoides variipennis sonorensis wirth & jones were tested using fluorescence spectrophotometry to determine whether age or sex influenced fluorescence. males and nulliparous females 0.5, 2.5, and 5.5 d after eclosion were processed, as were uniparous and biparous females 14 d after eclosion. variability among insects within a sex and age group was moderately high. males and nulliparous females showed significantly greater fluorescence when very young (0.5 d old). parous females had signi ... | 1995 | 7650721 |
| effects of temperature on virogenesis of bluetongue virus serotype 11 in culicoides variipennis sonorensis. | culicoides variipennis sonorensis females were fed bluetongue virus serotype 11 mixed in sheep blood and were held at constant temperatures of 32, 27, 21 and 15 degrees c. virogenesis, as measured by enzyme-linked immunosorbent assay (elisa), proceeded significantly faster at higher temperatures. based on elisa absorbance > or = 0.2, some flies first were categorized as infected after 1 day, 2 days and 4 days at 32, 27 and 21 degrees c, respectively. peak levels of virus antigen were seen after ... | 1995 | 7696691 |
| complex interactions between vectors and pathogens: culicoides variipennis sonorensis (diptera: ceratopogonidae) infection rates with bluetongue viruses. | two laboratory colonies of culicoides variipennis sonorensis wirth & jones were allowed to take blood meals containing the five u.s. serotypes (2, 10, 11, 13, and 17) of bluetongue (blu) virus. after 14 d of extrinsic incubation, the flies were assayed for the presence of virus using an antigen capture enzyme-linked immunosorbent assay (elisa). there was a significant effect of the serotype on infection of c. v. sonorensis with blu virus. there was no significant difference in infection of the t ... | 1994 | 7815405 |
| rearing culicoides variipennis sonorensis (diptera: ceratopogonidae) on agar and nematodes. | culicoides variipennis sonorensis wirth & jones was reared from egg to adult in petri dishes on a 0.5 or 1% agar substrate with bacterial-feeding nematodes (pelodera, panagrellus) as food. all larval stages except the first instar were observed attacking and feeding on nematodes. developmental rate on agar was approximately 25% slower than that of larvae reared in pans of water with bacteria, fungi, and algae as food. pupation success was approximately 75% from dishes (3.5 or 9 cm diameter) with ... | 1994 | 8158623 |
| rapid cold-hardening in culicoides variipennis sonorensis (diptera: ceratopogonidae). | rapid cold-hardening was studied in the adult stage of the biting midge culicoides variipennis sonorensis wirth & jones from a laboratory colony. no individuals could withstand a direct transfer from 20 degrees c (rearing temperature) to -10 degrees c for 2 h; however, an acclimation period of 1 h at 5 degrees c immediately before exposure to -10 degrees c yielded 96% survival. the cold-hardening response was very rapid; increased cold tolerance peaked after only a 1-h exposure to 5 degrees c. n ... | 1993 | 8254640 |
| cold storage effects on egg hatch in laboratory-reared culicoides variipennis sonorensis (diptera: ceratopogonidae). | the effects of cold storage (5 degrees c) on the hatching rates of laboratory-reared culicoides variipennis sonorensis eggs were examined. mortality increased with storage time. average maximum embryo survivorship for 4 trials was 55.0 +/- 4.2 (+/- sem) days. alternating daily cycles of high and then low mean hatching rates occurred and possibly were due to location differences in temperature within the temperature-controlled rearing system. during cold storage at 5 degrees c, c. v. sonorensis e ... | 1995 | 8551303 |
| susceptibility of culicoides variipennis sonorensis to infection by polymerase chain reaction-detectable bluetongue virus in cattle blood. | cattle bloods containing only polymerase chain reaction (pcr)--detectable bluetongue-10 viral nucleic acid, but as determined by virus isolation techniques, not bluetongue-10 virus, were incapable of infecting intrathoracically inoculated culicoides variipennis sonorensis. these insects also failed to transmit bluetongue-10 virus when fed on sheep. cattle whose blood contain only pcr-detectable bluetongue viral nucleic acid, but no infectious virus, are unlikely to play a role in the epidemiolog ... | 1996 | 8644902 |
| handling small arbovirus vectors safely during biosafety level 3 containment: culicoides variipennis sonorensis (diptera:ceratopogonidae) and exotic bluetongue viruses. | equipment and procedures are described for biosafety level 3 (bl-3) containment work with small, zoophilic arthropods. bl-3 classified pathogens always must be manipulated in biological safety cabinets. procedures, including physical barriers and handling methods, that prevent the escape of potentially virus-infected insects are discussed, and the use of a monitoring system for insect security is explained. the inability to recover escaped minute, flying insects poses a major difference from sim ... | 1996 | 8667371 |
| bluetongue virus in laboratory-reared culicoides variipennis sonorensis: applications of dot-blot, elisa, and immunoelectron microscopy. | an avidin-biotin complex (abc) dot-blot, an antigen capture enzyme-linked immunosorbent assay (elisa), and immunoelectron microscopy (iem) were used to detect bluetongue (blu) virus or viral antigen or both in adult culicoides variipennis sonorensis wirth & jones. the dot-blot and elisa procedures detected viral antigen in 10-22% (depending on serotype) of the biting midges infected with blu-2, blu-10, blu-13, and blu-17 and approximately 68% of the midges infected with blu-11. iem analyses reve ... | 1997 | 9086705 |
| applications of dot-blot, elisa, and immunoelectron microscopy to field detection of bluetongue virus in culicoides variipennis sonorensis: an ecological perspective. | an avidin-biotin complex (abc) dot-blot, an antigen capture enzyme-linked immunosorbent assay (elisa), and immunoelectron microscopy (iem) were used to detect bluetongue (blu) virus and viral antigen in field-collected c. varriipennis sonorensis wirth & jones from an enzootic blu area in northeastern colorado. this is the 1st attempt to apply these immunodiagnostic methods to an epidemiologically relevant, large-scale ecological system. one of the 1,800 midges (0.0005%) was positive by the dot-b ... | 1997 | 9086706 |
| field morphological variation and laboratory hybridization of culicoides variipennis sonorensis and c. v. occidentalis (diptera:ceratopogonidae) in southern california. | two field populations of culicoides variipennis (coquillett) from southern california, c. v. occidentalis wirth & jones from the salton sea and c. v. sonorensis wirth & jones from a dairy wastewater pond in the chino basin, were sampled monthly from february to july (6-7 mo). morphometric analyses of slide-mounted adults reared from field-collected larvae and pupae indicated that females of the 2 forms were indistinguishable. two of the standard characters, wing length and mandibular teeth, were ... | 1997 | 9151490 |
| improved rearing methods for heleidomermis magnapapula (nematoda: mermithidae), a larval parasite of culicoides variipennis sonorensis (diptera: ceratopogonidae). | improvements in rearing techniques have decreased maintenance needs and have increased the parasitism rate of larval culicoides variipennis sonorensis wirth & jones by the mermithid nematode, heleidomermis magnapapula poinar & mullens. in colony pans with 2,500-3,000 larval c. v. sonorensis, h. magnapapula adults emerged from 22.5% of hosts, with an average yield of 159 female h. magnapapula per pan. h. magnapapula females refrigerated for 1 wk showed no decline in preparasite infectivity compar ... | 1997 | 9439126 |
