| insight into the salivary gland transcriptome of lygus lineolaris (palisot de beauvois). | the tarnished plant bug (tpb), lygus lineolaris (palisot de beauvois) is a polyphagous, phytophagous insect that has emerged as a major pest of cotton, alfalfa, fruits, and vegetable crops in the eastern united states and canada. using its piercing-sucking mouthparts, tpb employs a "lacerate and flush" feeding strategy in which saliva injected into plant tissue degrades cell wall components and lyses cells whose contents are subsequently imbibed by the tpb. it is known that a major component of ... | 2016 | 26789269 |
| identification and mechanistic analysis of a novel tick-derived inhibitor of thrombin. | a group of peptides from the salivary gland of the tick hyalomma marginatum rufipes, a vector of crimean congo hemorrhagic fever show weak similarity to the madanins, a group of thrombin-inhibitory peptides from a second tick species, haemaphysalis longicornis. we have evaluated the anti-serine protease activity of one of these h. marginatum peptides that has been given the name hyalomin-1. hyalomin-1 was found to be a selective inhibitor of thrombin, blocking coagulation of plasma and inhibitin ... | 2015 | 26244557 |
| high prevalence of rickettsia africae variants in amblyomma variegatum ticks from domestic mammals in rural western kenya: implications for human health. | tick-borne spotted fever group (sfg) rickettsioses are emerging human diseases caused by obligate intracellular gram-negative bacteria of the genus rickettsia. despite being important causes of systemic febrile illnesses in travelers returning from sub-saharan africa, little is known about the reservoir hosts of these pathogens. we conducted surveys for rickettsiae in domestic animals and ticks in a rural setting in western kenya. of the 100 serum specimens tested from each species of domestic r ... | 0 | 25325312 |
| identification of rhipicephalus microplus genes that modulate the infection rate of the rickettsia anaplasma marginale. | arthropod vectors transmit a diversity of animal and human pathogens, ranging from rna viruses to protozoal parasites. chemotherapeutic control of pathogens has classically focused either on insecticides that kill the vector itself or antimicrobials for infected patients. the limitation of the former is that it targets both infected and uninfected vectors and selects for resistant populations while the latter requires prompt and accurate diagnosis. an alternative strategy is to target vector mol ... | 2014 | 24608654 |
| molecular cloning and sequence analysis of the cdnas encoding toxin-like peptides from the venom glands of tarantula grammostola rosea. | tarantula venom glands produce a large variety of bioactive peptides. here we present the identification of venom components obtained by sequencing clones isolated from a cdna library prepared from the venom glands of the chilean common tarantula, grammostola rosea. the cdna sequences of about 1500 clones out of 4000 clones were analyzed after selection using several criteria. forty-eight novel toxin-like peptides (gtx1 to gtx7, and gtx-tctp and gtx-crisp) were predicted from the nucleotide sequ ... | 2012 | 22500178 |
| transovarial transmission of rickettsia spp. and organ-specific infection of the whitefly bemisia tabaci. | the whitefly bemisia tabaci is a cosmopolitan insect pest that harbors portiera aleyrodidarum, the primary obligatory symbiotic bacterium, and several facultative secondary symbionts. secondary symbionts in b. tabaci are generally associated with the bacteriome, ensuring their vertical transmission; however, rickettsia is an exception and occupies most of the body cavity, except the bacteriome. the mode of rickettsia transfer between generations and its subcellular localization in insect organs ... | 2012 | 22660706 |
| antiplasmodial activity is an ancient and conserved feature of tick defensins. | ancestral sequence reconstruction has been widely used to test evolution-based hypotheses. the genome of the european tick vector, ixodes ricinus, encodes for defensin peptides with diverse antimicrobial activities against distantly related pathogens. these pathogens include fungi, gram-negative, and gram-positive bacteria, i.e., a wide antimicrobial spectrum. ticks do not transmit these pathogens, suggesting that these defensins may act against a wide range of microbes encountered by ticks duri ... | 2016 | 27822206 |
| borrelia miyamotoi disease: neither lyme disease nor relapsing fever. | borrelia miyamotoi disease (bmd) is a newly recognized borreliosis globally transmitted by ticks of the ixodes persulcatus species complex. once considered to be a tick symbiont with no public health implications, b miyamotoi is increasingly recognized as the agent of a nonspecific febrile illness often misdiagnosed as acute lyme disease without rash, or as ehrlichiosis. the frequency of its diagnosis in the northeastern united states is similar to that of human granulocytic ehrlichiosis. a diag ... | 2015 | 26593262 |
