Publications

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.	2009	19435496
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 ...	2009	19413369
babesia and its hosts: adaptation to long-lasting interactions as a way to achieve efficient transmission.	babesia, the causal agent of babesiosis, are tick-borne apicomplexan protozoa. true babesiae (babesia genus sensu stricto) are biologically characterized by direct development in erythrocytes and by transovarial transmission in the tick. a large number of true babesia species have been described in various vertebrate and tick hosts. this review presents the genus then discusses specific adaptations of babesia spp. to their hosts to achieve efficient transmission. the main adaptations lead to lon ...	2009	19379662
microbial communities and interactions in the lone star tick, amblyomma americanum.	to 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 ...	2008	19378409
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 ...	2009	19368764
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 ...	2009	19358804
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 ...	2009	19320755
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 ...	2009	19277106
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 ...	2009	19273271
the role of saliva in tick feeding.	when attempting to feed on their hosts, ticks face the problem of host hemostasis (the vertebrate mechanisms that prevent blood loss), inflammation (that can produce itching or pain and thus initiate defensive behavior on their hosts) and adaptive immunity (by way of both cellular and humoral responses). against these barriers, ticks evolved a complex and sophisticated pharmacological armamentarium, consisting of bioactive lipids and proteins, to assist blood feeding. recent progress in transcri ...	2009	19273185
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 ...	2009	19271281
79-year-old man with fever, malaise, and jaundice.		2009	19252117
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 ...	2009	19248784
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 ...	2009	19242658
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 ...	2009	19229557
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 ...	2009	19198527
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 ...	2009	19198523
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 ...	2009	19168288
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 ...	2009	19140016
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 ...	2009	19111543
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 ...	2009	19054615
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 ...	2008	19028013
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.	2008	19021911
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 ...	2008	18963493
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.	2009	18950590
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 ...	2008	18931313
key biosynthetic gene subfamily recruited for pheromone production prior to the extensive radiation of lepidoptera.	moths have evolved highly successful mating systems, relying on species-specific mixtures of sex pheromone components for long-distance mate communication. acyl-coa desaturases are key enzymes in the biosynthesis of these compounds and to a large extent they account for the great diversity of pheromone structures in lepidoptera. a novel desaturase gene subfamily that displays delta11 catalytic activities has been highlighted to account for most of the unique pheromone signatures of the taxonomic ...	2008	18831750
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 ...	2008	18826028
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 ...	2009	18800864
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 ...	2008	18770537
subversion of complement by hematophagous parasites.	the complement system is a crucial part of innate and adaptive immunity which exerts a significant evolutionary pressure on pathogens. it has selected for those pathogens, mainly microorganisms but also parasites, that have evolved countermeasures. the characterization of how pathogens evade complement attack is a rapidly developing field of current research. in recent years, multiple complement evasion strategies have been characterized. in this review, we focus on complement escape mechanisms ...	2009	18762211
prevention of lyme disease and other tick-borne infections.	prevention is the best method for avoiding potentially serious complications of lyme and other tick-borne diseases. in this article, we discuss preventative measures that can be used by individuals or communities. among the topics discussed are personal protective measures, tick reduction, reservoir reduction, and vaccination. additionally, new preventative measures that are in development-including new lyme disease vaccines, antitick vaccines, and reservoir-targeted vaccination-are discussed.	2008	18755380
