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Michael J. Turell - One of the best experts on this subject based on the ideXlab platform.
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Effect of Environmental Temperature on the Ability of Culex tarsalis and Aedes taeniorhynchus (Diptera: Culicidae) to Transmit Rift Valley Fever Virus.
Vector borne and zoonotic diseases (Larchmont N.Y.), 2020Co-Authors: Michael J. Turell, Lee W. Cohnstaedt, William C. WilsonAbstract:Rift Valley fever virus (RVFV) causes severe disease in domestic ungulates (cattle, goats, and sheep) and a febrile illness in humans (with ∼1% case fatality rate). This virus has been spreading geographically, and there is concern of it spreading to Europe or the Americas. Environmental temperature can significantly affect the ability of mosquitoes to transmit an arbovirus. However, these effects are not consistent among viruses or mosquito species. Therefore, we evaluated the effect of incubation temperatures ranging from 14°C to 30°C on infection and dissemination rates for Culex tarsalis and Aedes taeniorhynchus allowed to feed on hamsters infected with RVFV. Engorged mosquitoes were randomly allocated to cages and placed in incubators maintained at 14°C, 18°C, 22°C, 26°C, or 30°C. Although infection rates detected in Cx. tarsalis increased with increasing holding temperature, holding temperature had no effect on infection rates detected in Ae. taeniorhynchus. However, for both species, the percentage of mosquitoes with a disseminated infection after specific extrinsic incubation periods (4, 7, 10, 14, 17, or 21 days) increased with increasing incubation holding temperature, even after adjusting for the apparent increase in infection rate in Cx. tarsalis. The effects of environmental factors, such as ambient temperature, need to be taken into account when developing models for viral persistence and spread in nature.
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Mosquito survival, comparative infection rates, and estimated amount of virus delivered into the hemocoel of mosquitoes during trials comparing the kinetics of viral dissemination in Aedes taeniorhynchus mosquitoes infected per os on a dually-infecte
2017Co-Authors: Jefferson A. Vaughan, Michael J. TurellAbstract:Mosquito survival, comparative infection rates, and estimated amount of virus delivered into the hemocoel of mosquitoes during trials comparing the kinetics of viral dissemination in Aedes taeniorhynchus mosquitoes infected per os on a dually-infected gerbil with concurrent Venezuelan equine encephalitis virus viremia and Brugia malayi microfilaremia (VEEV + mf) versus mosquitoes injected with Venezuelan equine encephalitis virus directly into the thorax (VEEV inoc.).
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Comparative growth kinetics of Venezuelan equine encephalitis virus in Aedes taeniorhynchus mosquitoes when virus is introduced into the hemocoel via direct inoculation (VEE inoc.) versus Brugia malayi microfilarial passage through the midgut (VEE +
2017Co-Authors: Jefferson A. Vaughan, Michael J. TurellAbstract:Comparative growth kinetics of Venezuelan equine encephalitis virus in Aedes taeniorhynchus mosquitoes when virus is introduced into the hemocoel via direct inoculation (VEE inoc.) versus Brugia malayi microfilarial passage through the midgut (VEE + mf).
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Effect of environmental temperature on the vector competence of Aedes taeniorhynchus for Rift Valley fever and Venezuelan equine encephalitis viruses.
The American journal of tropical medicine and hygiene, 1993Co-Authors: Michael J. TurellAbstract:Studies were conducted to determine the effect of environmental temperature on the susceptibility of Aedes taeniorhynchus mosquitoes for Venezuelan equine encephalitis (VEE) and Rift Valley fever (RVF) viruses. Mosquitoes reared at low temperature (19 degrees C) were significantly more susceptible to infection with RVF virus (infection rate = 70%, 158 of 226) than were those mosquitoes reared at 26 degrees C (infection rate = 48%, 135 of 280), regardless of the temperature at which mosquitoes were held after exposure to virus (19 or 26 degrees C). Likewise, for Ae. taeniorhynchus exposed to VEE virus, the infection rate in mosquitoes reared at low temperature (97%, 236 of 243) was significantly greater than was that for mosquitoes reared at 26 degrees C (78%, 217 of 280), regardless of the temperature at which mosquitoes were held after exposure to virus (19 or 26 degrees C). Conversely, in mosquitoes infected with either RVF or VEE virus, virus disseminated from the midgut to the hemocoel more rapidly in mosquitoes held at 26 degrees C than in those held at 19 degrees C, regardless of the rearing temperature. Thus, a combination of low larval-rearing temperature and warm adult-holding temperature resulted in the most efficient mosquito transmission of both viruses.