| tissue distribution of the ehrlichia muris-like agent in a tick vector. | human pathogens transmitted by ticks undergo complex life cycles alternating between the arthropod vector and a mammalian host. while the latter has been investigated to a greater extent, examination of the biological interactions between microbes and the ticks that carry them presents an equally important opportunity for disruption of the disease cycle. in this study, we used in situ hybridization to demonstrate infection by the ehrlichia muris-like organism, a newly recognized human pathogen, ... | 2015 | 25781930 |
| what's left in asymmetry? | left-right patterning is a fascinating problem of morphogenesis, linking evolutionary and cellular signaling mechanisms across many levels of organization. in the past 15 years, enormous progress has been made in elucidating the molecular details of this process in embryos of several model species. while many outside the field seem to believe that the fundamental aspects of this pathway are now solved, workers on asymmetry are faced with considerable uncertainties over the details of specific me ... | 0 | 18488999 |
| findings of scientific misconduct. | | 0 | 27737130 |
| findings of scientific misconduct. | | 0 | 12666658 |
| anaplasma marginale: diversity, virulence, and vaccine landscape through a genomics approach. | in order to understand the genetic diversity of a. marginale, several efforts have been made around the world. this rickettsia affects a significant number of ruminants, causing bovine anaplasmosis, so the interest in its virulence and how it is transmitted have drawn interest not only from a molecular point of view but also, recently, some genomics research have been performed to elucidate genes and proteins with potential as antigens. unfortunately, so far, we still do not have a recombinant a ... | 2016 | 27610385 |
| tick holocyclotoxins trigger host paralysis by presynaptic inhibition. | ticks are important vectors of pathogens and secreted neurotoxins with approximately 69 out of 692 tick species having the ability to induce severe toxicoses in their hosts. the australian paralysis tick (ixodes holocyclus) is known to be one of the most virulent tick species producing a flaccid paralysis and fatalities caused by a family of neurotoxins known as holocyclotoxins (hts). the paralysis mechanism of these toxins is temperature dependent and is thought to involve inhibition of acetylc ... | 2016 | 27389875 |
| the characterization and manipulation of the bacterial microbiome of the rocky mountain wood tick, dermacentor andersoni. | 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-hos ... | 2015 | 26653035 |
| subdominant outer membrane antigens in anaplasma marginale: conservation, antigenicity, and protective capacity using recombinant protein. | anaplasma marginale is a tick-borne rickettsial pathogen of cattle with a worldwide distribution. currently a safe and efficacious vaccine is unavailable. outer membrane protein (omp) extracts or a defined surface protein complex reproducibly induce protective immunity. however, there are several knowledge gaps limiting progress in vaccine development. first, are these omps conserved among the diversity of a. marginale strains circulating in endemic regions? second, are the most highly conserved ... | 2015 | 26079491 |
| targeted knockout of the rickettsia rickettsii ompa surface antigen does not diminish virulence in a mammalian model system. | strains of rickettsia rickettsii, the causative agent of rocky mountain spotted fever (rmsf), differ dramatically in virulence despite >99% genetic homology. spotted fever group (sfg) rickettsiae produce two immunodominant outer membrane proteins, rickettsial ompa (rompa) and rompb, which are conserved throughout the sfg and thought to be fundamental to pathogenesis. rompa is present in all virulent strains of r. rickettsii but is not produced in the only documented avirulent strain, iowa, due t ... | 2015 | 25827414 |
| association of anaplasma marginale strain superinfection with infection prevalence within tropical regions. | strain superinfection occurs when a second strain infects a host already infected with and having mounted an immune response to a primary strain. the incidence of superinfection with anaplasma marginale, a tick-borne rickettsial pathogen of domestic and wild ruminants, has been shown to be higher in tropical versus temperate regions. this has been attributed to the higher prevalence of infection, with consequent immunity against primary strains and thus greater selective pressure for superinfect ... | 2015 | 25793966 |
