Publications

lone star tick-infecting borreliae are most closely related to the agent of bovine borreliosis.	although borrelia theileri, the agent of bovine borreliosis, was described at the turn of the century (in 1903), its relationship with borreliae causing lyme disease or relapsing fever remains undescribed. we tested the previously published hypothesis that spirochetes infecting lone star ticks (amblyomma americanum) may comprise b. theileri by analyzing the 16s ribosomal dnas (rdnas) and flagellin genes of these spirochetes. b. theileri, the amblyomma agent, and b. miyamotoi formed a natural gro ...	2001	11158095
sensitive detection of ehrlichia chaffeensis in cell culture, blood, and tick specimens by reverse transcription-pcr.	ehrlichia chaffeensis is an obligatory intracellular bacterium of monocytes and macrophages and the etiologic agent of human monocytic ehrlichiosis, an emerging zoonosis. the lone star tick (amblyomma americanum) has been implicated as the primary vector of e. chaffeensis. the present study examined the sensitivity of the nested reverse transcription (rt)-pcr based on the 16s rrna gene relative to that of the nested pcr for detection of e. chaffeensis in infected dh82 cells, experimentally infec ...	2001	11158090
isolation of a spotted fever group rickettsia, rickettsia peacockii, in a rocky mountain wood tick, dermacentor andersoni, cell line.	an embryonic cell line (dae100) of the rocky mountain wood tick, dermacentor andersoni, was observed by microscopy to be chronically infected with a rickettsialike organism. the organism was identified as a spotted fever group (sfg) rickettsia by pcr amplification and sequencing of portions of the 16s rrna, citrate synthase, rickettsia genus-specific 17-kda antigen, and sfg-specific 190-kda outer membrane protein a (rompa) genes. sequence analysis of a partial rompa gene pcr fragment and indirec ...	2001	11157215
host association and seasonal activity of amblyomma americanum (acari: ixodidae) in missouri.	from june 1993 through june 1996, 2,260 adult, 4,426 nymphal, and 2,178 larval lone star ticks amblyomma americanum (l.) were collected in missouri from vertebrate hosts and by dragging a cloth over vegetation. prevalence, mean intensity, and relative abundance of each stage varied among hosts. the relative abundance of adult lone star ticks was highest on white-tailed deer, but this stage was also collected from raccoons, opossum, red fox, coyotes, and wild turkey. nymphs were collected from gr ...	2000	11128501
efficacy of amitraz applied to white-tailed deer by the '4-poster' topical treatment device in controlling free-living lone star ticks (acari: ixodidae).	white-tailed deer treated themselves with a commercial pour-on acaricide formulation containing 2% amitraz as they fed from an ars-patented '4-poster' topical treatment device. whole kernel corn attracted deer to a single device placed in each of two deer-fenced pastures. in the treatment pasture, the rollers of the treatment device were charged with the acaricide, whereas the rollers of the device in the other pasture remained untreated. deer were allowed to use the '4-posters' during periods o ...	2000	11126544
what's eating you? amblyomma ticks (amblyomma americanum).		2000	11109142
detection of ehrlichia chaffeensis dna in amblyomma americanum ticks in connecticut and rhode island.	ehrlichia chaffeensis, the causative agent of human monocytic ehrlichiosis, is transmitted by amblyomma americanum ticks, which are most abundant in the southern united states. because serologic evidence suggests that residents of connecticut are exposed to e. chaffeensis, a. americanum ticks were collected in connecticut and rhode island for pcr analysis to detect e. chaffeensis dna. eight of 106 (7.6%) a. americanum ticks from connecticut and 6 of 52 (11.5%) from rhode island contained e. chaf ...	2000	11101616
analysis of the expressed genome of the lone star tick, amblyomma americanum (acari: ixodidae) using an expressed sequence tag approach.	an expressed sequence tag (est) approach was used to study the genome of two developmental stages of the lone star tick, amblyomma americanum. cdna libraries were constructed from the larval and adult stages of a. americanum. in total, 1942 ests were sequenced (1462 adult ests and 480 larval ests) and analyzed using bioinformatic programs. contig assembly using the capii program revealed 11% and 15% redundancy of sequences in the larval and adult ests, respectively. of the 1942 ests, 1738 sequen ...	2000	11087176
prostaglandin e(2)-stimulated secretion of protein in the salivary glands of the lone star tick via a phosphoinositide signaling pathway.	previous studies identified a prostaglandin e(2) (pge(2)) receptor in the salivary glands of partially fed female lone star ticks, amblyomma americanum (l.). in the present studies, protein secretion from dispersed salivary gland acini was shown to be specific for pge(2), as compared with pgf(2alpha) or the thromboxane analog u-46619, in accordance with their respective binding affinities for the pge(2) receptor. furthermore, the selective pge(2) ep1 receptor agonist, 17-phenyl trinor pge(2), wa ...	2000	10989297
prevalence of ehrlichia ewingii in amblyomma americanum in north carolina.		2000	10979750
a state-by-state survey of ticks recorded from humans in the united states.	based on tick specimens accessioned into the u.s. national tick collection, the species of ticks recorded as ectoparasites of humans are documented and compared for 49 u.s. states. a total of 44 tick species was recorded as parasites of humans, consisting of 11 species of soft ticks (argasidae) and 33 species of hard ticks (ixodidae). four of the hard tick species are not native to the u.s. and were removed from travelers returning from foreign destinations. therefore, we record 40 of the 84 spe ...	2000	10925803
distribution of ehrlichia chaffeensis (rickettsiales: rickettsiaeceae) in amblyomma americanum in southern indiana and prevalence of e. chaffeensis--reactive antibodies in white-tailed deer in indiana and ohio in 1998.	to continue monitoring the prevalence and distribution of ehrlichia chaffeensis (rickettsiales: rickettsiaeceae) in southern indiana, a total of 498 amblyomma americanum (l.) ticks (262 adults and 292 nymphs) was collected from five southern indiana counties during may and june 1998. ticks were pooled and examined for the presence of e. chaffeensis using nested polymerase chain reaction and primers specific for the 16s rrna gene of e. chaffeensis. the average minimum infection rate for adult tic ...	2000	10916302
the '4-poster' passive topical treatment device to apply acaricide for controlling ticks (acari: ixodidae) feeding on white-tailed deer.	a '4-poster' device that attracts white-tailed deer to a bait source, and as they feed, allows a self-application of a pesticide to the head, ears, and neck to control ticks was designed, constructed, and tested. the device consists of a central bin containing bait to attract deer and two feeding and application stations. these stations each have one bait port and two vertical pesticide-impregnated applicator rollers. this design allows unrestricted vertical retraction of the head to minimize in ...	2000	10916301
clinical manifestations of tick-borne infections in children.		2000	10882645