| anticoagulant activity in salivary glands of the insect vector culicoides variipennis sonorensis by an inhibitor of factor xa. | blood feeding by the insect vector culicoides variipennis sonorensis involves laceration of superficial host tissues, an injury that would be expected to trigger the coagulation cascade. accordingly, the salivary glands of c.v. sonorensis were examined for the presence of an antihemostatic that prevents blood coagulation. assays using salivary gland extracts showed a delay in the recalcification time of plasma devoid of platelets, indicating the presence of anticoagulant activity. retardation in ... | 1998 | 9538866 |
| epizootic hemorrhagic disease: analysis of tissues by amplification and in situ hybridization reveals widespread orbivirus infection at low copy numbers. | a recent outbreak of hemorrhagic fever in wild ruminants in the northwest united states was characterized by rapid onset of fever, followed shortly thereafter by hemorrhage and death. as a result, a confirmed 1,000 white-tailed deer and pronghorn antelope died over the course of 3 months. lesions were multisystemic and included severe edema, congestion, acute vascular necrosis, and hemorrhage. animals that died with clinical signs and/or lesions consistent with hemorrhagic fever had antibody to ... | 1998 | 9557671 |
| response of male culicoides variipennis sonorensis (diptera: ceratopogonidae) to carbon dioxide and observations of mating behavior on and near cattle. | the response of male culicoides variipennis sonorensis wirth & jones to carbon dioxide (co2) was examined at a dairy in the chino basin of southern california. males were collected using cdc-type suction traps (no light) during 6 evenings in september and october 1995 when c. v. sonorensis were abundant. traps were baited with 1.8 kg of dry ice, 200-350 nulliparous females, or nothing. greater than 8 times as many males were captured in co2-baited suction traps than in either female-baited or un ... | 1998 | 9615541 |
| comparison of bait cattle and carbon dioxide-baited suction traps for collecting culicoides variipennis sonorensis (diptera: ceratopogonidae) and culex quinquefasciatus (diptera: culicidae). | carbon dioxide-baited suction trap collections were related to simultaneous bait cattle collections of culicoides variipennis sonorensis wirth & jones. trap collections varied directly with numbers taken from each of 3 calves. more (3.4x) c. v. sonorensis were taken in a trap with 1,000 ml co2/min versus a trap baited with approximately 300 ml/min (matched to calves by weight). numbers of insects taken from three individual calves relative to their equivalent co2 output did not differ, but engor ... | 1998 | 9615542 |
| iridescent virus infection in culicoides variipennis sonorensis and interactions with the mermithid parasite heleidomermis magnapapula. | | 1999 | 10066406 |
| response of culicoides sonorensis (diptera: ceratopogonidae) to 1-octen-3-ol and three plant-derived repellent formulations in the field. | the potential attractant 1-octen-3-ol and 3 potential repellents were assayed for activity for culicoides sonorensis, the primary vector of bluetongue virus in north america. collections using octenol were low, but numbers in suction traps were greater in the high-octenol treatment (11.5 mg/h) than in the low-octenol treatment (1.2 mg/h) or unbaited control for both sexes. collections using high octenol, co2 (approximately 1,000 ml/min), or both showed octenol alone to be significantly less attr ... | 2000 | 10901641 |
| seasonal abundance and survivorship of culicoides sonorensis (diptera: ceratopogonidae) at a southern california dairy, with reference to potential bluetongue virus transmission and persistence. | seasonal abundance and survivorship of culicoides sonorensis wirth & jones were examined at a dairy in southern california from january 1995 to december 1997. insects were collected one to two times per week using five cdc-type suction traps (without light) baited with co2 at a constant release rate of 1,000 ml/min. female and male abundance was greatest during late summer and early fall and was directly correlated with mean monthly air temperature. parity of females was lowest during late summe ... | 2000 | 11004778 |
| oral infection of culicoides sonorensis (diptera: ceratopogonidae) by vesicular stomatitis virus. | vesicular stomatitis virus serotype new jersey (vsnjv) was mixed with bovine blood or fetal bovine serum (fbs) and fed across silicone membranes to laboratory populations of culicoides sonorensis wirth & jones. in an initial study, virus was detected after 13 d in 21% of the midges that received an fbs/vsnjv mixture. in subsequent time-course experiments, engorged females were collected and maintained at 20.0 degrees c and assayed for vsnjv immediately after feeding and at 1, 3, 7, 10 and 13 d a ... | 2000 | 11004797 |
| feeding and survival of culicoides sonorensis on cattle treated with permethrin or pirimiphos-methyl. | the persistence of permethrin (5% a.i.) and pirimiphos-methyl (27% a.i.), applied to the dorsum of calves in the field against culicoides sonorensis wirth and jones (diptera: ceratopogonidae), was estimated using a hair-blood-feeding bioassay in the laboratory. hair clippings were taken before treatment and 3, 7, 14, 21, 28, 42 and 56 days after treatment from the dorsum, side and belly of treated and control calves. laboratory-reared insects were allowed to feed through thin hair layers and a p ... | 2000 | 11016440 |
| identification and characterization of a cdna clone encoding the heat shock protein (hsp60) from the biting midge, culicoides variipennis sonorensis wirth and jones. | a cdna expression library constructed from culicoides variipennis sonorensis was screened using an antibody specific for hsp60 of heliothis virescens. a single clone encoding the complete heat shock protein (hsp60) of c. variipennis was identified and its 2400-bp insert was sequenced. the encoded 62-kda protein contains 581 amino acids and includes a 26-amino acid putative mitochondrial targeting sequence at its n terminus and a ggm motif at its carboxyl terminus. deduced amino acid sequences ar ... | 2000 | 11091906 |
| pharmacological factors in the saliva of blood-feeding insects. implications for vesicular stomatitis epidemiology. | vesicular stomatitis (vs) epizootics in the western united states have caused substantial economic losses to u.s. livestock industries in 1995, 1997, and 1998. the role of arthropods in transmitting vs to u.s. livestock is unclear. in particular, the impact of arthropod salivary gland factors in vs infections in livestock needs study. pharmacological effects of arthropod salivary gland factors on animals are reviewed. the potential effects of arthropod saliva on the transmission and spread of vs ... | 2000 | 11193659 |
| cryopreservation of embryos of culicoides sonorensis (diptera: ceratopogonidae). | the successful long-term storage of insects that are used for research purposes can eliminate the need for ongoing colony maintenance on a large scale. in addition, rare and valuable genotypes of insects can be preserved. this study was conducted to determine whether cryopreservation is a suitable means of storing embryos of culicoides sonorensis wirth & jones, an important vector of animal pathogens. we determined that eggs of c. sonorensis can withstand vigorous treatments of dechorionation, p ... | 2001 | 11268692 |
