intracellular infection of tick cell lines by the entomopathogenic fungus metarhizium anisopliae.several fungal pathogens are able to enter and persist within eukaryotic cells as part of their infectious life cycle. metarhizium anisopliae is a saprophytic entomopathogenic fungus virulent towards numerous tick species, including those within the genera ixodes and amblyomma. infection of the target organism by this fungus proceeds via several steps, including adhesion and penetration of the host cuticle, proliferation within tissues and the haemolymph, and eventual eruption through the host c ...200818524924
permeability of tarsal sensilla in the tick amblyomma americanum l. (acarina, ixodidae).ticks were submerged in silver-protein solution, prior to fixation for electron microscopy, in order to trace the pathway of molecules in supposed tarsal chemoreceptors. sensilla with radially arranged cuticular canals (100-200 a in diameter) leading to the centrally located dendrites show silver granules inside the canals and in the central lumen, thus directly making contact with the dendrites. sensilla with large, plugged pores (1200 a) exhibit an accumulation of silver granules in the pore o ...197218631584
prevalence and infection load dynamics of rickettsia felis in actively feeding cat fleas.rickettsia felis is a flea-associated rickettsial pathogen recurrently identified in both colonized and wild-caught cat fleas, ctenocephalides felis. we hypothesized that within colonized fleas, the intimate relationship between r. felis and c. felis allows for the coordination of rickettsial replication and metabolically active periods during flea bloodmeal acquisition and oogenesis.200818665265
a novel clade of cysteinyl leukotriene scavengers in soft ticks.inflammation is an important vertebrate defense mechanism against ecto-parasites for which ticks have evolved numerous mechanisms of modulation. am-33 and tsgp4, related lipocalins from the soft ticks argas monolakensis and ornithodoros savignyi bind cysteinyl leukotrienes with high affinity as measured by isothermal titration calorimetry. this was confirmed in a smooth muscle bioassay that measured contraction of guinea pig ileum induced by leukotriene c4 where both proteins inhibited contracti ...200818675910
identification of residual blood proteins in ticks by mass spectrometry proteomics.mass spectrometry-based proteomics of individual ticks demonstrated persistence of mammalian host blood components, including alpha- and beta-globin chains, histones, and mitochondrial enzymes, in ixodes scapularis and amblyomma americanum ticks for months after molting. residual host proteins may identify sources of infection for ticks.200818680654
the effects of vegetation density and habitat disturbance on the spatial distribution of ixodid ticks (acari: ixodidae).larval, nymphal, and adult amblyomma americanum (l.), and adult dermacentor variabilis (say) ticks were collected using timed dragging techniques, in an attempt to examine how different habitat variables affect models that describe the distribution of ticks in virginia, usa. tick count data were modeled using two approaches: (i) habitat and edge, and (ii) habitat, edge, vegetation density and levels of disturbance. nymphs and adults tended to follow a forest edge distribution when analysed by ha ...200818686272
function, mechanism and evolution of the moubatin-clade of soft tick lipocalins.the "moubatin-clade" of soft tick lipocalins, although monophyletic, shows clear signs of paralogy as indicated by the various functions associated with this protein family. this includes anti-platelet (moubatin), anti-complement (omci) and toxic (tsgp2) activities in the vertebrate host. in order to understand the evolution of function and how it relates to the various paralogs in this clade, we characterized a number of different proteins in regard to undefined function and mechanism. by utili ...200818694828
total, membrane, and immunogenic proteomes of macrophage- and tick cell-derived ehrlichia chaffeensis evaluated by liquid chromatography-tandem mass spectrometry and maldi-tof methods.ehrlichia chaffeensis, a tick-transmitted rickettsial, is the causative agent of human monocytic ehrlichiosis. to examine protein expression patterns, we analyzed total, membrane, and immunogenic proteomes of e. chaffeensis originating from macrophage and tick cell cultures. total proteins resolved by one-dimensional gel electrophoresis and subjected to liquid chromatography-electrospray ionization ion trap mass spectrometry allowed identification of 134 and 116 proteins from macrophage- and tic ...200818710870
evidence of the importance of host habitat use in predicting the dilution effect of wild boar for deer exposure to anaplasma spp.foci of tick-borne pathogens occur at fine spatial scales, and depend upon a complex arrangement of factors involving climate, host abundance and landscape composition. it has been proposed that the presence of hosts that support tick feeding but not pathogen multiplication may dilute the transmission of the pathogen. however, models need to consider the spatial component to adequately explain how hosts, ticks and pathogens are distributed into the landscape. in this study, a novel, lattice-deri ...200818714379
an insight into the salivary transcriptome and proteome of the soft tick and vector of epizootic bovine abortion, ornithodoros coriaceus.the salivary glands of blood-sucking arthropods contain a redundant 'magic potion' that counteracts their vertebrate host's hemostasis, inflammation, and immunity. we here describe the salivary transcriptome and proteomics (sialome) of the soft tick ornithodoros coriaceus. the resulting analysis helps to consolidate the classification of common proteins found in both soft and hard ticks, such as the lipocalins, kunitz, cystatin, basic tail, hebraein, defensin, til domain, metalloprotease, 5'-nuc ...200818725333
laboratory maintenance of ehrlichia chaffeensis and ehrlichia canis and recovery of organisms for molecular biology and proteomics studies.tick-borne illnesses are emerging as a major concern for human health in recent years. these include the human monocytic ehrlichiosis caused by the amblyomma americanum tick-transmitted bacterium, ehrlichia chaffeensis; human ewingii ehrlichiosis caused by ehrlichia ewingii (also transmitted by a. americanum ticks); and human granulocytic anaplasmosis caused by the ixodes scapularis tick-transmitted pathogen, anaplasma phagocytophilum. likewise, tick-borne rickettsial pathogens are also a major ...200818770537
detection of tick-borne pathogens by masstag polymerase chain reaction.masstag polymerase chain reaction (pcr) is a platform that enables microbe detection using primers labeled through a photocleavable link with tags that vary in molecular weight. after multiplex pcr, tags are released by ultraviolet irradiation and analyzed by mass spectroscopy. the identification of a microbe in a sample is determined by its cognate tags. here we describe establishment and implementation of a masstag pcr panel for surveillance of microbes implicated in tick-vectored infectious d ...200918800864
