Publications

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changing dynamics of human-rickettsial interactions. 201526556832
a review of theileria diagnostics and epidemiology.an extensive range of serological and molecular diagnostic assays exist for most of the economically important theileira species such as t. annulata, t. equi, t. lestoquardi, t. parva, t. uilenbergi and other more benign species. diagnostics of theileria is considered with regard to sensitivity and specificity of current molecular and serological assays and their use in epidemiology. in the case of serological assays, cross-reactivity of genetically closely related species reduces the use of the ...201525830110
reliability of molecular host-identification methods for ticks: an experimental in vitro study with ixodes ricinus.reliable information on host use by arthropod vectors is required to study pathogen transmission ecology and to predict disease risk. direct observation of host use is often difficult or impossible and indirect methods are therefore necessary. however, the reliability of currently available methods to identify the last host of blood-feeding arthropods has not been evaluated, and may be particularly problematic for ticks because host blood has been digested at capture. biases in host detection ma ...201526296344
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 ...201526593262
the role of cd8 t lymphocytes in rickettsial infections.arthropod-borne obligately intracellular bacteria pose a difficult challenge to the immune system. the genera rickettsia, orientia, ehrlichia, and anaplasma evolved mechanisms of immune evasion, and each interacts differently with the immune system. the roles of cd8 t cells include protective immunity and immunopathology. in rickettsia infections, cd8 t cells are protective mediated in part by cytotoxicity toward infected cells. in contrast, tnf-α overproduction by cd8 t cells is pathogenic in l ...201525823954
carbohydrates as food allergens.the literature supports the notion that carbohydrate epitopes, on their own, do not contribute significantly to the induction of allergic reactions. they bind weakly to ige antibodies and have been termed as cross reactive carbohydrate determinants. these epitopes cause confusion in in vitro ige testing through nonspecific cross-reactivity. coincident with the rising trends in food allergy prevalence, there has recently been reports of anaphylaxis induced by carbohydrate epitopes. there are two ...201525653916
characterization of a novel rxr receptor in the salmon louse (lepeophtheirus salmonis, copepoda) regulating growth and female reproduction.nuclear receptors have crucial roles in all metazoan animals as regulators of gene transcription. a wide range of studies have elucidated molecular and biological significance of nuclear receptors but there are still a large number of animals where the knowledge is very limited. in the present study we have identified an rxr type of nuclear receptor in the salmon louse (lepeophtheirus salmonis) (i.e. lsrxr). rxr is one of the two partners of the ecdysteroid receptor in arthropods, the receptor f ...201525765704
global transcriptome analysis of the tentacle of the jellyfish cyanea capillata using deep sequencing and expressed sequence tags: insight into the toxin- and degenerative disease-related transcripts.jellyfish contain diverse toxins and other bioactive components. however, large-scale identification of novel toxins and bioactive components from jellyfish has been hampered by the low efficiency of traditional isolation and purification methods.201526551022
prevalence of cytauxzoon felis infection in healthy cats from enzootic areas in arkansas, missouri, and oklahoma.infection with cytauxzoon felis in domestic cats can cause fever, lethargy, depression, inappetence, icterus, and often death. with a high mortality rate, cytauxzoonosis was historically considered a fatal disease. within the last 15 years, cats with or without treatment have been recognized as chronically infected survivors of c. felis infection. our objective was to determine the prevalence of c. felis in healthy domestic cats from arkansas, missouri, and oklahoma.201525566776
an insight into the sialome of the lone star tick, amblyomma americanum, with a glimpse on its time dependent gene expression.hard ticks feed for several days or weeks on their hosts. blood feeding is assisted by tick saliva, which is injected in the host skin regularly, alternating with blood ingestion. tick saliva contains hundreds or thousands of different peptides and other bioactive compounds that assist feeding by inhibiting their hosts' blood clotting, platelet aggregation, vasoconstriction, as well as pain and itching. immunomodulatory and antimicrobial peptides are also found in tick saliva. molecular characte ...201526131772
molecular detection of rickettsia species within ticks (acari: ixodidae) collected from arkansas united states.rocky mountain spotted fever (rmsf), caused by the etiological agent rickettsia rickettsii, is the most severe and frequently reported rickettsial illness in the united states, and is commonly diagnosed throughout the southeast. with the discoveries of rickettsia parkeri and other spotted fever group rickettsiae (sfgr) in ticks, it remains inconclusive if the cases reported as rmsf are truly caused by r. rickettsii or other sfgr. arkansas reports one of the highest incidence rates of rmsf in the ...201526334827
parasitology and serology of free-ranging coyotes (canis latrans) in north carolina, usa.coyotes (canis latrans) have expanded recently into the eastern us and can serve as a source of pathogens to domestic dogs (canis lupus familiaris), livestock, and humans. we examined free-ranging coyotes from central north carolina, us, for selected parasites and prevalence of antibodies against viral and bacterial agents. we detected ticks on most (81%) coyotes, with amblyomma americanum detected on 83% of those with ticks. fifteen (47%) coyotes were positive for heartworms (dirofilaria immiti ...201525984773
molecular identification of ehrlichia species and host bloodmeal source in amblyomma americanum l. from two locations in tennessee, united states.the current status of tick-borne diseases in the southeastern united states is challenging to define due to emerging pathogens, uncertain tick/host relationships, and changing disease case definitions. a golf-oriented retirement community on the cumberland plateau in tennessee experienced an ehrlichiosis outbreak in 1993, prompting efforts to reduce the local tick population using '4-poster' acaricide devices targeting white-tailed deer (odocoileus virginianus). in 2009, the prevalence of ehrlic ...201525682494
naturally occurring ehrlichia ewingii and mycoplasma sp. co-infection in a goat. 201526473432