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 ...	2008	18725333
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 ...	2008	18714379
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 ...	2008	18710870
relaxation of selective constraints causes independent selenoprotein extinction in insect genomes.	selenoproteins are a diverse family of proteins notable for the presence of the 21st amino acid, selenocysteine. until very recently, all metazoan genomes investigated encoded selenoproteins, and these proteins had therefore been believed to be essential for animal life. challenging this assumption, recent comparative analyses of insect genomes have revealed that some insect genomes appear to have lost selenoprotein genes.	2008	18698431
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 ...	2008	18694828
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 ...	2008	18686272
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.	2008	18680654
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 ...	2008	18675910
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.	2008	18665265
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 ...	1972	18631584
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 ...	2008	18524924
a leishmania ortholog of macrophage migration inhibitory factor modulates host macrophage responses.	parasitic organisms have evolved specialized strategies to evade immune defense mechanisms. we describe herein an ortholog of the cytokine, macrophage migration inhibitory factor (mif), which is produced by the obligate intracellular parasite, leishmania major. the leishmania mif protein, lm1740mif, shows significant structural homology with human mif as revealed by a high-resolution x-ray crystal structure (1.03 a). differences between the two proteins in the n-terminal tautomerization site are ...	2008	18523291
conjunctival attachment of a tick: clinicopathologic report of a case.	attachment by ticks to ocular surfaces is uncommon, but has been reported. the objective of this article is to describe a case of conjunctival tick attachment and a method for removal by conjunctival excision. a 39-year-old man presented to the emergency department with a complaint of foreign-body sensation in his right eye. he was found to have a live tick embedded in his conjunctiva. the tick was removed en bloc with surrounding conjunctiva by an ophthalmologist. the arthropod was identified a ...	2011	18514466
twelve-hour duration testing of cream formulations of three repellents against amblyomma americanum.	the repellent efficacies of the u.s. military repellent 33% n,n-diethyl-3-methylbenzamide (deet), 10% and 20% (1s, 2's) 2-methylpiperidinyl-3-cyclohexene-1-carboxamide (ss220) and 10% and 20% 1-methyl-propyl-2-(hydroxyethyl)-1-piperidinecarboxylate (bayrepel) cream formulations on human volunteers against the lone star tick amblyomma americanum (l.) were evaluated in a simulated forest floor environment over a 12-h testing period. at 2-h intervals, volunteers, with repellent applied in a 5-cm-wi ...	2008	18498614
failure by engorged stages of the lone star tick, amblyomma americanum, to react to assembly pheromone, guanine and uric acid.	response to tick-exposed filter paper discs (tick excreta) by fed and non-fed stages of the lone star tick amblyomma americanum (l.) (acari: ixodidae) was examined from larva to adult. by contrast with engorged stages, each non-fed stage exhibited a classic arrestment response to assembly pheromone, characterized by lack of movement, retraction of legs and formation of small groups; this response was seen in approximately 75% of ticks that made contact with pheromone-treated surfaces. less prono ...	2008	18498612
neuropeptide discovery in ixodoidea: an in silico investigation using publicly accessible expressed sequence tags.	the ixodoidea (ticks) are important vectors in the transmission of many human diseases; for example, the blacklegged tick ixodes scapularis is the major vector in the transmission of lyme disease, the most frequently reported vector-borne illness in the united states. the development of expressed sequence tags (ests) for ixodoidean cdna libraries, and their public deposition, has generated a rich resource for protein discovery in members of this taxon, thereby providing an opportunity for better ...	2008	18495123
