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T J Lysyk - One of the best experts on this subject based on the ideXlab platform.
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prevalence of anaplasma bovis in canadian populations of the rocky mountain wood tick Dermacentor Andersoni
Ticks and Tick-borne Diseases, 2018Co-Authors: Neil B Chilton, Shaun J Dergousoff, T J LysykAbstract:PCR and DNA sequencing were used to determine the prevalence of Anaplasma bovis in Rocky Mountain wood ticks (Dermacentor Andersoni) collected in Alberta and Saskatchewan, Canada. These analyses revealed that A. bovis DNA was present in 35 (2.1%) of 1679 ticks collected at 12 of the 24 localities. The discovery of A. bovis in host-seeking female and male D. Andersoni from multiple locations in southern Canada may have important implications for diagnosis of anaplasmosis in Canada.
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can subclinical infestation by paralyzing Dermacentor Andersoni acari ixodidae induce immunity to tick paralysis in sheep
Journal of Medical Entomology, 2016Co-Authors: T J Lysyk, Shaun J DergousoffAbstract:Cattle and sheep can develop immunity to paralysis caused by Dermacentor Andersoni Stiles; however, this has been reported only in animals that were initially challenged with a high dose of ticks and exhibited clear symptoms of paralysis. Paralysis in sheep occurs in a dose-dependent fashion, with no paralysis occurring in sheep exposed to 0.8 ticks per kilogram. This experiment was conducted to determine if sheep exposed to a low dose of ticks would also develop immunity to paralysis. Sheep were exposed to either a low (0.2 ticks per kilogram) or high dose of ticks (0.8 ticks per kilogram), then re-exposed to a second challenge of a paralyzing dose of ticks. All naive sheep (eight of the eight) were paralyzed, while paralysis occurred in only four of the eight sheep previously exposed to a low dose, and one of the eight sheep previously exposed to a high dose. Results indicate that immunity can develop when sheep are exposed to a subclinical dose of paralyzing ticks, but in a smaller percentage of animals than those exposed to a high dose of ticks. Vaccine development perhaps remains the best option for nonacaricidal control of tick paralysis.
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influence of temperature on oviposition by Dermacentor Andersoni acari ixodidae
Journal of Medical Entomology, 2014Co-Authors: T J LysykAbstract:ABSTRACT The effects of temperature on oviposition by Dermacentor Andersoni (Stiles) was examined using replete females ranging in weight from 30 to 1,198 mg. Survivorship was >96% during the preoviposition periods and declined during oviposition period. Egg production peaked earlier and at greater levels as temperature increased. Longevity, preoviposition period, and oviposition period declined as temperature increased. Replete weight had minor effects on measures of time, but smaller females tended to have greater longevity and preoviposition periods, and shorter oviposition periods. Temperature and replete weight both had large effects on measures of oviposition success such as the amount of eggs laid, the conversion efficiency index, and daily egg production. Lower temperatures and replete weight resulted in greater oviposition failure, and reduced egg production and conversion efficiency. Oviposition was greatly inhibited at 10°C, suggesting this is near the lower temperature limit for development. H...
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movement of male Dermacentor Andersoni acari ixodidae among cattle
Journal of Medical Entomology, 2013Co-Authors: T J LysykAbstract:ABSTRACT Movement of male Dermacentor Andersoni (Stiles) was examined among 54 pairs of artificially infested donor and recipient cattle during a 3-yr period. The number of males declined at a rate independent of the initial level of infestation, while the rate of decline of females on the donor animals tended to increase with initial infestation level. Male tick movement to recipient cattle was observed in 26 of 54 (48%) of the animal pairs, but varied among years and trials. Movement tended tobe greater during April compared with May and June. The daily probability of movement averaged (SD) 0.067 (0.082), and the number of males moving per day averaged (SD) 0.083 (0.228). Logistic and Poisson regression models were developed and indicated that movement was determined by interactions between the number of males on the donor animals, differences in the number of females on the donor and recipient cattle, temperature, and female age. These models can be used to incorporate movement into tick population models.