increasing incidence of ehrlichiosis in the united states: a summary of national surveillance of ehrlichia chaffeensis and ehrlichia ewingii infections in the united states, 2008-2012.human ehrlichiosis is a potentially fatal disease caused by ehrlichia chaffeensis and ehrlichia ewingii. cases of ehrlichiosis are reported to centers for disease control and prevention through two national surveillance systems: nationally notifiable diseases surveillance system (nndss) and case report forms. during 2008-2012, 4,613 cases of e. chaffeensis infections were reported through nndss. the incidence rate (ir) was 3.2 cases per million person-years (pys). the hospitalization rate (hr) w ...201526621561
fatal multiple deer tick-borne infections in an elderly patient with advanced liver disease.we present a case of a 66-year-old woman with decompensated alcoholic liver cirrhosis and poorly controlled non-insulin-dependent diabetes mellitus who was admitted with a 1 day history of altered mental status, high-grade fevers, worsening jaundice and generalised malaise with subsequent development of hypotension requiring intensive care. she was diagnosed with severe babesiosis with high-grade parasitaemia. she was also found to have lyme disease coinfection. despite aggressive therapeutic me ...201525733088
implications of xenoglycan sensitivity for increased cancer risk. 201525713132
attenuated mutants of ehrlichia chaffeensis induce protection against wild-type infection challenge in the reservoir host and in an incidental host.ehrlichia chaffeensis, a tick-borne rickettsial organism, causes the disease human monocytic ehrlichiosis. the pathogen also causes disease in several other vertebrates, including dogs and deer. in this study, we assessed two clonally purified e. chaffeensis mutants with insertions within the genes ech_0379 and ech_0660 as vaccine candidates in deer and dogs. infection with the ech_0379 mutant and challenge with wild-type e. chaffeensis 1 month following inoculation with the mutant resulted in t ...201525916990
landscape genetics of schistocephalus solidus parasites in threespine stickleback (gasterosteus aculeatus) from alaska.the nature of gene flow in parasites with complex life cycles is poorly understood, particularly when intermediate and definitive hosts have contrasting movement potential. we examined whether the fine-scale population genetic structure of the diphyllobothriidean cestode schistocephalus solidus reflects the habits of intermediate threespine stickleback hosts or those of its definitive hosts, semi-aquatic piscivorous birds, to better understand complex host-parasite interactions. seventeen lakes ...201525874710
persistent ehrlichia ewingii infection in dogs after natural tick infestation.ehrlichia ewingii, which causes disease in dogs and people, is the most common ehrlichia spp. infecting dogs in the united states, but little is known about how long e. ewingii infection persists in dogs.201525776536
development and characterization of monoclonal antibodies directed against the nucleoprotein of heartland virus.heartland virus (hrtv), a phlebovirus first isolated from two missouri farmers in 2009, has been proposed to be transmitted to humans by the bite of infected amblyomma americanum ticks. it is closely related to severe fever with thrombocytopenia syndrome virus (sftsv) from china, another previously unrecognized phlebovirus that has subsequently been associated with hundreds of cases of severe disease in humans. to expand diagnostic capacity to detect hrtv infections, 20 hybridoma clones secretin ...201526503274
comparative efficacy of an imidacloprid/flumethrin collar (seresto®) and an oral fluralaner chewable tablet (bravecto®) against tick (dermacentor variabilis and amblyomma americanum) infestations on dogs: a randomised controlled trial.this controlled laboratory study demonstrated the residual speed of efficacy of an imidacloprid/flumethrin collar (seresto(®), bayer) for the control of ticks (dermacentor variabilis, amblyomma americanum) at 6 and 12 hours post-infestation on dogs when compared to oral fluralaner (bravecto(®), merck). dogs were randomised by pre-treatment tick counts: group 1) imidacloprid 10 % (w/w)/flumethrin 4.5 % (w/w) collar, 2) fluralaner (dosage 25.1 - 49.4 mg/kg), and 3) non-treated controls. ticks (50/ ...201526152411
comparative efficacy of an imidacloprid/flumethrin collar (seresto®) and an oral afoxolaner chewable (nexgard®) against tick (dermacentor variabilis and amblyomma americanum) infestations on dogs: a randomised controlled trial.this randomised controlled laboratory study demonstrated the residual speed of efficacy of an imidacloprid/flumethrin collar (seresto(®), bayer) for the control of ticks (dermacentor variabilis, amblyomma americanum) at 6 and 12 hours postinfestation on dogs when compared to oral afoxolaner (nexgard(®), merial). dogs were randomised by pre-treatment tick counts: group 1) imidacloprid 10 % (w/w) / flumethrin 4.5 % (w/w) collar, 2) afoxolaner chewable (dosage 3.1 - 6.2 mg/kg), and 3) non-treated c ...201526152410
attempts to feed larval amblyomma americanum (l.) (acari: ixodidae) on three different arthropod hosts. 201526047205
county scale distribution of amblyomma americanum (ixodida: ixodidae) in oklahoma: addressing local deficits in tick maps based on passive reporting.geographic distribution records for the lone star tick [amblyomma americanum (l.)] in the peer-reviewed literature are incomplete for oklahoma, preventing accurate disease risk assessments. to address this issue and document the presence of a. americanum in available habitats throughout the state, county-scale tick records published in u.s. department of agriculture-cooperative economic insect reports and specimens maintained at the k.c. emerson entomology museum, oklahoma state university, were ...201526336311
comparison of dna and carbon and nitrogen stable isotope-based techniques for identification of prior vertebrate hosts of ticks.identification of the vertebrate hosts upon which hematophagous arthropods feed provides key information for understanding the ecology and transmission of vector-borne diseases. bloodmeal analysis of ticks presents unique challenges relative to other vectors, given the long interval between bloodmeal acquisition and host-seeking, during which dna degradation occurs. this study evaluates dna-based and stable isotope-based bloodmeal analysis methodologies for the lone star tick, amblyomma american ...201526336205
cutaneous lesions due to bites by larval amblyomma americanum ticks. 201526309141
the mitochondrial genome of the lone star tick (amblyomma americanum).amblyomma americanum is an abundant tick in the southeastern, midwestern, and northeastern united states. it is a vector of multiple diseases, but limited genomic resources are available for it. we sequenced the complete mitochondrial genome of a single female a. americanum collected in georgia using the illumina platform. the consensus sequence was 14,709 bp long, and the mean coverage across the assembly was >12,000×. all expected tick genomic features were present, including two "tick-box" mo ...201526189992