identification of ehrlichia chaffeensis by nested pcr in ticks from southern china.	a total of 717 ticks collected from southern china were examined by nested pcr for the presence of ehrlichia chaffeensis. sixteen (55. 2%) of 29 adult amblyomma testudinarium ticks and 28 (11.7%) of 240 adult and at least 4.2% of 215 nymphal (pooled specimens) haemaphysalis yeni ticks tested positive. four other species of ticks were negative. selected positive amplicons were confirmed by dna sequencing.	2000	10878087
isolation and molecular cloning of a secreted immunosuppressant protein from dermacentor andersoni salivary gland.	a 36-kda immunosuppressant protein (da-p36) was isolated from salivary glands of feeding female ixodid ticks dermacentor andersoni, using its affinity for ultralink biosupport medium (pierce, rockford, illinois)/protein complexes. using a nested set of forward degenerate oligonucleotide primers corresponding to da-p36 n-terminal amino acids, a cdna encoding the immunosuppressant protein was isolated by 3' rapid amplification of cdna ends. the resulting 772-base pair cdna encodes a novel protein ...	2000	10864249
short report: study on the efficacy of a new long-acting formulation of n, n-diethyl-m-toluamide (deet) for the prevention of tick attachment.	the beneficial effects of n, n-diethyl-m-toluamide (deet) against biting insects of human and animals appear to last <6 hr after a single application to the skin. to prolong the repellent effects of deet, recently we developed a new long-acting formulation of deet called lipodeet. this preparation was retained in the skin for a longer duration of time with minimal systemic absorption. in this study, we have evaluated the protective effect of three compounds (deet, lipodeet, and morpel 220) again ...	2000	10813468
molecular determinants of differential ligand sensitivities of insect ecdysteroid receptors.	the functional receptor for insect ecdysteroid hormones is a heterodimer consisting of two nuclear hormone receptors, ecdysteroid receptor (ecr) and the retinoid x receptor homologue ultraspiracle (usp). although ecdysone is commonly thought to be a hormone precursor and 20-hydroxyecdysone (20e), the physiologically active steroid, little is known about the relative activity of ecdysteroids in various arthropods. as a step toward characterization of potential differential ligand recognition, we ...	0	10805730
fine specificity of autoantibodies to calreticulin: epitope mapping and characterization.	extracellular calreticulin (crt) as well as anti-crt antibodies have been reported in patients with various autoimmune disorders and crt has been implicated in 'epitope spreading' to other autoantigens such as the ro/ss-a complex. in addition, antibodies against parasite forms of the endoplasmic reticulum chaperone, crt, have been found in patients suffering from onchocerciasis and schistosomiasis. in this study, we screened sera for anti-crt antibodies from patients with active and inactive sys ...	2000	10792392
tick infestations of birds in coastal georgia and alabama.	mist-netted birds were examined for ticks on jekyll island, glynn co., georgia (32 bird species) in 1996-1998, and at fort morgan, baldwin co., alabama (36 species) in 1998 during fall migration. sixty-two (14.7%) of 423 birds from jekyll island and 22 (13.3%) of 165 birds from fort morgan were infested with ticks. the mean number of ticks per infested bird was 2.0 on jekyll island and 6.3 at fort morgan. ten species of birds were infested with ticks on jekyl1 island where 87% of all ticks were ...	2000	10780541
detection of the agent of heartwater, cowdria ruminantium, in amblyomma ticks by pcr: validation and application of the assay to field ticks.	we have previously reported that the pcs20 pcr detection assay for cowdria ruminantium, the causative agent of heartwater disease of ruminants, is more sensitive than xenodiagnosis and the pcs20 dna probe for the detection of infection in the vector amblyomma ticks. here, we further assessed the reliability of the pcr assay and applied it to field ticks. the assay detected dna of 37 isolates of c. ruminantium originating from sites throughout the distribution of heartwater and had a specificity ...	2000	10747140
new ehrlichia species closely related to ehrlichia chaffeensis isolated from ixodes ovatus ticks in japan.	seven ehrlichia strains (six hf strains and one anan strain) that were obtained from laboratory mice by intraperitoneally inoculating homogenates of adult ixodes ovatus collected in japan were characterized. 16s rrna sequences of all six hf strains were identical, and the sequences were 99.7, 98.2, and 97.7% identical to those of anan strain, ehrlichia chaffeensis (human monocytic ehrlichiosis agent), and e. muris, respectively. partial groel amino acid sequencing also revealed that the six hf s ...	2000	10747103
prevalence of ehrlichia chaffeensis (rickettsiales: rickettsiaceae) in amblyomma americanum (acari: ixodidae) from the georgia coast and barrier islands.	human monocytic ehrlichiosis is an emerging zoonosis caused by infection with ehrlichia chaffeensis anderson, dawson, jones & wilson, which is transmitted to mammals by ixodid ticks. prevalence of infected ticks and distribution of infection foci indicate relative risk of human exposure to ehrlichiosis and may be influenced by factors such as geographic isolation, human disturbance, and the availability of suitable mammalian reservoir hosts. to test, this, individual and pooled lone star ticks, ...	2000	10730500
antibody-mediated elimination of the obligate intracellular bacterial pathogen ehrlichia chaffeensis during active infection.	it is generally accepted that cellular, but not humoral immunity, plays an important role in host defense against intracellular bacteria. however, studies of some of these pathogens have provided evidence that antibodies can provide immunity if present during the initiation of infection. here, we examined immunity against infection by ehrlichia chaffeensis, an obligate intracellular bacterium that causes human monocytic ehrlichiosis. studies with mice have demonstrated that immunocompetent strai ...	2000	10722619
comparison of efficacy of american and african amblyomma ticks as vectors of heartwater (cowdria ruminantium) infection by molecular analyses and transmission trials.	the ability of amblyomma americanum, amblyomma cajennense, amblyomma maculatum, and amblyomma variegatum to acquire and transmit cowdria ruminantium infection was investigated. uninfected nymphs were fed on clinically reacting c. ruminantium-infected sheep and then analyzed for infection by specific dna detection assays and by tick transmission trials. by polymerase chain reaction (pcr), the mean infection prevalence of a. maculatum ticks (50.7%) was similar to that of a. variegatum, elevage str ...	2000	10701562
helminthic transmission and isolation of ehrlichia risticii, the causative agent of potomac horse fever, by using trematode stages from freshwater stream snails.	we report successful helminthic transmission of ehrlichia risticii, the causative agent of potomac horse fever, using trematode stages collected from juga yrekaensis snails. the ehrlichial agent was isolated from the blood of experimentally infected horses by culture in murine monocytic cells and identified as e. risticii ultrastructurally and by characterization of three different genes.	2000	10699046