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dispersion and sampling of adult Dermacentor Andersoni in rangeland in western north america
Journal of Medical Entomology, 2012Co-Authors: Kateryn Rochon, Glen A. Scoles, T J LysykAbstract:A fixed precision sampling plan was developed for off-host populations of adult Rocky Mountain wood tick, Dermacentor Andersoni (Stiles) based on data collected by dragging at 13 locations in Alberta, Canada; Washington; and Oregon. In total, 222 site-date combinations were sampled. Each site-date combination was considered a sample, and each sample ranged in size from 86 to 250 10 m2 quadrats. Analysis of simulated quadrats ranging in size from 10 to 50 m2 indicated that the most precise sample unit was the 10 m2 quadrat. Samples taken when abundance <0.04 ticks per 10 m2 were more likely to not depart significantly from statistical randomness than samples taken when abundance was greater. Data were grouped into ten abundance classes and assessed for fit to the Poisson and negative binomial distributions. The Poisson distribution fit only data in abundance classes <0.02 ticks per 10 m2, while the negative binomial distribution fit data from all abundance classes. A negative binomial distribution with common k = 0.3742 fit data in eight of the 10 abundance classes. Both the Taylor and Iwao mean-variance relationships were fit and used to predict sample sizes for a fixed level of precision. Sample sizes predicted using the Taylor model tended to underestimate actual sample sizes, while sample sizes estimated using the Iwao model tended to overestimate actual sample sizes. Using a negative binomial with common k provided estimates of required sample sizes closest to empirically calculated sample sizes.
Stephen K Wikel - One of the best experts on this subject based on the ideXlab platform.
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murine cutaneous responses to the rocky mountain spotted fever vector Dermacentor Andersoni feeding
Frontiers in Microbiology, 2014Co-Authors: Dar Heinze, Stephen K Wikel, Russ J Carmical, Judith F Aronson, Franscisco Alarconchaidez, Saravanan ThangamaniAbstract:Tick salivary glands produce complex cocktails of bioactive molecules that facilitate blood feeding and pathogen transmission by modulating host hemostasis, pain/itch responses, wound healing, and both innate and adaptive immunity. In this study, cutaneous responses at Dermacentor Andersoni bite-sites were analyzed using Affymetrix mouse genome arrays and histopathology at 12, 48, 96 and 120 hours post- infestation (hpi) during primary infestations and 120hpi during secondary infestations. The microarray data suggests: (1) chemotaxis of neutrophils, monocytes, and other cell types; (2) production and scavenging of reactive oxygen species; and, (3) keratin- based wound healing responses. Histological analysis supported the microarray findings. At 12hpi, a mild inflammatory infiltrate was present in the dermis, especially concentrated at the junction between dermal connective tissue and underlying adipose tissue. A small lesion was located immediately under the hypostome and likely represents the feeding “pool.” Surprisingly, at 48hpi, the number of inflammatory cells had not increased from 12hpi, perhaps mirroring the reduction in gene expression seen at this time point. The feeding lesion is very well defined, and extravasated erythrocytes are readily evident around the hypostome. By 96hpi, the inflammatory infiltrate has increased dramatically and the feeding lesion appears to have moved deeper into the dermis. At 120hpi, most of the changes at 96hpi are intensified. The infiltrate is very dense, the epidermis is markedly thickened, the feeding lesion is poorly defined and the dermal tissue near the hypostome appears to be loosing its normal architecture. In conclusion, during D. Andersoni feeding infiltration of inflammatory cells increases across time concurrent with significant changes in the epidermal and dermal compartments near the feeding tick. The importance of changes in the epidermal layer in the host response to ticks is not known, however, it is possib
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blood feeding by the rocky mountain spotted fever vector Dermacentor Andersoni induces interleukin 4 expression by cognate antigen responding cd4 t cells
Parasites & Vectors, 2009Co-Authors: Venkata D Boppana, Francisco J Alarconchaidez, Saravanan Thangamani, Adam J Adler, Stephen K WikelAbstract:Background Tick modulation of host defenses facilitates both blood feeding and pathogen transmission. Several tick species deviate host T cell responses toward a Th2 cytokine profile. The majority of studies of modulation of T cell cytokine expression by ticks were performed with lymphocytes from infested mice stimulated in vitro with polyclonal T cell activators. Those reports did not examine tick modulation of antigen specific responses. We report use of a transgenic T cell receptor (TCR) adoptive transfer model reactive with influenza hemagglutinin peptide (110-120) to examine CD4+ T cell intracellular cytokine responses during infestation with the metastriate tick, Dermacentor Andersoni, or exposure to salivary gland extracts.