| seasonal transmission of bluetongue virus by culicoides sonorensis (diptera: ceratopogonidae) at a southern california dairy and evaluation of vectorial capacity as a predictor of bluetongue virus transmission. | vectorial capacity of culicoides sonorensis wirth & jones for the transmission of bluetongue (blu) virus was examined at a southern california dairy from january 1995 to december 1997. insects were collected one to two times per week in five cdc-type suction traps (without light) baited with co2 at a constant release rate of 1,000 ml/min. blu virus was detected in midges collected from may through december with an estimated overall infection rate of 0.08%. the blu virus infection rate of field-c ... | 2001 | 11296823 |
| isolation and characterization of a cdna clone coding for a glutathione s-transferase class delta enzyme from the biting midge culicoides variipennis sonorensis wirth and jones. | culicoides variipennis sonorensis is the primary vector of bluetongue viruses in north america. glutathione s-transferases (gsts) are enzymes that catalyze nucleophilic substitutions, converting reactive lipophilic molecules into soluble conjugates. increased gst activity is associated with development of insecticide resistance. described here is the isolation of the first cdna encoding a c. variipennis gst. the clone consists of 720 translated bases encoding a protein with a m(r) of approximate ... | 2000 | 11301916 |
| occurrence of genetic drift and founder effect during quasispecies evolution of the vp2 and ns3/ns3a genes of bluetongue virus upon passage between sheep, cattle, and culicoides sonorensis. | bluetongue virus (btv) is the cause of an insect-transmitted virus infection of ruminants that occurs throughout much of the world. individual gene segments differ between field strains of btv; thus, we hypothesized that key viral genes undergo genetic drift during alternating passage of btv in its ruminant and insect hosts. to test this hypothesis, variation in the consensus sequence and quasispecies heterogeneity of the vp2 and ns3/ns3a genes of a plaque-purified strain of btv serotype 10 was ... | 2001 | 11483775 |
| failure of a permethrin treatment regime to protect cattle against bluetongue virus. | holstein heifers in a confined feedlot setting on a southern california dairy were either sprayed individually along the ventral midline using 0.2% permethrin (250 ml/animal) (two pens) or were not treated (two pens). treatments (n = 6 dates) were applied every 2 wk during the peak fall bluetongue virus transmission season (22 august-29 october). animals seronegative for bluetongue virus antibodies at the initial bleeding on 15-18 september (n - 106 in the treatment pens and n = 117 in the contr ... | 2001 | 11580054 |
| variation in the ns3/ns3a gene of bluetongue viruses contained in culicoides sonorensis collected from a single site in southern california. | to determine the variability of the ns3/ns3a gene of field strains of btv contained in culicoides sonorensis collected from a single site in california (ca), the ns3/ns3a gene was directly amplified and sequenced from 22 pools of c. sonorensis and compared with those of previously characterized field isolates from ca, as well as to viruses that caused recent outbreaks of bluetongue disease in ruminants in ca. phylogenetic analysis established that the ns3/ns3a gene of strains of btv contained in ... | 2002 | 11900839 |
| effect of temperature on the transmission of orbiviruses by the biting midge, culicoides sonorensis. | the influence of temperature on the likelihood of culicoides sonorensis wirth & jones (diptera: ceratopogonidae) transmitting african horse sickness virus (ahsv) serotypes 4 and 6, bluetongue virus (btv) serotypes 10 and 16 and epizootic haemorrhagic disease of deer virus (ehdv) serotype 1 was investigated. extrinsic incubation periods (eip), vector competence and vector survival were determined at 15, 20, 25 and 30 degrees c. the effect of humidity on vector survival was also investigated by ma ... | 2002 | 12109708 |
| duration of viraemia infectious to culicoides sonorensis in bluetongue virus-infected cattle and sheep. | the duration of viraemia infectious to culicoides sonorensis (c. sonorensis) was evaluated in bluetongue virus (btv)-infected sheep and cattle by feeding laboratory-reared c. sonorensis directly on the skin of ruminants that previously were infected with btv by insect inoculation. the intervals after infection when infectious btv and btv nucleic acids were present in the blood of infected cattle and sheep, respectively, were determined by virus isolation and reverse transcriptase (rt)-nested pol ... | 2002 | 12135632 |
| differentially expressed midgut transcripts in culicoides sonorensis (diptera: ceratopogonidae) following orbivirus (reoviridae) oral feeding. | understanding the vector insect's gene expression response to a virus infection may aid design of control measures for arbovirus diseases. culicoides sonorensis is a vector of several agriculturally important pathogens, such as epizootic haemorrhagic disease virus (ehdv) that causes disease in ruminants. two approaches, differential display and suppression subtractive hybridization, were used to identify 400+ culicoides transcripts that were more abundant in midguts 1 day following an oral meal ... | 2002 | 12421417 |
| papular dermatitis induced in guinea pigs by the biting midge culicoides sonorensis (diptera: ceratopogonidae). | histological, ultrastructural, and virological examinations were performed on abdominal skin from guinea pigs after a blood meal by colony-bred biting midges, culicoides sonorensis. small, superficial, cutaneous, crateriform ulcers with necrosis of superficial dermis developed at feeding sites and healed within 24-48 hours. animals developed nonpruritic erythematous papules 5 days after feeding that persisted until the study ended at 12 days after feeding. papules corresponded histologically to ... | 2003 | 12580301 |
| characterization of cell lines developed from field populations of culicoides sonorensis (diptera: ceratopogonidae). | two cell lines, abadrl-cs-w3 (w3) and abadrl-cs-w8a (w8), were developed from a field population of culicoides sonorensis wirth & jones. the cell lines were characterized by isozyme phenotyping and the ability to support the replication of bluetongue virus (blu) and epizootic hemorrhagic disease virus (ehdv) (orbivirus, reoviridae). comparison of isozymes found in the cell lines with those found in adult c. sonorensis colony insects confirmed that the cell lines were of c. sonorensis origin. the ... | 2003 | 12943114 |
| culture-independent analysis of midgut microbiota in the arbovirus vector culicoides sonorensis (diptera: ceratopogonidae). | differences in midgut microbial communities inhabiting culicoides spp., insect vectors of virus pathogens, may affect the variation observed in the ability of these biting midges to propagate arthropod-borne viruses. as a first step toward addressing this hypothesis, midgut bacterial communities were compared between culicoides species expected to be efficient and inefficient vectors of virus pathogens. we used 16s rdna sequence and restriction fragment information to provisionally identify 36 b ... | 2004 | 15185934 |