insight into the sialome of the castor bean tick, ixodes ricinus.	in recent years, there have been several sialome projects revealing transcripts expressed in the salivary glands of ticks, which are important vectors of several human diseases. here, we focused on the sialome of the european vector of lyme disease, ixodes ricinus.	2008	18489795
stari, or masters disease: lone star tick-vectored lyme-like illness.	lyme-like illness (also known as southern tick-associated rash illness [stari] or masters disease) is vectored by the lone star tick (amblyomma americanum). lyme-like illness lesions, which are similar to the erythema migrans rash of lyme disease, tend to have lymphocytic dermal infiltrates. with the exception of borrelia lonestari, the possible causative agent or agents of lyme-like illness have not been cultured. more research is needed to fully understand this newly recognized zoonosis. clini ...	2008	18452807
the first report of human illness associated with the panola mountain ehrlichia species: a case report.	two species of ehrlichia are known to cause human illness. several other species have been discovered in ticks and animals, and recent reports suggest that some of these ehrlichia species might be human pathogens. we report here the first association of a recently discovered pathogen, the panola mountain ehrlichia species, with a case of human illness.	2008	18447934
tick-borne diseases in north carolina: is "rickettsia amblyommii" a possible cause of rickettsiosis reported as rocky mountain spotted fever?	cases of rocky mountain spotted fever (rmsf) in north carolina have escalated markedly since 2000. in 2005, we identified a county in the piedmont region with high case numbers of rmsf. we collected ticks and examined them for bacterial pathogens using molecular methods to determine if a novel tick vector or spotted fever group rickettsiae (sfgr) might be emerging. amblyomma americanum, the lone star tick, comprised 99.6% of 6,502 specimens collected in suburban landscapes. in contrast, dermacen ...	2008	18447622
natural and experimental infection of white-tailed deer (odocoileus virginianus) from the united states with an ehrlichia sp. closely related to ehrlichia ruminantium.	an ehrlichia sp. (panola mountain [pm] ehrlichia sp.) closely related to ehrlichia ruminantium was recently detected in a domestic goat experimentally infested with lone star ticks (lsts, amblyomma americanum) collected from georgia, usa. the infected goat exhibited pyrexia and mild clinical pathologic abnormalities consistent with ehrlichiosis. at least two other ehrlichia species (ehrlichia chaffeensis and ehrlichia ewingii) are maintained in nature by a cycle involving lsts as the primary vec ...	2008	18436670
geographic distribution and genetic diversity of the ehrlichia sp. from panola mountain in amblyomma americanum.	a novel ehrlichia, closely related to ehrlichia ruminantium, was recently discovered from panola mountain state park, ga, usa. we conducted a study to determine if this agent was recently introduced into the united states.	2008	18433500
experimental and field studies on the suitability of raccoons (procyon lotor) as hosts for tick-borne pathogens.	we investigated the experimental susceptibility and natural exposure of raccoons (procyon lotor) to five tick-borne pathogens of human and veterinary importance, ehrlichia canis, e. chaffeensis, e. ewingii, anaplasma phagocytophilum (apvariant 1 and ap-ha hge-1 strains), and borrelia lonestari. infections were assessed by polymerase chain reaction (pcr), indirect fluorescent antibody (ifa) testing, and/or culture isolation methods for at least 30 days postinoculation (dpi). two e. chaffeensis-in ...	2008	18429696
enhanced spatial models for predicting the geographic distributions of tick-borne pathogens.	disease maps are used increasingly in the health sciences, with applications ranging from the diagnosis of individual cases to regional and global assessments of public health. however, data on the distributions of emerging infectious diseases are often available from only a limited number of samples. we compared several spatial modelling approaches for predicting the geographic distributions of two tick-borne pathogens: ehrlichia chaffeensis, the causative agent of human monocytotropic ehrlichi ...	2008	18412972
characterization of rickettsial infection in amblyomma americanum (acari: ixodidae) by quantitative real-time polymerase chain reaction.	several species of the spotted fever group rickettsia (sfgr), with considerable variation in vertebrate host pathogenicity, are present in ticks in the united states. in this study, quantitative real-time pcr (qpcr) was used to characterize the growth and the distribution of rickettsia amblyommii in selected tissues (salivary glands, gut, and ovaries) of naturally infected amblyomma americanum (l.) (acari: ixodidae), during bloodmeal acquisition and throughout vertical transmission to eggs and p ...	2008	18402143