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transcriptome analysis of the salivary glands of Dermacentor Andersoni stiles acari ixodidae
Insect Biochemistry and Molecular Biology, 2007Co-Authors: Francisco J Alarconchaidez, Stephen K WikelAbstract:Amongst blood-feeding arthropods, ticks of the family Ixodidae (hard ticks) are vectors and reservoirs of a greater variety of infectious agents than any other ectoparasite. Salivary glands of ixodid ticks secrete a large number of pharmacologically active molecules that not only facilitate feeding but also promote establishment of infectious agents. Genomic, proteomic and immunologic characterization of bioactive salivary gland molecules are, therefore, important as they offer new insights into molecular events occurring at the tick-host interface and they have implications for development of novel control strategies. The present work uses complementary DNA (cDNA) sequence analysis to identify salivary gland transcripts expressed by the Rocky Mountain wood tick, Dermacentor Andersoni, a vector of the human pathogens causing Rocky Mountain spotted fever, Colorado tick fever, tularemia, and Powassan encephalitis as well as the veterinary pathogen Anaplasma marginale. Dermacentor Andersoni is also capable of inducing tick paralysis. Automated single-pass DNA sequencing was conducted on 1440 randomly selected cDNA clones from the salivary glands of adult female D. Andersoni collected during the early stages of feeding (18-24h). Analysis of the expressed sequence tags (ESTs) resulted in 544 singletons and 218 clusters with more than one quality read and attempts were made to assign putative functions to tick genes based on amino acid identity to published protein databases. Approximately 25.6% (195) of the sequences showed limited or no homology to previously identified gene products. A number of novel sequences were identified which presented significant sequence similarity to mammalian genes normally associated with extracellular matrix (ECM), regulation of immune responses, tumor suppression, and wound healing. Several coding sequences possessed various degrees of homology to previously described proteins from other tick species. Preliminary nucleotide variation analysis of these and other tick sequences suggests extensive nucleotide diversity, which has implications for evolution of tick feeding. Intra-species diversity studies can be a promising tool for identifying sequence variations potentially associated with phenotypic traits affecting vector-host-pathogen interactions.
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characterization of a recombinant immunomodulatory protein from the salivary glands of Dermacentor Andersoni
Parasite Immunology, 2003Co-Authors: Francisco J Alarconchaidez, U W E U Mullerdoblies, Stephen K WikelAbstract:SUMMARY The gene encoding a 36-kDa (p36) immunomodulatory protein present in saliva of Dermacentor Andersoni was cloned in prokaryotic and eukaryotic expression vectors. A polymerase chain reaction (PCR)-generated cDNA lacking signal peptide was cloned into the Escherichia coli expression vector pET28 and a similar sequence was cloned into pIB/V5-His-TOPO expression vector for stable transfection of insect cells, High 5™. The 26-kDa molecular mass of p36 expressed by bacteria is in agreement with that predicted from the translated full-length cDNA sequence. Eukaryotic-cell-expressed p36 consisted of multiple forms with molecular masses between 34 and 36 kDa. These multiple forms were attributed to differences in post-translational modifications. N-linked mannose was detected on insect-cell-expressed and tick-derived p36. Multiple bands remained after endoglycosidase removal of N-linked sugars, indicating the presence of other modifications. Both bacterial- and insect-cell-expressed p36 reacted on immunoblots with polyclonal antibodies raised against tick-derived p36. Insect-cell-expressed p36 suppressed T-lymphocyte-mitogen-driven in vitro proliferation of splenocytes from tick-naive mice in a dose-dependent manner. Bacterial-cell-expressed p36 lacked immunomodulatory activity.