| reduced infectivity in cattle for an outer membrane protein mutant of anaplasma marginale. | anaplasma marginale is the causative agent of anaplasmosis in cattle. transposon mutagenesis of this pathogen using the himar1 system resulted in the isolation of an omp10 operon insertional mutant referred to as the omp10::himar1 mutant. the work presented here evaluated if this mutant had morphological and/or growth rate defects compared to wild-type a. marginale. results showed that the morphology, developmental cycle, and growth in tick and mammalian cell cultures are similar for the mutant ... | 2015 | 25595772 |
| rocky mountain spotted fever characterization and comparison to similar illnesses in a highly endemic area-arizona, 2002-2011. | rocky mountain spotted fever (rmsf) has emerged as a significant cause of morbidity and mortality since 2002 on tribal lands in arizona. the explosive nature of this outbreak and the recognition of an unexpected tick vector, rhipicephalus sanguineus, prompted an investigation to characterize rmsf in this unique setting and compare rmsf cases to similar illnesses. | 2015 | 25697743 |
| community-based control of the brown dog tick in a region with high rates of rocky mountain spotted fever, 2012-2013. | rocky mountain spotted fever (rmsf) transmitted by the brown dog tick (rhipicephalus sanguineus sensu lato) has emerged as a significant public health risk on american indian reservations in eastern arizona. during 2003-2012, more than 250 rmsf cases and 19 deaths were documented among arizona's american indian population. the high case fatality rate makes community-level interventions aimed at rapid and sustained reduction of ticks urgent. beginning in 2012, a two year pilot integrated tick pre ... | 2014 | 25479289 |
| anaplasma marginale superinfection attributable to pathogen strains with distinct genomic backgrounds. | strain superinfection occurs when a second pathogen strain infects a host already infected with a primary strain. the selective pressures that drive strain divergence, which underlies superinfection, and allow penetration of a new strain into a host population are critical knowledge gaps relevant to shifts in infectious disease epidemiology. in regions of endemicity with a high prevalence of infection, broad population immunity develops against anaplasma marginale, a highly antigenically variant ... | 2014 | 25287920 |
| peripheral neuropathy due to vitamin deficiency, toxins, and medications. | peripheral neuropathies secondary to vitamin deficiencies, medications, or toxins are frequently considered but can be difficult to definitively diagnose. accurate diagnosis is important since these conditions are often treatable and preventable. this article reviews the key features of different types of neuropathies caused by these etiologies and provides a comprehensive list of specific agents that must be kept in mind. | 0 | 25299283 |
| inadequacy of igm antibody tests for diagnosis of rocky mountain spotted fever. | among 13 suspected rocky mountain spotted fever (rmsf) cases identified through an enhanced surveillance program in tennessee, antibodies to rickettsia rickettsii were detected in 10 (77%) patients using a standard indirect immunofluorescent antibody (ifa) assay. immunoglobulin m (igm) antibodies were observed for 6 of 13 patients (46%) without a corresponding development of igg, and for 3 of 10 patients (30%) at least 1 year post-onset. however, recent infection with a spotted fever group ricke ... | 2014 | 25092818 |
| phylogeography of rickettsia rickettsii genotypes associated with fatal rocky mountain spotted fever. | rocky mountain spotted fever (rmsf), a tick-borne zoonosis caused by rickettsia rickettsii, is among the deadliest of all infectious diseases. to identify the distribution of various genotypes of r. rickettsii associated with fatal rmsf, we applied molecular typing methods to samples of dna extracted from formalin-fixed, paraffin-embedded tissue specimens obtained at autopsy from 103 case-patients from seven countries who died of rmsf. complete sequences of one or more intergenic regions were am ... | 2014 | 24957541 |
| immunization-induced anaplasma marginale-specific t-lymphocyte responses impaired by a. marginale infection are restored after eliminating infection with tetracycline. | infection of cattle with anaplasma marginale fails to prime sustained effector/memory t-cell responses, and high bacterial load may induce antigen-specific cd4 t exhaustion and deletion. we tested the hypothesis that clearance of persistent infection restores the exhausted t-cell response. we show that infection-induced t-cell exhaustion, characterized as loss of antigen-specific proliferation, and gamma interferon (ifn-γ) and tumor necrosis factor alpha (tnf-α) production are partially restored ... | 2014 | 25008904 |