rickettsia parkeri transmission to amblyomma americanum by cofeeding with amblyomma maculatum (acari: ixodidae) and potential for spillover.amblyomma americanum (l.) is a human-biting ixodid tick distributed throughout much of the southeastern united states. rickettsia parkeri is a member of the spotted fever group rickettsiae and causes a febrile illness in humans commonly referred to as "tidewater spotted fever" or "r. parkeri rickettsiosis." although the gulf coast tick, amblyomma maculatum koch, is the primary vector of r. parkeri, a small proportion of a. americanum have also been shown to harbor r. parkeri. the purpose of this ...201526336226
modeling the biotic and abiotic factors that describe the number of active off-host amblyomma americanum larvae.amblyomma americanum (l.) is a three-host tick that spends most of its life off-host and is an important vector of pathogens in the eastern united states. our objectives were to develop a predictive statistical model that describes the number of active, off-host larvae from 2007 to 2011 and to determine the environmental variables associated with this pattern. data used in this study came from monitoring conducted in northeast missouri in which off-host ticks were collected from a permanent plot ...201526047177
tickbot: a novel robotic device for controlling tick populations in the natural environment.a semi-autonomous 4-wheeled robot (tickbot) was fitted with a denim cloth treated with an acaricide (permethrin™) and tested for its ability to control ticks in a tick-infested natural environment in portsmouth, virginia. the robot's sensors detect a magnetic field signal from a guide wire encased in 80m polyethylene tubing, enabling the robot to follow the trails, open areas and other terrain where the tubing was located. to attract ticks to the treated area, co2 was distributed through the sam ...201525499615
simulation of climate-tick-host-landscape interactions: effects of shifts in the seasonality of host population fluctuations on tick densities.tick vector systems are comprised of complex climate-tick-host-landscape interactions that are difficult to identify and estimate from empirical observations alone. we developed a spatially-explicit, individual-based model, parameterized to represent ecological conditions typical of the south-central united states, to examine effects of shifts in the seasonal occurrence of fluctuations of host densities on tick densities. simulated shifts in the seasonal occurrence of periods of high and low hos ...201526611958
evaluation of deet and eight essential oils for repellency against nymphs of the lone star tick, amblyomma americanum (acari: ixodidae).deet and eight commercially available essential oils (oregano, clove, thyme, vetiver, sandalwood, cinnamon, cedarwood, and peppermint) were evaluated for repellency against host-seeking nymphs of the lone star tick, amblyomma americanum. concentration-repellency response was established using the vertical paper bioassay technique for each essential oil and compared with that of n,n-diethyl-3-methyl benzamide (deet), a standard repellent compound present in many commercial repellent formulations. ...201626590930
determination of the effective dose of a novel oral formulation of sarolaner (simparica™) for the treatment and month-long control of fleas and ticks on dogs.three laboratory studies were conducted to determine the appropriate dose of sarolaner, a novel isoxazoline, for the treatment and month-long control of infestations of fleas and ticks on dogs. in the first study, dogs were treated orally with sarolaner suspension formulations at 1.25, 2.5 or 5.0mg/kg, and infested with dermacentor reticulatus, rhipicephalus sanguineus ticks and with ctenocephalides felis felis (cat flea) prior to treatment and then weekly for up to 8 weeks. fleas and ticks were ...201626948830
target validation of highly conserved amblyomma americanum tick saliva serine protease inhibitor 19.amblyomma americanum tick serine protease inhibitor (serpin, aas) 19, is a highly conserved protein that is characterized by its functional domain being 100% conserved across tick species. we also reported that aas19 was an immunogenic tick saliva protein with anti-haemostatic functions and an inhibitor of trypsin-like proteases including five of the eight serine protease factors in the blood clotting cascade. in this study the goal was to validate the importance of aas19 in a. americanum tick p ...201626746129
panola mountain ehrlichia in amblyomma maculatum from the united states and amblyomma variegatum (acari: ixodidae) from the caribbean and africa.panola mountain ehrlichia (pme) has been suggested as an emerging pathogen of humans and dogs. domestic goats and white-tailed deer (odocoileus virginianus) are also susceptible and likely serve as reservoirs. experimentally, both the lone star tick (amblyomma americanum (l.)) and the gulf coast tick (amblyomma maculatum koch) can transmit pme among deer and goats. in the current study, we detected pme in adult wild-caught a. maculatum from the united states and amblyomma variegatum (f.) from th ...201626744465
sustained efficacy of the novel topical repellent tt-4302 against mosquitoes and ticks.mosquitoes and ticks are blood-feeding pests of humans and animals that can vector many important aetiological agents of disease. previous research demonstrated that tt-4302 (guardian(®) wilderness) containing 5% geraniol applied to human subjects gave 5-6 h of repellency against mosquitoes (depending on species) and was repellent to ticks in vitro. this study was conducted to obtain an independent third-party evaluation of tt-4302 against stegomyia aegypti (= aedes aegypti) (diptera: culicidae) ...201626614394
surveillance for heartland virus (bunyaviridae: phlebovirus) in missouri during 2013: first detection of virus in adults of amblyomma americanum (acari: ixodidae).during 2013, we collected and tested ticks for heartland virus (hrtv), a recently described human pathogen in the genus phlebovirus (bunyaviridae), from six sites in northwestern missouri. five sites were properties owned by hrtv patients, and the sixth was a conservation area that yielded virus in ticks during 2012. we collected 39,096 ticks representing five species; however, two species, amblyomma americanum (l.) (97.6%) and dermacentor variabilis (say) (2.3%), accounted for nearly all ticks ...201627032416
the putative role of rhipicephalus microplus salivary serpins in the tick-host relationship.inflammation and hemostasis are part of the host's first line of defense to tick feeding. these systems are in part serine protease mediated and are tightly controlled by their endogenous inhibitors, in the serpin superfamily (serine protease inhibitors). from this perspective ticks are thought to use serpins to evade host defenses during feeding. the cattle tick rhipicephalus microplus encodes at least 24 serpins, of which rms-3, rms-6, and rms-17 were previously identified in saliva of this ti ...201626844868