exotic grass invasion reduces survival of amblyomma americanum and dermacentor variabilis ticks (acari: ixodidae).exotic plants often invade areas of high human activity, such as along trails, roads, and forest edges, and in disturbed riparian areas. these same habitat types are also favored by ticks. this convergence suggests that habitat modifications caused by exotic plant invasions may mediate disease vector habitat quality, indirectly affecting human disease risk at the local spatial scale. we tested the hypothesis that experimental invasions of japanese stiltgrass, microstegium vimineum (trin.) a. cam ...200818826028
molecular and biological characterization of the amblyomma americanum organic anion transporter polypeptide.the organic anion transporting polypeptides (oatps in rodents and other organism; oatps in human) are na(+)-independent transporters that shuttle a wide range of endogenous and xenobotic amphipathic compounds across plasma membranes. we previously discovered an amblyomma americanum tick (aam) oatp cdna among genes that were upregulated or induced in ticks that were stimulated to start feeding. in this study, we have characterized a 2860 bp full-length cdna that encode a 724 amino acid putative p ...200818931313
francisella tularensis: an arthropod-borne pathogen.arthropod transmission of tularemia occurs throughout the northern hemisphere. few pathogens show the adaptability of francisella tularensis to such a wide array of arthropod vectors. nonetheless, arthropod transmission of f. tularensis was last actively investigated in the first half of the 20th century. this review will focus on arthropod transmission to humans with respect to vector species, modes of transmission, geographic differences and f. tularensis subspecies and clades.200918950590
host surveys, ixodid tick biology and transmission scenarios as related to the tick-borne pathogen, ehrlichia canis.the ehrlichioses have been subject to increasing interest from veterinary and public health perspectives, but experimental studies of these diseases and their etiologic agents can be challenging. ehrlichia canis, the primary etiologic agent of canine monocytic ehrlichiosis, is relatively well characterized and offers unique advantages and opportunities to study interactions between a monocytotropic pathogen and both its vertebrate and invertebrate hosts. historically, advances in tick-borne dise ...200818963493
exploring the mialome of ticks: an annotated catalogue of midgut transcripts from the hard tick, dermacentor variabilis (acari: ixodidae).ticks are obligate blood feeders. the midgut is the first major region of the body where blood and microbes ingested with the blood meal come in contact with the tick's internal tissues. little is known about protein expression in the digestive tract of ticks. in this study, for analysis of global gene expression during tick attachment and feeding, we generated and sequenced 1,679 random transcripts (ests) from cdna libraries from the midguts of female ticks at varying stages of feeding.200819021911
defining the immune response to ehrlichia species using murine models.pathogenic bacteria belonging to the family anaplasmataceae include species of the genera ehrlichia and anaplasma. ehrlichia chaffeensis, first known as the causative agent of human monocytic ehrlichiosis, also infects several vertebrate hosts including white-tailed deer, dogs, coyotes and goats. e. chaffeensis is transmitted from the bite of an infected hard tick, such as amblyomma americanum. e. chaffeensis and other tick-transmitted pathogens have adapted to both the tick and vertebrate host ...200819028013
role of the lone star tick, amblyomma americanum (l.), in human and animal diseases.we reviewed scientific literature pertaining to known and putative disease agents associated with the lone star tick, amblyomma americanum. reports in the literature concerning the role of the lone star tick in the transmission of pathogens of human and animal diseases have sometimes been unclear and even contradictory. this overview has indicated that a. americanum is involved in the ecology of several disease agents of humans and other animals, and the role of this tick as a vector of these di ...200919054615
amblyomma americanum (l): tick macrophage migration inhibitory factor peptide immunization lengthens lone star tick feeding intervals in vivo.immunizations of new zealand white rabbits with specific macrophage migration inhibitory factor (mif) tick peptide (pep) produced circulating anti-tick pep antibodies in the hosts. antibody titers of greater than 1:5000 to tick mif peptide were observed for crude sera from pep-immunized rabbits. pep- and bsa-vaccinated rabbits were infested with amblyomma americanum adults. feeding intervals, female weights, egg masses and percent egg hatch were measured for ticks feeding on control and immunize ...200919111543
efficacy of the new repellent bioud against three species of ixodid ticks.bioud with the active ingredient 2-undecanone originally derived from wild tomato plants is a new repellent recently registered by the us epa. repellent efficacy of bioud (7.75% 2-undecanone) and deet (98.11%) was examined in the laboratory using a choice test between repellent-treated and control filter paper surfaces for amblyomma americanum, dermacentor variabilis, and ixodes scapularis. bioud provided greater repellency against a. americanum and i. scapularis than deet. no difference was fou ...200919140016
transmission of cytauxzoon felis to a domestic cat by amblyomma americanum.cytauxzoon felis was transmitted to a domestic cat by amblyomma americanum. the infection was produced by the bite of a. americanum adults that were acquisition fed as nymphs on a domestic cat that naturally survived infection of c. felis. fever, inappetence, depression, and lethargy were first noted 11 days post-infestation (dpi). pale mucus membranes, splenomegaly, icterus, and dyspnea were also observed during the course of the disease. the body temperature of the experimentally infected c. f ...200919168288
isolongifolenone: a novel sesquiterpene repellent of ticks and mosquitoes.a naturally occurring sesquiterpene, isolongifolenone, derivatives of which have been used extensively as ingredients in the cosmetics industry, was discovered to effectively repel blood-feeding arthropods that are important disease vectors. we show that (-)-isolongifolenone deters the biting of the mosquitoes, aedes aegypti (l.) and anopheles stephensi liston, more effectively than the widely used synthetic chemical repellent, n,n-diethyl-3-methyl benzamide (deet), in laboratory bioassays. the ...200919198523
detection of borrelia burgdorferi and borrelia lonestari in birds in tennessee.lyme disease in the united states is caused by the bacterial spirochete borrelia burgdorferi s.s. (johnson, schmid, hyde, steigerwalt, and brenner), which is transmitted by tick vectors ixodes scapularis (say) and i. pacificus (cooley and kohls). borrelia lonestari, transmitted by the tick amblyomma americanum l., may be associated with a related syndrome, southern tick-associated rash illness (stari). borrelia lonestari sequences, reported primarily in the southeastern states, have also been de ...200919198527