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Dermacentor Andersoni effects of repeated infestations on lymphocyte proliferation cytokine production and adhesion molecule expression by balb c mice
Annals of Tropical Medicine and Parasitology, 2001Co-Authors: K R Macaluso, Stephen K WikelAbstract:The effects of repeated infestations with Dermacentor Andersoni nymphs on the lymphocyte functions of BALB/c mice were investigated. The in-vitro proliferation responses to concanavalin-A or saliva...
Neil B Chilton - One of the best experts on this subject based on the ideXlab platform.
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identification of bacteria in the rocky mountain wood tick Dermacentor Andersoni using single strand conformation polymorphism sscp and dna sequencing
Experimental and Applied Acarology, 2020Co-Authors: Shaun J Dergousoff, Clare A Anstead, Neil B ChiltonAbstract:PCR-based single-strand conformation polymorphism (SSCP) analyses combined with DNA sequencing of the prokaryotic 16S ribosomal (r) RNA gene encompassing the hypervariable V4 region was used to determine the bacterial composition of Rocky Mountain wood ticks (Dermacentor Andersoni) attached to Richardson’s ground squirrels (Urocitellus richardsonii) and questing on vegetation in southern Saskatchewan, Canada. The bacteria present in questing adult ticks from Saskatchewan Landing Provincial Park included Rickettsia peacockii, a Francisella-like endosymbiont (FLE) and an Arsenophonus-like endosymbiont. Bacteria in the adult and nymphal ticks attached to U. richardsonii collected from Beechy included R. peacockii, a FLE, and several other genera (e.g., Ralstonia, Sphingobium, Comamonas and Pseudomonas). The bacteria detected in D. Andersoni in the present study are consistent with the findings of other studies that have characterized the microbiome of this tick species in the USA using next generation sequencing. This result demonstrates that the SSCP-based approach used in this study is cost- and time-effective for examining bacterial composition in ticks.
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prevalence of anaplasma bovis in canadian populations of the rocky mountain wood tick Dermacentor Andersoni
Ticks and Tick-borne Diseases, 2018Co-Authors: Neil B Chilton, Shaun J Dergousoff, T J LysykAbstract:PCR and DNA sequencing were used to determine the prevalence of Anaplasma bovis in Rocky Mountain wood ticks (Dermacentor Andersoni) collected in Alberta and Saskatchewan, Canada. These analyses revealed that A. bovis DNA was present in 35 (2.1%) of 1679 ticks collected at 12 of the 24 localities. The discovery of A. bovis in host-seeking female and male D. Andersoni from multiple locations in southern Canada may have important implications for diagnosis of anaplasmosis in Canada.
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range expansion of Dermacentor variabilis and Dermacentor Andersoni acari ixodidae near their northern distributional limits
Journal of Medical Entomology, 2013Co-Authors: Shaun J Dergousoff, Terry D Galloway, Robbin L Lindsay, Philip S Curry, Neil B ChiltonAbstract:Distributional ranges of the ticks Dermacentor Andersoni Stiles and Dermacentor variabilis (Say) in the Canadian Prairies were determined by passive surveillance and active collection. These findings were compared with historical records of both species, particularly in the province of Saskatchewan, where the northern distributional limits of both tick species occur. Before the 1960s, D. variabilis and D. Andersoni were allopatric in Saskatchewan; however, since then, the distribution of D. variabilis has expanded westward and northward. Although the range of D. Andersoni has remained relatively stable, range expansion of D. variabilis has resulted in a zone of sympatry at least 200 km wide. Twenty-nine species of mammals and three species of birds were identified as hosts for different life stages of these ticks.
