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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 ...19989645873
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 ...199910515901
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 ...199910534951
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 ...199910515907
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 ...199910593071
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 ...200010618074
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 ...19989684330
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 ...199910672552
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, ...200010698761
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.200010699046
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 ...19989687446
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 ...200010722619
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 ...200010701562
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, ...200010730500
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 ...19989705408
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 ...200010747140
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 ...200010780541
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 ...19989705073
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 ...19989794627
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 ...200010864249
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 ...19989801331
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 ...19989828526
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 ...200010925803
prevalence of ehrlichia ewingii in amblyomma americanum in north carolina. 200010979750
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 ...19989831955
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 ...200011101616
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 ...200011128501
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 ...19979103764
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 ...19989860961
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 ...19979090120
what's eating you? amblyomma ticks (amblyomma americanum). 200011109142
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 ...200111158095
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 ...199910074536
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 ...19979131554
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 ...199910074538
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 ...199910083757
analysis of transcriptionally active gene clusters of major outer membrane protein multigene family in ehrlichia canis and e. chaffeensis.ehrlichia canis and e. chaffeensis are tick-borne obligatory intramonocytic ehrlichiae that cause febrile systemic illness in humans and dogs, respectively. the current study analyzed the pleomorphic multigene family encoding approximately 30-kda major outer membrane proteins (omps) of e. canis and e. chaffeensis. upstream from seca and downstream of hypothetical transcriptional regulator, 22 paralogs of the omp gene family were found to be tandemly arranged except for one or two genes with oppo ...200111254561
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 ...199910203503
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 ...199910337091
ticks (acari: ixodidae) and spirochetes (spirochaetaceae: spirochaetales) recovered from birds on a georgia barrier island.from september 1997 through july 1999, 300 individuals and 46 species of birds were mist-netted and screened for ticks and spirochetes on st. catherine's island, liberty county, ga. seventy-six (25%) of the birds were parasitized by a meal intensity of 4.6 ticks. seasonally, more birds were infested with ticks during the summer (50% in 1998, 34% in 1999) than in spring (15% in 1998, 11% in 1999) or fall (21% in 1997, 20% in 1998), mainly because of severe infestations on some birds by immature s ...200111296828
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 ...199910084999
prevalence of infection in ticks submitted to the human tick test kit program of the u.s. army center for health promotion and preventive medicine.in 1997, ticks removed from humans and received alive by the tick-borne disease laboratory of the u.s. army center for health promotion and preventive medicine (usachppm) were tested for pathogens by polymerase chain reaction (pcr). thirty-three of 222 (15%) amblyomma americanum (l.) dnas produced amplicons of the expected size of ehrlichia chaffeensis anderson, dawson & wilson and 26/222 (12%) produced amplicons indicating borrelia burgdorferi johnson, schmid, hyde, steigalt & brenner. five (2% ...200111268694
borrelia lonestari infection after a bite by an amblyomma americanum tick.erythematous rashes that are suggestive of early lyme disease have been associated with the bite of amblyomma americanum ticks, particularly in the southern united states. however, borrelia burgdorferi, the causative agent of lyme disease, has not been cultured from skin biopsy specimens from these patients, and diagnostic serum antibodies usually have not been found. borrelia lonestari sp nov, an uncultured spirochete, has been detected in a. americanum ticks by dna amplification techniques, bu ...200111372036