ligand specificity and evolution of liver x receptors.	liver x receptors (lxrs) are key regulators of lipid and cholesterol metabolism in mammals. little is known, however, about the function and evolution of lxrs in non-mammalian species. the present study reports the cloning of lxrs from african clawed frog (xenopus laevis), western clawed frog (xenopus tropicalis), and zebrafish (danio rerio), and their functional characterization and comparison with human and mouse lxrs. additionally, an ortholog of lxr in the chordate invertebrate ciona intesti ...	2008	18395439
a possible canine tick-bite reaction to ixodes muris.	an airedale terrier became acutely ill following attachment of an ixodes muris tick. clinical signs waned within hours of tick removal, similar to a pattern previously documented in animals harboring i. muris. this supports the theory that i. muris can induce a noninfectious, severe inflammatory reaction in domestic animals.	2008	18390101
evolution of pharmacologic specificity in the pregnane x receptor.	the pregnane x receptor (pxr) shows the highest degree of cross-species sequence diversity of any of the vertebrate nuclear hormone receptors. in this study, we determined the pharmacophores for activation of human, mouse, rat, rabbit, chicken, and zebrafish pxrs, using a common set of sixteen ligands. in addition, we compared in detail the selectivity of human and zebrafish pxrs for steroidal compounds and xenobiotics. the ligand activation properties of the western clawed frog (xenopus tropica ...	2008	18384689
rnai-mediated gene silencing in tick synganglia: a proof of concept study.	progress in generating comprehensive est libraries and genome sequencing is setting the stage for reverse genetic approaches to gene function studies in the blacklegged tick (ixodes scapularis). however, proving that rnai can work in nervous tissue has been problematic. developing an ability to manipulate gene expression in the tick synganglia likely would accelerate understanding of tick neurobiology. here, we assess gene silencing by rna interference in the adult female black-legged tick synga ...	2008	18366768
revealing pancrustacean relationships: phylogenetic analysis of ribosomal protein genes places collembola (springtails) in a monophyletic hexapoda and reinforces the discrepancy between mitochondrial and nuclear dna markers.	in recent years, several new hypotheses on phylogenetic relations among arthropods have been proposed on the basis of dna sequences. one of the challenged hypotheses is the monophyly of hexapods. this discussion originated from analyses based on mitochondrial dna datasets that, due to an unusual positioning of collembola, suggested that the hexapod body plan evolved at least twice. here, we re-evaluate the position of collembola using ribosomal protein gene sequences.	2008	18366624
expression and porin activity of p28 and omp-1f during intracellular ehrlichia chaffeensis development.	ehrlichia chaffeensis, an obligatory intracellular gram-negative bacterium, must take up various nutrients and metabolic compounds because it lacks many genes involved in metabolism. nutrient uptake by a gram-negative bacterium occurs primarily through pores or channels in the bacterial outer membrane. here we demonstrate that isolated e. chaffeensis outer membranes have porin activities, as determined by a proteoliposome swelling assay. the activity was partially blocked by an antibody that rec ...	2008	18359808
a critical analysis of disease-associated dna polymorphisms in the genes of cattle, goat, sheep, and pig.	genetic variations through their effects on gene expression and protein function underlie disease susceptibility in farm animal species. the variations are in the form of single nucleotide polymorphisms, deletions/insertions of nucleotides or whole genes, gene or whole chromosomal rearrangements, gene duplications, and copy number polymorphisms or variants. they exert varying degrees of effects on gene action, such as substitution of an amino acid for another, shift in reading frame and prematur ...	2008	18350334
two usa ehrlichia spp. cause febrile illness in goats.	ehrlichia spp. are not currently recognized as a cause of illness in goats in the usa, but three ehrlichia are enzootic in lone star ticks (amblyomma americanum) in the eastern usa, and related bacteria in other countries cause illness in goats. we exposed naïve goats to ehrlichia-infected amblyomma and demonstrated that infection and clinical illness can be caused by two usa species, e. ewingii and the recently discovered panola mountain ehrlichia sp. clinical features in all five goats are des ...	2008	18328644