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genetic variation in the 16s mitochondrial dna gene of two canadian populations of Dermacentor Andersoni acari ixodidae
Journal of Medical Entomology, 2009Co-Authors: Edward Patterson, Shaun J Dergousoff, Neil B ChiltonAbstract:The Rocky Mountain wood tick, Dermacentor Andersoni Stiles, 1908, is of medical and veterinary importance because it can transmit pathogenic agents to humans, domestic livestock, and wildlife. The preferred attachment sites of D. Andersoni adults and their ability to induce paralysis in hosts vary among populations, which may have a genetic basis. In this study, polymerase chain reaction (PCR)-single-strand conformation polymorphism (SSCP) analyses and DNA sequencing were used to determine the genetic variation in the 16S mitochondrial DNA gene of two D. Andersoni populations from the Canadian prairies: Saskatchewan Landing Provincial Park, Saskatchewan, and Lethbridge, Alberta. Five haplotypes were detected in each population, but this was considerably lower than the 14 haplotypes reported in a previous study of a laboratory colony of D. Andersoni originating from the Rocky Mountains in Montana. In addition, the Canadian populations did not share any haplotypes with the population from Montana. Differences in the genetic composition of the two Canadian prairie populations of D. Andersoni compared with the montane population in the United States may have arisen through geographical isolation. These genetic differences between tick populations may also have important implications with respect to their ability to transmit pathogens to hosts. Further studies are needed to determine the extent of genetic variation and the vector potential of ticks from different populations throughout the range of D. Andersoni in the United States and Canada.
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prevalence of rickettsia species in canadian populations of Dermacentor Andersoni and d variabilis
Applied and Environmental Microbiology, 2009Co-Authors: Shaun J Dergousoff, Andrew J A Gajadhar, Neil B ChiltonAbstract:We determined the prevalence of rickettsiae in Dermacentor adults at 15 localities in Canada. Rickettsia rickettsii was not detected in any tick, whereas Rickettsia peacockii was present in 76% of Dermacentor Andersoni adults and Rickettsia montanensis in 8% of Dermacentor variabilis adults. This host specificity was maintained in localities where both tick species occurred in sympatry.
Glen A. Scoles - One of the best experts on this subject based on the ideXlab platform.
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quantitative analysis of anaplasma marginale acquisition and transmission by Dermacentor Andersoni fed in vitro
Scientific Reports, 2020Co-Authors: Rubikah Vimonish, Glen A. Scoles, Kelly A Brayton, M R Mousel, Massaro W Ueti, Wendell C JohnsonAbstract:In this study, we describe a new in vitro tick feeding system that facilitates the study of ticks and tick-borne pathogens. To optimize the system, we used Dermacentor Andersoni and Anaplasma marginale as a tick-pathogen interaction model. Ticks were fed on bovine blood containing 10-fold dilutions of the pathogen to determine the effect of dose on tick infection rate. After feeding on infected blood, ticks were transferred to uninfected blood to stimulate bacterial replication within the tick vector. During stimulation feeding, blood samples were collected daily to determine if infected ticks secreted viable A. marginale. The results demonstrated similar attachment rates between the first and second tick feeding. Tick midgut and salivary glands were infected with A. marginale. However, salivary gland infection rates decreased as the percentage of parasitized erythrocytes decreased during tick acquisition feeding. Bacteria recovered from the in vitro system were able to infect a naive bovine host. Using the highly transmissible A. marginale St. Maries strain, we demonstrated that the artificial tick feeding system is a suitable tool to study tick-pathogen interactions and that A. marginale tick salivary gland infection is dose dependent. This work demonstrates the utility of an artificial tick feeding system to directly study the association between the number of acquired pathogens and transmissibility by ticks.