identification of ehrlichia spp. and borrelia burgdorferi in ixodes ticks in the baltic regions of russia.the presence and distribution of ehrlichia spp. and borrelia burgdorferi sensu lato was demonstrated among ixodid ticks collected in the baltic regions of russia, where lyme borreliosis is endemic. a total of 3,426 ixodes ricinus and 1,267 ixodes persulcatus specimens were collected, and dark-field microscopy showed that 265 (11.5%) i. ricinus and 333 (26.3%) i. persulcatus ticks were positive. from these samples, 472 dark-field-positive and 159 dark-field-negative ticks were subjected to pcr an ...200111376063
borrelia lonestari dna in adult amblyomma americanum ticks, alabama.polymerase chain reaction analysis of 204 amblyomma americanum and 28 a. maculatum ticks collected in august 1999 near the homes of patients with southern tick-associated rash illness and in control areas in choctaw county, alabama, showed borrelia lonestari flagellin gene sequence from two adult a. americanum. the presence of b. lonestari in a. americanum ticks from alabama suggests that this suspected pathogen may be widespread in the southeastern united states.200111384533
quantitative analyses of variations in the injury of endothelial cells elicited by 11 isolates of rickettsia rickettsii.eleven isolates of spotted fever group rickettsiae from the blood of patients or ixodid ticks from north and south america were characterized. all isolates were identified as rickettsia rickettsii using restriction fragment length polymorphism analysis of a 532-bp rompa gene fragment obtained by pcr. the ability of the r. rickettsii isolates to elicit cytopathic effects and parameters of oxidative injury were examined in cultured human ea.hy 926 endothelial cells. cytopathic effects were determi ...200111427428
genetic heterogeneity of borrelia burgdorferi sensu lato in the southern united states based on restriction fragment length polymorphism and sequence analysis.fifty-six strains of borrelia burgdorferi sensu lato, isolated from ticks and vertebrate animals in missouri, south carolina, georgia, florida, and texas, were identified and characterized by pcr-restriction fragment length polymorphism (rflp) analysis of rrf (5s)-rrl (23s) intergenic spacer amplicons. a total of 241 to 258 bp of intergenic spacers between tandemly duplicated rrf (5s) and rrl (23s) was amplified by pcr. msei and drai restriction fragment polymorphisms were used to analyze these ...200111427560
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 ...199910405394
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 ...199910405403
ixodid ticks on white-tailed deer and feral swine in florida.a state-wide survey was conducted in florida during the 1997-99 hunting seasons to examine white-tailed deer (odocoileus virginianus) and feral swine (sus scrofa) for potential indigenous vectors of the rickettsial agent of heartwater, cowdria ruminantium. a total of 504 white-tailed deer and 166 feral swine was examined from 30 wildlife management areas across the state. amblyomma maculatum, an experimental vector of c. ruminantium, was common on both deer and feral swine throughout the state. ...200111469190
birds disperse ixodid (acari: ixodidae) and borrelia burgdorferi-infected ticks in canada.a total of 152 ixodid ticks (acari: ixodidae) consisting of nine species was collected from 82 passerine birds (33 species) in 14 locations in canada from 1996 to 2000. the lyme disease spirochete borrelia burgdorferi johnson, schmidt, hyde, steigerwaldt & brenner was cultured from the nymph of a blacklegged tick, ixodes scapularis say, that had been removed from a common yellowthroat, geothlypis trichas l., from bon portage island, nova scotia. as a result of bird movement, a nymphal i. scapula ...200111476328
effects of pyriproxyfen on off-host water-balance and survival of adult lone star ticks (acari: ixodidae).newly engorged nymphs of the lone star tick, amblyoma americanum (l.), were continuously exposed to 4 microg/cm2 of pyriproxyfen residues in glass vials. treatment of engorged nymphs (n = 285) resulted in significant molting inhibition, with more than one-fourth (26.7%, n = 76) of nymphs dying before or during ecdysis. treatment effects were evident among ticks that molted to the adult stage, with 26.7% (n = 76) of females, and 17.9% (n = 51) of males exhibiting moribund physical characteristics ...200111476341