| murine cutaneous responses to the rocky mountain spotted fever vector, dermacentor andersoni, feeding. | 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 h post- infestation (hpi) during primary infestations and 120 hpi during secondary infestations. the micr ... | 2014 | 24847317 |
| gene expression of tissue-specific molecules in ex vivo dermacentor variabilis (acari: ixodidae) during rickettsial exposure. | ticks serve as both vectors and the reservoir hosts capable of transmitting spotted fever group rickettsia by horizontal and vertical transmission. persistent maintenance of rickettsia species in tick populations is dependent on the specificity of the tick and rickettsia relationship that limits vertical transmission of particular rickettsia species, suggesting host-derived mechanisms of control. tick-derived molecules are differentially expressed in a tissue-specific manner in response to ricke ... | 0 | 24180114 |
| asymptomatic petechial eruption on the lower legs. | the authors report an unusual case of rocky mountain spotted fever that presented as an asymptomatic petechial eruption on the lower legs. rocky mountain spotted fever is rare in new england and, as such, is typically not on the differential diagnosis when presented with such patients. what began as an asymptomatic eruption progressed to more classic signs of the disease, including a positive rocky mountain spotted fever titer. the patient was successfully treated with doxycydine and within a sh ... | 0 | 24062875 |
| reinstatement of dermacentor kamshadalus neumann (acari: ixodidae) as a valid species parasitizing mountain goats and sheep in the united states, canada, and russia. | reexamination of dermacentor albipictus (packard, 1869) holdings stored in the united states national tick collection revealed several collections of a morphologically distinct dermacentor species. comparison of these specimens with other dermacentor taxa showed that they are identical to an old taxon originally described as dermacentor variegatus kamshadalus neumann, 1908. for more than a century, this taxon was known only from the male holotype specimen collected in russia, and the name was co ... | 0 | 23926766 |
| novel immunomodulators from hard ticks selectively reprogramme human dendritic cell responses. | hard ticks subvert the immune responses of their vertebrate hosts in order to feed for much longer periods than other blood-feeding ectoparasites; this may be one reason why they transmit perhaps the greatest diversity of pathogens of any arthropod vector. tick-induced immunomodulation is mediated by salivary components, some of which neutralise elements of innate immunity or inhibit the development of adaptive immunity. as dendritic cells (dc) trigger and help to regulate adaptive immunity, the ... | 2013 | 23825947 |
| protective immunity induced by immunization with a live, cultured anaplasma marginale strain. | despite significant economic losses resulting from infection with anaplasma marginale, a tick-transmitted rickettsial pathogen of cattle, available vaccines provide, at best, only partial protection against clinical disease. the green-fluorescent protein expressing mutant of the a. marginale st. maries strain is a live, marked vaccine candidate (amstm-gfp). to test whether amstm-gfp is safe and provides clinical protection, a group of calves was vaccinated, and clinical parameters, including per ... | 2013 | 23664994 |
| identification of multilocus genetic heterogeneity in anaplasma marginale subsp. centrale and its restriction following tick-borne transmission. | anaplasma marginale subsp. centrale was the first vaccine used to protect against a rickettsial disease and is still in widespread use a century later. as its use preceded development of either cryopreservation or cell culture, the vaccine strain was maintained for decades by sequential passage among donor animals, excluding the natural tick-borne transmission cycle that provides a selective pressure or population "bottleneck." we demonstrated that the vaccine strain is genetically heterogeneous ... | 2013 | 23509140 |
| hitch-hiker taken for a ride: an unusual cause of myocarditis, septic shock and adult respiratory distress syndrome. | rocky mountain spotted fever (rmsf) is a serious tick-borne illness caused by rickettsia rickettsii that is endemic in southeastern usa. although rmsf has been described as causing the classic clinical triad of fever, headache and a characteristic rash, serious and potentially life-threatening manifestations can occur. cardiopulmonary involvement, although infrequent, may occur with severe cases of rmsf. rickettsial myocarditis is an uncommon occurrence. we present a case of a previously healthy ... | 2013 | 23314875 |