conservation and immunogenicity of the mosquito ortholog of the tick-protective antigen, subolesin.the control of arthropod vectors of pathogens that affect human and animal health is important for the eradication of vector-borne diseases. the ortholog of the tick-protective antigen, subolesin, was identified in aedes albopictus and found to have conserved epitopes in ticks and mosquitoes. rna interference with the tick and mosquito double-stranded rna in three tick species resulted in significant gene knockdown and decreased tick weight and/or survival. feeding anopheles atroparvus, aedes ca ...200919229557
infection and replication of bartonella species within a tick cell line.bartonella species are fastidious, gram negative bacteria, some of which are transmitted by arthropod vectors, including fleas, sandflies, and lice. there is very little information regarding the interaction and/or transmission capabilities of bartonella species by ticks. in the present study, we demonstrate successful infection of the amblyomma americanum cell line, aae12, by seven bartonella isolates and three candidatus bartonella species by electron or light microscopy. with the exception of ...200919242658
antibody responses of domestic animals to salivary antigens of triatomainfestans as biomarkers for low-level infestation of triatomines.hematophagous arthropods such as triatoma infestans, the vector of trypanosoma cruzi, elicit host-immune responses during feeding. characterization of antibody responses to salivary antigens offers the potential to develop immunologically based monitoring techniques for exposure to re-emergent triatomine bug populations in peridomestic animals. igg-antibody responses to the salivary antigens of t.infestans have been detected in chickens as soon as 2 days after the first exposure to five adult bu ...200919248784
79-year-old man with fever, malaise, and jaundice. 200919252117
a borreliacidal factor in amblyomma americanum saliva is associated with phospholipase a2 activity.previous work in our laboratory described the in vitro killing of borrelia burgdorferi when co-cultured with saliva from adult amblyomma americanum. borreliacidal activity was not evident using ixodes scapularis saliva. mixing trypsin with saliva eliminated the borreliacidal activity of a. americanum saliva, while incorporating a trypsin inhibitor restored all borreliacidal activity, indicating this factor was of protein or peptide origin. one-dimensional page indicated at least 7 major protein ...200919271281
molecular characterization of ehrlichia interactions with tick cells and macrophages.several tick-transmitted anaplasmataceae family rickettsiales of the genera ehrlichia and anaplasma have been discovered in recent years. some species are classified as pathogens causing emerging diseases with growing health concern for people. they include human monocytic ehrlichiosis, human granulocytic ewingii ehrlichiosis and human granulocytic anaplasmosis which are caused by ehrlichia chaffeensis, e. ewingii and anaplasma phagocytophilum, respectively. despite the complex cellular environm ...200919273271
effects of climate change on ticks and tick-borne diseases in europe.zoonotic tick-borne diseases are an increasing health burden in europe and there is speculation that this is partly due to climate change affecting vector biology and disease transmission. data on the vector tick ixodes ricinus suggest that an extension of its northern and altitude range has been accompanied by an increased prevalence of tick-borne encephalitis. climate change may also be partly responsible for the change in distribution of dermacentor reticulatus. increased winter activity of i ...200919277106
transcriptome analysis of the salivary glands of the female tick amblyomma americanum (acari: ixodidae).ticks infest a wide range of hosts while bypassing their immune, inflammatory and haemostatic responses during their extended feeding, which may last for more than two weeks. here, we present a transcriptome analysis of 3868 expressed sequence tags (ests) from three cdna libraries generated from the salivary glands of adult female ambyomma americanum ticks at different stages of feeding. we applied a normalization step for one library, significantly decreasing the abundance of mitochondrial sequ ...200919320755
the relationship between spotted fever group rickettsiae and ixodid ticks.spotted fever group rickettsiae are predominantly transmitted by ticks. rickettsiae have developed many strategies to adapt to different environmental conditions, including those within their arthropod vectors and vertebrate hosts. the tick-rickettsiae relationship has been a point of interest for many researchers, with most studies concentrating on the role of ticks as vectors. unfortunately, less attention has been directed towards the relationship of rickettsiae with tick cells, tissues, and ...200919358804
reviewing molecular adaptations of lyme borreliosis spirochetes in the context of reproductive fitness in natural transmission cycles.lyme borreliosis (lb) is caused by a group of pathogenic spirochetes - most often borrelia burgdorferi, b. afzelii, and b. garinii - that are vectored by hard ticks in the ixodes ricinus-persulcatus complex, which feed on a variety of mammals, birds, and lizards. although lb is one of the best-studied vector-borne zoonoses, the annual incidence in north america and europe leads other vector-borne diseases and continues to increase. what factors make the lb system so successful, and how can resea ...200919368764
microbial communities and interactions in the lone star tick, amblyomma quantify microbial composition and interactions, we identified prokaryotic communities in the lone star tick (amblyomma americanum) based on 16s rrna gene sequences and direct probing. the lone star tick is the vector of emerging diseases and host to additional symbionts of unknown activity, and is representative of other blood-sucking arthropods. we evaluated the potential for vertical (transovarial) transmission by molecular analysis of microbial symbionts from egg and larval clutches. dire ...200819378409
ticks and tick-borne pathogens and putative symbionts of black bears (ursus americanus floridanus) from georgia and florida.ticks were collected from 38 black bears (ursus americanus floridanus) from northwestern florida (n = 18) from 2003 to 2005 and southern georgia (n = 20) in 2006. five species (amblyomma americanum, a. maculatum, dermacentor variabilis, ixodes scapularis, and i. affinis) were collected from florida bears, and 4 species (a. americanum, a. maculatum, d. variabilis, i. scapularis) were collected from bears in georgia. ixodes scapularis was the most frequently collected tick, followed by d. variabil ...200919413369
ixodes scapularis tick serine proteinase inhibitor (serpin) gene family; annotation and transcriptional analysis.serine proteinase inhibitors (serpins) are a large superfamily of structurally related, but functionally diverse proteins that control essential proteolytic pathways in most branches of life. given their importance in the biology of many organisms, the concept that ticks might utilize serpins to evade host defenses and immunizing against or disrupting their functions as targets for tick control is an appealing option.200919435496
