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Donald P Knowles - One of the best experts on this subject based on the ideXlab platform.
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Conservation of Transmission Phenotype of Anaplasma marginale (Rickettsiales: Anaplasmataceae) Strains Among Dermacentor and Rhipicephalus Ticks (Acari: Ixodidae)
Journal of medical entomology, 2007Co-Authors: Glen A Scoles, Massaro W Ueti, Donald P Knowles, Susan M. Noh, Guy H. PalmerAbstract:Abstract Before the eradication of Boophilus ticks from the United States, Rhipicephalus (Boophilus) microplus (Canestrini) and Rhipicephalus (Boophilus) annulatus (Say) were important biological vectors of the cattle pathogen Anaplasma marginale Theiler. In the absence of Boophilus ticks, A. marginale continues to be transmitted by Dermacentor ticks. However, a few U.S. strains are not transmissible by Dermacentor andersoni Stiles, Dermacentor variabilis (Say), or both, raising the question of how these strains evolved and how they are maintained. We hypothesize that the U.S. non-Dermacentor-transmissible strains of A. marginale were formerly Boophilus-transmitted strains that have been maintained by a combination of persistent infection and mechanical transmission since the eradication of their biological vector from the United States. To test this hypothesis, we attempted to transmit a well-documented non-Dermacentor-transmissible A. marginale strain (Florida), by using D. andersoni and the two Boophil...
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transovarial transmission efficiency of babesia bovis tick stages acquired by rhipicephalus Boophilus microplus during acute infection
Journal of Clinical Microbiology, 2007Co-Authors: Jeanne M Howell, Massaro W Ueti, Glen A Scoles, Guy H. Palmer, Donald P KnowlesAbstract:The protozoan parasite Babesia bovis, a reemerging threat to U.S. cattle, is acquired by adult female ticks of the subgenus Boophilus and is transovarially transmitted as the kinete stage to developing larval offspring. Sporozoites develop within larvae and are transmitted during larval feeding on a bovine host. This study evaluated the efficiency of B. bovis infection within Rhipicephalus (Boophilus) microplus following acquisition feeding on acutely parasitemic cattle. Parasite levels were quantified in blood from experimentally infected cattle and within hemolymph and larvae derived from acquisition-fed female B. microplus. There was a positive correlation between blood parasite levels in acutely parasitemic cattle and kinete levels in the hemolymph of adult female Boophilus ticks following acquisition feeding; however, there was no relationship between kinete levels in females and infection rates of larval progeny. Boophilus microplus females that acquisition fed produced larval progeny with infection rates of 12% to 48%. Importantly, larvae derived from replete females with very low levels of kinete infection, as demonstrated by microscopy and PCR, had infection rates of 22% to 30% and transmitted B. bovis during transmission feeding. These data demonstrate that although hemolymph infection may be undetectable, transmission to larval progeny occurs at a level which ensures transmission to the bovine host.
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Expression of Equi Merozoite Antigen 2 during Development of Babesia equi in the Midgut and Salivary Gland of the Vector Tick Boophilus microplus
Journal of clinical microbiology, 2003Co-Authors: Massaro W Ueti, Glen A Scoles, Guy H. Palmer, Lowell S. Kappmeyer, Donald P KnowlesAbstract:Equi merozoite antigens 1 and 2 (EMA-1 and EMA-2) are Babesia equi proteins expressed on the parasite surface during infection in horses and are orthologues of proteins in Theileria spp., which are also tick-transmitted protozoal pathogens. We determined in this study whether EMA-1 and EMA-2 were expressed within the vector tick Boophilus microplus. B. equi transitions through multiple, morphologically distinct stages, including sexual stages, and these transitions culminate in the formation of infectious sporozoites in the tick salivary gland. EMA-2-positive B. equi stages in the midgut lumen and midgut epithelial cells of Boophilus microplus nymphs were identified by reactivity with monoclonal antibody 36/253.21. This monoclonal antibody also recognized B. equi in salivary glands of adult Boophilus microplus. In addition, quantification of B. equi in the mammalian host and vector tick indicated that the duration of tick feeding and parasitemia levels affected the percentage of nymphs that contained morphologically distinct B. equi organisms in the midgut. In contrast, there was no conclusive evidence that B. equi EMA-1 was expressed in either the Boophilus microplus midgut or salivary gland when monoclonal antibody 36/18.57 was used. The expression of B. equi EMA-2 in Boophilus microplus provides a marker for detecting the various development stages and facilitates the identification of novel stage-specific Babesia proteins for testing transmission-blocking immunity.