emerging tick-borne rickettsia and ehrlichia at joint base langley-eustis, fort eustis, virginia.four species of ticks known to parasitize humans (amblyomma americanum (lone star tick), dermacentor variabilis (american dog tick), amblyomma maculatum (gulf coast tick), and ixodes scapularis (black-legged tick)) were collected at joint base langley-eustis, fort eustis, virginia during 2009. these ticks were tested individually (adults and nymphs) and in pools of 15 (larvae) for pathogens of public health importance within the genera: rickettsia, borrelia, and ehrlichia, by quantitative real-t ...201627613206
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 ...201627524823
repellency to ticks (acari: ixodidae) of extracts of nigella sativa (ranunculaceae) and the anti-inflammatory dogsbestfriend™.motivated by observations that the canine anti-inflammatory cream dogsbestfriend™ (dbf) appeared to deter flies, mosquitoes, and ticks from treated animals, repellent efficacy bioassays using four species of ticks were conducted with three extracts of nigella sativa l. (ranunculaceae), a constituent of dbf. the dbf cream was tested against nymphs of lone star tick, amblyomma americanum (l.). in vertical filter paper assays, the three extracts applied at 0.413 mg extract/cm(2) filter paper repell ...201627394440
neuronal projections from the haller's organ and palp sensilla to the synganglion of amblyomma americanum§.the present study was conducted to elucidate the neuronal pathways between peripheral olfactory and taste sensilla and the synganglion in an ixodidae tick species. the tarsus of the front legs (olfactory nerves) and the fourth palpal segment (gustatory nerves) of unfed amblyomma americanum males and females were excised. a neuronal tracer, dextran tetramethylrhodamine, was used for filling of the sensory neurons. the synganglion preparations were examined using a confocal microscope. neuronal ar ...201627334823
neuronal projections from the haller's organ and palp sensilla to the synganglion of amblyomma americanum§.the present study was conducted to elucidate the neuronal pathways between peripheral olfactory and taste sensilla and the synganglion in an ixodidae tick species. the tarsus of the front legs (olfactory nerves) and the fourth palpal segment (gustatory nerves) of unfed amblyomma americanum males and females were excised. a neuronal tracer, dextran tetramethylrhodamine, was used for filling of the sensory neurons. the synganglion preparations were examined using a confocal microscope. neuronal ar ...201627304521
structural characterization of tick cement cones collected from in vivo and artificial membrane blood-fed lone star ticks (amblyomma americanum).the lone star tick, amblyomma americanum, is endemic to the southeastern united states and capable of transmitting pathogenic diseases and causing non-pathogenic conditions. to remain firmly attached to the host, the tick secretes a proteinaceous matrix termed the cement cone which hardens around the tick's mouthparts to assist in the attachment of the tick as well as to protect the mouthparts from the host immune system. cement cones collected from ticks on a host are commonly contaminated with ...201627118479
thermacell and off! clip-on devices tested for repellency and mortality against amblyomma americanum (acari: ixodida: amblyommidae).the thermacell with allethrin and off! clip-on with metofluthrin were tested in a 939 m(2) vented enclosure against nymphal lone star ticks, amblyomma americanum (l.). repellency assays were conducted at varying distances relative to product specifications for repellency range. nymphal ticks acclimated for 24 h in chambers attached to 10 repellency tracks per repetition. devices were turned on, and the tick travel distance and delay until beginning to travel were recorded. mortality of ticks was ...201627113108
manual for maintenance of multi-host ixodid ticks in the laboratory.use of laboratory animals as hosts for blood-sucking arthropods remains a time-proven and the most efficient method for establishment and propagation of slowly feeding ixodid ticks, despite introduction of techniques involving artificial feeding on either animal skins or synthetic membranes. new zealand white rabbits are usually the most accessible and most suitable hosts routinely used for establishment and maintenance of a large variety of multi-host tick species. here we describe standard pro ...201627651325
rickettsia amblyommatis sp. nov., a spotted fever group rickettsia associated with multiple species of amblyomma ticks in north, central and south america.in 1973, investigators isolated a rickettsial organism, designated strain wb-8-2t, from an adult amblyomma americanum tick collected at land between the lakes national recreation area, tn, usa. this organism is now recognized as highly prevalent in a. americanum, as well as several other amblyomma species found throughout the western hemisphere. it has been suggested that cross-reactivity to wb-8-2t and similar strains contributes to the increasing number of spotted fever cases reported in the u ...201627638476
efficacy of a novel oral formulation of sarolaner (simparica™) against five common tick species infesting dogs in the united states.the efficacy of a single oral treatment with sarolaner (simparica™, zoetis), a novel isoxazoline compound, was evaluated against five tick species known to infest dogs in the united states. a total of 10 laboratory studies, two against each species, were conducted using adult purpose-bred mongrels or beagle dogs. in each study, 16 dogs were randomly allocated to one of two treatment groups based on pre-treatment host-suitability tick counts. dogs were infested with approximately 50 unfed adult a ...201626935819
ticks associated with domestic dogs and cats in florida, usa.voluntary collections of ticks from domestic dogs and cats by veterinary practitioners across florida, usa, were conducted over a 10 month period. of the 1337 ticks submitted, five species of ixodid ticks were identified and included rhipicephalus sanguineus, amblyomma americanum, a. maculatum, dermacentor variabilis, and ixodes scapularis. most ticks were collected from dogs (98.4%) with the most predominant species being r. sanguineus (94.3%). of the ticks collected from cats (1.6%), a. americ ...201626888081
a comparison of the performance of regression models of amblyomma americanum (l.) (ixodidae) using life cycle or landscape data from administrative divisions.the distribution of amblyomma americanum (l.) in the continental united states has been modelled using the reported distribution in counties as "established" (six or more ticks or two or more life stages were recorded during a specified time period), "reported" (fewer than six ticks of a single life stage were recorded), or "absent" (neither of the above categories were met) and a set of environmental and biotic explanatory variables. categorical (vegetation, climate, and habitat suitability for ...201626826973
maximum entropy-based ecological niche model and bio-climatic determinants of lone star tick (amblyomma americanum) niche.the potential distribution of amblyomma americanum ticks in kansas was modeled using maximum entropy (maxent) approaches based on museum and field-collected species occurrence data. various bioclimatic variables were used in the model as potentially influential factors affecting the a. americanum niche. following reduction of dimensionality among predictor variables using principal components analysis, which revealed that the first two principal axes explain over 87% of the variance, the model i ...201626824880