ehrlichia chaffeensis in child, venezuela.		2008	18325283
detection of two bartonella tamiae-like sequences in amblyomma americanum (acari: ixodidae) using 16s-23s intergenic spacer region-specific primers.	four hundred and sixty-six questing amblyomma americanum (l.) (acari: ixodidae) from carolina county, va, and 98 questing a. americanum from chatham county, nc, were screened by polymerase chain reaction (pcr) for the bartonella 16s-23s intergenic spacer region. two amplicons, approximately 270-280 bp, were detected in two ticks from virginia. based upon pcr and sequencing, an adult male and adult female tick harbored dna sequences closely related to bartonella tamiae (dq395180). bartonella dna ...	2008	18283962
use of drosophila s2 cells as a model for studying ehrlichia chaffeensis infections.	ehrlichia chaffeensis is an obligate intracellular bacterium and the causative agent of human monocytic ehrlichiosis. although this pathogen grows in several mammalian cell lines, no general model for eukaryotic cellular requirements for bacteria replication has yet been proposed. we found that drosophila s2 cells are permissive for the growth of e. chaffeensis. we saw morulae (aggregates of bacteria) by microscopy, detected the e. chaffeensis 16s rrna gene by reverse transcriptase pcr, and used ...	2008	18245255
identity and transfer of male reproductive gland proteins of the dengue vector mosquito, aedes aegypti: potential tools for control of female feeding and reproduction.	male reproductive gland proteins (mrgps) impact the physiology and/or behavior of mated females in a broad range of organisms. we sought to identify mrgps of the yellow fever mosquito, aedes aegypti, the primary vector of dengue and yellow fever viruses. earlier studies with ae. aegypti demonstrated that "matrone" (a partially purified male reproductive accessory gland substance) or male accessory gland fluid injected into virgin female ae. aegypti affect female sexual refractoriness, blood feed ...	2008	18207079
donning your enemy's cloak: ground squirrels exploit rattlesnake scent to reduce predation risk.	ground squirrels (spermophilus spp.) have evolved a battery of defences against the rattlesnakes (crotalus spp.) that have preyed on them for millions of years. the distinctive behavioural reactions by these squirrels to rattlesnakes have recently been shown to include self-application of rattlesnake scent-squirrels apply scent by vigorously licking their fur after chewing on shed rattlesnake skins. here, we present evidence that this behaviour is a novel antipredator defence founded on exploita ...	0	18198147
rickettsia amblyommii infecting amblyomma americanum larvae.	polymerase chain reaction analysis of amblyomma americanum adults, nymphs, and larvae from aberdeen proving ground, md (apg), revealed a very high prevalence of a spotted fever group (sfg) rickettsia. restriction fragment length polymorphism (rflp) and sequence analysis identified "rickettsia amblyommii." this organism is not yet described or well studied, and its pathogenicity is unknown; however, investigations of the organism are warranted because of its high prevalence in a. americanum. this ...	2008	18171102
variability and action mechanism of a family of anticomplement proteins in ixodes ricinus.	ticks are blood feeding arachnids that characteristically take a long blood meal. they must therefore counteract host defence mechanisms such as hemostasis, inflammation and the immune response. this is achieved by expressing batteries of salivary proteins coded by multigene families.	2008	18167559
identification of 19 polymorphic major outer membrane protein genes and their immunogenic peptides in ehrlichia ewingii for use in a serodiagnostic assay.	ehrlichia ewingii, a tick-transmitted rickettsia previously known only as a canine pathogen, was recently recognized as a human pathogen. e. ewingii has yet to be cultivated, and there is no serologic test available to diagnose e. ewingii infection. previously, a fragment (505 bp) of a single e. ewingii gene homologous to 1 of 22 genes encoding ehrlichia chaffeensis immunodominant major outer membrane proteins 1 (omp-1s)/p28s was identified. the purposes of the present study were to (i) determin ...	2008	18094116
comparative sialomics between hard and soft ticks: implications for the evolution of blood-feeding behavior.	ticks evolved various mechanisms to modulate their host's hemostatic and immune defenses. differences in the anti-hemostatic repertoires suggest that hard and soft ticks evolved anti-hemostatic mechanisms independently, but raise questions on the conservation of salivary gland proteins in the ancestral tick lineage. to address this issue, the sialome (salivary gland secretory proteome) from the soft tick, argas monolakensis, was determined by proteomic analysis and cdna library construction of s ...	2008	18070664