| subdominant antigens in bacterial vaccines: am779 is subdominant in the anaplasma marginale outer membrane vaccine but does not associate with protective immunity. | identification of specific antigens responsible for the ability of complex immunogens to induce protection is a major goal in development of bacterial vaccines. much of the investigation has focused on highly abundant and highly immunodominant outer membrane proteins. recently however, genomic and proteomic approaches have facilitated identification of minor components of the bacterial outer membrane that have previously been missed or ignored in immunological analyses. immunization with anaplas ... | 2012 | 23029498 |
| tropism and pathogenicity of rickettsiae. | rickettsiae are obligate intracellular parasitic bacteria that cause febrile exanthematous illnesses such as rocky mountain spotted fever, mediterranean spotted fever, epidemic, and murine typhus, etc. although the vector ranges of each rickettsia species are rather restricted; i.e., ticks belonging to arachnida and lice and fleas belonging to insecta usually act as vectors for spotted fever group (sfg) and typhus group (tg) rickettsiae, respectively, it would be interesting to elucidate the mec ... | 2012 | 22737150 |
| parasite diversity and coinfection determine pathogen infection success and host fitness. | while the importance of changes in host biodiversity for disease risk continues to gain empirical support, the influence of natural variation in parasite diversity on epidemiological outcomes remains largely overlooked. here, we combined field infection data from 2,191 amphibian hosts representing 158 parasite assemblages with mechanistic experiments to evaluate the influence of parasite richness on both parasite transmission and host fitness. using a guild of larval trematode parasites (six spe ... | 2012 | 22615371 |
| expression patterns of anaplasma marginale msp2 variants change in response to growth in cattle, and tick cells versus mammalian cells. | antigenic variation of major surface proteins is considered an immune-evasive maneuver used by pathogens as divergent as bacteria and protozoa. likewise, major surface protein 2 (msp2) of the tick-borne pathogen, anaplasma marginale, is thought to be involved in antigenic variation to evade the mammalian host immune response. however, this dynamic process also works in the tick vector in the absence of immune selection pressure. we examined msp2 variants expressed during infection of four tick a ... | 2012 | 22558307 |
| phylogenetic analysis of myobia musculi (schranck, 1781) by using the 18s small ribosomal subunit sequence. | we used high-fidelity pcr to amplify 2 overlapping regions of the ribosomal gene complex from the rodent fur mite myobia musculi. the amplicons encompassed a large portion of the mite's ribosomal gene complex spanning 3128 nucleotides containing the entire 18s rrna, internal transcribed spacer (its) 1,5.8s rrna, its2, and a portion of the 5'-end of the 28s rrna. m. musculi's 179-nucleotide 5.8s rrna nucleotide sequence was not conserved, so this region was identified by conservation of rrna seco ... | 0 | 22330574 |
| the bacterial microbiome of dermacentor andersoni ticks influences pathogen susceptibility. | 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 charac ... | 2016 | 26882265 |
| morphology of colonies of anaplasma marginale in nymphal dermacentor andersoni. | colonies of anaplasma marginale theiler were studied in midgut epithelial cells of nymphal dermacentor andersoni stiles that had become infected by feeding on splenectomized calves with anaplasmosis. colonies of a marginale were not observed in nymphal ticks killed during the 6-day feeding period, but were present in sections of midgut epithelial cells of ticks killed as early as 5 days after repletion. colonies of a marginale also were present in ticks examined throughout development to the adu ... | 1984 | 24049913 |
| distribution and habitat of ixodes pacificus (acari: ixodidae) and prevalence of borrelia burgdorferi in utah. | knowledge about the distribution and abundance of the western black-legged tick, ixodes pacificus cooley and kohls, in utah is limited. recent concerns over tick-borne diseases in utah, primarily lyme disease, have reinvigorated the need to understand the distribution and habitats favored by this tick species. we surveyed 157 sites throughout utah to examine the distribution, abundance, and habitat of i. pacificus. in total, 343 adult ticks were collected from 2011 to 2013. specifically, 119 i. ... | 2015 | 26336263 |
| effect of rickettsia rickettsii (rickettsiales: rickettsiaceae) infection on the biological parameters and survival of its tick vector-dermacentor variabilis (acari: ixodidae). | rocky mountain spotted fever, caused by rickettsia rickettsii, is a potentially fatal tick-borne disease spread from north america to argentina. the major vectors of r. rickettsii in the united states are dermacentor andersoni stiles and dermacentor variabilis (say). it is generally believed that vector ticks serve as major reservoirs of r. rickettsii in nature; however, the ability of ticks to support the indefinite perpetuation of r. rickettsii has been challenged by reports of deleterious eff ... | 2016 | 26494822 |