comparison of novel and conventional methods of trapping ixodid ticks in the southeastern u.s.a.tick-borne disease surveillance and research rely on resource-effective methods for tick collection. this study compared the respective performances of several trapping methods in a mixed grassland-forest habitat in western tennessee. to test for temporal differences in effectiveness, sites were sampled monthly (april-august 2013) using dry ice, dragging, flagging, sweep netting, carbon dioxide (co2 ) dragging and co2 flagging methods. to evaluate the effect of habitat on method effectiveness, f ...201626801319
a dynamic population model to investigate effects of climate and climate-independent factors on the lifecycle of amblyomma americanum (acari: ixodidae).the lone star tick, amblyomma americanum, is a disease vector of significance for human and animal health throughout much of the eastern united states. to model the potential effects of climate change on this tick, a better understanding is needed of the relative roles of temperature-dependent and temperature-independent (day-length-dependent behavioral or morphogenetic diapause) processes acting on the tick lifecycle. in this study, we explored the roles of these processes by simulating seasona ...201626502753
hacker within! ehrlichia chaffeensis effector driven phagocyte reprogramming strategy.ehrlichia chaffeensis is a small, gram negative, obligately intracellular bacterium that preferentially infects mononuclear phagocytes. it is the etiologic agent of human monocytotropic ehrlichiosis (hme), an emerging life-threatening tick-borne zoonosis. mechanisms by which e. chaffeensis establishes intracellular infection, and avoids host defenses are not well understood, but involve functionally relevant host-pathogen interactions associated with tandem and ankyrin repeat effector proteins. ...201627303657
correction: the microbiome of ehrlichia-infected and uninfected lone star ticks (amblyomma americanum).[this corrects the article doi: 10.1371/journal.pone.0146651.].201627158898
the retinoid x receptor from mud crab: new insights into its roles in ovarian development and related signaling pathway.in arthropods, retinoid x receptor (rxr) is a highly conserved nuclear hormone receptor. by forming a heterodimeric complex with the ecdysone receptor (ecr), rxr is known to be vital importance for various physiological processes. however, in comparison to ecr, the rxr signaling pathway and its roles in crustacean reproduction are poorly understood. in the present study, the rxr mrna was detected in the ovarian follicular cells of mud crab scylla paramamosain (sprxr) and during ovarian maturatio ...201627009370
coxiella symbionts are widespread into hard ticks.ticks are blood-feeding arthropods and can harbor several bacteria, including the worldwide zoonotic disease q-fever agent coxiella burnetii. recent studies have reported a distinct group of coxiella mostly associated with ixodidae ticks, including the primary endosymbionts of amblyomma americanum. in the present work, a screening for coxiella infection was performed by 16s ribosomal dna (rdna) gene analyses in 293 tick samples of 15 different species sampled worldwide, including brazil, colombi ...201627595990
survey of ticks collected from tennessee cattle and their pastures for anaplasma and ehrlichia species.anaplasma marginale is the causative agent for bovine anaplasmosis (ba) and ehrlichia ruminantium is the causative agent for heartwater, 2 devastating diseases of cattle. ba is common in the united states and frequently reported in western tennessee cattle; however, cases of heartwater are not yet established in the continental united states. because both pathogens are transmitted via the bites of infected ticks, the objective of this study was to survey cattle and pastures for ticks and for eac ...201626348980
use of extracorporeal support in hemophagocytic lymphohistiocytosis secondary to ehrlichiosis.ehrlichiosis, caused by transmission of ehrlichia chaffeensis to humans through the bite of an infected lone star tick, can lead to secondary hemophagocytic lymphohistiocytosis (hlh), a life-threatening condition caused by uncontrolled activation of the cellular immune system. we describe a child with hlh secondary to ehrlichiosis who developed multiorgan failure and was successfully managed with extracorporeal membrane oxygenation (ecmo). a 9-year-old boy developed headaches, fever, and sore th ...201627633921
the diversity and prevalence of hard ticks attacking human hosts in eastern siberia (russian federation) with first description of invasion of non-endemic tick species.hard ticks are the vectors of many pathogens including tick-borne encephalitis virus and the lyme disease agent borrelia burgdorferi sensu lato. in eastern siberia, ixodes persulcatus, dermacentor nuttalli, dermacentor silvarum and haemaphysalis concinna are regarded as aggressive to humans. recently, significant changes in world tick fauna have been reported and this affects the spread of tick-borne pathogens. we studied the current species diversity, population structure and prevalence of tick ...201626443685
detection of borrelia, ehrlichia, and rickettsia spp. in ticks in northeast missouri.we evaluated amblyomma americanum (lone star tick) and dermacentor variabilis (american dog tick) in northeast missouri for the presence of borrelia, ehrlichia, and rickettsia bacteria. we collected actively questing ticks from four sites within adair county, missouri. a total of 15,162 ticks were collected, of which 13,980 were grouped in 308 pools (lone star ticks, 288 pools; american dog ticks, 20 pools) and tested for presence/absence of bacteria using polymerase chain reaction. infection ra ...201627133163
prevalence of tick-borne pathogens in host-seeking amblyomma americanum (acari: ixodidae) and odocoileus virginianus (artiodactyla: cervidae) in florida.amblyomma americanum (l.), the lone star tick, is an aggressive tick that is expanding its geographic range within the united states. this tick is the vector for the human and veterinary pathogens ehrlichia chaffeensis and ehrlichia ewingii and is associated with other microbes of unspecified pathogenicity including rickettsia amblyommii, panola mountain ehrlichia, and borrelia lonestari in florida, there has been sparse contemporary data on the prevalence of these organisms in host-seeking lone ...201627117680
new records of ixodes affinis (acari: ixodidae) parasitizing avian hosts in southeastern virginia.ixodes affinis neumann (acari: ixodidae) is a hard-bodied tick species distributed throughout much of the southeastern united states. although i. affinis does not parasitize humans, it is a competent vector of borrelia burgdorferi sensu stricto, the causative-agent of lyme disease, and thus contributes to the enzootic maintenance of this pathogen. this study presents evidence of i. affinis parasitizing five new host passerine species. during 2012-2014, 1,888 birds were captured and examined for ...201626586535