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the bacterial microbiome of Dermacentor Andersoni ticks influences pathogen susceptibility
The ISME Journal, 2016Co-Authors: Cory A Gall, Glen A. Scoles, Kathryn E Reif, Kathleen L Mason, M R Mousel, Kelly A BraytonAbstract:Ticks are of medical importance owing to their ability to transmit pathogens to humans and animals. The Rocky Mountain wood tick, Dermacentor Andersoni, is a vector of a number of pathogens, including Anaplasma marginale, which is the most widespread tick-borne pathogen of livestock. Although ticks host pathogenic bacteria, they also harbor bacterial endosymbionts that have a role in tick physiology, survival, as well as pathogen acquisition and transmission. The goal of this study was to characterize the bacterial microbiome and examine the impact of microbiome disruption on pathogen susceptibility. The bacterial microbiome of two populations of D. Andersoni with historically different susceptibilities to A. marginale was characterized. In this study, the microbiome was disrupted and then ticks were exposed to A. marginale or Francisella novicida to determine whether the microbiome correlated with pathogen susceptibility. Our study showed that an increase in proportion and quantity of Rickettsia bellii in the microbiome was negatively correlated to A. marginale levels in ticks. Furthermore, a decrease in Francisella endosymbionts was associated with lower F. novicida infection levels, demonstrating a positive pathogen–endosymbiont relationship. We demonstrate that endosymbionts and pathogens have varying interactions, and suggest that microbiome manipulation may provide a possible method for biocontrol by decreasing pathogen susceptibility of ticks.
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the characterization and manipulation of the bacterial microbiome of the rocky mountain wood tick Dermacentor Andersoni
Parasites & Vectors, 2015Co-Authors: Katie A Clayton, Glen A. Scoles, Cory A Gall, Katheen L Mason, Kelly A BraytonAbstract:Background In North America, ticks are the most economically impactful vectors of human and animal pathogens. The Rocky Mountain wood tick, Dermacentor Andersoni (Acari: Ixodidae), transmits Rickettsia rickettsii and Anaplasma marginale to humans and cattle, respectively. In recent years, studies have shown that symbiotic organisms are involved in a number of biochemical and physiological functions. Characterizing the bacterial microbiome of D. Andersoni is a pivotal step towards understanding symbiont-host interactions.
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proteomics informed by transcriptomics identifies novel secreted proteins in Dermacentor Andersoni saliva
International Journal for Parasitology, 2014Co-Authors: Lwiindi Mudenda, Glen A. Scoles, Sebastian Aguilar Pierle, Joshua E Turse, Samuel O Purvine, Carrie D Nicora, Therese R W Clauss, Massaro W Ueti, Wendy C Brown, Kelly A BraytonAbstract:Dermacentor Andersoni, known as the Rocky Mountain wood tick, is found in the western United States and transmits pathogens that cause diseases of veterinary and public health importance including Rocky Mountain spotted fever, tularemia, Colorado tick fever and bovine anaplasmosis. Tick saliva is known to modulate both innate and acquired immune responses, enabling ticks to feed for several days without detection. During feeding ticks subvert host defences such as hemostasis and inflammation, which would otherwise result in coagulation, wound repair and rejection of the tick. Molecular characterization of the proteins and pharmacological molecules secreted in tick saliva offers an opportunity to develop tick vaccines as an alternative to the use of acaricides, as well as new anti-inflammatory drugs. We performed proteomics informed by transcriptomics to identify D. Andersoni saliva proteins that are secreted during feeding. The transcript data generated a database of 21,797 consensus sequences, which we used to identify 677 proteins secreted in the saliva of D. Andersoni ticks fed for 2 and 5 days, following proteomic investigations of whole saliva using mass spectrometry. Salivary gland transcript levels of unfed ticks were compared with 2 and 5 day fed ticks to identify genes upregulated early during tick feeding. Wemore » cross-referenced the proteomic data with the transcriptomic data to identify 157 proteins of interest for immunomodulation and blood feeding. Proteins of unknown function as well as known immunomodulators were identified.« less