prevalence of lyme disease borrelia spp. in ticks from migratory birds on the japanese mainland.	borrelia sp. prevalence in ticks on migratory birds was surveyed in central japan. in autumn, a total of 1,733 birds representing 40 species were examined for ticks. a total of 361 ticks were obtained from 173 birds of 15 species, and these ticks were immature haemaphysalis flava (94.4%), haemaphysalis longicornis, ixodes columnae, ixodes persulcatus, ixodes turdus, and an unidentified ixodes species. of these, 27 juveniles of h. flava on turdus pallidus, turdus cardis, or emberiza spodocephala, ...	2000	10698761
ticks of south carolina (acari: ixodoidea).	county and host records are reported for 19 species of ticks from south carolina: amblyomma americanum, amblyomma maculatum, amblyomma tuberculatum, aponomma latum, boophilus annulatus, boophilus microplus, dermacentor albipictus, dermacentor variablis, haemaphysalis leporispalustris, ixodes affinis, ixodes brunneus, ixodes cookei, ixodes marxi, ixodes minor, ixodes scapularis, ixodes texanus, ixodes woodi, rhipicephalus sanguineus, and ornithodoros capensis. ixodes woodi is recorded from south ...	1999	10672552
natural infection of domestic goats with ehrlichia chaffeensis.	thirty-eight domestic goats from an area of ehrlichia chaffeensis endemicity were tested for antibodies reactive to e. chaffeensis and for e. chaffeensis-specific 16s rrna gene fragments by an indirect fluorescent antibody test and a nested pcr assay, respectively. twenty-eight of 38 (73.7%) goats had antibodies reactive to e. chaffeensis (>/=1:128), and 6 of 38 (15.8%) goats were positive by diagnostic pcr; e. chaffeensis was isolated in cell culture from one goat. our data indicate that goats ...	2000	10618139
isolation, cultivation, and characterization of borrelia burgdorferi from rodents and ticks in the charleston area of south carolina.	twenty-eight borrelia burgdorferi isolates from the charleston, s.c., area are described. this represents the first report and characterization of the lyme disease spirochete from that state. the isolates were obtained from december 1994 through december 1995 from the tick ixodes scapularis, collected from vegetation, and from the rodents peromyscus gossypinus (cotton mouse), neotoma floridana (eastern wood rat), and sigmodon hispidus (cotton rat). all isolates were screened immunologically by i ...	2000	10618074
infection rates of amblyomma americanum (acari: ixodidae) by ehrlichia chaffeensis (rickettsiales: ehrlichieae) and prevalence of e. chaffeensis-reactive antibodies in white-tailed deer in southern indiana, 1997.	to monitor the percentage and stability of ehrlichia chaffeensis-infected ticks in southern indiana over time, pools of amblyomma americanum (l.) ticks were screened for infection in southern indiana for a 2nd time. nested polymerase chain reaction (with 6% dmso included only in the 2nd reaction) was performed on 920 ticks in pools of 5 individuals from 9 sites (5 sites previously examined and 4 new ones) in 6 counties. the average minimum infection rate for all sites for 1997 was 1.6%, lower th ...	1999	10593071
ticks and antibodies to borrelia burgdorferi from mammals at cape hatteras, nc and assateague island, md and va.	results of a survey for ixodid ticks and/or serum antibodies to borrelia burgdorferi from 14 species of small to large mammals from eastern coastal areas of the united states are presented. most samples were obtained from july 1987 through june 1989 (excluding december-march) at 3 locales: assateague is. national seashore, worcester co., md., and accomack co., va. (approximately 38 degrees 05' n 75 degrees 10' w), and cape hatteras national seashore, dare co., nc (approximately 35 degrees 30' n ...	1999	10534951
molecular typing of borrelia burgdorferi sensu lato: taxonomic, epidemiological, and clinical implications.	borrelia burgdorferi sensu lato, the spirochete that causes human lyme borreliosis (lb), is a genetically and phenotypically divergent species. in the past several years, various molecular approaches have been developed and used to determine the phenotypic and genetic heterogeneity within the lb-related spirochetes and their potential association with distinct clinical syndromes. these methods include serotyping, multilocus enzyme electrophoresis, dna-dna reassociation analysis, rrna gene restri ...	1999	10515907
q fever.	q fever is a zoonosis with a worldwide distribution with the exception of new zealand. the disease is caused by coxiella burnetii, a strictly intracellular, gram-negative bacterium. many species of mammals, birds, and ticks are reservoirs of c. burnetii in nature. c. burnetii infection is most often latent in animals, with persistent shedding of bacteria into the environment. however, in females intermittent high-level shedding occurs at the time of parturition, with millions of bacteria being r ...	1999	10515901
squalene: a naturally abundant mammalian skin secretion and long distance tick-attractant (acari: ixodidae).	squalene is a naturally occurring lipid on mammalian skin and is an attractant to the lone star tick, amblyomma americanum (l.). in this study, we compared squalene to the standard tick-attractants, benzaldehyde, isobutyric acid, methyl salicylate, nonanoic acid, and o-nitrophenol identified as active ingredients of tick aggregation-attachment pheromones and determined its effectiveness in field and laboratory settings at varying distances. squalene was detected from 1/4 m greater than the stand ...	1999	10467784
comparison of methods for introducing and producing artificial infection of ixodid ticks (acari: ixodidae) with ehrlichia chaffeensis.	only 29.5 +/- 8.91% of engorged amblyomma americanum (l.) nymphs that we inoculated with ehrlichia chaffeensis molted successfully to adults compared with 75.8 +/- 7.46% of engorged nymphs that were not inoculated. however, 65.4 +/- 6.02% of unfed nymphs of this species were exposed for 2 h to e. chaffeensis suspension introduced to them through glass capillaries gained weight. these nymphs were placed on rabbits, and approximately 50% of them completed their feeding and molted successfully to a ...	1999	10467766
theileria sp. infections associated with bovine fatalities in the united states confirmed by small-subunit rrna gene analyses of blood and tick samples.	theileria sp.-specific small subunit (ssu) rrna gene amplification confirmed the presence of the organism in cattle and in amblyomma americanum and dermacentor variabilis ticks collected from a cattle herd in missouri. blood from the index animal had type a and type d theileria ssu rrna genes. the type d gene was also found in blood from two cohort cattle and tick tissues. the type a ssu rrna gene was previously reported from bovine theileria isolates from texas and north carolina; the type d ge ...	1999	10449501
coinfection with multiple tick-borne pathogens in a walker hound kennel in north carolina.	both dogs and humans can be coinfected with various ehrlichia, bartonella, rickettsia, and babesia species. we investigated a kennel of sick walker hounds and their owners in southeastern north carolina for evidence of tick-borne infections and associated risk factors. a high degree of coinfection was documented in the dog population. of the 27 dogs, 26 were seroreactive to an ehrlichia sp., 16 to babesia canis, and 25 to bartonella vinsonii, and 22 seroconverted to rickettsia rickettsii antigen ...	1999	10405413