a sustained release gel formulation of doramectin for control of lone star ticks (acari: ixodidae) and horn flies (diptera: muscidae) on cattle.a gel formulation formed by incorporating technical doramectin into a 10% hydroxypropyl methylcellulose aqueous solution was used to subcutaneously inject steers at varying dosages. doramectin serum concentration of steers receiving 600 microg (ai)/kg body weight declined from 21.9 ppb at 0.5 wk to below detectable at 8 wk postinjection. the 1,200 microg (ai)/kg injection resulted in serum concentrations of 29.1 ppb at 0.5 wk and declined to 0.5 ppb at 8 wk postinjection. both the 600 and 1,200 ...200919449664
efficacy of eprinomectin and doramectin against amblyomma americanum (acari: ixodidae) on cattle.steers were treated with doramectin or eprinomectin by daily oral capsule for 28 consecutive days. the level of doramectin in the serum of steers treated at 200 microg/kg/d reached a maximum of 104.0 +/- 22.1 ppb at day 21 and declined from 93.3 +/- 20.5 ppb on the final day of treatment to below detectable by day 56. steers treated at 50 microg/kg/d reached a maximum level of doramectin in the serum of 24.7 +/- 1.2 ppb on day 21 and declined from 24.7 +/- 0.6 ppb on the final day of treatment t ...200919449665
promoter analysis of macrophage- and tick cell-specific differentially expressed ehrlichia chaffeensis p28-omp genes.ehrlichia chaffeensis is a rickettsial agent responsible for an emerging tick-borne illness, human monocytic ehrlichiosis. recently, we reported that e. chaffeensis protein expression is influenced by macrophage and tick cell environments. we also demonstrated that host response differs considerably for macrophage and tick cell-derived bacteria with delayed clearance of the pathogen originating from tick cells.200919454021
prospective health assessment of fort campbell, kentucky patrons bitten by ticks.amblyomma americanum is an aggressive human-biting tick that transmits several known human pathogens and is associated with a lyme disease-like illness of unknown etiology. to determine the frequency, distinguishing clinical characteristics, and etiology ofa. americanum-associated illness and identify associated risk factors, a prospective study of adult tick-bite victims was conducted at fort campbell from 2005-2007. forty-two participants submitted ticks, none of which contained borrelia lones ...200919485114
isolation of entomopathogenic fungi from soils and ixodes scapularis (acari: ixodidae) ticks: prevalence and methods.entomopathogenic fungi are commonly found in forested soils that provide tick habitat, and many species are pathogenic to ixodes scapularis say, the blacklegged tick. as a first step to developing effective biocontrol strategies, the objective of this study was to determine the best methods to isolate entomopathogenic fungal species from field-collected samples of soils and ticks from an eastern deciduous forest where i. scapularis is common. several methods were assessed: (1) soils, leaf litter ...200919496427
transovarial transmission of francisella-like endosymbionts and anaplasma phagocytophilum variants in dermacentor albipictus (acari: ixodidae).dermacentor albipictus (packard) is a north american tick that feeds on cervids and livestock. it is a suspected vector of anaplasmosis in cattle, but its microbial flora and vector potential remain underevaluated. we screened d. albipictus ticks collected from minnesota white-tailed deer (odocoileus virginianus) for bacteria of the genera anaplasma, ehrlichia, francisella, and rickettsia using polymerase chain reaction (pcr) gene amplification and sequence analyses. we detected anaplasma phagoc ...200919496436
microarray analysis of gene expression changes in feeding female and male lone star ticks, amblyomma americanum (l).a collection of est clones from female tick amblyomma americanum salivary glands was hybridized to rna from different feeding stages of female tick salivary glands and from unfed or feeding adult male ticks. in the female ticks, the expression patterns changed dramatically upon starting feeding, then changed again towards the end of feeding. on beginning feeding, genes possibly involved in survival on the host increased in expression as did many housekeeping genes. as feeding progressed, some of ...200919514082
[stari--a new tick borne spirochetosis].southern tick associated rash illness (stari), also known as masters disease is caused by borrelia lonestari spirochetes and it is transmitted by amblyomma americanum tick. early symptoms of stari are similar to early lyme borreliosis (skin rash resembling erythema migrans). in diagnostic of stari traditional methods are not effective. the decision of antibiotic treatment (similar to lyme borreliosis) still remain based on clinical picture.200919522220
a borreliacidal factor in amblyomma americanum saliva is associated with phospholipase a(2) activity.previous work in our laboratory described the in vitro killing of borrelia burgdorferi when co-cultured with saliva from adult amblyomma americanum. borreliacidal activity was not evident using ixodes scapularis saliva. mixing trypsin with saliva eliminated the borreliacidal activity of a. americanum saliva, while incorporating a trypsin inhibitor restored all borreliacidal activity, indicating this factor was of protein or peptide origin. one dimensional page indicated at least 7 major protein ...200919545533
silencing of genes involved in anaplasma marginale-tick interactions affects the pathogen developmental cycle in dermacentor variabilis.the cattle pathogen, anaplasma marginale, undergoes a developmental cycle in ticks that begins in gut cells. transmission to cattle occurs from salivary glands during a second tick feeding. at each site of development two forms of a. marginale (reticulated and dense) occur within a parasitophorous vacuole in the host cell cytoplasm. however, the role of tick genes in pathogen development is unknown. four genes, found in previous studies to be differentially expressed in dermacentor variabilis ti ...200919607704
metapopulation structure for perpetuation of francisella tularensis tularensis.outbreaks of type a tularemia due to francisella tularensis tularensis are typically sporadic and unstable, greatly hindering identification of the determinants of perpetuation and human risk. martha's vineyard, massachusetts has experienced an outbreak of type a tularemia which has persisted for 9 years. this unique situation has allowed us to conduct long-term eco-epidemiologic studies there. our hypothesis is that the agent of type a tularemia is perpetuated as a metapopulation, with many sma ...200919627585
community-based prevention of lyme disease and other tick-borne diseases through topical application of acaricide to white-tailed deer: background and rationale.this series of articles describes the first large-scale experiment designed to explore the efficacy of reducing the risk of tick-borne disease in highly endemic communities of the northeastern and mid-atlantic united states through deployment of a self-application device that treats white-tailed deer with acaricide to prevent feeding by adult ixodes scapularis ticks and all stages of amblyomma americanum ticks where both species occur. the results of the multicenter study are reported in the acc ...200919650729