Scott C. Weaver - One of the best experts on this subject based on the ideXlab platform.
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venezuelan equine encephalitis virus in the mosquito vector Aedes taeniorhynchus infection initiated by a small number of susceptible epithelial cells and a population bottleneck
Virology, 2008Co-Authors: D Smith, Paige A Adams, Joan L Kenney, Eryu Wang, Scott C. WeaverAbstract:We evaluated infection of Aedes taeniorhynchus mosquitoes, vectors of Venezuelan equine encephalitis virus (VEEV), using radiolabeled virus and replicon particles expressing green (GFP) or cherry fluorescent protein (CFP). More epidemic VEEV bound to and infected mosquito midguts compared to an enzootic strain, and a small number of midgut cells was preferentially infected. Chimeric replicons infected midgut cells at rates comparable to those of the structural gene donor. The numbers of midgut cells infected averaged 28, and many infections were initiated in only 1-5 cells. Infection by a mixture of GFP- and CFP-expressing replicons indicated that only about 100 midgut cells were susceptible. Intrathoracic injections yielded similar patterns of replication with both VEEV strains, suggesting that midgut infection is the primary limitation to transmission. These results indicate that the structural proteins determine initial infection of a small number of midgut cells, and that VEEV undergoes population bottlenecks during vector infection.
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Infection and dissemination of Venezuelan equine encephalitis virus in the epidemic mosquito vector, Aedes taeniorhynchus.
The American journal of tropical medicine and hygiene, 2007Co-Authors: Darci R. Smith, Nicole C. Arrigo, Grace Leal, Linda E. Muehlberger, Scott C. WeaverAbstract:The mosquito Aedes taeniorhynchus is an important epidemic vector of Venezuelan equine encephalitis virus (VEEV), but detailed studies of its infection are lacking. We compared infection by an epidemic VEEV strain to that by an enzootic strain using virus titrations, immunohistochemistry, and a virus expressing the green fluorescent protein. Ae. taeniorhynchus was more susceptible to the epidemic strain, which initially infected the posterior midgut and occasionally the anterior midgut and cardia. Once dissemination beyond the midgut occurred, virus was present in nearly all tissues. Transmission of the epidemic strain to mice was first detected 4 days after infection. In contrast, the enzootic strain did not efficiently infect midgut cells but replicated in muscles and nervous tissue on dissemination. Because VEEV emergence can depend on adaptation to epidemic vectors, these results show that epidemic/enzootic strain comparisons not only comprise a useful model system to study alphavirus transmission by mosquitoes, but also have important public health implications.
William C. Wilson - One of the best experts on this subject based on the ideXlab platform.
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Effect of Environmental Temperature on the Ability of Culex tarsalis and Aedes taeniorhynchus (Diptera: Culicidae) to Transmit Rift Valley Fever Virus.
Vector borne and zoonotic diseases (Larchmont N.Y.), 2020Co-Authors: Michael J. Turell, Lee W. Cohnstaedt, William C. WilsonAbstract:Rift Valley fever virus (RVFV) causes severe disease in domestic ungulates (cattle, goats, and sheep) and a febrile illness in humans (with ∼1% case fatality rate). This virus has been spreading geographically, and there is concern of it spreading to Europe or the Americas. Environmental temperature can significantly affect the ability of mosquitoes to transmit an arbovirus. However, these effects are not consistent among viruses or mosquito species. Therefore, we evaluated the effect of incubation temperatures ranging from 14°C to 30°C on infection and dissemination rates for Culex tarsalis and Aedes taeniorhynchus allowed to feed on hamsters infected with RVFV. Engorged mosquitoes were randomly allocated to cages and placed in incubators maintained at 14°C, 18°C, 22°C, 26°C, or 30°C. Although infection rates detected in Cx. tarsalis increased with increasing holding temperature, holding temperature had no effect on infection rates detected in Ae. taeniorhynchus. However, for both species, the percentage of mosquitoes with a disseminated infection after specific extrinsic incubation periods (4, 7, 10, 14, 17, or 21 days) increased with increasing incubation holding temperature, even after adjusting for the apparent increase in infection rate in Cx. tarsalis. The effects of environmental factors, such as ambient temperature, need to be taken into account when developing models for viral persistence and spread in nature.
Felio J Bello - One of the best experts on this subject based on the ideXlab platform.