comparison of ehrlichia chaffeensis recombinant proteins for serologic diagnosis of human monocytotropic ehrlichiosis.	diagnosis of human monocytotropic ehrlichiosis (hme) generally depends on serology that detects the antibody response to immunodominant proteins of ehrlichia chaffeensis. protein immunoblotting was used to evaluate the reaction of the antibodies in patients' sera with the recombinant e. chaffeensis 120- and 28-kda proteins as well as the 106- and the 37-kda proteins. the cloning of the genes encoding the latter two proteins is described in this report. immunoelectron microscopy demonstrated that ...	1999	10405403
invasion and intracellular development of the human granulocytic ehrlichiosis agent in tick cell culture.	human granulocytotropic ehrlichias are tick-borne bacterial pathogens that cause an acute, life-threatening illness, human granulocytic ehrlichiosis (hge). ehrlichias within neutrophil granulocytes that invade tick bite sites are likely ingested by the vector, to be transmitted to another mammalian host during the tick's next blood meal. thus, the cycle of replication and development in the vector is prerequisite to mammalian infection, and yet these events have not been described. we report tic ...	1999	10405394
effects of environmental ph on membrane proteins in borrelia burgdorferi.	borrelia burgdorferi, the causative agent of lyme disease, alternates between the microenvironments of the tick vector, ixodes scapularis, and a mammalian host. the environmental conditions the spirochete encounters during its infectious cycle are suspected to differ greatly in many aspects, including available nutrients, temperature, and ph. here we identify alterations in the membrane protein profile, as determined by immunoblotting and two-dimensional nonequilibrium ph gradient gel electropho ...	1999	10377088
detection and identification of ehrlichia, borrelia burgdorferi sensu lato, and bartonella species in dutch ixodes ricinus ticks.	a sensitive and specific pcr hybridization assay was developed for the simultaneous detection and identification of ehrlichia and borrelia burgdorferi sensu lato. in separate assays the 16s rrna gene of ehrlichia species and the 23s-5s rrna spacer region of b. burgdorferi sensu lato were amplified and labeled by pcr. these pcr products were used in a reverse line blot hybridization assay in which oligonucleotide probes are covalently linked to a membrane in parallel lines. hybridization of the s ...	1999	10364588
palp-splaying behavior and a specific mouthpart site associated with active water vapor uptake in amblyomma americanum (acari: ixodidae).	ticks actively absorb water vapor from unsaturated air via their mouthparts. a wax technique was used to cover select areas of the mouthparts of the lone star tick, amblyomma americanum (l.), to examine whether a specific site is involved in uptake. covering dorsal, ventral, and distal regions failed to inhibit uptake, whereas wax applied to the proximal region, specifically the hypostome-cheliceral junction, blocked water absorption. a novel occurrence of a palp-splaying behavior was observed d ...	1999	10337109
attachment sites of four tick species (acari: ixodidae) parasitizing humans in georgia and south carolina.	from june 1995 through january 1998, 677 tick specimens were submitted by 521 humans from 14 states. analysis was limited to specimens originating in georgia and south carolina, representing 87.3% of total submissions. attachment sites were specified in 367 specimens (62.3%). the american dog tick, dermacentor variabilis (say), a vector of the agent of rocky mountain spotted fever, favored the head and neck in 59% of attached specimens. the lone star tick, amblyomma americanum (l.), a strongly i ...	1999	10337108
responses of three species of adult ticks (acari: ixodidae) to chemicals in the coats of principal and minor hosts.	in laboratory bioassays, host-seeking adult blacklegged ticks, ixodes scapularis say, lone star ticks, amblyomma americanum (l.), and american dog ticks, dermacentor variabilis (say), were exposed to substances from the pelage of dogs and white-tailed deer, odocoileus virginianus (zimmermann). male a. americanum exhibited an arrestant response to all samples of deer tarsal gland substances tested, whereas female a. americanum, female i. scapularis, and male and female d. variabilis responded to ...	1999	10337091
molecular cloning and characterization of the ehrlichia chaffeensis variable-length pcr target: an antigen-expressing gene that exhibits interstrain variation.	a clone expressing an immunoreactive protein with an apparent molecular mass of 44 kda was selected from an ehrlichia chaffeensis arkansas genomic library by probing with anti-e. chaffeensis hyperimmune mouse ascitic fluid. nucleotide sequencing revealed an open reading frame (orf) capable of encoding a 198-amino-acid polypeptide. the orf contained four imperfect, direct, tandem 90-bp repeats. the nucleotide and deduced amino acid sequences did not show close homologies to entries in the molecul ...	1999	10203503
evidence of the human granulocytic ehrlichiosis agent in ixodes ricinus ticks in switzerland.	a total of 1,667 ixodes ricinus ticks were collected from five regions in switzerland where there have been sporadic occurrences of granulocytic ehrlichiosis in dogs and horses. the ticks were examined for rickettsiae of the ehrlichia phagocytophila group via nested pcr. twenty-one ticks (1.3%) were positive; 3 (0.5%) were nymphs, 6 (1.3%) were adult males, and 12 (1.9%) were adult females. the number of positive ticks varied with the stage of development and with the geographical origin. nucleo ...	1999	10203481
molecular characterization of a haemaphysalis longicornis tick salivary gland-associated 29-kilodalton protein and its effect as a vaccine against tick infestation in rabbits.	the use of tick vaccines in mammalian hosts has been shown to be the most promising alternative tick control method to current use of acaricides, which suffers from a number of limitations. however, the success of this method is dependent on the identification, cloning, and in vitro expression of tick molecules involved in the mediation of key physiological roles with respect to the biological success of a tick as a vector and pest. we have sequenced and characterized a haemaphysalis longicornis ...	1999	10084999
novel ehrlichia organism (rickettsiales: ehrlichieae) in white-tailed deer associated with lone star tick (acari: ixodidae) parasitism.	polymerase chain reaction (pcr) evidence of a novel ehrlichia organism was found recently in wild white-tailed deer, odocoileus virginianus zimmermann, and lone star ticks, amblyomma americanum l., from the southeastern united states. to evaluate whether lone star tick parasitism was associated with the presence of this novel ehrlichia organism in deer, 2 retrospective studies were conducted using specific nested pcr to test archived deer serum samples. the 1st study of 150 serum samples collect ...	1999	10083757
genetic diversity of the 28-kilodalton outer membrane protein gene in human isolates of ehrlichia chaffeensis.	the ehrlichia chaffeensis 28-kda outer membrane protein (p28) gene was sequenced completely by genomic walking with adapter pcr. the dna sequence of the p28 gene was nearly identical to the previously reported sequence (n. ohashi, n. zhi, y. zhang, and y. rikihisa, infect. immun. 66:132-139, 1998), but analysis of a further 75 bp on the 5' end of the gene revealed dna that encoded a 25-amino-acid signal sequence. the leader sequence was removed from the n terminus of a 30-kda precursor to genera ...	1999	10074538