effectiveness of the 4-poster passive topical treatment device in the control of ixodes scapularis and amblyomma americanum (acari: ixodidae) in new jersey.twenty-five "4-poster" feeders were placed throughout a 5.2 km(2) study area within a secured military facility situated in a hyperendemic area for lyme disease in central monmouth county, new jersey. calculated levels of control, relative to untreated areas, peaked at 82.7%, 77.3%, and 94.2% for of host-seeking ixodes scapularis say larvae, nymphs, and adults, respectively, within 5 years of deployment. control of host-seeking amblyomma americanum (l.) peaked at 99.2%, 89.5%, and 96.9% for larv ...200919650733
the impact of 4-poster deer self-treatment devices at three locations in maryland.from 1998-2002 twenty-five deer self-treatment devices (4-posters), using 2% amitraz, were operated at three locations in maryland to determine their effectiveness in controlling blacklegged ticks, ixodes scapularis say, and lone star ticks, amblyomma americanum (l.). each treatment site was approximately 518 ha and paired with a similar site lacking 4-posters. locations varied in deer density, tick abundance, and land use. flagging for host-seeking ticks showed declines in tick populations at a ...200919650735
sustained control of gibson island, maryland, populations of ixodes scapularis and amblyomma americanum (acari: ixodidae) by community-administered 4-poster deer self-treatment bait 1998, twenty-five 4-poster deer treatment bait stations were deployed on gibson island (gi), maryland, as part of the u.s. department of agriculture (usda) northeast area-wide tick control project. treatments concluded in june 2002, having achieved 80% and 99.5% control of blacklegged ticks, ixodes scapularis, and lone star ticks, amblyomma americanum, respectively. no area-wide tick control was attempted again on the island until 2003, when 15 dandux-manufactured 4-posters were purchased by ...200919650736
the united states department of agriculture's northeast area-wide tick control project: summary and conclusions.from 1997 to 2002, the u.s. department of agriculture's northeast area-wide tick control project used acaricide-treated 4-poster deer treatment bait stations in five eastern states to control ticks feeding on white-tailed deer. the objectives of this host-targeted technology were to reduce free-living blacklegged (ixodes scapularis say) and lone star (amblyomma americanum [l.]) tick populations and thereby to reduce the risk of tick-borne disease. during 2002 to 2004, treatments were suspended, ...200919650739
analysis of complete genome sequence of neorickettsia risticii: causative agent of potomac horse fever.neorickettsia risticii is an obligate intracellular bacterium of the trematodes and mammals. horses develop potomac horse fever (phf) when they ingest aquatic insects containing encysted n. risticii-infected trematodes. the complete genome sequence of n. risticii illinois consists of a single circular chromosome of 879 977 bp and encodes 38 rna species and 898 proteins. although n. risticii has limited ability to synthesize amino acids and lacks many metabolic pathways, it is capable of making m ...200919661282
current management of human granulocytic anaplasmosis, human monocytic ehrlichiosis and ehrlichia ewingii ehrlichiosis.anaplasma phagocytophilum, ehrlichia chaffeensis and ehrlichia ewingii are emerging tick-borne pathogens and are the causative agents of human granulocytic anaplasmosis, human monocytic ehrlichiosis and e. ewingii ehrlichiosis, respectively. collectively, these are referred to as human ehrlichioses. these obligate intracellular bacterial pathogens of the family anaplasmataceae are transmitted by ixodes spp. or amblyomma americanum ticks and infect peripherally circulating leukocytes to cause inf ...200919681699
ehrlichia chaffeensis infections in drosophila melanogaster.ehrlichia chaffeensis is an obligate, intracellular bacterium, transmitted by the tick amblyomma americanum, and is the causative agent of human monocytic ehrlichiosis infections. we previously demonstrated that e. chaffeensis is capable of growing in drosophila s2 cells. therefore, we tested the hypothesis that e. chaffeensis can infect adult drosophila melanogaster. adult drosophila organisms were experimentally challenged with intra-abdominal injections of bacteria. ehrlichia-infected flies s ...200919687202
predominance of ehrlichia chaffeensis in rhipicephalus sanguineus ticks from kennel-confined dogs in limbe, cameroon.rhipicephalus sanguineus ticks (n = 63) collected from five dogs (two adults and three puppies) housed in a kennel were screened for ehrlichial agents (ehrlichia canis, e. chaffeensis, and e. ewingii) using a species-specific multicolor real-time taqman pcr amplification of the disulphide bond formation protein (dsb) gene. ehrlichia chaffeensis dna was detected in 33 (56%) ticks, e. canis dna was detected in four (6%) ticks, and one tick was coinfected. the e. chaffeensis and e. canis nucleotide ...201019693681
directed evolution of a filamentous fungus for thermotolerance.filamentous fungi are the most widely used eukaryotic biocatalysts in industrial and chemical applications. consequently, there is tremendous interest in methodology that can use the power of genetics to develop strains with improved performance. for example, metarhizium anisopliae is a broad host range entomopathogenic fungus currently under intensive investigation as a biologically based alternative to chemical pesticides. however, it use is limited by the relatively low tolerance of this spec ...200919709419
assessment of polymicrobial infections in ticks in new york state.ixodes scapularis ticks are clinically important hematophagous vectors. a single tick bite can lead to a polymicrobial infection. we determined the prevalence of polymicrobial infection with borrelia burgdorferi, anaplasma phagocytophilum, babesia microti, borrelia miyamotoi, and powassan virus in 286 adult ticks from the two counties in new york state where lyme disease is endemic, utilizing a masstag multiplex polymerase chain reaction assay. seventy-one percent of the ticks harbored at least ...201019725770
efficacy of a topical ectoparasiticide containing dinotefuran, pyriproxyfen, and permethrin against amblyomma americanum (lone star tick) and amblyomma maculatum (gulf coast tick) on dogs.amblyomma americanum (lone star tick) and amblyomma maculatum (gulf coast tick) are important disease vectors for both dogs and humans. this article describes two studies conducted to evaluate the efficacy of a new topical spot-on ectoparasiticide containing dinotefuran, permethrin, and pyriproxyfen (vectra 3d, summit vetpharm) against a. maculatum and a. americanum in dogs. dogs were treated on day 0 and infested on days -1, 7, 14, 21, and 28 with approximately 40 ticks each day. live tick coun ...200919742444
influence of prescribed burns on the abundance of amblyomma americanum (acari: ixodidae) in the missouri ozarks.the increasingly widespread use of prescribed burns to manage oak (quercus spp.)-hickory (carya spp.) forests in the missouri ozarks, usa, has considerable potential to alter the abundance of amblyomma americanum (l.) (acari: ixodidae), the lone star tick, an important vector of several emerging pathogens. in particular, responses of important tick hosts, primarily white-tailed deer (odocoileus virginianus), to fire management and the resultant changes in the distribution and abundance of a. ame ...200919769033