Guy H. Palmer - One of the best experts on this subject based on the ideXlab platform.
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Conservation of Transmission Phenotype of Anaplasma marginale (Rickettsiales: Anaplasmataceae) Strains Among Dermacentor and Rhipicephalus Ticks (Acari: Ixodidae)
Journal of medical entomology, 2007Co-Authors: Glen A Scoles, Massaro W Ueti, Donald P Knowles, Susan M. Noh, Guy H. PalmerAbstract:Abstract Before the eradication of Boophilus ticks from the United States, Rhipicephalus (Boophilus) microplus (Canestrini) and Rhipicephalus (Boophilus) annulatus (Say) were important biological vectors of the cattle pathogen Anaplasma marginale Theiler. In the absence of Boophilus ticks, A. marginale continues to be transmitted by Dermacentor ticks. However, a few U.S. strains are not transmissible by Dermacentor andersoni Stiles, Dermacentor variabilis (Say), or both, raising the question of how these strains evolved and how they are maintained. We hypothesize that the U.S. non-Dermacentor-transmissible strains of A. marginale were formerly Boophilus-transmitted strains that have been maintained by a combination of persistent infection and mechanical transmission since the eradication of their biological vector from the United States. To test this hypothesis, we attempted to transmit a well-documented non-Dermacentor-transmissible A. marginale strain (Florida), by using D. andersoni and the two Boophil...
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transovarial transmission efficiency of babesia bovis tick stages acquired by rhipicephalus Boophilus microplus during acute infection
Journal of Clinical Microbiology, 2007Co-Authors: Jeanne M Howell, Massaro W Ueti, Glen A Scoles, Guy H. Palmer, Donald P KnowlesAbstract:The protozoan parasite Babesia bovis, a reemerging threat to U.S. cattle, is acquired by adult female ticks of the subgenus Boophilus and is transovarially transmitted as the kinete stage to developing larval offspring. Sporozoites develop within larvae and are transmitted during larval feeding on a bovine host. This study evaluated the efficiency of B. bovis infection within Rhipicephalus (Boophilus) microplus following acquisition feeding on acutely parasitemic cattle. Parasite levels were quantified in blood from experimentally infected cattle and within hemolymph and larvae derived from acquisition-fed female B. microplus. There was a positive correlation between blood parasite levels in acutely parasitemic cattle and kinete levels in the hemolymph of adult female Boophilus ticks following acquisition feeding; however, there was no relationship between kinete levels in females and infection rates of larval progeny. Boophilus microplus females that acquisition fed produced larval progeny with infection rates of 12% to 48%. Importantly, larvae derived from replete females with very low levels of kinete infection, as demonstrated by microscopy and PCR, had infection rates of 22% to 30% and transmitted B. bovis during transmission feeding. These data demonstrate that although hemolymph infection may be undetectable, transmission to larval progeny occurs at a level which ensures transmission to the bovine host.
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Expression of Equi Merozoite Antigen 2 during Development of Babesia equi in the Midgut and Salivary Gland of the Vector Tick Boophilus microplus
Journal of clinical microbiology, 2003Co-Authors: Massaro W Ueti, Glen A Scoles, Guy H. Palmer, Lowell S. Kappmeyer, Donald P KnowlesAbstract:Equi merozoite antigens 1 and 2 (EMA-1 and EMA-2) are Babesia equi proteins expressed on the parasite surface during infection in horses and are orthologues of proteins in Theileria spp., which are also tick-transmitted protozoal pathogens. We determined in this study whether EMA-1 and EMA-2 were expressed within the vector tick Boophilus microplus. B. equi transitions through multiple, morphologically distinct stages, including sexual stages, and these transitions culminate in the formation of infectious sporozoites in the tick salivary gland. EMA-2-positive B. equi stages in the midgut lumen and midgut epithelial cells of Boophilus microplus nymphs were identified by reactivity with monoclonal antibody 36/253.21. This monoclonal antibody also recognized B. equi in salivary glands of adult Boophilus microplus. In addition, quantification of B. equi in the mammalian host and vector tick indicated that the duration of tick feeding and parasitemia levels affected the percentage of nymphs that contained morphologically distinct B. equi organisms in the midgut. In contrast, there was no conclusive evidence that B. equi EMA-1 was expressed in either the Boophilus microplus midgut or salivary gland when monoclonal antibody 36/18.57 was used. The expression of B. equi EMA-2 in Boophilus microplus provides a marker for detecting the various development stages and facilitates the identification of novel stage-specific Babesia proteins for testing transmission-blocking immunity.