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estudios comparativos del ciclo de vida del mosquito Aedes taeniorhynchus diptera culicidae de dos colonias de la costa atlantica colombiana
Biomedica, 1996Co-Authors: Claribell Hernandez, Víctor Alberto Olano, Felio J Bello, Felisa Duran, Cristina FerroAbstract:This pilot study was carried out in the laboratory to establish whether the Aedes taeniorhynchus mosquito, found in Cartagena and Barranquilla, is really a single strain and if the colonisation process (cultured in the laboratory) influences the time taken in the developmental stages of this dipthera's life cycle. Colonies were established with adult mosquitoes, both males and females, collected from sites close to the cities of Cartagena and Barranquilla.The insects were taxonomically identified and placed in Gerberg jars into which cupfuls of humid earth were introduced so that oviposition could take place. Six continuous generations were kept at an average temperature of 27°C and 80% average relative humidity. lmmature forms were fed with minced Ken-L; sugar solution was given to adults of both sexes and females were given a guinea pig to provide their blood intake. The duration of each stage of the biological cycle for each generation was recorded and these were analysed by means of the t-test for comparison of averages of independent samples. For larva (t=1 .SI) and pupa (k0.30) duration time for the two mosquito populations no significant differences were found; however, hatching time, when it occurred, was k4.21. No significant differences were found for pupa or for larva hatching duration time for the six generations of mosquito from Cartagena, but when significant differences in larval stage duration time were presented, they occurred from the fourth generation onwards. This pilot study's results suggest that the Aedes taeniorhynchus mosquito from Cartagena and Barranquilla represents a sole species. Furthermore, it shows that its colonisation process, being that which involves the adaptation of this insect to the special conditions and have an influence on the duration of its biological cycle.
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caracteristicas de una linea celular de crecimiento continuo de Aedes taeniorhynchus diptera culicidae
Biomedica, 1996Co-Authors: Felio J Bello, Gloria Rey, Alberto Morales, Víctor Alberto Olano, Jaime A Rodriguez, Jorge Boschell, William RamirezAbstract:A new cell line was established, LSB-AT793, from the embryonic tissues of the mosquito Aedes taeniorhynchus. The first subculture was iniciated in July 1993. Up to the present, October 1995, 360 passages have been performed. The culture media used for cell growth and maintenance was MMNP12, with a pH of 6.8 and a temperature of 28°C. The majority of cells in the confluent monolayers were epithelial-like. The characteristics of the karyotype species were recognized and the G and C-banding patterns were established. Also, the isoenzyme profiles of the cell line, using four differents systems, PGI, PGM, MPI and 6-PGDH, were determined which coincide with the isoenzyme patterns derived from pupae extracts. The isoenzyme profiles of this cell line was compared with the isoenzyme phenotype of Anopheles albimanus and with the clone C6136. It was shown that cells are free of bacteria and fungi. The frozen technique in liquid nitrogen was standarized. This technique has allowed the storage of a variety of subcultures in different passages.
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Características de una línea celular de crecimiento continuo de Aedes taeniorhynchus (Diptera: Culicidae)
Instituto Nacional de Salud, 1996Co-Authors: Felio J Bello, Gloria Rey, Alberto Morales, Jaime A Rodriguez, Jorge Boschell, Víctor A. Olano, William RamirezAbstract:Se estableció una nueva línea celular, LSB-AT0793, a partir de tejidos embrionarios del mosquito Aedes taeniorhynchus. El primer subcultivo se inició en julio de 1993 y hasta la fecha, octubre de 1995, se han efectuado 360 pases. El medio de cultivo utilizado para el crecimiento y mantenimiento de las células fue MMNP12, con un pH de 6,8 y una temperatura promedio de 28°C. La mayoría de las células en las monocapas confluentes fueron de formas epitelioides. Se reconocieron las características del cariotipo de la especie y se establecieron los patrones de bandas C y G. Se determinaron los perfiles isoenzimáticos de la línea celular, utilizando cuatro sistemas diferentes: PGI, PGM, MPI y 6-PGDH, los cuales coincidieron con los patrones obtenidos a partir de extractos de pupas de la especie. También, se compararon los perfiles isoenzimáticos de la presente Iínea celular con los de Anopheles albimanus y con los del clon C6136. Se demostró que las células están libres de bacterias y hongos. Se estandarizó la técnica de congelación en nitrógeno líquido en donde se mantienen varios subcultivos en diferentes pases
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Estudios comparativos del ciclo de vida del mosquito Aedes taeniorhynchus (Diptera: culicidae) de dos colonias de la costa atlántica colombiana