sensitivity of host-seeking nymphal lone star ticks (acari: ixodidae) to immersion in heated nymphal amblyomma americanum (l.) (acari: ixodidae) were placed into heated water, and their survival or their torpidity was recorded as a function of exposure time. exposures were determined that either kill the nymphs or affect their mobility. all nymphs died when exposed for a minute or more to a temperature > 51 degrees c. nearly all nymphs remained motionless for a period of time when exposed for 3 min to a temperature > 44 degrees c.200919769061
anaplasmosis and ehrlichiosis - maine, 2008.anaplasmosis and ehrlichiosis are rickettsial tickborne diseases that have had at least a twofold increase in prevalence in the united states since 2000. despite similar clinical presentations, the causative organisms are carried by different ticks with distinct geographic and ecologic associations. surveillance efforts are complicated by ambiguous terminology and serologic testing with antibody cross-reactivity. although anaplasmosis historically has been reported in maine, ehrlichiosis has bee ...200919779398
macrophage migration inhibitory factor expression and protein localization in amblyomma americanum (ixodidae).amblyomma americanum (l.) ticks continue to emerge as disease vectors in many areas of the united states. tick macrophage migration inhibitory factor (mif) was first identified in a. americanum females and has been demonstrated to inhibit macrophage movement to the same extent as human mif. this study was conducted to further characterize and elucidate the physiological role for mif in tick feeding. a relative quantitative pcr assay was developed to determine the level of mif gene expression dur ...201019784782
rickettsia parkeri in amblyomma americanum ticks, tennessee and georgia, determine the geographic distribution of the newly recognized human pathogen rickettsia parkeri, we looked for this organism in ticks from tennessee and georgia, usa. using pcr and sequence analysis, we identified r. parkeri in 2 amblyomma americanum ticks. this rickettsiosis may be underdiagnosed in the eastern united states.200919788817
comparative efficacy of bioud to other commercially available arthropod repellents against the ticks amblyomma americanum and dermacentor variabilis on cotton cloth.bioud is an arthropod repellent that contains the active ingredient 2-undecanone originally derived from wild tomato plants. repellency of bioud was compared with five commercially available arthropod repellents against the ticks amblyomma americanum (l.) and dermacentor variabilis say in two-choice bioassays on treated versus untreated cotton cheesecloth. overall mean percentage repellency against both species was greatest for and did not differ significantly between bioud (7.75% 2-undecanone) ...200919815887
natural history of ehrlichia chaffeensis: vertebrate hosts and tick vectors from the united states and evidence for endemic transmission in other countries.ehrlichia chaffeensis, an intracellular gram-negative zoonotic bacterium, is the causative agent of human monocytotropic ehrlichiosis (hme). in humans, the disease can range from a mild, non-specific illness with few to no clinical signs to a moderately severe to fatal disease, especially those with compromised immune systems. e. chaffeensis is maintained in a complex cycle involving white-tailed deer (wtd; odocoileus virginianus) as a primary reservoir and the lone star tick (lst; amblyomma ame ...201019819631
molecular events involved in cellular invasion by ehrlichia chaffeensis and anaplasma phagocytophilum.ehrlichia chaffeensis and anaplasma phagocytophilum are obligatory intracellular bacteria that preferentially replicate inside leukocytes by utilizing biological compounds and processes of these primary host defensive cells. these bacteria incorporate cholesterol from the host for their survival. upon interaction with host monocytes and granulocytes, respectively, these bacteria usurp the lipid raft domain containing gpi-anchored protein to induce a series of signaling events that result in inte ...201019836896
distribution of antibodies reactive to borrelia lonestari and borrelia burgdorferi in white-tailed deer (odocoileus virginianus) populations in the eastern united states.southern tick-associated rash illness is a lyme-like syndrome that occurs in the southern states. borrelia lonestari, which has been suggested as a possible causative agent of southern tick-associated rash illness, naturally infects white-tailed deer (wtd; odocoileus virginianus) and is transmitted by the lone star tick (amblyomma americanum). to better understand the prevalence and distribution of borrelia exposure among wtd, we tested wtd from 21 eastern states for antibodies reactive to b. lo ...200919874183
molecular detection of rickettsia amblyommii in amblyomma americanum parasitizing humans.a quantitative real-time polymerase chain reaction assay to detect and quantify a portion of the outer membrane protein b gene (ompb) of rickettsia amblyommii was employed to assess the threat of r. amblyommii exposure to humans parasitized by amblyomma americanum (the lone star tick). a total of 72 pools of lone star ticks removed from humans were acquired from two collections and used in this study: 44 pools of a. americanum submitted to the department of defense human tick test kit program in ...201019877809
prevalence of ehrlichia chaffeensis and ehrlichia ewingii in ticks from tennessee.human ehrlichiosis is the second most common tick-borne disease reported in tennessee after rocky mountain spotted fever. two closely related ehrlichiae, ehrlichia chaffeensis and ehrlichia ewingii, are both causative agents of human disease and are transmitted by amblyomma americanum, the lone star tick. prevalence rates and distribution patterns of these pathogens among ticks in tennessee are currently unknown. to understand prevalence and exposure risk of ehrlichia spp., we tested 616 ticks ( ...201019877819
burden of tick-borne infections on american companion animals.this review examines the biology of ticks and tick-borne infections in the united states. the most common tick-borne diseases in dogs and cats are discussed. we demonstrate that there is much interest in tick-borne infections at the level of the lay public (pet owners), describe trends in the distribution and prevalence of tick-borne infections in the united states, summarize some issues in understanding the degree of ill health due to tick-borne infections, and suggest some avenues for research ...200919945085
strains of ehrlichia chaffeensis in southern indiana, kentucky, mississippi, and north carolina.rates of infection of amblyomma americanum (l.) by ehrlichia chaffeensis were compared in 100 ticks collected from sites in each of four states: indiana, north carolina, kentucky, and mississippi. the overall infection rates were similar among sites, ranging from 1 to 4%. because pathogenic differences may exist between e. chaffeensis strains, nested polymerase chain reaction (pcr) amplification of the variable-length pcr target (vlpt), and sequencing of the amplicons were performed to different ...200919960699