Ronald B Davey - One of the best experts on this subject based on the ideXlab platform.
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distribution of rhipicephalus Boophilus microplus and rhipicephalus Boophilus annulatus acari ixodidae infestations detected in the united states along the texas mexico border
Journal of Medical Entomology, 2011Co-Authors: Kimberly H Lohmeyer, J M Pound, D M Kammlah, Ronald B DaveyAbstract:Species identification and global positioning system coordinates of infestations of cattle fever ticks, Rhipicephalus (Boophilus) annulatus (Say) and Rhipicephalus (Boophilus) microplus (Canestrini), were determined for 790 specimens submitted to the National Veterinary Services Laboratory between 1 October 1999 and 30 September 2010. Cattle fever tick specimens obtained by personnel of the United States Department of Agriculture-Animal and Plant Health Inspection Service-Cattle Fever Tick Eradication Program from infested cattle and wildlife along the Texas/ Mexico border were submitted for identification, as required by the program. A geographic information system database was developed that incorporates location, collection, and infestation records. Submitted ticks came from 11 Texas counties and were comprised of 19.5% R. (B.) annulatus and 80.5% R. (B.) microplus. Maps produced from this study locate and define the parapatric boundary between R. (B.) annulatus and R. (B.) microplus.
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Test for assortative mating between Boophilus microplus and Boophilus annulatus (Acari: Ixodidae).
Journal of medical entomology, 1992Co-Authors: Larry R. Hilburn, Ronald B DaveyAbstract:The closely related cattle ticks, Boophilus microplus (Canestrini) and B. annulatus (Say), were tested for possible assortative mating under conditions designed to mimic those in the field. Patterns in the numbers of the four possible types of matings were generally indicative of a preference for conspecific mates in both species. There were significantly more conspecific and fewer interspecific matings than would be predicted from the observed frequencies of males and females among the two species had they mated at random.
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Computer simulation of Boophilus cattle tick (Acari: Ixodidae) population dynamics.
Journal of medical entomology, 1991Co-Authors: G. A. Mount, Ronald B Davey, D. G. Haile, L. M. CookseyAbstract:A comprehensive computer model was developed for simulation of the population dynamics of the cattle ticks, Boophilus microplus (Canestrini) and B. annulatus (Say). The model is deterministic and based on a dynamic life table with weekly time steps. The model simulates the effects of major environmental variables, such as ambient temperature, saturation deficit, precipitation, type of pasture, type of cattle, and cattle density on Boophilus cattle tick population dynamics. General validity of the model is established by comparing simulated and observed yearly densities of standard female ticks/host/day. B. microplus population comparisons were made for a series of years using weekly weather data from two locations in Queensland, Australia. The model also produced acceptable values for initial population growth rate, generation time, and 3-yr population density when historical weather at 7 locations in Australia and 23 locations in the Americas were used. This model provides a framework for the study of Babesia transmission by Boophilus ticks, and can be used to study the effects of control technologies and to develop more efficient and environmentally acceptable eradication strategies for Boophilus ticks.
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Survival of larvae of Boophilus annulatus, Boophilus microplus, and Boophilus hybrids (acari: ixodidae) in different temperature and humidity regimes in the laboratory
Veterinary parasitology, 1991Co-Authors: Ronald B Davey, Lynita M. Cooksey, Joseph L. DespinsAbstract:Abstract The survival period for larvae of Boophilus annulatus (Say), Boophilus microplus (Canestrini) and hybridized Boophilus ticks was determined by exposure to various combinations of temperature (20, 25, 30 and 35°C) and relative humidity (32, 63, 75, 84 and 97% RH) in the laboratory. Results indicated that within a given temperature and RH regime, there was no difference ( P > 0.05) in larval survival among the three species tested, indicating that these ticks respond similarly over a wide range of temperature and RH combinations. Larval survival in all three species was longest ( P P P > 0.05) was observed among the treatment regimes included. Results suggest that at a RH of 75% and more, the temperature is the determining factor in larval survival, whereas at a RH of 63% and less the RH is the determining factor in larval survival, regardless of temperature.
Glen A Scoles - One of the best experts on this subject based on the ideXlab platform.