effects of habitat structure on the retention of ixodes scapularis and amblyomma americanum (acari: ixodidae) adults during drag sampling surveys.the ability of ixodes scapularis say and amblyomma americanum (l.) to remain on drags, once acquired, was tested in sparse and dense shrub layer vegetation. when placed on bottoms of drags, adults of both species remained attached for distances three to four times greater in sparse vegetation compared with dense vegetation. when attached to the tops of drags, the differences in retention of ticks on drags between vegetation densities were significant only for a. americanum. in dense vegetation, ...200111476345
different activities and footwear influence exposure to host-seeking nymphs of ixodes scapularis and amblyomma americanum (acari: ixodidae).the relative potential for a person accidentally acquiring host-seeking nymphs of the blacklegged tick, ixodes scapularis say, and lone star tick, amblyomma americanum (l.), while wearing either of two types of footwear, walking, crawling on hands and knees, and sitting on large fallen logs in deciduous woods, was evaluated. although flag samples indicated substantial populations of i. scapularis nymphs and low to moderate numbers of a. americanum at the study sites, relatively few i. scapularis ...200111476342
identification and characterization of a homologue of the pro-inflammatory cytokine macrophage migration inhibitory factor in the tick, amblyomma americanum.studying tick feeding and digestion, we discovered in a cdna library from partially fed amblyomma americanum ticks the first known arthropod homologue of a human cytokine, the pro-inflammatory macrophage migration inhibitory factor (mif). the tick origin of the mif cdna clone was confirmed by sequencing a genomic fragment that contained the full-length tick mif gene with two introns. antiserum to a tick mif-specific peptide as well as antiserum to complete tick mif revealed the expression of tic ...200111520355
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 ...199910405413
western blot analysis of sera reactive to human monocytic ehrlichiosis and human granulocytic ehrlichiosis agents.laboratory diagnosis of human ehrlichioses is routinely made by an indirect immunofluorescence assay (ifa) using cultured ehrlichia-infected whole cells as antigen. concern has been raised that incorrect diagnoses of human monocytic ehrlichiosis (hme) or human granulocytic ehrlichiosis (hge) may be made on the basis of serologic cross-reactivity between ehrlichia chaffeensis and the agent of hge. the present study examined whether two recombinant major outer membrane proteins, rp30 and rp44, tha ...200111682518
risk of lyme disease: perceptions of residents of a lone star tick-infested community.lone star ticks (amblyomma americanum) have been suggested as a vector of the agent of lyme disease (borrelia burgdorferi sensu lato) in the usa, based on associations with an infection manifesting mainly as erythema migrans. in laboratory experiments, however, they failed to transmit b. burgdorferi sensu stricto.200111693973
lone-star tick bite of the conjunctiva. 200111735801
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 ...199910467766
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 ...200010618139
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 ...199910467784
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 ...200010747103
ticks parasitizing dogs in northwestern georgia.from january 1998 through september 1999, 324 dogs in three northwestern georgia counties were examined for ticks. six species of ticks were recovered. the three most commonly collected ticks were the american dog tick, dermacentor variabilis (say) (310 male male, 352 female female; prevalence, 97%; mean intensity 2.1); the brown dog tick, rhipicephalus sanguineus (latreille) (118 male male, 119 female female, 38 nymphs; prevalence, 22%; mean intensity, 3.8); and the lone star tick, amblyomma am ...200211931241
evaluation of three commercial tick removal tools.to evaluate three commercially available tick removal tools against medium-tipped nontissue tweezers.199811990185
analysis of serum and whole blood values in relation to helminth and ectoparasite infections of feral pigs in texas.in the summers of 1996 and 1997, 60 wild pigs (sus scrofa) were necropsied from three sites in south texas (usa) to test the hypothesis that serum and whole blood parameters vary significantly (p < or = 0.05) with the prevalence and intensity of parasites infecting wild pigs. we found ten parasite species: five nematodes (metastrongylus salmi, metastrongylus pudentotectus, stephanurus dentatus, oesophagostomum dentatum, and physocephalus sexalatus); four ixodid ticks (amblyomma cajennense, ambly ...200212038138
simultaneous detection of anaplasma marginale and a new ehrlichia species closely related to ehrlichia chaffeensis by sequence analyses of 16s ribosomal dna in boophilus microplus ticks from tibet.to identify ehrlichial agents in boophilus microplus ticks, dna samples of b. microplus collected from the tibet autonomous region and sichuan province of china were screened by a nested pcr. sixteen of 43 (37%) dna samples of b. microplus from tibet were positive in nested pcr analysis. all 27 samples from sichuan were negative. the screen identified two ehrlichial agents based on different 16s rrna genes that were found after amplifying and sequencing the 5'-end fragments of the 16s rrna genes ...200212202567