an insight into the sialome of the soft tick, ornithodorus parkeri.	while hard ticks (ixodidae) take several days to feed on their hosts, soft ticks (argasidae) feed faster, usually taking less than 1h per meal. saliva assists in the feeding process by providing a cocktail of anti-hemostatic, anti-inflammatory and immunomodullatory compounds. saliva of hard ticks has been shown to contain several families of genes each having multiple members, while those of soft ticks are relatively unexplored. analysis of the salivary transcriptome of the soft tick ornithodoru ...	2008	18070662
plasmids of the prm/prf family occur in diverse rickettsia species.	the recent discoveries of the prf and prm plasmids of rickettsia felis and r. monacensis have contravened the long-held dogma that plasmids are not present in the bacterial genus rickettsia (rickettsiales; rickettsiaceae). we report the existence of plasmids in r. helvetica, r. peacockii, r. amblyommii, and r. massiliae isolates from ixodid ticks and in an r. hoogstraalii isolate from an argasid tick. r. peacockii and four isolates of r. amblyommii from widely separated geographic locations cont ...	2008	18065613
detection of rickettsia amblyommii in association with a tick bite rash.	in the summer of 2006, an amblyomma americanum tick was removed from a woman in central north carolina, who subsequently developed a rash at the site of tick attachment. when examined by polymerase chain reaction (pcr) for borrelia, anaplasma, ehrlichia, babesia, rickettsia, and bartonella dna, only the rickettsia primers generated an amplicon, which was identified as "r. amblyommii" by sequencing. to our knowledge, this is the first case in which r. amblyommii was temporally associated with a r ...	2007	18052716
basophils and type 2 immunity.	mechanisms involved in the development of in-vivo type 2 immunity are poorly defined. basophils are potent il-4-producing cells and may contribute to the process of polarizing immune responses.	0	18043247
serotonin-like immunoreactivity in the central nervous system of two ixodid tick species.	immunocytochemistry was used to describe the distribution of serotonin-like immunoreactive (5ht-ir) neurons and neuronal processes in the central nervous system (cns), the synganglion, of two ixodid tick species; the winter tick, dermacentor albipictus and the lone star tick, amblyomma americanum. 5ht-ir neurons were identified in the synganglion of both tick species. d. albipictus had a significantly higher number of 5ht-ir neurons than a. americanum. the labeling pattern and number of 5ht-ir n ...	2007	18040871
experimental infection of dairy calves with ehrlichia chaffeensis.	human monocytic ehrlichiosis (hme) is a zoonotic emerging tick-borne disease with clinical signs that range from mild symptoms to multiple organ failure and death. ehrlichia chaffeensis, the aetiologic agent of hme, is reported to infect a divergent range of mammals. although cattle are common hosts of the primary vector of this pathogen, the susceptibility of this host to e. chaffeensis has not been reported to date. this study was undertaken to determine if cattle could provide a useful infect ...	2007	18033836
molecular cloning of the ecdysone receptor and the retinoid x receptor from the scorpion liocheles australasiae.	cdnas of the ecdysone receptor and the retinoid x receptor were cloned from the japanese scorpion liocheles australasiae, and the amino acid sequences were deduced. the full-length cdna sequences of the l. australasiae ecdysone receptor and the l. australasiae retinoid x receptor were 2881 and 1977 bp in length, respectively, and the open reading frames encoded proteins of 560 and 414 amino acids. the amino acid sequence of the l. australasiae ecdysone receptor was similar to that of the ecdyson ...	2007	18028192
functional evolution of the vitamin d and pregnane x receptors.	the vitamin d receptor (vdr) and pregnane x receptor (pxr) are nuclear hormone receptors of the nr1i subfamily that show contrasting patterns of cross-species variation. vdr and pxr are thought to have arisen from duplication of an ancestral gene, evident now as a single gene in the genome of the chordate invertebrate ciona intestinalis (sea squirt). vdr genes have been detected in a wide range of vertebrates including jawless fish. to date, pxr genes have not been found in cartilaginous fish. i ...	2007	17997857