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Conservation of Transmission Phenotype of Anaplasma marginale (Rickettsiales: Anaplasmataceae) Strains Among Dermacentor and Rhipicephalus Ticks (Acari: Ixodidae)
Journal of medical entomology, 2007Co-Authors: Glen A Scoles, Massaro W Ueti, Donald P Knowles, Susan M. Noh, Guy H. PalmerAbstract:Abstract Before the eradication of Boophilus ticks from the United States, Rhipicephalus (Boophilus) microplus (Canestrini) and Rhipicephalus (Boophilus) annulatus (Say) were important biological vectors of the cattle pathogen Anaplasma marginale Theiler. In the absence of Boophilus ticks, A. marginale continues to be transmitted by Dermacentor ticks. However, a few U.S. strains are not transmissible by Dermacentor andersoni Stiles, Dermacentor variabilis (Say), or both, raising the question of how these strains evolved and how they are maintained. We hypothesize that the U.S. non-Dermacentor-transmissible strains of A. marginale were formerly Boophilus-transmitted strains that have been maintained by a combination of persistent infection and mechanical transmission since the eradication of their biological vector from the United States. To test this hypothesis, we attempted to transmit a well-documented non-Dermacentor-transmissible A. marginale strain (Florida), by using D. andersoni and the two Boophil...
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transovarial transmission efficiency of babesia bovis tick stages acquired by rhipicephalus Boophilus microplus during acute infection
Journal of Clinical Microbiology, 2007Co-Authors: Jeanne M Howell, Massaro W Ueti, Glen A Scoles, Guy H. Palmer, Donald P KnowlesAbstract:The protozoan parasite Babesia bovis, a reemerging threat to U.S. cattle, is acquired by adult female ticks of the subgenus Boophilus and is transovarially transmitted as the kinete stage to developing larval offspring. Sporozoites develop within larvae and are transmitted during larval feeding on a bovine host. This study evaluated the efficiency of B. bovis infection within Rhipicephalus (Boophilus) microplus following acquisition feeding on acutely parasitemic cattle. Parasite levels were quantified in blood from experimentally infected cattle and within hemolymph and larvae derived from acquisition-fed female B. microplus. There was a positive correlation between blood parasite levels in acutely parasitemic cattle and kinete levels in the hemolymph of adult female Boophilus ticks following acquisition feeding; however, there was no relationship between kinete levels in females and infection rates of larval progeny. Boophilus microplus females that acquisition fed produced larval progeny with infection rates of 12% to 48%. Importantly, larvae derived from replete females with very low levels of kinete infection, as demonstrated by microscopy and PCR, had infection rates of 22% to 30% and transmitted B. bovis during transmission feeding. These data demonstrate that although hemolymph infection may be undetectable, transmission to larval progeny occurs at a level which ensures transmission to the bovine host.
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Expression of Equi Merozoite Antigen 2 during Development of Babesia equi in the Midgut and Salivary Gland of the Vector Tick Boophilus microplus
Journal of clinical microbiology, 2003Co-Authors: Massaro W Ueti, Glen A Scoles, Guy H. Palmer, Lowell S. Kappmeyer, Donald P KnowlesAbstract:Equi merozoite antigens 1 and 2 (EMA-1 and EMA-2) are Babesia equi proteins expressed on the parasite surface during infection in horses and are orthologues of proteins in Theileria spp., which are also tick-transmitted protozoal pathogens. We determined in this study whether EMA-1 and EMA-2 were expressed within the vector tick Boophilus microplus. B. equi transitions through multiple, morphologically distinct stages, including sexual stages, and these transitions culminate in the formation of infectious sporozoites in the tick salivary gland. EMA-2-positive B. equi stages in the midgut lumen and midgut epithelial cells of Boophilus microplus nymphs were identified by reactivity with monoclonal antibody 36/253.21. This monoclonal antibody also recognized B. equi in salivary glands of adult Boophilus microplus. In addition, quantification of B. equi in the mammalian host and vector tick indicated that the duration of tick feeding and parasitemia levels affected the percentage of nymphs that contained morphologically distinct B. equi organisms in the midgut. In contrast, there was no conclusive evidence that B. equi EMA-1 was expressed in either the Boophilus microplus midgut or salivary gland when monoclonal antibody 36/18.57 was used. The expression of B. equi EMA-2 in Boophilus microplus provides a marker for detecting the various development stages and facilitates the identification of novel stage-specific Babesia proteins for testing transmission-blocking immunity.
Massaro W Ueti - One of the best experts on this subject based on the ideXlab platform.