determination of novel borrelia genospecies in swedish ixodes ricinus ticks.a total of 301 adult questing ixodes ricinus ticks were collected at 15 different locations along the south and east coasts of sweden to determine the borrelia genospecies diversity. thirty-two ticks (11%) were found to be positive by nested pcr with borrelia burgdorferi sensu lato-specific primers. species determination was based on partial sequencing of the 16s rrna gene and the flagellin gene. five different borrelia species were found. the nucleotide sequence of the borrelia dna found in two ...200212202571
transmission of hepatozoon americanum (apicomplexa: adeleorina) by ixodids (acari: ixodidae).american canine hepatozoonosis (ach) caused by hepatozoon americanum vincent-johnson, macintire, lindsay, lenz, baneth, and shkap is an emerging, often fatal, tick-borne protozoal disease of dogs in the united states of america. dogs acquire infection by ingesting ticks that contain oocysts. to understand the invertebrate (definitive) host range of h. americanum, experiments were carried out using four ixodids, rhipicephalus sanguineus (latreille), dermacentor variabilis say, amblyomma americanu ...200212144294
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 ...200010792392
the omp-1 major outer membrane multigene family of ehrlichia chaffeensis is differentially expressed in canine and tick hosts.sixteen of 22 omp-1 paralogs encoding 28-kda-range immunodominant outer membrane proteins of ehrlichia chaffeensis were transcribed in blood monocytes of dogs throughout a 56-day infection period. only one paralog was transcribed by e. chaffeensis in three developmental stages of amblyomma americanum ticks before or after e. chaffeensis transmission to naïve dogs.200212117987
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 ...200010813468
detection of borrelia lonestari, putative agent of southern tick-associated rash illness, in white-tailed deer (odocoileus virginianus) from the southeastern united states.to determine if white-tailed deer may serve as a reservoir host for borrelia lonestari, we used a nested pcr for the borrelia flagellin gene to evaluate blood samples collected from deer from eight southeastern states. seven of 80 deer (8.7%) from 5 of 17 sites (29.4%) had sequence-confirmed evidence of a b. lonestari flagellin gene by pcr, indicating that deer are infected with b. lonestari or another closely related borrelia species. our findings expand the known geographic range of b. lonesta ...200312517884
the ascendancy of amblyomma americanum as a vector of pathogens affecting humans in the united states.until the 1990s, amblyomma americanum was regarded primarily as a nuisance species, but a tick of minor importance as a vector of zoonotic pathogens affecting humans. with the recent discoveries of ehrlichia chaffeensis, ehrlichia ewingii, and "borrelia lonestari," the public health relevance of lone star ticks is no longer in question. during the next 25 years, the number of cases of human disease caused by a. americanum-associated pathogens will probably increase. based on current trajectories ...200312414740
naturally occurring ehrlichia chaffeensis infection in two prosimian primate species: ring-tailed lemurs (lemur catta) and ruffed lemurs (varecia variegata).a naturally occurring infection of ehrlichia chaffeensis in lemurs is described. dna of ehrlichia chaffeensis was identified by polymerase chain reaction in peripheral blood from six of eight clinically ill lemurs. organisms were cultured from the blood of one lemur exhibiting clinical and hematologic abnormalities similar to those of humans infected with e. chaffeensis.200212498671
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.200010878087
ehrlichia chaffeensis: a prototypical emerging pathogen.ehrlichia chaffeensis is an obligately intracellular, tick-transmitted bacterium that is maintained in nature in a cycle involving at least one and perhaps several vertebrate reservoir hosts. the moderate to severe disease caused by e. chaffeensis in humans, first identified in 1986 and reported for more than 1,000 patients through 2000, represents a prototypical "emerging infection." knowledge of the biology and natural history of e. chaffeensis, and of the epidemiology, clinical features, and ...200312525424
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 ...200010916301
detection of borrelia lonestari in amblyomma americanum (acari: ixodidae) from tennessee.genetic sequences characteristic of borrelia lonestari (barbour et al. 1996) were detected in two pools of adult amblyomma americanum (l.) from tennessee, corresponding to an estimated minimum field infection rate of 8.4 infected ticks/1000 adults. dna amplification was conducted using primers derived from the b. lonestari flagellin gene that would also amplify borrelia burgdorferi (johnson, schmid, hyde, steigerwalt, and brenner). species-specific, internal probes were then used to differentiat ...200312597661