confirmation of the efficacy of a novel formulation of metaflumizone plus amitraz for the treatment and control of fleas and ticks on dogs.	a novel spot-on formulation containing metaflumizone plus amitraz (promeris/promeris duo for dogs, fort dodge animal health, overland park, ks) was evaluated in four laboratory studies to confirm efficacy against fleas and ticks on dogs for 1 month. three different strains of cat flea (ctenocephalides felis felis) and four tick species were used. rhipicephalus sanguineus and dermacentor variabilis were evaluated concurrently in two studies and ixodes scapularis and amblyomma americanum in one st ...	2007	17923330
life cycles of seven ixodid tick species (acari: ixodidae) under standardized laboratory conditions.	studies of transmission, maintenance, infectivity, virulence, and pathogenicity of tick-borne agents require the use of large numbers of live laboratory-raised ticks. colonies of ixodes scapularis say, ixodes pacificus cooley & kohls, amblyomma americanum (l.), dermacentor occidentalis marx, dermacentor variabilis (say), hemaphysalis leporispalustris (packard), and rhipicephalus sanguineus (latrielle) have been maintained in our laboratory at the centers for disease control and prevention for fi ...	2007	17915502
gene knockdown by rnai in the pea aphid acyrthosiphon pisum.	rna interference (rnai) is a powerful method to inhibit gene expression in a sequence specific manner.	2007	17903251
modeling and biological control of mosquitoes.	models can be useful at many different levels when considering complex issues such as biological control of mosquitoes. at an early stage, exploratory models are valuable in exploring the characteristics of an ideal biological control agent and for guidance in data collection. when more data are available, models can be used to explore alternative control strategies and the likelihood of success. there are few modeling studies that explicitly consider biological control in mosquitoes; however, t ...	0	17853610
ecological havoc, the rise of white-tailed deer, and the emergence of amblyomma americanum-associated zoonoses in the united states.	two infectious diseases, and one presumably infectious disease, each vectored by or associated with the bite of the lone star tick (amblyomma americanum), were identified and characterized by clinicians and scientists in the united states during the 1980s and 1990s. these three conditions-human monocytic (or monocytotropic) ehrlichiosis (hme), ehrlichia ewingii ehrlichiosis, and southern tick-associated rash illness (stari)-undoubtedly existed in the united states prior to this time. however, th ...	2007	17848069
bartonella vinsonii subsp. berkhoffii endocarditis in a dog from saskatchewan.	a dog referred for lameness was diagnosed with culture-negative endocarditis. antibodies to bartonella spp. were detected. antibiotic treatment resulted in transient clinical improvement, but the dog developed cardiac failure and was euthanized. bartonella vinsonii subsp. berkhoffii genotype iv was identified within the aortic heart valve lesions by pcr amplification and dna sequencing.	2007	17824328
molecular and expression analysis of a family of the amblyomma americanum tick lospins.	serine proteinase inhibitors (serpins) are a family of structurally similar but functionally diverse proteins that regulate several important proteolytic cascades in most branches of life. we have characterized 17 amblyomma americanum serpin cdnas here named as ;lospins' (l; an acronym for lone star tick serpin) that possess three beta-sheets, eight alpha-helices and a reactive center loop consistent with the consensus serpin superfamily secondary structures. visual inspection of deduced amino a ...	2007	17766296
thyroid hormone receptor orthologues from invertebrate species with emphasis on schistosoma mansoni.	thyroid hormone receptors (trs) function as molecular switches in response to thyroid hormone to regulate gene transcription. trs were previously believed to be present only in chordates.	2007	17727708
localization and visualization of a coxiella-type symbiont within the lone star tick, amblyomma americanum.	a coxiella-type microbe occurs at 100% frequency in all amblyomma americanum ticks thus far tested. using laboratory-reared ticks free of other microbes, we identified the amblyomma-associated coxiella microbe in several types of tissue and at various stages of the life cycle of a. americanum by 16s rrna gene sequencing and diagnostic pcr. we visualized amblyomma-associated coxiella through the use of a diagnostic fluorescence in situ hybridization (fish) assay supplemented with pcr-based detect ...	2007	17720830