comparison of ehrlichia muris strains isolated from wild mice and ticks and serologic survey of humans and animals with e. muris as antigen.	in metropolitan tokyo, the ehrlichia muris seropositivity rate of 24 wild mice was 63% in hinohara village, but in the surrounding areas, it was 0 to 5%. this finding suggests that the reservoir of e. muris is focal. among the 15 seropositive mice, ehrlichiae were isolated from 9 apodemus speciosus mice and 1 a. argenteus mouse, respectively. five ehrlichial isolates were obtained from 10 ticks (haemaphysalis flava) collected in asuke town, aichi prefecture, where the e. muris type strain had be ...	1999	10074536
molecular cloning of camp-dependent protein kinase catalytic subunit isoforms from the lone star tick, amblyomma americanum (l.).	the salivary glands of ixodid ticks are central to tick feeding and to survival during off-host periods. they produce and secrete a number of molecules critical to maintaining the complex host-vector interface and to maintaining osmotic balance. we have previously shown that a cyclic amp-dependent protein kinase (capk) is involved in the mechanism of salivary gland secretion. we have now cloned cdnas encoding three isoforms of the catalytic subunit (capk-c) of the capk from amblyomma americanum, ...	1999	10070744
serologic testing for human granulocytic ehrlichiosis at a national referral center.	an indirect immunofluorescence assay (ifa) was used to identify patients with antibodies reactive to the human granulocytic ehrlichiosis (hge) agent. serum samples collected from clinically ill individuals were submitted to the centers for disease control and prevention by physicians via state health departments from throughout the united states and tested against a panel of ehrlichial and rickettsial pathogens. antibodies reactive to the hge agent were detected in 142 (8.9%) of 1,602 individual ...	1999	9986812
experimental transmission of hepatozoon americanum vincent-johnson et al., 1997 to dogs by the gulf coast tick, amblyomma maculatum koch.	experimental transmission of hepatozoon americanum to dogs was attempted with four ixodid ticks, viz., rhipicephalus sanguineus, amblyomma americanum, amblyomma maculatum and dermacentor variabilis. ticks that dogs ingested included some that were laboratory-reared and experimentally fed as nymphs on a dog with naturally occurring hepatozoonosis; other ticks were collected as replete or partially engorged larvae, nymphs and adults from dogs that had hepatozoonosis and natural infestations of tic ...	1998	9877066
cloning and functional expression of a cdna encoding a pheromone gland-specific acyl-coa delta11-desaturase of the cabbage looper moth, trichoplusia ni.	desaturation of coenzyme-a esters of saturated fatty acids is a common feature of sex pheromone biosynthetic pathways in the lepidoptera. the enzymes that catalyze this step share several biochemical properties with the ubiquitous acyl-coa delta9-desaturases of animals and fungi, suggesting a common ancestral origin. unlike metabolic acyl-coa delta9-desaturases, pheromone desaturases have evolved unusual regio- and stereoselective activities that contribute to the remarkable diversity of chemica ...	1998	9860961
a molecular and serologic survey of ehrlichia canis, e. chaffeensis, and e. ewingii in dogs and ticks from oklahoma.	polymerase chain reaction and southern hybridization were used to survey for the presence of ehrlichia canis, ehrlichia chaffeensis, and ehrlichia ewingii in blood samples of 65 dogs that harbored ticks from northcentral and northeastern oklahoma. dog blood samples were also examined for antibodies against e. canis and e. chaffeensis, using an immunofluorescent antibody test. ten of 65 dogs (15.4%) examined were positive for ehrlichia spp. by pcr. four (6.2%) were positive for e. ewingii, 2 (3.1 ...	1998	9831955
ticks and tick-borne diseases in oklahoma.	tick-borne diseases are common in oklahoma, especially the eastern part of the state where tick prevalence is highest. three species of hard ticks are present in oklahoma that are known vectors of human disease--the american dog tick (rocky mountain spotted fever; rmsf), the lone star tick (ehrlichiosis) and the black-legged tick (lyme disease). oklahoma consistently ranks among the top states in numbers of reported rmsf cases, and ehrlichiosis may be as prevalent as rmsf. although lyme disease ...	1998	9828526
serologic evidence of a natural infection of white-tailed deer with the agent of human granulocytic ehrlichiosis in wisconsin and maryland.	white-tailed deer participate in the maintenance of the ixodes tick life cycle and are reservoirs for some tick-borne infectious agents. deer may be useful sentinels for tick-transmitted agents, such as ehrlichiae. in order to determine whether white-tailed deer are markers of natural transmission or are reservoirs for the human granulocytic ehrlichiosis (hge) agent, we performed indirect immunofluorescent-antibody (ifa) tests and immunoblotting with the hge agent and ehrlichia chaffeensis on se ...	1998	9801331
natural coinfection of a white-tailed deer (odocoileus virginianus) population with three ehrlichia spp.	the ticks amblyomma americanum and ixodes scapularis, strongly implicated vectors of ehrlichia chaffeensis and the human granulocytic ehrlichiosis (hge) agent, respectively, commonly are found on white-tailed deer (odocoileus virginianus). as deer can be infected with e. chaffeensis, the hge agent, and another ehrlichia-like organism, a deer population parasitized by both tick species in coastal georgia was tested for evidence of ehrlichia spp. infection using serologic, molecular, and culture t ...	1998	9794627
ehrlichia chaffeensis in missouri ticks.	a nested polymerase chain reaction specific for ehrlichia chaffeensis was used to attempt to amplify dna from extracts of 100 individual ticks collected from 13 counties in central missouri. seventeen of 59 amblyomma americanum and six of 41 dermacentor variabilis ticks exhibited the characteristic 389-basepair product. this supports the hypothesis that these tick species may be vectors of human monocytic ehrlichiosis.	1998	9790445
kinetics and cross-species comparisons of host antibody responses to lone star ticks and american dog ticks (acari: ixodidae).	understanding of the animal antibody response to tick salivary gland proteins is necessary to identify candidate antibodies that may have use as species- and feeding-duration-specific biomarkers of tick exposure in humans. the kinetics of the humoral immune response of rabbits to challenge feeding by 2 tick species [amblyomma americanum (l.) and dermacentor variabilis (say)] was characterized by both enzyme-linked immunosorbent assay and immunoblot. western blot analysis revealed that rabbits pr ...	1998	9775620
human exposure to a granulocytic ehrlichia and other tick-borne agents in connecticut.	indirect fluorescent-antibody (ifa) staining methods with ehrlichia equi (mrk or bds strains) and western blot analyses containing a human granulocytic ehrlichiosis (hge) agent (nch-1 strain) were used to confirm probable human cases of infection in connecticut during 1995 and 1996. also included were other tests for ehrlichia chaffeensis, the agent of human monocytic ehrlichiosis (hme), babesia microti, and borrelia burgdorferi. thirty-three (8.8%) of 375 patients who had fever accompanied by m ...	1998	9738027
physician-diagnosed erythema migrans and erythema migrans-like rashes following lone star tick bites.	to differentiate cases of physician-diagnosed erythema migrans and erythema migrans-like rashes associated with lone star tick (amblyomma americanum) bites.	1998	9722725