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Conservation of Transmission Phenotype of Anaplasma marginale (Rickettsiales: Anaplasmataceae) Strains Among Dermacentor and Rhipicephalus Ticks (Acari: Ixodidae)
Journal of medical entomology, 2007Co-Authors: Glen A Scoles, Massaro W Ueti, Donald P Knowles, Susan M. Noh, Guy H. PalmerAbstract:Abstract Before the eradication of Boophilus ticks from the United States, Rhipicephalus (Boophilus) microplus (Canestrini) and Rhipicephalus (Boophilus) annulatus (Say) were important biological vectors of the cattle pathogen Anaplasma marginale Theiler. In the absence of Boophilus ticks, A. marginale continues to be transmitted by Dermacentor ticks. However, a few U.S. strains are not transmissible by Dermacentor andersoni Stiles, Dermacentor variabilis (Say), or both, raising the question of how these strains evolved and how they are maintained. We hypothesize that the U.S. non-Dermacentor-transmissible strains of A. marginale were formerly Boophilus-transmitted strains that have been maintained by a combination of persistent infection and mechanical transmission since the eradication of their biological vector from the United States. To test this hypothesis, we attempted to transmit a well-documented non-Dermacentor-transmissible A. marginale strain (Florida), by using D. andersoni and the two Boophil...
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transovarial transmission efficiency of babesia bovis tick stages acquired by rhipicephalus Boophilus microplus during acute infection
Journal of Clinical Microbiology, 2007Co-Authors: Jeanne M Howell, Massaro W Ueti, Glen A Scoles, Guy H. Palmer, Donald P KnowlesAbstract:The protozoan parasite Babesia bovis, a reemerging threat to U.S. cattle, is acquired by adult female ticks of the subgenus Boophilus and is transovarially transmitted as the kinete stage to developing larval offspring. Sporozoites develop within larvae and are transmitted during larval feeding on a bovine host. This study evaluated the efficiency of B. bovis infection within Rhipicephalus (Boophilus) microplus following acquisition feeding on acutely parasitemic cattle. Parasite levels were quantified in blood from experimentally infected cattle and within hemolymph and larvae derived from acquisition-fed female B. microplus. There was a positive correlation between blood parasite levels in acutely parasitemic cattle and kinete levels in the hemolymph of adult female Boophilus ticks following acquisition feeding; however, there was no relationship between kinete levels in females and infection rates of larval progeny. Boophilus microplus females that acquisition fed produced larval progeny with infection rates of 12% to 48%. Importantly, larvae derived from replete females with very low levels of kinete infection, as demonstrated by microscopy and PCR, had infection rates of 22% to 30% and transmitted B. bovis during transmission feeding. These data demonstrate that although hemolymph infection may be undetectable, transmission to larval progeny occurs at a level which ensures transmission to the bovine host.
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Expression of Equi Merozoite Antigen 2 during Development of Babesia equi in the Midgut and Salivary Gland of the Vector Tick Boophilus microplus
Journal of clinical microbiology, 2003Co-Authors: Massaro W Ueti, Glen A Scoles, Guy H. Palmer, Lowell S. Kappmeyer, Donald P KnowlesAbstract:Equi merozoite antigens 1 and 2 (EMA-1 and EMA-2) are Babesia equi proteins expressed on the parasite surface during infection in horses and are orthologues of proteins in Theileria spp., which are also tick-transmitted protozoal pathogens. We determined in this study whether EMA-1 and EMA-2 were expressed within the vector tick Boophilus microplus. B. equi transitions through multiple, morphologically distinct stages, including sexual stages, and these transitions culminate in the formation of infectious sporozoites in the tick salivary gland. EMA-2-positive B. equi stages in the midgut lumen and midgut epithelial cells of Boophilus microplus nymphs were identified by reactivity with monoclonal antibody 36/253.21. This monoclonal antibody also recognized B. equi in salivary glands of adult Boophilus microplus. In addition, quantification of B. equi in the mammalian host and vector tick indicated that the duration of tick feeding and parasitemia levels affected the percentage of nymphs that contained morphologically distinct B. equi organisms in the midgut. In contrast, there was no conclusive evidence that B. equi EMA-1 was expressed in either the Boophilus microplus midgut or salivary gland when monoclonal antibody 36/18.57 was used. The expression of B. equi EMA-2 in Boophilus microplus provides a marker for detecting the various development stages and facilitates the identification of novel stage-specific Babesia proteins for testing transmission-blocking immunity.