Instituto Nacional de Salud, 1996Co-Authors: Claribell Hernandez, Felio J Bello, Víctor A. Olano, Felisa Duran, Cristina FerroAbstract:Este estudio se realizó con el propósito de establecer, en forma preliminar, en el laboratorio, si el mosquito Aedes taeniorhynchus procedente de Barranquilla y Cartagena es realmente una sola cepa y si el proceso de colonización (cría en el laboratorio) influye en el tiempo de duración de las etapas de desarrollo del ciclo de vida de este díptero. Las colonias se establecieron con mosquitos adultos, machos y hembras, recolectados en lugares cercanos a Barranquilla y Cartagena. Los insectos se identificaron taxonómicamente y se colocaron en jaulas Gerberg, en las que se introdujeron tazas con tierra húmeda para que las hembras ovipositaran. De cada localidad, se mantuvieron seis generaciones continuas a una temperatura promedio de 27°C y una humedad relativa promedio de 80%. Los estadios inmaduros se alimentaron con Ken-L molido; los adultos de los dos sexos, con solución azucarada y a las hembras se les colocó un curí para que tomaran su comida de sangre. Se registraron los tiempos de duración de cada etapa del ciclo biológico en cada una de las generaciones y se analizaron por medio de la prueba t de comparación de promedios para muestras independientes. Para los tiempos de duración de larva (t=1,51) y pupa (t=0,30) de las dos poblaciones del mosquito, no se encontraron diferencias significativas; sin embargo, para el tiempo de eclosión de la larva sí las hubo (t=4,21). Al relacionar las seis generaciones de Cartagena no se encontraron diferencias significativas para el tiempo de duración de pupa y eclosión de la larva, pero sí se presentaron a partir de la cuarta generación, para el tiempo de duración de los estadios larvarios. Los resultados de este estudio preliminar sugieren que el mosquito Aedes taeniorhynchus de Barranquilla y Cartagena representa una sola especie. Se demostró, además, que su proceso de colonización, el cual involucra la adaptación de este insecto a las condiciones específicas de un insectario, influye en la duración de su ciclo biológico
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evaluacion de tres tecnicas citogeneticas diferentes en los estudios morfometricos del carioti po de Aedes taeniorhynchus di ptera culicidae
Biomedica, 1995Co-Authors: Felio J Bello, Gloria Rey, Alberto Morales, Víctor Alberto Olano, Jorge Boschell, Felisa DuranAbstract:Morphometric studies of the Aedes taeniorhynchus mosquito karyotype are of veterinary medical interest because this mosquito is a vector of epidemo-epizootic Venezuelan equine encephalitis. Three different cytogenetic techniques were used for chromosome preparation: squash, air-drying and cell culture. These three techniques were compared to each other to evaluate the obtained metaphases' chromosome length and morphology. The diploid number of the species was 6 in al1 the cariological preparations when any one of the three procedures was used. However, with the squash technique, brain-cell mytotic chromosomes were shorter, discontinuous and had less apparent grades of chromatin compaction. When air-drying was used, better cytological extensions were obtained, the chromosomes being more separated and of a slightly greater length. The best resolution was obtained using ceil culture because of the structure and separation of chromosome homology and length.
Lee W. Cohnstaedt - One of the best experts on this subject based on the ideXlab platform.
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Effect of Environmental Temperature on the Ability of Culex tarsalis and Aedes taeniorhynchus (Diptera: Culicidae) to Transmit Rift Valley Fever Virus.
Vector borne and zoonotic diseases (Larchmont N.Y.), 2020Co-Authors: Michael J. Turell, Lee W. Cohnstaedt, William C. WilsonAbstract:Rift Valley fever virus (RVFV) causes severe disease in domestic ungulates (cattle, goats, and sheep) and a febrile illness in humans (with ∼1% case fatality rate). This virus has been spreading geographically, and there is concern of it spreading to Europe or the Americas. Environmental temperature can significantly affect the ability of mosquitoes to transmit an arbovirus. However, these effects are not consistent among viruses or mosquito species. Therefore, we evaluated the effect of incubation temperatures ranging from 14°C to 30°C on infection and dissemination rates for Culex tarsalis and Aedes taeniorhynchus allowed to feed on hamsters infected with RVFV. Engorged mosquitoes were randomly allocated to cages and placed in incubators maintained at 14°C, 18°C, 22°C, 26°C, or 30°C. Although infection rates detected in Cx. tarsalis increased with increasing holding temperature, holding temperature had no effect on infection rates detected in Ae. taeniorhynchus. However, for both species, the percentage of mosquitoes with a disseminated infection after specific extrinsic incubation periods (4, 7, 10, 14, 17, or 21 days) increased with increasing incubation holding temperature, even after adjusting for the apparent increase in infection rate in Cx. tarsalis. The effects of environmental factors, such as ambient temperature, need to be taken into account when developing models for viral persistence and spread in nature.