antibody to a cdna-derived calreticulin protein from amblyomma americanum as a biomarker of tick exposure in humans.	the antibody responses of human and animal hosts were studied to determine the utility of antibody against recombinant tick calreticulin (rtc), a cdna-derived protein isolated from salivary glands of amblyomma americanum l., as a biologic marker of tick exposure. rabbits fed upon by either a. americanum or dermacentor variabilis say developed significant anti-rtc antibody responses, as measured by both elisa and immunoblot assay. in contrast, gerbils exposed to aedes aegypti did not develop anti ...	1998	9715947
the travels of a lone star tick.	a lone-star tick, amblyomma americanum, was found as a pedunculated lesion on the back of the arm of an 84 year old man in northern ireland. this was acquired on a visit to the usa. the tick is found mainly in texas and the ozark mountains of missouri, with scattered foci in other parts of southern usa. it is the vector of rocky mountain spotted fever. as worldwide travel becomes increasingly common, exotic parasites make occasional appearances in northern europe.	1998	9708212
detection of ehrlichia phagocytophila dna in ixodes ricinus ticks from areas in switzerland where tick-borne fever is endemic.	a total of 1,523 adult ixodes ricinus ticks were collected from regions where bovine ehrlichiosis is endemic and were examined for ehrlichia phagocytophila via pcr. of the ticks from cattle with ehrlichiosis, the ticks from healthy cattle, and the free-living ticks, 26.5% (18 of 68), 4.4% (35 of 802), and 0.8% (5 of 653), respectively, were positive.	1998	9705425
sequential evaluation of dogs naturally infected with ehrlichia canis, ehrlichia chaffeensis, ehrlichia equi, ehrlichia ewingii, or bartonella vinsonii.	historically, disease manifestations in dogs seroreactive to ehrlichia canis antigens by indirect immunofluorescent antibody testing have been attributed to infection with either e. canis or ehrlichia ewingii. a 1996 study by dawson and colleagues provided pcr evidence that healthy dogs from southeastern virginia could be naturally infected with ehrlichia chaffeensis. this observation stimulated us to determine which ehrlichia spp. infected sick dogs that were referred to our hospital from the s ...	1998	9705408
isolation of two functional retinoid x receptor subtypes from the ixodid tick, amblyomma americanum (l.).	retinoid x receptors (rxr) play a central role in a variety of nuclear signaling pathways in both vertebrates and invertebrates. vertebrate rxrs are encoded by a multigene family whereas the insect rxr homologue, ultraspiracle (usp), is encoded by a single gene. to determine if acarines possess an rxr homologue similar to insect usps, we isolated cdnas encoding two distinct rxr genes, aamrxr1 and aamrxr2, from the ixodid tick, amblyomma americanum (l.). the dna binding domains share 95 and 87% i ...	1998	9705073
phospholipase a2 activity in salivary glands and saliva of the lone star tick (acari: ixodidae) during tick feeding.	phospholipase a2 (pla2) activity levels in tick [amblyomma americanum (l.)] salivary glands and saliva were examined during tick feeding by using 14c-phosphatidylcholine as the substrate. saliva produced by stimulating female ticks to salivate with dopamine contains pla2 (ts-pla2) activity. the ts-pla2 activity level in saliva did not change significantly during tick feeding except for a decrease in the last rapid feeding phase (> 200 mg) and in replete ticks. phospholipase a2 activity was highe ...	1998	9701935
detection of ehrlichia risticii, the agent of potomac horse fever, in freshwater stream snails (pleuroceridae: juga spp.) from northern california.	ehrlichia dna was identified by nested pcr in operculate snails (pleuroceridae: juga spp.) collected from stream water in a northern california pasture in which potomac horse fever (phf) is enzootic. sequencing of pcr-amplified dna from a suite of genes (the 16s rrna, groesl heat shock operon, 51-kda major antigen genes) indicated that the source organism closely resembled ehrlichia risticii, the causative agent of phf. the minimum percentage of juga spp. harboring the organism in the population ...	1998	9687446
prostaglandin e2 in the salivary glands of the female tick, amblyomma americanum (l.): calcium mobilization and exocytosis.	a cholera toxin-sensitive, prostaglandin e2 (pge2) specific receptor has been identified in the plasma membrane fraction of tick salivary glands. in the present study, we report that stimulation of dispersed salivary glands of the lone star tick amblyomma americanum (l.) with 1 nm to 10 microm pge2 increased the intracellular concentration of inositol trisphosphate (ip3) in a dose-dependent manner. incubation of dispersed tissue with 1 nm to 10 microm pge2 also stimulated release of 45ca2+ from ...	1998	9684330
distribution, abundance, and seasonal activities of ticks collected from rodents and vegetation in south carolina.	ixodid ticks were collected from live-trapped rodents and by flagging vegetation at sites in the piedmont, sandhills, coastal plain, and coastal zone of south carolina from may 1994 through december 1995. a total of 1,514 ticks was recovered from 237 live-trapped rodents. host-attached species included ixodes minor neumann (n = 818), dermacentor variabilis (say) (n = 346), amblyomma maculatum koch (n = 209), ixodes affinis neumann (n = 89), and ixodes scapularis say (n = 52). species of questing ...	1998	9673934
entomopathogenic nematodes as a potential biological control method for ticks.	entomopathogenic nematodes have been used for biological control of certain insect pests. in these studies the nematodes were tested as a possible biological control agent for engorged female ticks. five species of infective juveniles (ijs) were tested initially for their ability to penetrate and kill ticks, including steinernema glaseri (sg), s. riobravus (sr), s. carpocapsae (dt), s. feltiae (sf) and heterorhabiditis bacteriophora (hp88). infective juveniles (ijs) of srs and sfs appeared to be ...	1998	9668486
delivery of ivermectin by injectable microspheres.	a bioabsorbable, injectable microsphere formulation containing ivermectin in poly-(lactide-co-glycolide) copolymer (pla/pga) was developed to provide long-lasting delivery of the drug for control of livestock pests. a solvent-evaporation technique was used to produce the spherical beads containing approximately 30% ivermectin and ranging in size from 25-250 microns. the pattern of delivery of the drug into the blood stream of spanish goats was characterized for a 50:50 pla/pga, a 90:10 pla/pga c ...	1998	9650514
first records of amblyomma americanum, ixodes (ixodes) dentatus, and ixodes (ceratixodes) uriae (acari: ixodidae) from maine.	the first records of 3 ixodid tick species collected in the state of maine are reported. a total of 23 records of the lone star tick, amblyomma americanum (l., 1758), in 11 counties from hosts with no history of travel outside the state demonstrates that this tick is now a resident of maine. ixodes dentatus marx, 1899 is recorded from waldo and lincoln counties, and ixodes uriae white, 1852 is recorded from matinicus rock in knox county. this is the first report of i. uriae from the eastern unit ...	1998	9645873