| sympatry in the culicoides variipennis complex (diptera: ceratopogonidae): a taxonomic reassessment. | we report sympatry among larval populations of the culicoides variipennis complex in widespread and diverse aquatic habitats throughout the united states. six sites in california, nevada, new mexico, and texas were co-inhabited by c. v. occidentalis and c. v. sonorensis, whereas 8 sites in florida, georgia, louisiana, maryland, and texas were co-occupied by c. v. sonorensis and c. v. variipennis. no intermediate forms were identified either electrophoretically or morphologically in adults reared ... | 2000 | 15218909 |
| studies on overwintering of bluetongue viruses in insects. | bluetongue viruses (btvs) are economically important arboviruses that affect sheep and cattle. the overwintering mechanism of btvs in temperate climates has eluded researchers for many years. many arboviruses overwinter in their invertebrate vectors. to test the hypothesis that btvs overwinter in their vertically infected insect vectors, culicoides sonorensis larvae were collected from long-term study sites in northern colorado, usa, and assayed for the presence of btv rna by nested rt-pcr. sequ ... | 2005 | 15659765 |
| midgut and salivary gland transcriptomes of the arbovirus vector culicoides sonorensis (diptera: ceratopogonidae). | numerous culicoides spp. are important vectors of livestock or human disease pathogens. transcriptome information from midguts and salivary glands of adult female culicoides sonorensis provides new insight into vector biology. of 1719 expressed sequence tags (ests) from adult serum-fed female midguts harvested within 5 h of feeding, twenty-eight clusters of serine proteases were derived. four clusters encode putative iron binding proteins (fer1, ferl, pxdl1, pxdl2), and two clusters encode metal ... | 2005 | 15796745 |
| culicoides and other biting flies on the palos verdes peninsula of southern california, and their possible relationship to equine dermatitis. | biting insects were sampled to investigate the cause(s) of dermatitis (putative culicoides hypersensitivity [chs]) on horses on the palos verdes peninsula, los angeles county, california. suction traps baited with co2 were operated at 5 sites from april 2002 to august 2003, supplemented by sampling from horses. six species of culicoides, 7 species of mosquitoes, and occasional simulium and stomoxys were collected in traps. culicoides sonorensis was the most common midge trapped, although c. obso ... | 2005 | 15825768 |
| vector competence of culicoides sonorensis (diptera: ceratopogonidae) for vesicular stomatitis virus. | to determine the vector competence of culicoides sonorensis wirth & jones midges for vesicular stomatitis virus (vsv)-new jersey, insects were experimentally infected per os and sampled over time. viral replication, as determined by in situ hybridization, was seen in epithelial, neural, and hemolymph cell types throughout the insect. spatial and temporal distribution of virus was determined by immunohistochemical examination of sequentially sampled insects. tissues of the alimentary canal were i ... | 2005 | 15962795 |
| genetic variation in west nile virus from naturally infected mosquitoes and birds suggests quasispecies structure and strong purifying selection. | intrahost genetic diversity was analysed in naturally infected mosquitoes and birds to determine whether west nile virus (wnv) exists in nature as a quasispecies and to quantify selective pressures within and between hosts. wnv was sampled from ten infected birds and ten infected mosquito pools collected on long island, ny, usa, during the peak of the 2003 wnv transmission season. a 1938 nt fragment comprising the 3' 1159 nt of the wnv envelope (e) coding region and the 5' 779 nt of the non-stru ... | 2005 | 16033965 |
| comparative salivary gland transcriptomics of sandfly vectors of visceral leishmaniasis. | immune responses to sandfly saliva have been shown to protect animals against leishmania infection. yet very little is known about the molecular characteristics of salivary proteins from different sandflies, particularly from vectors transmitting visceral leishmaniasis, the fatal form of the disease. further knowledge of the repertoire of these salivary proteins will give us insights into the molecular evolution of these proteins and will help us select relevant antigens for the development of a ... | 2006 | 16539713 |
| transmission of vesicular stomatitis new jersey virus to cattle by the biting midge culicoides sonorensis (diptera: ceratopogonidae). | laboratory-reared culicoides sonorensis wirth & jones were infected with vesicular stomatitis virus serotype new jersey (family rhabdoviridae, genus vesiculovirus, vsnjv) through intrathoracic inoculation. after 10-d incubation at 25 degrees c, these insects were allowed to blood feed on four steers. two other steers were exposed to vsnjv through intralingual inoculation with 10(8) tissue culture infective dose50 vsnjv. all six steers became seropositive for vsnjv. the results demonstrate the ab ... | 2006 | 16619618 |
| infection of guinea pigs with vesicular stomatitis new jersey virus transmitted by culicoides sonorensis (diptera: ceratopogonidae). | intrathoracically inoculated culicoides sonorensis wirth & jones were capable of transmitting vesicular stomatitis new jersey virus (family rhabdoviridae, genus vesiculovirus, vsnjv) during blood feeding on the abdomen of six guinea pigs. none of the guinea pigs infected in this manner developed clinical signs of vesicular stomatitis despite seroconversion for vsnjv. guinea pigs infected by intradermal inoculations of vsnjv in the abdomen also failed to develop clinical signs of vesicular stomat ... | 2006 | 16739417 |
| prevalence of antibodies to serotypes of bluetongue virus and anaplasma marginale in montana feeder cattle: 2002-2003. | in a serologic survey of montana-source weaned calves and yearling cattle, the apparent prevalence of antibodies to bluetongue virus was 0.68% and 1.26% in 2002 and 2003, respectively, and to anaplasma marginale at a positive cutoff at 30% inhibition it was 1.82% and 1.35% in 2002 and 2003, and at a positive cutoff at 42% inhibition it was 0.76% and 0.55% in 2002 and 2003, respectively, suggesting that the risk of importing infected animals was very low. | 2006 | 16898114 |
| the emerging diversity of rickettsia. | the best-known members of the bacterial genus rickettsia are associates of blood-feeding arthropods that are pathogenic when transmitted to vertebrates. these species include the agents of acute human disease such as typhus and rocky mountain spotted fever. however, many other rickettsia have been uncovered in recent surveys of bacteria associated with arthropods and other invertebrates; the hosts of these bacteria have no relationship with vertebrates. it is therefore perhaps more appropriate t ... | 2006 | 16901827 |
| high degree of conservancy among secreted salivary gland proteins from two geographically distant phlebotomus duboscqi sandflies populations (mali and kenya). | salivary proteins from sandflies are potential targets for exploitation as vaccines to control leishmania infection; in this work we tested the hypothesis that salivary proteins from geographically distant phlebotomus duboscqi sandfly populations are highly divergent due to the pressure exerted by the host immune response. salivary gland cdna libraries were prepared from wild-caught p. duboscqi from mali and recently colonised flies of the same species from kenya. | 2006 | 16952314 |