| new records of ticks (acari: ixodidae) from dogs, cats, humans, and some wild vertebrates in alaska: invasion potential. | during 2010-2016, tick specimens were solicited from veterinarians, biologists, and members of the public in alaska. eight species of ticks were recorded from domestic dogs. some ticks were collected from dogs with recent travel histories to other countries or other u.s. states, which appears to explain records of ticks not native to alaska such as amblyomma americanum (l.) (lone star tick), ixodes scapularis (say) (blacklegged tick), and ixodes ricinus (l.). however, we recorded dermacentor var ... | 2016 | 27524823 |
| occurrence and county-level distribution of ticks (acari: ixodoidea) in nebraska using passive surveillance. | a 100 yr (1911-2011) examination of tick submissions was compiled from the u.s. national tick collection and three state databases to determine tick species occurrence in nebraska sixteen tick species were identified including amblyomma americanum (l.), dermacentor variabilis (say), dermacentor albipictus (packard), dermacentor andersoni stiles, haemaphysalis leporispalustris (packard), rhipicephalus sanguineus (latreille), and otobius megrini (dughs). amblyomma maculatum koch and ixodes scapula ... | 2014 | 24724283 |
| salivary gland degeneration and ovarian development in the rocky mountain wood tick, dermacentor andersoni stiles (acari: ixodidae). i. post-engorgement events. | it is well known that female ixodid ticks undergo salivary gland degeneration and the greater part of ovarian development following engorgement. the process has been particularly well studied in amblyomma hebraeum, including the hormonal control of these processes. the purpose of this study, and the second one in this series, is to compare the processes in dermacentor andersoni with those of a. hebraeum. a major difference between the two species is that virgin female d. andersoni feed to a much ... | 2014 | 24973274 |
| salivary gland degeneration and ovary development in the rocky mountain wood tick, dermacentor andersoni stiles (acari: ixodidae). ii. determination of the 'critical weight'. | the feeding cycle of female ixodid ticks is divided into preparatory, slow, and rapid feeding phases. when a female amblyomma hebraeum is removed from the host after achieving a minimum size of about 10-13× the unfed weight, various physiological and behavioural changes occur: (a) haemolymph ecdysteroid concentration rises dramatically, (b) the tick does not reattach to the host when given the opportunity, (c) its salivary glands degenerate within about 4 days (if mated) or 8 days (if virgin), a ... | 2014 | 24865927 |
| infection with colorado tick fever virus among humans and ticks in a national park and forest, wyoming, 2010. | colorado tick fever (ctf) is an underreported tick-borne viral disease occurring in the western united states. ctf illness includes fever, headache, and severe myalgia lasting for weeks. wyoming has one of the highest ctf incidence rates with approximately 30% of infected persons reporting tick exposure in a wyoming national park or forest before symptom onset. we assessed ctf virus infections among humans and dermacentor andersoni ticks in grand teton national park (grte) and bridger-teton nati ... | 2014 | 25229706 |
| can subclinical infestation by paralyzing dermacentor andersoni (acari: ixodidae) induce immunity to tick paralysis in sheep? | 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 <0.2 ticks per kilogram sheep weight, and 100% paralysis in sheep exposed to >0.8 ticks per kilogram. this experiment was conducted to determine if sheep expo ... | 2016 | 26802171 |
| proteomics informed by transcriptomics identifies novel secreted proteins in dermacentor andersoni saliva. | 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, wh ... | 2014 | 25110293 |
| movement of male dermacentor andersoni (acari: ixodidae) among cattle. | 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 to be great ... | 2013 | 24180101 |
| embryo development and morphology of the rocky mountain wood tick (acari: ixodidae). | dermacentor andersoni stiles embryogenesis was observed using fluorescent and scanning electron microscopy for eggs held under laboratory conditions (25°c and at 93% relative humidity). early embryonic cell divisions appeared to be synchronous and holoblastic, giving rise to a uniform blastoderm surrounding the yolk. the cells of the blastoderm became concentrated on one side of the embryo, forming the segmented germ band. distinct opisthosomal and prosomal segment morphologies, which are charac ... | 2016 | 26668102 |