production and characterization of ehrlichia risticii, the agent of potomac horse fever, from snails (pleuroceridae: juga spp.) in aquarium culture and genetic comparison to equine strains.	we report on the production and characterization of ehrlichia risticii, the agent of potomac horse fever (phf), from snails (pleuroceridae: juga spp.) maintained in aquarium culture and compare it genetically to equine strains. snails were collected from stream waters on a pasture in siskiyou county, calif., where phf is enzootic and were maintained for several weeks in freshwater aquaria in the laboratory. upon exposure to temperatures above 22 degrees c the snails released trematode cercariae ...	1998	9620368
immunodiagnosis of human granulocytic ehrlichiosis by using culture-derived human isolates.	human granulocytic ehrlichiosis (hge) is an emerging infection caused by an ehrlichia species closely related to ehrlichia equi and ehrlichia phagocytophila. recent advances in the isolation and cultivation of this organism have allowed us to develop an immunofluorescence assay (ifa), enzyme immunoassay (eia), and western immunoblotting (wb) using hl-60 cell culture-derived human isolates. antibody was detected in sera from culture-confirmed hge patients by ifa and eia, and these samples were re ...	1998	9620365
protein kinase a-mediated inhibition of gamma interferon-induced tyrosine phosphorylation of janus kinases and latent cytoplasmic transcription factors in human monocytes by ehrlichia chaffeensis.	ehrlichia chaffeensis, an obligatory intracellular bacterium of monocytes or macrophages, is the etiologic agent of human monocytic ehrlichiosis. our previous study showed that gamma interferon (ifn-gamma) added prior to or at early stage of infection inhibited infection of human monocytes with e. chaffeensis; however, after 24 h of infection, ifn-gamma had no antiehrlichial effect. to test whether ehrlichial infection disrupts janus kinase (jak) and signal transducer and activator of transcript ...	1998	9596710
phylogenetic placement of rickettsiae from the ticks amblyomma americanum and ixodes scapularis.	a rickettsial isolate (isolate moaa) belonging to the spotted fever group (sfg) was obtained from the lone star tick amblyomma americanum. we used pcr to characterize the genes for the rickettsial outer membrane proteins rompa and rompb. we sequenced the pcr products (domains i of both the rompa gene and the rompb gene) of moaa and wb-8-2, another rickettsial isolate from a. americanum. to place moaa and wb-8-2 and two other nonpathogenic isolates (rickettsia rickettsii hip2 and rickettsia monta ...	1998	9574696
erythema migrans-like rash illness at a camp in north carolina: a new tick-borne disease?	borrelia burgdorferi, the causative agent of lyme disease, has never been isolated from a patient thought to have acquired lyme disease in any southeastern state.	1997	9531233
human ehrlichioses: newly recognized infections transmitted by ticks.	human ehrlichioses are tick-borne infections caused by bacteria in the genus ehrlichia. human monocytic ehrlichiosis is caused by ehrlichia chaffeensis and human granulocytic ehrlichiosis is caused by an agent similar to ehrlichia equi. e. chaffeensis infects mononuclear phagocytes and is transmitted by lone star ticks (amblyomma americanum) found in the south central and eastern united states. the agent of human granulocytic ehrlichiosis infects mostly neutrophils, it transmitted by ixodes spec ...	1998	9509259
isolation of a functional ecdysteroid receptor homologue from the ixodid tick amblyomma americanum (l.).	ecdysteroids are assumed to be the major steroid hormones in arthropods. however, with the exception of insects and crustaceans, very little is known about ecdysteroid action in other arthropods. to determine if ecdysteriods play a functional role in the ixodid tick, amblyomma americanum (l.), we isolated cdnas encoding three presumed ecdysteroid receptor isoforms (aamecra1, aamecra2, and aamecra3) that have common dna and ligand binding domains linked to distinct amino termini. the dna and liga ...	1997	9501418
new distribution records of amblyomma americanum (l.) (acari: ixodidae) in new york state.	amblyomma americanum, commonly called the lone star tick, has been widely-distributed in the southeastern united states for many years. distribution of this species apparently did not extend to new york state until the 1970s, after which the northern distribution in new york was limited to long island (suffolk and nassau counties), where it has become locally abundant. since then, there has been just one published record from new york state, in westchester county, just north of new york city. fr ...	1997	9491364
biases associated with several sampling methods used to estimate abundance of ixodes scapularis and amblyomma americanum (acari: ixodidae).	several tick sampling methods were evaluated for ixodes scapularis say and amblyomma americanum (i.) in oak-dominated mixed hard-wood, pitch pine-dominated, and mixed hardwood and pine forests in coastal new jersey. walking surveys were more efficient for collecting i. scapularis adults than dragging by a factor of > 2:1. in contrast, drag sampling yielded nearly twice as many a. americanum adults compared with walking surveys. i. scapularis subadults were rarely collected during walking surveys ...	1997	9439115
first isolation and cultivation of borrelia burgdorferi sensu lato from missouri.	five borrelia burgdorferi sensu lato isolates from missouri are described. this represents the first report and characterization of such isolates from that state. the isolates were obtained from either ixodes dentatus or amblyomma americanum ticks that had been feeding on cottontail rabbits (sylvilagus floridanus) from a farm in bollinger county, mo., where a human case of lyme disease had been reported. all isolates were screened immunologically by indirect immunofluorescence by using monoclona ...	1998	9431909
natural history of ehrlichia chaffeensis (rickettsiales: ehrlichieae) in the piedmont physiographic province of georgia.	the roles of wild mammals and ticks in the epidemiology of ehrlichia chaffeensis at a suspected endemic site were investigated using serologic testing, culture, and polymerase chain reaction (pcr) supported by restriction endonuclease analysis and dna sequencing. antibodies reactive to e. chaffeensis (> or = 1:64) were detected in 92% of white-tailed deer (odocoileus virginianus), 21% of raccoons (procyon lotor), and 8% of opossums (didelphis virginianus), but not in 8 other species of mammals. ...	1997	9379294
a novel phospholipase a2 activity in saliva of the lone star tick, amblyomma americanum (l.).	saliva from female lone star ticks, amblyomma americanum, contained a novel phospholipase a2 (pla2) activity that hydrolyzed 14c-arachidonate from 14c-arachidonyl phosphatidylcholine. the tick saliva pla2 (ts-pla2) was active over a broad ph range (4.5-11.5) with two distinct ph optima of ph 5.5 and 9.5. though extracellular pla2s are reported to be activated by millimolar ca2+, ts-pla2 was sensitive to submicromolar ca2+ and was half-maximally activated by 3.5 microm ca2+. tick saliva contains ...	1997	9326887
isolation and characterization of americanin, a specific inhibitor of thrombin, from the salivary glands of the lone star tick amblyomma americanum (l.).	a thrombin (ec 3.4.21.5) inhibitor (americanin) was isolated from the salivary glands of the lone star tick amblyomma americanum (l.) using reversed-phase chromatography and anion-exchange chromatography. americanin did not inhibit any other protease tested, including factor xa, plasmin, trypsin, chymotrypsin, elastase, papain, pepsin, and carboxypeptidase. the inhibition of thrombin by americanin decreased dramatically with dilution of the reaction mixture including thrombin, its substrate, and ...	1997	9287955