| salivary gland extracts of culicoides sonorensis inhibit murine lymphocyte proliferation and no production by macrophages. | culicoides biting midges serve as vectors of pathogens affecting humans and domestic animals. culicoides sonorensis is a vector of several arboviruses in north american that cause substantial economic losses to the us livestock industry. previous studies showed that c. sonorensis saliva, like the saliva of many hematophagous arthropods, contains numerous pharmacological agents that affect hemostasis and early events in the inflammatory response, which may enhance the infectivity of culicoides-bo ... | 2006 | 16968936 |
| abundance and species composition of culicoides (diptera: ceratopogonidae) at cattle facilities in southern alberta, canada. | culicoides fauna was examined at seven feedlots and one rangeland site (warner) in southern alberta, canada, during a 3-yr period. eight species and species groups accounted for > 99% of the culicoides (diptera: ceratopogonidae) captured. the most abundant species or groups were culicoides gigas root and hoffman, culicoides sonorensis (wirth and jones), culicoides (selfia) group, and culicoides palmerae group. these accounted for 78-88% of the culicoides captured, with the balance being members ... | 2006 | 17017217 |
| comparative analysis of serine protease-related genes in the honey bee genome: possible involvement in embryonic development and innate immunity. | we have identified 44 serine protease (sp) and 13 serine protease homolog (sph) genes in the genome of apis mellifera. most of these genes encode putative secreted proteins, but four sps and three sphs may associate with the plasma membrane via a transmembrane region. clip domains represent the most abundant non-catalytic structural units in these sp-like proteins -12 sps and six sphs contain at least one clip domain. some of the family members contain other modules for protein-protein interacti ... | 2006 | 17069636 |
| the west nile virus mutant spectrum is host-dependant and a determinant of mortality in mice. | to define the impact of mosquitoes and birds on intrahost wnv population dynamics, the mutant spectra that arose as a result of 20 serial in vivo passages in culex pipiens and young chickens were examined. genetically homogeneous wnv was serially passaged 20 times in each host. genetic diversity was greater in mosquito-passaged wnv compared to chicken-passaged wnv. changes in the viral consensus sequence occurred in wnv passaged in mosquitoes earlier and more frequently than in chicken-passaged ... | 2007 | 17134731 |
| an insight into the sialome of anopheles funestus reveals an emerging pattern in anopheline salivary protein families. | anopheles funestus, together with anopheles gambiae, is responsible for most malaria transmission in sub-saharan africa, but little is known about molecular aspects of its biology. to investigate the salivary repertoire of this mosquito, we randomly sequenced 916 clones from a salivary-gland cdna library from adult female f1 offspring of field-caught an. funestus. thirty-three protein sequences, mostly full-length transcripts, are predicted to be secreted salivary proteins. we additionally descr ... | 2007 | 17244545 |
| collection and analysis of salivary proteins from the biting midge culicoides nubeculosus (diptera: ceratopogonidae). | salivary proteins of hematophagous culicoides spp. are thought to play an important role in pathogen transmission and skin hypersensitivity. analysis of these proteins, however, has been problematic due to the difficulty in obtaining adequate amounts of secreted culicoides saliva. in the current study, a collection method for midge saliva was developed. over a 3-d period, 3- to 5-d-old male and female culicoides nubeculosus meigen (diptera: ceratopogonidae) were repeatedly placed onto the collec ... | 2007 | 17427692 |
| the sialotranscriptome of the blood-sucking bug triatoma brasiliensis (hemiptera, triatominae). | triatoma brasiliensis is the most important autochthon vector of trypanosoma cruzi in brazil, where it is widely distributed in the semiarid areas of the northeast. in order to advance the knowledge of the salivary biomolecules of triatominae, a salivary gland cdna library of t. brasiliensis was mass sequenced and analyzed. polypeptides were sequenced by hplc/edman degradation experiments. then 1712 cdna sequences were obtained and grouped in 786 clusters. the housekeeping category had 24.4% and ... | 2007 | 17550826 |
| assessing the risk of bluetongue to uk livestock: uncertainty and sensitivity analyses of a temperature-dependent model for the basic reproduction number. | since 1998 bluetongue virus (btv), which causes bluetongue, a non-contagious, insect-borne infectious disease of ruminants, has expanded northwards in europe in an unprecedented series of incursions, suggesting that there is a risk to the large and valuable british livestock industry. the basic reproduction number, r(0), provides a powerful tool with which to assess the level of risk posed by a disease. in this paper, we compute r(0) for btv in a population comprising two host species, cattle an ... | 2008 | 17638649 |
| exploring the midgut transcriptome of phlebotomus papatasi: comparative analysis of expression profiles of sugar-fed, blood-fed and leishmania-major-infected sandflies. | in sandflies, the blood meal is responsible for the induction of several physiologic processes that culminate in egg development and maturation. during blood feeding, infected sandflies are also able to transmit the parasite leishmania to a suitable host. many blood-induced molecules play significant roles during leishmania development in the sandfly midgut, including parasite killing within the endoperitrophic space. in this work, we randomly sequenced transcripts from three distinct high quali ... | 2007 | 17760985 |
| analysis of the immune-inducible transcriptome from microbial stress resistant, rat-tailed maggots of the drone fly eristalis tenax. | the saprophagous and coprophagous maggots of the drone fly eristalis tenax (insecta, diptera) have evolved the unique ability to survive in aquatic habitats with extreme microbial stress such as drains, sewage pools, and farmyard liquid manure storage pits. therefore, they represent suitable models for the investigation of trade-offs between the benefits resulting from colonization of habitats lacking predators, parasitoids, or competitors and the investment in immunity against microbial stress. ... | 2007 | 17875201 |
| effect of temperature on life history parameters of adult culicoides sonorensis (diptera: ceratopogonidae) in relation to geographic origin and vectorial capacity for bluetongue virus. | the effect of temperature on survival, oviposition, gonotrophic development, and a life history factor of vectorial capacity were examined in adult culicoides sonorensis (wirth & jones) (diptera: ceratopogonidae) that originated from two geographic locations. flies originating from the united states (colorado) had slightly reduced survival after a bloodmeal compared with wild flies collected in southern alberta (ab), canada. survival of ab flies declined in a curvilinear manner with temperature, ... | 2007 | 17915503 |
| seasonal abundance, parity, and survival of adult culicoides sonorensis (diptera: ceratopogonidae) in southern alberta, canada. | culicoides sonorensis (wirth & jones) (diptera: ceratopogonidae) adults were active from may through october during 2002-2006 in southern alberta, canada. adults were first captured in may, and populations peaked in early june, late july, and late august. the first population peak occurred when mean weekly temperatures exceeded 16 degrees c, resulting in a variable amount of time for spring emergence. this asynchrony in spring emergence accounted for much of the annual variation in timing of sub ... | 2007 | 18047194 |