| influence of temperature on oviposition by dermacentor andersoni (acari: ixodidae). | 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 ... | 2014 | 25276920 |
| ticks (acari: ixodidae) on small mammals in kootenay national park, british columbia, canada. | two hundred and ninety-one ticks (i.e., 185 larvae, 72 nymphs, and 34 adults) were removed from 153 small mammals comprising six species collected in verdant forest, numa forest, and marble canyon within kootenay national park, british columbia, canada. morphological examination and molecular analyses (i.e., polymerase chain reaction-single-strand conformation polymorphism [pcr-sscp] and dna sequencing of the mitochondrial 16s rrna gene) of the ticks revealed that most individuals were ixodes an ... | 2013 | 24843924 |
| comparative off-host survival of larval rocky mountain wood ticks (dermacentor andersoni) collected from ecologically distinct field populations. | dermacentor andersoni (ixodida: ixodidae) stiles, also known as the rocky mountain wood tick (rmwt), is found throughout the western united states and transmits pathogens of importance to human and animal health. the distributions and activity patterns of rmwts are shaped by regional climatic variation. however, it is unknown if responses to climatic variation differ across the tick's geographical range. the objective of this narrow study was to test the hypothesis that the responses of rmwts to ... | 2014 | 24665893 |
| mutation scanning-based identification of larval and nymphal ticks (acari: ixodidae) from richardson's ground squirrels (spermophilus richardsonii). | the objective of this study was to identify the tick species parasitizing richardson's ground squirrels (spermophilus richardsonii) in southern saskatchewan (canada). morphological examination of the adult ticks revealed the presence of three tick species, ixodes sculptus, ixodes kingi and dermacentor andersoni. however, given the difficulties in identifying some of the larval and nymphal (immature) ticks using this approach, pcr-based single-strand conformation polymorphism (sscp) and dna seque ... | 2014 | 24075866 |
| range expansion of dermacentor variabilis and dermacentor andersoni (acari: ixodidae) near their northern distributional limits. | 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. vari ... | 2013 | 23802445 |
| dispersion and sampling of adult dermacentor andersoni in rangeland in western north america. | 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 ... | 2012 | 22493841 |
| case report: a case of colorado tick fever acquired in southwestern saskatchewan. | colorado tick fever virus is transmitted by dermacentor andersoni ticks. in canada, these ticks are found in the southern regions of british columbia (rocky mountains) and alberta, as well as southwestern saskatchewan. colorado tick fever should be clinically suspected in patients presenting with a biphasic febrile illness and leukopenia following tick exposure in the appropriate geographic area. | 2018 | 29363458 |
| a retrospective cohort study of tick paralysis in british columbia. | tick paralysis is a frequently overlooked severe disease characterized by bilateral ascending flaccid paralysis caused by a neurotoxin produced by feeding ticks. we aimed to characterize suspected tick paralysis cases documented at the bc centre for disease control (bccdc) in british columbia (bc) from 1993 to 2016 and reviewed prevention, diagnosis, and treatment considerations. | 2017 | 29083955 |
| laboratory colonization stabilizes the naturally dynamic microbiome composition of field collected dermacentor andersoni ticks. | nearly a quarter of emerging infectious diseases identified in the last century are arthropod-borne. although ticks and insects can carry pathogenic microorganisms, non-pathogenic microbes make up the majority of their microbial communities. the majority of tick microbiome research has had a focus on discovery and description; very few studies have analyzed the ecological context and functional responses of the bacterial microbiome of ticks. the goal of this analysis was to characterize the stab ... | 2017 | 28978338 |
| the immunomodulatory protein rh36 is relating to blood-feeding success and oviposition in hard ticks. | an immunomodulatory protein designated rh36 was identified in the tick rhipicephalus haemaphysaloides. the cdna sequence of rh36 has 844bp and encodes a deduced protein with a predicted molecular weight of 24kda. bioinformatics analysis indicated that rh36 presented a degree of similarity of 34.36% with the immunomodulatory protein p36 from the tick dermacentor andersoni. the recombinant rh36 (rrh36) expressed in sf9 insect cells suppressed the t-lymphocyte mitogen-driven in vitro proliferation ... | 2017 | 28449954 |