occurrence of amblyomma americanum (acari: ixodidae) and human infection with ehrlichia chaffeensis in wisconsin, 2008-2015.because of the increasing incidence of human ehrlichiosis in wisconsin, we assessed reports of human infections by ehrlichia chaffeensis and the distribution of its vector, the lone star tick (amblyomma americanum (l.)). from 2008 through 2015, 158 probable and confirmed human cases of e. chaffeensis infections were reported to the wisconsin department of health services. five cases without travel history outside of wisconsin were confirmed as e. chaffeensis by polymerase chain reaction. surveil ...201628011735
heterogeneous associations of ecological attributes with tick-borne rickettsial pathogens in a periurban landscape.the variations in prevalence levels of two tick-borne rickettsial pathogens, ehrlichia chaffeensis and ehrlichia ewingii, in a periurban environment were evaluated along with their ecological determinants. tick life stage and sex, month of tick collection, landscape fragmentation, and ecological covariates specific to pasture and woodland sites were considered as explanatory covariates. questing lone star ticks (amblyomma americanum) were collected by flagging for an hour once every week during ...201627454144
note on ehrlichia chaffeensis, ehrlichia ewingii, and "borrelia lonestari" infection in lone star ticks (acari: ixodidae), nebraska, usa.the lone star tick, amblyomma americanum (l.) (acari: ixodidae), is established in southeastern nebraska yet the prevalence of tick-associated microorganisms is not known. an initial pcr-based analysis for ehrlichia chaffeensis, ehrlichia ewingii, and borrelia infection in host-seeking adult ticks collected in southeast nebraska was conducted. a total of 251 adult ticks collected in six sites in southeast nebraska were tested. e. chaffeensis, e. ewingii, and borrelia spp. were present, and the p ...201626515060
transmission of heartland virus (bunyaviridae: phlebovirus) by experimentally infected amblyomma americanum (acari: ixodidae).heartland virus (hrtv; bunyaviridae: phlebovirus) is a recently described cause of human illness in the united states. after field studies conducted in 2012 implicated amblyomma americanum (l.) as a vector of hrtv, we initiated experiments to assess the vector competence of a. americanum larval and nymphal ticks were immersed in high-titered suspensions of hrtv, and then tested for virus at various intervals postimmersion. in a later trial larval ticks were immersed in hrtv, followed by engorgem ...201627330103
the chemosensory appendage proteome of amblyomma americanum (acari: ixodidae) reveals putative odorant-binding and other chemoreception-related proteins.proteomic analyses were done on 2 chemosensory appendages of the lone star tick, amblyomma americanum. proteins in the fore tarsi, which contain the olfactory haller's organ, and in the palps, that include gustatory sensilla, were compared with proteins in the third tarsi. also, male and female ticks were compared. proteins were identified by sequence similarity to known proteins, and by 3-dimensional homology modeling. proteomic data were also compared with organ-specific transcriptomes from th ...201627307202
evaluation of human attachment by larval amblyomma maculatum (acari: ixodidae).the tick, amblyomma maculatum koch (gulf coast tick), has recently been shown to be an important disease vector of both medical and veterinary concern. although much is known about the behavior and ecology of adults, little is known of the immatures. larval feeding on humans has never been demonstrated (and thus, there are no collection records from humans). in this experiment, 10 larval a. maculatum, amblyomma americanum (l.) (a positive control), and dermacentor variabilis (say) (a negative co ...201626576936
ectoparasites of free-roaming domestic cats in the central united states.free-roaming domestic cat (felis catus) populations serve as a valuable resource for studying ectoparasite prevalence. while they share a similar environment as owned cats, free-roaming cats do not receive routine veterinary care or ectoparasiticide application, giving insight into parasite risks for owned animals. we examined up to 673 infested cats presented to a trap-neuter-return (tnr) clinic in the central united states. ectoparasite prevalences on cats were as follows: fleas (71.6%), ticks ...201627692321
isolation and short-term persistence of ehrlichia ewingii in cell culture.ehrlichia ewingii is the causative agent of human and canine granulocytic ehrlichiosis. since its discovery in 1970, little work has been done to characterize the pathogen or study the transmission dynamics due to the inability to grow the agent in vitro. the aim of this study was to assess the suitability of multiple cell lines and media formulations for propagation of e. ewingii in cell culture. in this study, we present an overview of attempts to isolate e. ewingii from the buffy coat of goat ...201627228133
low rate of cetuximab hypersensitivity reactions in northeast tennessee: an appalachian effect?cetuximab is a monoclonal antibody with a known risk of hypersensitivity reactions. early studies showed hypersensitivity reaction rates of 3%, but there appears to be a higher incidence in the southeastern united states. to confirm the findings from nearby institutions that cetuximab-associated hypersensitivity reactions occur in approximately 20% of patients in the southeastern united states.201626590031
comparative speed of kill of sarolaner (simparica) and afoxolaner (nexgard) against induced infestations of amblyomma americanum on dogs.the lone star tick, amblyomma americanum, infests dogs and cats in north america and is the vector of the pathogens that cause monocytic and granulocytic ehrlichiosis in dogs and humans. a parasiticide's speed of kill is important to minimize the direct and deleterious effects of tick infestation and especially to reduce the risk of transmission of tick-borne pathogens. in this study, speed of kill of a novel orally administered isoxazoline parasiticide, sarolaner (simparica chewable tablets), a ...201626897175
the red meat allergy syndrome in sweden.in the last decade, a novel type of food allergy presenting with severe allergic reactions several hours after consumption of red meat has been recognized. the allergic responses are due to ige antibodies directed against the carbohydrate epitope galactose-α-1,3-galactose (α-gal) found in mammalian meat. this review presents the red meat allergy syndrome in sweden, discusses the features of the immune response to carbohydrates, and highlights the presence of heat stable α-gal-containing proteins ...201627656352