| an insight into the sialome of the soft tick, ornithodorus parkeri. | while hard ticks (ixodidae) take several days to feed on their hosts, soft ticks (argasidae) feed faster, usually taking less than 1h per meal. saliva assists in the feeding process by providing a cocktail of anti-hemostatic, anti-inflammatory and immunomodullatory compounds. saliva of hard ticks has been shown to contain several families of genes each having multiple members, while those of soft ticks are relatively unexplored. analysis of the salivary transcriptome of the soft tick ornithodoru ... | 2008 | 18070662 |
| the midgut transcriptome of lutzomyia longipalpis: comparative analysis of cdna libraries from sugar-fed, blood-fed, post-digested and leishmania infantum chagasi-infected sand flies. | in the life cycle of leishmania within the alimentary canal of sand flies the parasites have to survive the hostile environment of blood meal digestion, escape the blood bolus and attach to the midgut epithelium before differentiating into the infective metacyclic stages. the molecular interactions between the leishmania parasites and the gut of the sand fly are poorly understood. in the present work we sequenced five cdna libraries constructed from midgut tissue from the sand fly lutzomyia long ... | 2008 | 18194529 |
| hematophagous diptera collected from a horse and paired carbon dioxide-baited suction trap in southern california: relevance to west nile virus epizootiology. | hematophagous diptera landing on a horse were removed by vacuum, and their numbers were related to a paired carbon dioxide-baited suction trap at three locations in southern california where west nile virus activity was high during the preceding year. insects collected from the horse included mosquitoes (nine species), biting midges (culicoides sonorensis wirth & jones), and black flies (simulium bivittatum malloch). mosquitoes were predominantly collected from the head, crest, withers, neck, ch ... | 2008 | 18283951 |
| quantifying bluetongue virus in adult culicoides biting midges (diptera: ceratopogonidae). | a tissuelyser system (qiagen) was used to rapidly and accurately estimate bluetongue virus "loads" in individual adult culicoides sonorensis wirth & jones (diptera: ceratopogonidae). the optimized homogenization program that was developed, involved shaking insects for 1 min at 25 hz with 2- or 3-mm stainless steel ball bearings. this program was used to measure the quantities of bluetongue virus present in insects that had either been inoculated or had ingested a viremic bloodmeal through an art ... | 2008 | 18283953 |
| temperature, viral genetics, and the transmission of west nile virus by culex pipiens mosquitoes. | the distribution and intensity of transmission of vector-borne pathogens can be strongly influenced by the competence of vectors. vector competence, in turn, can be influenced by temperature and viral genetics. west nile virus (wnv) was introduced into the united states of america in 1999 and subsequently spread throughout much of the americas. previously, we have shown that a novel genotype of wnv, wn02, first detected in 2001, spread across the us and was more efficient than the introduced gen ... | 2008 | 18584026 |
| identification, expression and characterisation of a major salivary allergen (cul s 1) of the biting midge culicoides sonorensis relevant for summer eczema in horses. | salivary proteins of culicoides biting midges are thought to play a key role in summer eczema (se), a seasonal recurrent allergic dermatitis in horses. the present study describes the identification, expression and clinical relevance of a candidate allergen of the north american midge culicoides sonorensis. immunoblot analysis of midge saliva revealed a 66 kda protein (cul s 1) that was bound by ige from several se-affected (se+) horses. further characterisation by fragmentation, mass spectromet ... | 2009 | 18708061 |
| where does bluetongue virus sleep in the winter? | | 2008 | 18752350 |
| rates of bluetongue virus transmission between culicoides sonorensis and sheep. | two experiments were undertaken to estimate the transmission rates of bluetongue virus (btv) serotype 1 between a biting midge vector, culicoides sonorensis (wirth & jones) (ceratopogonidae), and a natural host, sheep. in an experiment to measure the transmission rate from vector to host (v-->h), six batches of one, five and 20 intrathoracically infected midges were fed on a total of 18 bluetongue (bt)-naïve sheep. the sheep were then monitored for 21 days for clinical signs of bt, viraemia and ... | 2008 | 18816271 |
| hyaluronidase of bloodsucking insects and its enhancing effect on leishmania infection in mice. | salivary hyaluronidases have been described in a few bloodsucking arthropods. however, very little is known about the presence of this enzyme in various bloodsucking insects and no data are available on its effect on transmitted microorganisms. here, we studied hyaluronidase activity in thirteen bloodsucking insects belonging to four different orders. in addition, we assessed the effect of hyaluronidase coinoculation on the outcome of leishmania major infection in balb/c mice. | 2008 | 18820742 |
| blood-feeding behavior of vesicular stomatitis virus infected culicoides sonorensis (diptera: ceratopogonidae). | to determine whether vesicular stomatitis virus (vsv) infection of culicoides sonorensis wirth & jones (diptera: ceratopogonidae) affects subsequent blood-feeding behavior, midges injected with either virus-infected or virus-free cell lysates were allowed to blood feed for short (10-min) or long (60-min) periods on 2, 3, and 4 d postinoculation (dpi). generalized linear mixed models were fit to test the effects of infection status, duration of feeding period, and dpi on the percentage of females ... | 2008 | 18826036 |
| exploring the mialome of ticks: an annotated catalogue of midgut transcripts from the hard tick, dermacentor variabilis (acari: ixodidae). | ticks are obligate blood feeders. the midgut is the first major region of the body where blood and microbes ingested with the blood meal come in contact with the tick's internal tissues. little is known about protein expression in the digestive tract of ticks. in this study, for analysis of global gene expression during tick attachment and feeding, we generated and sequenced 1,679 random transcripts (ests) from cdna libraries from the midguts of female ticks at varying stages of feeding. | 2008 | 19021911 |
| adaptive strategies of african horse sickness virus to facilitate vector transmission. | african horse sickness virus (ahsv) is an orbivirus that is usually transmitted between its equid hosts by adult culicoides midges. in this article, we review the ways in which ahsv may have adapted to this mode of transmission. the ahsv particle can be modified by the ph or proteolytic enzymes of its immediate environment, altering its ability to infect different cell types. the degree of pathogenesis in the host and vector may also represent adaptations maximising the likelihood of successful ... | 2009 | 19094921 |