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dispersion and sampling of adult Dermacentor Andersoni in rangeland in western north america
Journal of Medical Entomology, 2012Co-Authors: Kateryn Rochon, Glen A. Scoles, T J LysykAbstract:A fixed precision sampling plan was developed for off-host populations of adult Rocky Mountain wood tick, Dermacentor Andersoni (Stiles) based on data collected by dragging at 13 locations in Alberta, Canada; Washington; and Oregon. In total, 222 site-date combinations were sampled. Each site-date combination was considered a sample, and each sample ranged in size from 86 to 250 10 m2 quadrats. Analysis of simulated quadrats ranging in size from 10 to 50 m2 indicated that the most precise sample unit was the 10 m2 quadrat. Samples taken when abundance <0.04 ticks per 10 m2 were more likely to not depart significantly from statistical randomness than samples taken when abundance was greater. Data were grouped into ten abundance classes and assessed for fit to the Poisson and negative binomial distributions. The Poisson distribution fit only data in abundance classes <0.02 ticks per 10 m2, while the negative binomial distribution fit data from all abundance classes. A negative binomial distribution with common k = 0.3742 fit data in eight of the 10 abundance classes. Both the Taylor and Iwao mean-variance relationships were fit and used to predict sample sizes for a fixed level of precision. Sample sizes predicted using the Taylor model tended to underestimate actual sample sizes, while sample sizes estimated using the Iwao model tended to overestimate actual sample sizes. Using a negative binomial with common k provided estimates of required sample sizes closest to empirically calculated sample sizes.
Shaun J Dergousoff - One of the best experts on this subject based on the ideXlab platform.
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identification of bacteria in the rocky mountain wood tick Dermacentor Andersoni using single strand conformation polymorphism sscp and dna sequencing
Experimental and Applied Acarology, 2020Co-Authors: Shaun J Dergousoff, Clare A Anstead, Neil B ChiltonAbstract:PCR-based single-strand conformation polymorphism (SSCP) analyses combined with DNA sequencing of the prokaryotic 16S ribosomal (r) RNA gene encompassing the hypervariable V4 region was used to determine the bacterial composition of Rocky Mountain wood ticks (Dermacentor Andersoni) attached to Richardson’s ground squirrels (Urocitellus richardsonii) and questing on vegetation in southern Saskatchewan, Canada. The bacteria present in questing adult ticks from Saskatchewan Landing Provincial Park included Rickettsia peacockii, a Francisella-like endosymbiont (FLE) and an Arsenophonus-like endosymbiont. Bacteria in the adult and nymphal ticks attached to U. richardsonii collected from Beechy included R. peacockii, a FLE, and several other genera (e.g., Ralstonia, Sphingobium, Comamonas and Pseudomonas). The bacteria detected in D. Andersoni in the present study are consistent with the findings of other studies that have characterized the microbiome of this tick species in the USA using next generation sequencing. This result demonstrates that the SSCP-based approach used in this study is cost- and time-effective for examining bacterial composition in ticks.
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prevalence of anaplasma bovis in canadian populations of the rocky mountain wood tick Dermacentor Andersoni
Ticks and Tick-borne Diseases, 2018Co-Authors: Neil B Chilton, Shaun J Dergousoff, T J LysykAbstract:PCR and DNA sequencing were used to determine the prevalence of Anaplasma bovis in Rocky Mountain wood ticks (Dermacentor Andersoni) collected in Alberta and Saskatchewan, Canada. These analyses revealed that A. bovis DNA was present in 35 (2.1%) of 1679 ticks collected at 12 of the 24 localities. The discovery of A. bovis in host-seeking female and male D. Andersoni from multiple locations in southern Canada may have important implications for diagnosis of anaplasmosis in Canada.