temporal gene expression analysis and rna silencing of single and multiple members of gene family in the lone star tick amblyomma americanum.saliva is an integral factor in the feeding success of veterinary and medically important ticks. therefore, the characterization of the proteins present in tick saliva is an important area of tick research. here, we confirmed previously generated sialotranscriptome data using quantitative real-time pcr. the information obtained in this in-depth study of gene expression was used to measure the effects of metalloprotease gene silencing on tick feeding. we analyzed the temporal expression of seven ...201626872360
first report of cytauxzoon sp. infection in a domestic cat from portugal.cytauxzoonosis is an emerging and life-threatening tick-borne feline disease caused by haemoprotozoan parasites of the genus cytauxzoon. information regarding epidemiological and clinical presentation of infections by species other than cytauxzoon felis is scant. a case of cytauxzoon sp. infection is described in a 2-year-old mixed breed male domestic cat from portugal, presenting a history of acute lethargy, anorexia and pyrexia.201627160193
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 ...201627822206
population and evolutionary genomics of amblyomma americanum, an expanding arthropod disease vector.the lone star tick, amblyomma americanum, is an important disease vector and the most frequent tick found attached to humans in the eastern united states. the lone star tick has recently experienced a rapid range expansion into the northeast and midwest, but despite this emerging infectious threat to wildlife, livestock, and human health, little is known about the genetic causes and consequences of the geographic expansion. in the first population genomic analysis of any tick species, we charact ...201627190204
successful treatment of human monocytic ehrlichiosis with rifampin.currently recommended treatment regimens for human monocytic ehrlichiosis (hme) include doxycycline or tetracycline. antibiotic susceptibility studies demonstrate that rifampin has in vitro bactericidal activity against ehrlichia. case reports have suggested clinical response with rifampin treatment of human granulocytic anaplasmosis (hga). we report the first case of hme successfully treated with rifampin.201626918212
is the antitumor property of trypanosoma cruzi infection mediated by its calreticulin?eight to 10 million people in 21 endemic countries are infected with trypanosoma cruzi. however, only 30% of those infected develop symptoms of chagas' disease, a chronic, neglected tropical disease worldwide. similar to other pathogens, t. cruzi has evolved to resist the host immune response. studies, performed 80 years ago in the soviet union, proposed that t. cruzi infects tumor cells with similar capacity to that displayed for target tissues such as cardiac, aortic, or digestive. an antagoni ...201627462315
efficient enrichment of bacterial mrna from host-bacteria total rna samples.despite numerous advances in genomics and bioinformatics, technological hurdles remain to examine host-microbe transcriptomics. sometimes the transcriptome of either or both can be ascertained merely by generating more sequencing reads. however, many cases exist where bacterial mrna needs to be enriched further to enable cost-effective sequencing of the pathogen or endosymbiont. while a suitable method is commercially available for mammalian samples of this type, development of such methods has ...201627713560
male tarsi specific odorant-binding proteins in the diving beetle cybister japonicus sharp.odorant binding proteins (obps) play critical roles in chemical communication of insects, as they recognize and transport environmental chemical signals to receptors. the diving beetle cybister japonicus sharp shows a remarkable sexual dimorphism. the foreleg tarsi of males are equipped with large suction cups, believed to help holding the female during underwater courtship and mating. here, we identified two obps highly and specifically expressed in male tarsi, suggesting important functions of ...201627545810
molecular diagnosis and genetic diversity of tick-borne anaplasmataceae agents infecting the african buffalo syncerus caffer from marromeu reserve in mozambique.tick-borne diseases (tbds) are very important in relation to domestic ruminants, but their occurrence among wild ruminants, mainly in the african buffalo syncerus caffer, remains little known.201627531003
the intracellular bacterium anaplasma phagocytophilum selectively manipulates the levels of vertebrate host proteins in the tick vector ixodes scapularis.the intracellular bacteria anaplasma phagocytophilum are emerging zoonotic pathogens affecting human and animal health, and a good model for the study of tick-host-pathogen interactions. this tick-borne pathogen is transmitted by ixodes scapularis in the united states where it causes human granulocytic anaplasmosis. tick midguts and salivary glands play a major role during tick feeding and development, and in pathogen acquisition, multiplication and transmission. vertebrate host proteins are fou ...201627561965
vaccination with an attenuated mutant of ehrlichia chaffeensis induces pathogen-specific cd4+ t cell immunity and protection from tick-transmitted wild-type challenge in the canine host.ehrlichia chaffeensis is a tick-borne rickettsial pathogen and the causative agent of human monocytic ehrlichiosis. transmitted by the amblyomma americanum tick, e. chaffeensis also causes disease in several other vertebrate species including white-tailed deer and dogs. we have recently described the generation of an attenuated mutant strain of e. chaffeensis, with a mutation in the ech_0660 gene, which is able to confer protection from secondary, intravenous-administered, wild-type e. chaffeens ...201626841025
development and validation of an improved pcr method using the 23s-5s intergenic spacer for detection of rickettsiae in dermacentor variabilis ticks and tissue samples from humans and laboratory animals.a novel nested pcr assay was developed to detectrickettsiaspp. in ticks and tissue samples from humans and laboratory animals. primers were designed for the nested run to amplify a variable region of the 23s-5s intergenic spacer (igs) ofrickettsiaspp. the newly designed primers were evaluated using genomic dna from 11rickettsiaspecies belonging to the spotted fever, typhus, and ancestral groups and, in parallel, compared to otherrickettsia-specific pcr targets (ompa,glta, and the 17-kda protein ...201626818674
arsenophonus nasoniae and rickettsiae infection of ixodes ricinus due to parasitic wasp ixodiphagus hookeri.arsenophonus nasoniae, a male-killing endosymbiont of chalcid wasps, was recently detected in several hard tick species. following the hypothesis that its presence in ticks may not be linked to the direct occurrence of bacteria in tick's organs, we identified a. nasoniae in wasps emerging from parasitised nymphs. we confirmed that 28.1% of ixodiphagus hookeri wasps parasitizing ixodes ricinus ticks were infected by a. nasoniae. moreover, in examined i. ricinus nymphs, a. nasoniae was detected on ...201626901622