cloning and sequence of a gene for the homologue of the stearoyl coa desaturase from salivary glands of the tick amblyomma americanum.	a 1488 base pair cdna clone has been isolated from a cdna library made from salivary glands from 3-day feeding adult female ticks. the sequence of this cdna suggests it is the gene for the tick homologue of the stearoyl coa desaturase. this gene is expressed in eggs and all feeding stages of the adult examined, but appears to be transcribed to an 8 kb mrna as well as a 1.5 kb mrna. because ticks have the ability to synthesize monounsaturated fatty acids and demonstrate a large increase in saliva ...	1997	9272444
short report: geographic distribution of different genetic types of ehrlichia chaffeensis.	the 120-kd protein gene of ehrlichia chaffeensis was used to characterize ehrlichial dna from seven pools of adult amblyomma americanum ticks. ticks from missouri, kentucky, and north carolina contained e. chaffeensis dna of the arkansas strain genotype. ticks from north carolina also contained ehrlichiae of the sapulpa strain genotype, originally identified in oklahoma.	1997	9230803
ability of the lyme disease spirochete borrelia burgdorferi to infect rodents and three species of human-biting ticks (blacklegged tick, american dog tick, lone star tick) (acari:ixodidae).	the infectivity of a diverse collection of borrelia burgdorferi strains from north america for mice was determined as a prelude to vector competence experiments with the 3 primary human-biting tick species in the eastern united states (ixodes scapularis say, dermacentor variabilis (say), amblyomma americanum (l.)]. of the 34 b. burgdorferi strains inoculated into mice, 29 were infectious; the exceptions were 5 isolates from texas. vector competence experiments were conducted with 2 strains from ...	1997	9220680
a specific prostaglandin e2 receptor and its role in modulating salivary secretion in the female tick, amblyomma americanum (l.).	prostaglandins of the 2-series (e.g. pge2) are typically synthesized from arachidonic acid (aa) after aa is released from cellular phospholipids after activation of an intracellular phospholipase a2 (pla2). treatment of isolated salivary glands with pla2 inhibitor oleyloxyethyl phosphorylcholine (opc) or prostaglandin synthetase inhibitors reduced dopamine-induced fluid secretion and cyclic amp (camp) levels in isolated salivary glands. pge2 and its analog, 17-phenyl trinor pge2, partly reversed ...	1997	9219365
isolation of ehrlichia chaffeensis from wild white-tailed deer (odocoileus virginianus) confirms their role as natural reservoir hosts.	field and experimental studies have implicated white-tailed deer (odocoileus virginianus) as probable reservoir hosts for ehrlichia chaffeensis, the causative agent of human monocytic ehrlichiosis, but natural infection in deer has not been confirmed through isolation of e. chaffeensis. thirty-five white-tailed deer collected from three amblyomma americanum-infested populations in georgia were examined for evidence of e. chaffeensis infection by serologic, molecular, cell culture, and xenodiagno ...	1997	9196173
attempted transmission of human granulocytotropic ehrlichia (hge) by amblyomma americanum and amblyomma maculatum.	transstadial transmission of human granulocytotrophic ehrlichia (hge) was attempted in dogs using amblyomma americanum (l.) and a. maculatum koch, two species that, as adults, feed readily on human beings. larvae and nymphs were acquisition-fed on a dog that was parasitemic with hge. two months later, following digestion of the blood meal and subsequent molting to nymphal or adult stage, these ticks were fed to repletion on hge-naive dogs. none of the dogs developed clinical evidence of ehrlichi ...	1997	9195722
assay for phenoloxidase activity in amblyomma americanum, dermacentor variabilis, and ixodes scapularis.	phenoloxidase activity in amblyomma americanum, dermacentor variabilis, and ixodes scapularis was assayed. no phenoloxidase activity was detected compared to high activity through time in larvae of the greater wax moth (galleria mellonella). we conclude that activated prophenoloxidase does not act as an opsonin in ixodid ticks tested to date.	1997	9194851
some factors affecting infestation of white-tailed deer by blacklegged ticks and winter ticks (acari:ixodidae) in southeastern missouri.	a total of 5,669 ticks of 4 species was collected from 515 hunter killed, white-tailed deer. odocoileus virginianus (zimmerman), in southeastern missouri from 1993 through 1995. the american dog tick, dermacentor variabilis (say) (4 adults), the lone star tick, amblyomma americanum (l.) (57 adults, 2 nymphs), the blacklegged tick, ixodes scapularis (say) (3,120 adults), and the winter tick, dermacentor albipictus (packard) (2.059 adults, 436 nymphs, 1 larva) were collected. patterns of adult d. ...	1997	9151505
development and use of specific polymerase reaction for the detection of an organism resembling ehrlichia sp. in white-tailed deer.	the role of white-tailed deer (odocoileus virginianus) in the epidemiology of ehrlichia chaffeensis and the agent of human granulocytic ehrlichiosis (hge) is not fully understood, and diagnostic procedures may be complicated by the recent detection of 16s rdna sequence from an ehrlichia sp.-like organism in wild deer. a specific forward primer (dga) and an ehrlichia spp. reverse primer (ga1ur) were constructed to amplify this new, distinct ehrlichia sp.-like 16s rdna. the dga primer, a forward p ...	1997	9131554
pyriproxyfen effects on newly engorged larvae and nymphs of the lone star tick (acari:ixodidae).	newly engorged larvae and nymphs of the lone star tick, amblyomma americanum (l.), were exposed to 9 treatments of pyriproxyfen in glass vials consisting of dosages of 4, 8, and 16 micrograms/cm2 for 7 d, 14 d, and continuous exposure periods at each concentration. treatment of newly engorged larvae resulted in decreased molting, altered postmolt defecation, and nymphal survival with results being dose and exposure dependent. molting inhibition ranged from 35.9 to 68.4%. successfully molted nymp ...	1997	9103764
identification of hemolytic activity in saliva of the lone star tick (acari:ixodidae).	hemolytic activity was identified in the saliva of amblyomma americanum (l.) when red blood cells from sheep were incubated with tick saliva in the presence of phosphatidylcholine and sodium deoxycholate. the hemolytic activity was destroyed by boiling or treating with trypsin. the hemolytic activity in tick saliva was calcium-dependent, and inhibited by a phospholipase a2 inhibitor oleyloxyethyl phosphorylcholine. phosphatidylserine could replace phosphatidylcholine in the hemolytic assays but ...	1997	9103758
prostaglandin biosynthesis by salivary glands isolated from the lone star tick, amblyomma americanum.	salivary glands separated from internal tissues of the lone star tick, amblyomma americanum, are competent to synthesize prostaglandins (pgs). using an in vitro pg biosynthesis assay four major pgs, namely, pga2/pgb2, pgd2, pge2, and pgf2 alpha were synthesized. under standard assay conditions pga2/pgb2 was the predominant product. salivary tissues as well as non-salivary internal tissues were capable of pg biosynthesis. we observed that storing ticks at -80 degrees c for 3 months resulted in re ...	1997	9090120