ehrlichia chaffeensis infection of sika deer, determine whether ehrlichia chaffeensis exists in japan, we used pcr to examine blood from sika deer in nara, japan. of 117 deer, 36 (31%) were infected with e. chaffeensis. the e. chaffeensis 16s rrna base and groel amino acid sequences from japan were most closely related to those of e. chaffeensis arkansas.200919961683
niche partitioning of borrelia burgdorferi and borrelia miyamotoi in the same tick vector and mammalian reservoir species.the lyme borreliosis agent borrelia burgdorferi and the relapsing fever group species borrelia miyamotoi co-occur in the united states. we used species-specific, quantitative polymerase chain reaction to study both species in the blood and skin of peromyscus leucopus mice and host-seeking ixodes scapularis nymphs at a connecticut site. bacteremias with b. burgdorferi or b. miyamotoi were most prevalent during periods of greatest activity for nymphs or larvae, respectively. whereas b. burgdorferi ...200919996447
elemol and amyris oil repel the ticks ixodes scapularis and amblyomma americanum (acari: ixodidae) in laboratory bioassays.the essential oil from amyris balsamifera (rutaceae) and elemol, a principal constituent of the essential oil of osage orange, maclura pomifera (moraceae) were evaluated in in vitro and in vivo laboratory bioassays for repellent activity against host-seeking nymphs of the blacklegged tick, ixodes scapularis, and the lone star tick, amblyomma americanum. both bioassays took advantage of the tendency of these host-seeking ticks to climb slender vertical surfaces. in one bioassay, the central porti ...201020016930
identification of protective antigens by rna interference for control of the lone star tick, amblyomma americanum.the lone star tick, amblyomma americanum, vectors pathogens of emerging diseases of humans and animals in the united states. currently, measures are not available for effective control of a. americanum infestations. development of vaccines directed against tick proteins may reduce tick infestations and the transmission of tick-borne pathogens. however, the limiting step in tick vaccine development has been the identification of tick protective antigens. herein, we report the application of rna i ...201020018267
molecular and clinical evidence of ehrlichia chaffeensis infection in cameroonian patients with undifferentiated febrile the u.s.a., human monocytotropic ehrlichiosis (hme) caused by ehrlichia chaffeensis is an emerging tick-transmitted zoonosis. in cameroon, where e. canis, e. chaffeensis and e. ewingii have recently been detected in dogs and/or ticks (rhipicephalus sanguineus), the potential exists for human infections. patients from the coastal region of cameroon who had acute fevers of unknown aetiology were therefore checked for ehrlichial infection, using a real-time pcr that amplifies part of a genus-spe ...200920030996
rhipicephalus (boophilus) microplus: clotting time in tick-infested skin varies according to local inflammation and gene expression patterns in tick salivary glands.ticks deposit saliva at the site of their attachment to a host in order to inhibit haemostasis, inflammation and innate and adaptive immune responses. the anti-haemostatic properties of tick saliva have been described by many studies, but few show that tick infestations or its anti-haemostatic components exert systemic effects in vivo. in the present study, we extended these observations and show that, compared with normal skin, bovine hosts that are genetically susceptible to tick infestations ...201020045690
severe ehrlichia infection in pediatric oncology and stem cell transplant patients.ehrlichiosis, a tickborne illness transmitted by tick vectors amblyomma americanum and ixodes scapularis, can be acquired in endemic areas. clinical manifestations range from asymptomatic to fulminant in nature. we report three cases of ehrlichiosis in pediatric oncology patients, one of whom was a stem cell transplant recipient. early symptoms included fever, malaise, and vague gastrointestinal symptoms. laboratory abnormalities were initially attributed to chemotherapy toxicity. illness was se ...201020052776
ability of two natural products, nootkatone and carvacrol, to suppress ixodes scapularis and amblyomma americanum (acari: ixodidae) in a lyme disease endemic area of new jersey.we evaluated the ability of the natural, plant-derived acaricides nootkatone and carvacrol to suppress ixodes scapularis say and amblyomma americanum (l.) (acari: ixodidae). aqueous formulations of 1 and 5% nootkatone applied by backpack sprayer to the forest litter layer completely suppressed i. scapularis nymphs through 2 d. thereafter, the level of reduction gradually declined to < or =50% at 28 d postapplication. against a. americanum nymphs, 1% nootkatone was less effective, but at a 5% con ...200920069863
[ehrlichiosis/anaplasmosis].ehrlichiosis and anaplasmosis are zoonoses caused by bacteria from the family anaplasmataceae, including human and animal pathogens. the human pathogens are ehrlichia chaffeensis, the causative agent of human monocytic ehrlichiosis (hme), anaplasma phagocytophilum, the pathogen causing human granulocytic anaplasmosis (hga), e. ewingii and neorickettsia sennetsu, granulocytotropic and monocytotropic ehrlichia species, respectively. ehrlichia spp. are small, gram-negative, obligate intracellular b ...200920077398
wide dispersal and possible multiple origins of low-copy-number plasmids in rickettsia species associated with blood-feeding arthropods.plasmids are mobile genetic elements of bacteria that can impart important adaptive traits, such as increased virulence or antibiotic resistance. we report the existence of plasmids in rickettsia (rickettsiales; rickettsiaceae) species, including rickettsia akari, "candidatus rickettsia amblyommii," r. bellii, r. rhipicephali, and reis, the rickettsial endosymbiont of ixodes scapularis. all of the rickettsiae were isolated from humans or north and south american ticks. r. parkeri isolates from b ...201020097813
endemic tickborne infectious diseases in louisiana and the gulf south.most emerging infectious diseases today, such as west nile virus and sudden acute respiratory distress syndrome (sars), arise from zoonotic reservoirs and many are transmitted by arthropod vectors. ticks are among the most competent and versatile arthropod vectors of infectious diseases because ticks of all ages and both sexes remain infectious for generations without having to reacquire infections from reservoir hosts. today, ticks transmit the most common arthropod-borne infectious disease in ...200920108827
extraction of total nucleic acids from ticks for the detection of bacterial and viral pathogens.ticks harbor numerous bacterial, protozoal, and viral pathogens that can cause serious infections in humans and domestic animals. active surveillance of the tick vector can provide insight into the frequency and distribution of important pathogens in the environment. nucleic-acid based detection of tick-borne bacterial, protozoan, and viral pathogens requires the extraction of both dna and rna (total nucleic acids) from ticks. traditional methods for nucleic acid extraction are limited to extrac ...201020180313