| insight into the sialome of the black fly, simulium vittatum. | adaptation to vertebrate blood feeding includes development of a salivary "magic potion" that can disarm host hemostasis and inflammatory reactions. within the lower diptera, a vertebrate blood-sucking mode evolved in the psychodidae (sand flies), culicidae (mosquitoes), ceratopogonidae (biting midges), simuliidae (black flies), and the frog-feeding corethrellidae. sialotranscriptome analyses from several species of mosquitoes and sand flies and from one biting midge indicate divergence in the e ... | 2009 | 19166301 |
| evolution and diversity of rickettsia bacteria. | rickettsia are intracellular symbionts of eukaryotes that are best known for infecting and causing serious diseases in humans and other mammals. all known vertebrate-associated rickettsia are vectored by arthropods as part of their life-cycle, and many other rickettsia are found exclusively in arthropods with no known secondary host. however, little is known about the biology of these latter strains. here, we have identified 20 new strains of rickettsia from arthropods, and constructed a multi-g ... | 2009 | 19187530 |
| rickettsia phylogenomics: unwinding the intricacies of obligate intracellular life. | completed genome sequences are rapidly increasing for rickettsia, obligate intracellular alpha-proteobacteria responsible for various human diseases, including epidemic typhus and rocky mountain spotted fever. in light of phylogeny, the establishment of orthologous groups (ogs) of open reading frames (orfs) will distinguish the core rickettsial genes and other group specific genes (class 1 ogs or c1ogs) from those distributed indiscriminately throughout the rickettsial tree (class 2 og or c2ogs) ... | 2008 | 19194535 |
| infection of melanoplus sanguinipes grasshoppers following ingestion of rangeland plant species harboring vesicular stomatitis virus. | knowledge of the many mechanisms of vesicular stomatitis virus (vsv) transmission is critical for understanding of the epidemiology of sporadic disease outbreaks in the western united states. migratory grasshoppers [melanoplus sanguinipes (fabricius)] have been implicated as reservoirs and mechanical vectors of vsv. the grasshopper-cattle-grasshopper transmission cycle is based on the assumptions that (i) virus shed from clinically infected animals would contaminate pasture plants and remain inf ... | 2009 | 19286779 |
| in situ immune infrared fluorescent staining for detection and quantitation of bluetongue virus in culicoides insect cell culture. | bluetongue virus (btv) is transmitted to sheep, cattle and other ruminants by culicoides spp. of biting midges. cell lines have been developed from culicoides sonorensis; however, techniques to detect and quantitate viable virus directly in these insect cells are lacking. in situ immune infrared fluorescent staining techniques were developed to visualize and quantitate btv infection in culicoides cell culture by both an endpoint titration and an agarose overlay fluorescent focus assay. insect ce ... | 2009 | 19428578 |
| analysis of salivary transcripts and antigens of the sand fly phlebotomus arabicus. | sand fly saliva plays an important role in blood feeding and leishmania transmission as it was shown to increase parasite virulence. on the other hand, immunity to salivary components impedes the establishment of infection. therefore, it is most desirable to gain a deeper insight into the composition of saliva in sand fly species which serve as vectors of various forms of leishmaniases. in the present work, we focused on phlebotomus (adlerius) arabicus, which was recently shown to transmit leish ... | 2009 | 19555500 |
| an insight into the transcriptome and proteome of the salivary gland of the stable fly, stomoxys calcitrans. | adult stable flies are blood feeders, a nuisance, and mechanical vectors of veterinary diseases. to enable efficient feeding, blood sucking insects have evolved a sophisticated array of salivary compounds to disarm their host's hemostasis and inflammatory reaction. while the sialomes of several blood sucking nematocera flies have been described, no thorough description has been made so far of any brachycera, except for a detailed proteome analysis of a tabanid (xu et al., 2008). in this work we ... | 2009 | 19576987 |
| present and future arboviral threats. | arthropod-borne viruses (arboviruses) are important causes of human disease nearly worldwide. all arboviruses circulate among wild animals, and many cause disease after spillover transmission to humans and agriculturally important domestic animals that are incidental or dead-end hosts. viruses such as dengue (denv) and chikungunya (chikv) that have lost the requirement for enzootic amplification now produce extensive epidemics in tropical urban centers. many arboviruses recently have increased i ... | 2010 | 19857523 |
| analysis of rickettsia typhi-infected and uninfected cat flea (ctenocephalides felis) midgut cdna libraries: deciphering molecular pathways involved in host response to r. typhi infection. | murine typhus is a flea-borne febrile illness that is caused by the obligate intracellular bacterium, rickettsia typhi. the cat flea, ctenocephalides felis, acquires r. typhi by imbibing a bloodmeal from a rickettsemic vertebrate host. to explore which transcripts are expressed in the midgut in response to challenge with r. typhi, cdna libraries of r. typhi-infected and uninfected midguts of c. felis were constructed. in this study, we examined midgut transcript levels for select c. felis serine ... | 2010 | 20017753 |
| an insight into the sialotranscriptome of the west nile mosquito vector, culex tarsalis. | saliva of adult female mosquitoes help sugar and blood feeding by providing enzymes and polypeptides that help sugar digestion, control microbial growth and counteract their vertebrate host hemostasis and inflammation. mosquito saliva also potentiates the transmission of vector borne pathogens, including arboviruses. culex tarsalis is a bird feeding mosquito vector of west nile virus closely related to c. quinquefasciatus, a mosquito relatively recently adapted to feed on humans, and the only mo ... | 2010 | 20089177 |
| age-grading the biting midge culicoides sonorensis using near-infrared spectroscopy. | age-grading of insects is important in the control and monitoring of both insect populations and vector-borne diseases. microscopy and morphological techniques exist to age-grade most blood-feeding flies, but these techniques are laborious, often destructive to the insects, and slow. near-infrared spectroscopy (nirs) can be automated and is a non-destructive technique for age-grading. we applied nirs techniques to age-grade females of the biting midge, culicoides sonorensis wirth & jones (dipter ... | 2010 | 20377729 |
| culicoides and the global epidemiology of bluetongue virus infection. | the distribution of the bluetongue viruses (btv) is limited to geographic areas containing competent vector species. all btv-competent species belong to the genus culicoides. in the new world, two different btv epidemiological systems (episystems) occur. culicoides sonorensis is responsible for transmitting btv serotypes in north america that differ from south american serotypes transmitted by c. insignis. there are other episystems in the world. the role of different culicoides vector species a ... | 2004 | 20419653 |
| environmental effects on vector competence and virogenesis of bluetongue virus in culicoides: interpreting laboratory data in a field context. | environmental factors profoundly affect vectorial capacity, governing dynamics and intensity of vector-vertebrate contact in time and space (e.g. seasonal vector population densities, biting rates, and feeding frequencies). temperature influences vector developmental rates and life history parameters, and may modify vector competence. studies should move iteratively from field to laboratory, as attempts are made to understand complex epidemiological patterns. simulation models can be extremely h ... | 2004 | 20419655 |