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can subclinical infestation by paralyzing Dermacentor Andersoni acari ixodidae induce immunity to tick paralysis in sheep
Journal of Medical Entomology, 2016Co-Authors: T J Lysyk, Shaun J DergousoffAbstract:Cattle and sheep can develop immunity to paralysis caused by Dermacentor Andersoni Stiles; however, this has been reported only in animals that were initially challenged with a high dose of ticks and exhibited clear symptoms of paralysis. Paralysis in sheep occurs in a dose-dependent fashion, with no paralysis occurring in sheep exposed to 0.8 ticks per kilogram. This experiment was conducted to determine if sheep exposed to a low dose of ticks would also develop immunity to paralysis. Sheep were exposed to either a low (0.2 ticks per kilogram) or high dose of ticks (0.8 ticks per kilogram), then re-exposed to a second challenge of a paralyzing dose of ticks. All naive sheep (eight of the eight) were paralyzed, while paralysis occurred in only four of the eight sheep previously exposed to a low dose, and one of the eight sheep previously exposed to a high dose. Results indicate that immunity can develop when sheep are exposed to a subclinical dose of paralyzing ticks, but in a smaller percentage of animals than those exposed to a high dose of ticks. Vaccine development perhaps remains the best option for nonacaricidal control of tick paralysis.
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range expansion of Dermacentor variabilis and Dermacentor Andersoni acari ixodidae near their northern distributional limits
Journal of Medical Entomology, 2013Co-Authors: Shaun J Dergousoff, Terry D Galloway, Robbin L Lindsay, Philip S Curry, Neil B ChiltonAbstract:Distributional ranges of the ticks Dermacentor Andersoni Stiles and Dermacentor variabilis (Say) in the Canadian Prairies were determined by passive surveillance and active collection. These findings were compared with historical records of both species, particularly in the province of Saskatchewan, where the northern distributional limits of both tick species occur. Before the 1960s, D. variabilis and D. Andersoni were allopatric in Saskatchewan; however, since then, the distribution of D. variabilis has expanded westward and northward. Although the range of D. Andersoni has remained relatively stable, range expansion of D. variabilis has resulted in a zone of sympatry at least 200 km wide. Twenty-nine species of mammals and three species of birds were identified as hosts for different life stages of these ticks.
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genetic variation in the 16s mitochondrial dna gene of two canadian populations of Dermacentor Andersoni acari ixodidae
Journal of Medical Entomology, 2009Co-Authors: Edward Patterson, Shaun J Dergousoff, Neil B ChiltonAbstract:The Rocky Mountain wood tick, Dermacentor Andersoni Stiles, 1908, is of medical and veterinary importance because it can transmit pathogenic agents to humans, domestic livestock, and wildlife. The preferred attachment sites of D. Andersoni adults and their ability to induce paralysis in hosts vary among populations, which may have a genetic basis. In this study, polymerase chain reaction (PCR)-single-strand conformation polymorphism (SSCP) analyses and DNA sequencing were used to determine the genetic variation in the 16S mitochondrial DNA gene of two D. Andersoni populations from the Canadian prairies: Saskatchewan Landing Provincial Park, Saskatchewan, and Lethbridge, Alberta. Five haplotypes were detected in each population, but this was considerably lower than the 14 haplotypes reported in a previous study of a laboratory colony of D. Andersoni originating from the Rocky Mountains in Montana. In addition, the Canadian populations did not share any haplotypes with the population from Montana. Differences in the genetic composition of the two Canadian prairie populations of D. Andersoni compared with the montane population in the United States may have arisen through geographical isolation. These genetic differences between tick populations may also have important implications with respect to their ability to transmit pathogens to hosts. Further studies are needed to determine the extent of genetic variation and the vector potential of ticks from different populations throughout the range of D. Andersoni in the United States and Canada.