detection of a new arsenophonus-type bacterium in canadian populations of the rocky mountain wood tick, dermacentor andersoni.ticks of the genus dermacentor are important vectors of human and animal pathogens in north america. they also carry a variety of endosymbiotic (i.e. non-pathogenic) bacteria. the american dog tick, d. variabilis, is known to be infected with gammaproteobacteria of the genus arsenophonus. however, there have been no previous reports of arsenophonus-type bacteria in the rocky mountain wood tick, d. andersoni, a species that is sympatric with d. variabilis in the western parts of its distributiona ...201020186465
bartonella spp. transmission by ticks not established.bartonella spp. infect humans and many animal species. mainly because pcr studies have demonstrated bartonella dna in ticks, some healthcare providers believe that these microorganisms are transmitted by ticks. b. henselae, in particular, is regarded as being present in and transmissible by the ixodes scapularis tick. the presence of a microbial agent within a tick, however, does not imply that the tick might transmit it during the course of blood feeding and does not confer epidemiologic import ...201020202410
potential for tick-borne worldwide vectors of human infectious diseases, ticks are considered to be second only to mosquitoes. each tick species has preferred environmental conditions and biotopes that determine its geographic distribution, the pathogens it vectors, and the areas that pose risk for tick-borne diseases. researchers have identified an increasing number of bacterial pathogens that are transmitted by ticks, including anaplasma, borrelia, ehrlichia, and rickettsia spp. recent reports involving humans and ...201020202411
blood meal analysis to identify reservoir hosts for amblyomma americanum ticks.efforts to identify wildlife reservoirs for tick-borne pathogens are frequently limited by poor understanding of tick-host interactions and potentially transient infectivity of hosts under natural conditions. to identify reservoir hosts for lone star tick (amblyomma americanum)-associated pathogens, we used a novel technology. in field-collected ticks, we used pcr to amplify a portion of the 18s rrna gene in remnant blood meal dna. reverse line blot hybridization with host-specific probes was th ...201020202418
borrelia, ehrlichia, and rickettsia spp. in ticks removed from persons, texas, regarding the type, frequency, and distribution of tick-borne pathogens and bacterial agents are not widely available for many tick species that parasitize persons in the southern united states. we therefore analyzed the frequency and identity of pathogens and bacterial agents in ticks removed from humans and subsequently submitted to the texas department of state health services, zoonosis control program, from october 1, 2004, through september 30, 2008. the data showed associations of bac ...201020202419
silencing of three amblyomma americanum (l.) insulin-like growth factor binding protein-related proteins prevents ticks from feeding to repletion.the insulin-like growth factor (igf) binding proteins (igfbp) family is the regulatory arm of the igf signaling system that control mitogenic and anabolic actions of igf peptide hormones. this study describes cloning and biological characterization of three amblyomma americanum (l.) (aam) proteins that show amino-terminal sequence and secondary structure similarity to the igfbp superfamily. the three molecules here provisionally identified as aamigfbp-rp1 and short (s) and long (l) aamigfbp-rp6 ...201020228352
insecticides to control the european corn borer in field corn. 194720264508
infestation of a raccoon by amblyomma americanum. 194720264533
rite of amblyomma americanum associated with possible tick paralysis. 194720340890
population genetics of amblyomma americanum (acari: ixodidae) collected from arkansas.lone star ticks, amblyomma americanum l. (acari: ixodidae),infest multiple hosts such as birds, and mammals of various sizes (rodents to white-tailed deer) and can harbor human pathogens such as borrelia lonestari and ehrlichiosis chaffeensis. the population structure of 251 a. americanum ticks, collected from canines and two white-tailed deer in six arkansas ecoregions, was examined using dna sequences of a 247-bp region of the mitochondrial dna ribosomal rna 16s gene. of the 247 nucleotide cha ...201020380295
bacterial diversity in amblyomma americanum (acari: ixodidae) with a focus on members of the genus rickettsia.the lone star tick, amblyomma americanum (acari: ixodidae), is commonly reported from people and animals throughout the eastern u.s. and is associated with transmission of a number of emerging diseases. to better define the microbial communities within lone star ticks, 16s rrna gene based analysis using bacteria-wide primers, followed by sequencing of individual clones (n = 449) was used to identify the most common bacterial operational taxonomic units (otus) present within colony-reared and wil ...201020380308
disrupting the amblyomma americanum (l.) cd147 receptor homolog prevents ticks from feeding to repletion and blocks spontaneous detachment of ticks from their host.the cd147 receptor is a cell-surface glycoprotein in the igg family that plays pivotal roles in intercellular interactions involved with numerous physiological and pathological processes such as extracellular matrix remodeling. we previously found an amblyomma americanum (aam) tick cd147 receptor homolog among genes that were up regulated in response to tick feeding stimuli. this study characterizes an aamcd147 receptor protein that is 72-83% conserved in other tick species and possess character ...201020451606
bacterial pathogens in ixodid ticks from a piedmont county in north carolina: prevalence of rickettsial north carolina, reported human cases of tick-borne illness, specifically rocky mountain spotted fever, have escalated over the past decade. to determine the relative abundance of vectors and to estimate the risk of acquiring a tick-borne illness in peri-residential landscapes, ticks were collected in chatham county, a typical piedmont county and, samples of the ticks were tested for infection with selected bacterial pathogens using real-time quantitative polymerase chain reaction assays. tick ...201020455778
host associations of dermacentor, amblyomma, and ixodes (acari: ixodidae) ticks in tennessee.from april 2007 to september 2008, 1,793 adult and nymphal ixodid ticks were collected from 49 counties in tennessee. six species were identified, including dermacentor variabilis (say), amblyomma americanum (l.), ixodes texanus (banks), ixodes cookei packard, ixodes scapularis (say), and amblyomma maculatum koch, from 13 medium- to large-sized mammalian hosts and dragging through vegetation. raccoons were the most common vertebrate source (198 captures), accounting for 60% of ticks collected. d ...201020496589
sdetection of vector-borne agents in lone star ticks, amblyomma americanum (acari: ixodidae), from this study, we evaluated amblyomma americanum (lone star tick) in mississippi for the presence of ehrlichia chaffeensis, causative agent of human monocytic ehrlichiosis; ehrlichia ewingii, causative agent of human and canine granulocytic ehrlichiosis; borrelia lonestari, putative agent of southern tick-associated rash illness; francisella tularensis, the agent of tularemia; and rickettsia spp., particularly r. amblyommii, a suspected pathogen. we collected adult a. americanum from four region ...201020496596
Displaying items 601 - 700 of 1263