| bluetongue surveillance methods in the united states of america. | historical surveillance for bluetongue virus (btv) exposure in the united states of america (usa) has relied on periodical serological surveillance using samples collected from cattle at slaughter. most of this surveillance has been focused on the north-eastern portion of the usa due to the lack of competent vectors of btv in this region. for most of the states tested in this region, the prevalence of seropositive animals has been less than 2%. recently, a study was conducted in north-central us ... | 2004 | 20419659 |
| molecular investigations of orbivirus/vector interactions. | defining predictors for insect-transmitted virus (arbovirus) disease cycles requires an understanding of the molecular interactions between the virus and vector insect. studies of orbiviruses from numerous geographic regions have indicated that virus genes are affected by insect population differences. therefore, the authors have initiated genetic studies of culicoides sonorensis, isolating cdnas for characterisation of differential insect gene expression, as well as a gene discovery project. pr ... | 2004 | 20419697 |
| lack of detectable bluetongue virus in skin of seropositive cattle: implications for vertebrate overwintering of bluetongue virus. | the overwintering mechanism of bluetongue virus (btv) has eluded researchers for many years. it was recently proposed that ovine gamma delta t-cells may become persistently infected with btv, and serve as a reservoir for infection of naive vectors in the next transmission season. since cattle are more numerous than sheep in the western united states (where btv is endemic), this hypothesis was tested in bovines. in the winter of 2002-2003, 54 cattle from an endemic site in northern colorado were ... | 2004 | 20422579 |
| homogeneity of powassan virus populations in naturally infected ixodes scapularis. | powassan virus (powv, flaviviridae: flavivirus) is the sole north american member of the tick-borne encephalitis complex and consists of two distinct lineages that are maintained in ecologically discrete enzootic transmission cycles. the underlying genetic mechanisms that lead to niche partitioning in arboviruses are poorly understood. therefore, intra- and interhost genetic diversity was analyzed to determine if powv exists as a quasispecies in nature and quantify selective pressures within and ... | 2010 | 20434750 |
| aedes aegypti saliva alters leukocyte recruitment and cytokine signaling by antigen-presenting cells during west nile virus infection. | west nile virus (wnv) is transmitted during mosquito bloodfeeding. consequently, the first vertebrate cells to contact wnv are cells in the skin, followed by those in the draining lymph node. macrophages and dendritic cells are critical early responders in host defense against wnv infection, not just because of their role in orchestrating the immune response, but also because of their importance as sites of early peripheral viral replication. antigen-presenting cell (apc) signals have a profound ... | 2010 | 20661470 |
| effects of ivermectin on the susceptibility of culicoides sonorensis (diptera: ceratopogonidae) to bluetongue and epizootic hemorrhagic disease viruses. | | 2009 | 20836819 |
| rt-pcr assays for seven serotypes of epizootic haemorrhagic disease virus & their use to type strains from the mediterranean region and north america. | epizootic haemorrhagic disease virus (ehdv) infects wild ruminants, causing a frequently fatal haemorrhagic disease. however, it can also cause bluetongue-like disease in cattle, involving significant levels of morbidity and mortality, highlighting a need for more rapid and reliable diagnostic assays. ehdv outer-capsid protein vp2 (encoded by genome-segment 2 [seg-2]) is highly variable and represents the primary target for neutralising antibodies generated by the mammalian host. consequently vp ... | 2010 | 20862243 |
| climate, landscape, and the risk of orbivirus exposure in cattle in illinois and western indiana. | climate and environmental data were used to estimate the risk of testing positive for antibodies to bluetongue (btv) and epizootic hemorrhagic disease viruses (ehdv) in cattle in illinois and western indiana over three transmission seasons (2000-2002). the risks of btv and ehdv seropositivity were positively associated with temperature during every year of the study. the ehdv seropositivity was also positively associated with forest patchiness in two of the years. during 2002, a year with unusua ... | 2010 | 20889866 |
| potential for north american mosquitoes (diptera: culicidae) to transmit rift valley fever virus. | to determine which arthropods should be targeted for control should rift valley fever virus (rvfv) be detected in north america, we evaluated culex erraticus (dyar and knab), culex erythrothorax dyar, culex nigripalpus theobald, culex pipiens l., culex quinquefasciatus say, culex tarsalis coquillett, aedes dorsalis (wiedemann), aedes vexans (meigen), anopheles quadrimaculatus say, and culicoides sonorensis wirth and jones from the western, midwestern, and southern united states for their ability ... | 2010 | 20939385 |
| control of culicoides sonorensis (diptera: ceratopogonidae) blood feeding on sheep with long-lasting repellent pesticides. | culicoides sonorensis is the primary vector of bluetongue and epizootic hemorrhagic disease viruses in north america. bluetongue disease is one of the most economically important arthropod-borne diseases of sheep in north america, because it causes significant morbidity and mortality and can lead to local quarantines and international trade restrictions. long-lasting repellent pesticides could be applied to sheep as they are moved down from mountain pastures to protect them from biting midges un ... | 2010 | 21033057 |
| multiple serotypes of bluetongue virus in sheep and cattle, israel. | | 2010 | 21122245 |
| global analysis of the transcriptional response of whitefly to tomato yellow leaf curl china virus reveals the relationship of coevolved adaptations. | the begomoviruses are the largest and most economically important group of plant viruses transmitted exclusively by the whitefly bemisia tabaci in a circulative, persistent manner. the circulation of the viruses within the insect vectors involves complex interactions between virus and vector components; however, the molecular mechanisms of these interactions remain largely unknown. here we investigated the transcriptional response of the invasive b. tabaci middle east-asia minor 1 species to tom ... | 2011 | 21270146 |
| saliva proteins of vector culicoides modify structure and infectivity of bluetongue virus particles. | bluetongue virus (btv) and epizootic haemorrhagic disease virus (ehdv) are related orbiviruses, transmitted between their ruminant hosts primarily by certain haematophagous midge vectors (culicoides spp.). the larger of the btv outer-capsid proteins, 'vp2', can be cleaved by proteases (including trypsin or chymotrypsin), forming infectious subviral particles (isvp) which have enhanced infectivity for adult culicoides, or kc cells (a cell-line derived from c. sonorensis). we demonstrate that vp2 ... | 2011 | 21423801 |