risk factors for bartonella species infection in blood donors from southeast brazil.bacteria from the genus bartonella are emerging blood-borne bacteria, capable of causing long-lasting infection in marine and terrestrial mammals, including humans. bartonella are generally well adapted to their main host, causing persistent infection without clinical manifestation. however, these organisms may cause severe disease in natural or accidental hosts. in humans, bartonella species have been detected from sick patients presented with diverse disease manifestations, including cat scrat ...201626999057
longipin: an amyloid antimicrobial peptide from the harvestman acutisoma longipes (arachnida: opiliones) with preferential affinity for anionic vesicles.in contrast to vertebrate immune systems, invertebrates lack an adaptive response and rely solely on innate immunity in which antimicrobial peptides (amps) play an essential role. most of them are membrane active molecules that are typically unstructured in solution and adopt secondary/tertiary structures upon binding to phospholipid bilayers. this work presents the first characterization of a constitutive amp from the hemolymph of an opiliones order animal: the harvestman acutisoma longipes. th ...201627997568
comparative speed of kill of sarolaner (simparica™ chewables) and fluralaner (bravecto(®)) against induced infestations of amblyomma americanum on dogs.the lone star tick, amblyomma americanum, infests dogs and cats in north america and transmits the pathogens ehrlichia chaffeensis and ehrlichia ewingii, which cause monocytic and granulocytic ehrlichiosis in dogs and humans, and cytauxzoon felis which causes cytauxzoonosis in cats. a parasiticide's speed of kill is important to minimize the direct deleterious effects [related to blood-feeding] of tick infestation and reduce the risk of transmission of tick-borne pathogens. in this study the spe ...201627430425
evasins: therapeutic potential of a new family of chemokine-binding proteins from ticks.blood-sucking parasites, such as ticks, remain attached to their hosts for relatively long periods of time in order to obtain their blood meal without eliciting an immune response. one mechanism used to avoid rejection is the inhibition of the recruitment of immune cells, which can be achieved by a class of chemokine-binding proteins (ckbps) known as evasins. we have identified three distinct evasins produced by the salivary glands of the common brown dog tick, rhipicephalus sanguineus. they dis ...201627375615
the genome of the crustacean parhyale hawaiensis, a model for animal development, regeneration, immunity and lignocellulose digestion.the amphipod crustacean parhyale hawaiensis is a blossoming model system for studies of developmental mechanisms and more recently regeneration. we have sequenced the genome allowing annotation of all key signaling pathways, transcription factors, and non-coding rnas that will enhance ongoing functional studies. parhyale is a member of the malacostraca clade, which includes crustacean food crop species. we analysed the immunity related genes of parhyale as an important comparative system for the ...201627849518
a review of piroplasmid infections in wild carnivores worldwide: importance for domestic animal health and wildlife conservation.piroplasmids are tick-borne protozoan parasites that infect blood cells (erythrocytes, lymphocytes or other leukocytes) or endothelial cells of numerous wild and domestic vertebrates worldwide. they cause severe disease in livestock, dogs, cats, wild mammals and, occasionally, in humans. piroplasmid infections are prevalent in wild carnivores worldwide although there is limited information about their clinical and epidemiological importance. there are currently nine recognized species of babesia ...201627724937
saliva of rhipicephalus (boophilus) microplus (acari: ixodidae) inhibits classical and alternative complement pathways.rhipicephalus (boophilus) microplus is the main ectoparasite affecting livestock worldwide. for a successful parasitism, ticks need to evade several immune responses of their hosts, including the activation of the complement system. in spite of the importance of r. microplus, previous work only identified one salivary molecule that blocks the complement system. the current study describes complement inhibitory activities induced by r. microplus salivary components and mechanisms elicited by puta ...201627515662
unique strain of borrelia miyamotoi in ixodes pacificus ticks, california, usa. 201627479523
in vitro effect of seven essential oils on the reproduction of the cattle tick rhipicephalus microplus.the acaricidal effect of seven essential oils was examined in vitro against the cattle tick (rhipicephalus microplus). engorged female ticks were manually collected in farms of southern brazil and placed into petri dishes (n = 10) in order to test the following oils: juniper (juniperus communis), palmarosa (cymbopogon martinii), cedar (cedrus atlantica), lemon grass (cymbopogon citratus), ginger (zingiber officinale), geranium (pelargonium graveolens) and bergamot (citrus aurantium var bergamia) ...201627857849
gray wolf exposure to emerging vector-borne diseases in wisconsin with comparison to domestic dogs and humans.world-wide concern over emerging vector-borne diseases has increased in recent years for both animal and human health. in the united sates, concern about vector-borne diseases in canines has focused on lyme disease, anaplasmosis, ehrlichiosis, and heartworm which infect domestic and wild canids. of these diseases, lyme and anaplasmosis are also frequently diagnosed in humans. gray wolves (canis lupus) recolonized wisconsin in the 1970s, and we evaluated their temporal and geographic patterns of ...201627898670
systemically and cutaneously distributed ectoparasiticides: a review of the efficacy against ticks and fleas on dogs.acaricidal (tick) and insecticidal (flea) efficacy of systemically and cutaneously distributed ectoparasiticide products for dogs are compared based on permethrin and fluralaner as representative molecules. results of efficacy studies against fleas and ticks are reviewed that show generally good to excellent results. both externally and systemically distributed treatments have benefits and weaknesses in potentially preventing pathogen transmission by these arthropod vectors.four general properti ...201627502490
passive surveillance of ixodes scapularis (say), their biting activity, and associated pathogens in massachusetts.a passive surveillance of tick-borne pathogens was conducted over a 7-year period (2006-2012), in which a total of 3551 ticks were submitted to the university of massachusetts for pcr testing. the vast majority of these ticks were ixodes scapularis from massachusetts (n = 2088) and hence were the focus of further analysis. two taqman duplex qpcr assays were developed to test i. scapularis ticks for the presence of three human pathogens: borrelia burgdorferi, anaplasma phagocytophilum, and babesi ...201627248292
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