transmission of ehrlichia chaffeensis from lone star ticks (amblyomma americanum) to white-tailed deer (odocoileus virginianus).	amblyomma americanum is an aggressive ixodid tick that has been implicated as a vector for several bacterial agents. among these is ehrlichia chaffeensis, which causes human monocytic (or monocytotropic) ehrlichiosis. in this study, experimental tick transmission of e. chaffeensis from infected lone star ticks to deer was revisited, and the question of whether it would be possible to re-isolate the organism from deer was asked, because this had not been done previously. here, we were able to tra ...	2007	17699076
structural and functional characterization of a novel type of ligand-independent rxr-usp receptor.	retinoid x receptor (rxr) and ultraspiracle (usp) play a central role as ubiquitous heterodimerization partners of many nuclear receptors. while it has long been accepted that a wide range of ligands can activate vertebrate/mollusc rxrs, the existence and necessity of specific endogenous ligands activating rxr-usp in vivo is still matter of intense debate. here we report the existence of a novel type of rxr-usp with a ligand-independent functional conformation. our studies involved tribolium usp ...	2007	17673910
multiplication of tularemia organisms in the lone star tick.		1955	17648838
tissue and life-stage distribution of a defensin gene in the lone star tick, amblyomma americanum.	the transcript sequence of the amblyomma americanum linnaeus (acari: ixodidae) defensin, termed amercin (amn), was ascertained and a 219-bp amn coding region identified. the gene encodes a 72-amino acid prepropeptide with a putative 37-amino acid mature peptide. this gene shows little similarity to either of the defensins from amblyomma hebraeum koch, the only other amblyomma species for which a defensin has been described. sequence comparisons with other tick defensins reveal amn to be shorter ...	2007	17550433
transmission of bacterial agents from lone star ticks to white-tailed deer.	amblyomma americanum (l.), the lone star tick, is an aggressive ixodid tick that has been implicated as a vector for several bacteria. among these bacteria are the disease agents ehrlichia chaffeensis and ehrlichia ewingii, and the putative disease agent "borrelia lonestari." the hypothesis in this study was that wild lone star ticks from northeastern georgia are capable of transmitting all three agents to white-tailed deer, odocoileus virginianus, a known reservoir host for e. chaffeensis. in t ...	2007	17547234
a call for renewed research on tick-borne francisella tularensis in the arkansas-missouri primary national focus of tularemia in humans.	arkansas-missouri has emerged as the primary u.s. focus of tularemia, which is caused by the national institute of allergy and infectious diseases category a priority pathogen francisella tularensis, over the past 30 yr. there are several pieces of indirect evidence suggesting that a key role of ticks in the transmission of f. tularensis to humans in arkansas-missouri is the primary reason why tularemia has remained a prominent disease of humans in this two-state area while fading away from othe ...	2007	17547223
purification and characterization of two larval glycoproteins from the cattle tick, boophilus annulatus.	the present study was conducted to identify new target immunogenic molecules from the larval stage of the cattle tick, boophilus annulatus (acari: ixodidae). two specific larval glycoproteins (glps) were isolated by two-step affinity chromatography. the larval immunogens were first purified with cnbr-sepharose coupled to rabbit anti-larval immunoglobulins, and the glycoproteins were then purified with con-a sepharose. these glycoproteins have molecular weights of approximately 32 and 15 kda with ...	2007	17519572
surface-exposed proteins of ehrlichia chaffeensis.	the surface proteins of ehrlichia chaffeensis provide an important interface for pathogen-host interactions. to investigate the surface proteins of e. chaffeensis, membrane-impermeable, cleavable sulfo-nhs-ss-biotin was used to label intact bacteria. the biotinylated bacterial surface proteins were isolated by streptavidin-agarose affinity purification. the affinity-captured proteins were separated by electrophoresis, and five relatively abundant protein bands containing immunoreactive proteins ...	2007	17517859
evolution of the iron-responsive element.	an rna hairpin structure referred to as the iron-responsive element (ire) and iron regulatory proteins (irps) are key players in the control of iron metabolism in animal cells. they regulate translation initiation or mrna stability, and the ire is found in a variety of mrnas, such as those encoding ferritin, transferrin receptor (tfr), erythroid aminolevulinic acid synthase (ealas), mitochondrial aconitase (maco), ferroportin, and divalent metal transporter 1 (dmt1). we have studied the evolutio ...	2007	17513696