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 ...200010916302
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 ...200010989297
efficacy of two 65% permethrin spot-on formulations against induced infestations of ctenocephalides felis (insecta: siphonaptera) and amblyomma americanum (acari: ixodidae) on beagles.the efficacy of two formulations of a topically applied 65% permethrin spot-on (defend exspot treatment for dogs, schering-plough animal health) was evaluated against experimental infestations of the cat flea ctenocephalides felis and the lone star tick amblyomma americanum in dogs. eighteen dogs were randomly assigned to treatment with 65% permethrin in either diethylene glycol monomethyl ether (dgme; original formulation) or propylene glycol monomethyl ether (pgme) or to be untreated as a cont ...200312756635
comprehensive analysis of the factor h binding capabilities of borrelia species associated with lyme disease: delineation of two distinct classes of factor h binding proteins.some lyme disease spirochete isolates can bind complement regulatory protein factor h (fh), a process that may allow evasion of complement-mediated killing. here we demonstrate significant differences in the fh binding capabilities of species of the borrelia burgdorferi sensu lato complex. the percentages of b. burgdorferi, b. afzelii, and b. garinii bacteria that bound fh in either enzyme-linked immunosorbent assays or affinity ligand binding immunoblot assays were 100, 83, and 29%, respectivel ...200312761145
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 ...200011087176
a method for extraction and analysis of high quality genomic dna from ixodid ticks.currently, no published methods describe the extraction of high molecular weight genomic dna from ixodid ticks (acari: ixodidae) and commonly used methods of extraction are not well adapted for use with members of this family. a method for extraction of minimally degraded genomic dna from ixodid ticks that can be completed in one or two days is described. the method produces dna which is of sufficient size (>24 kb) for use in southern analysis and which is readily digestible by restriction endon ...200312823841
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 ...200111158090
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 ...200111157215
a ten-year study of tick biting in mississippi: implications for human disease transmission.to determine exactly which tick species bit people in mississippi, information was gathered on ticks involved in human biting cases for the ten-year period, january 1, 1990-december 31, 1999. specimens were identified by the author and, in most cases, confirmed by personnel at the institute of arthropodology and parasitology, georgia southern university. a total of 119 ticks were recovered from 73 humans during the study period. seven tick species were represented; most common included the lone ...200212853269
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, ...199910070744
interdigital gland substances of white-tailed deer and the response of host-seeking ticks (acari: ixodidae).host-seeking male and female blacklegged ticks, ixodes scapularis say, exhibited an arrestant response when contacting substances from front and rear interdigital glands of male and female white-tailed deer, odocoileus virginianus (zimmermann). female i. scapularis responded positively to substances from interdigital glands on the fore legs and hind legs of female deer, whereas male i. scapularis responded only to samples from the fore legs of does. these results showed that previously reported ...200111268681
preliminary survey of ticks (acari: ixodidae) parasitizing wild turkeys (aves: phasianidae) in eastern kansas.during the spring and fall turkey hunting seasons of 1999, hunters and kansas department of wildlife and parks field personnel examined wild turkeys, meleagris gallopavo l., for ticks and submitted them to us for identification. from springtime hunting, we received 113 ticks from 12 turkeys killed in nine counties, all in the eastern one-third of kansas. collectors reported examining three additional wild turkeys on which no ticks were found. all ticks were nymphal lone star ticks, amblyomma ame ...200111268682
effects of selected meterological factors on diurnal questing of ixodes scapularis and amblyomma americanum (acari: ixodidade).the diurnal questing behavior of adult ixodes scapularis say and amblyomma americanum (l.) were monitored in the field to determine whether ticks would be collected with greater frequency during certain times of the day and under certain ambient meteorological conditions. temperature and relative humidity explained a significant amount of the total variation in tick collections. although both species were collected during every period, i. scapularis adults tended to quest earlier and later in th ...200111296842
efficacy of granular deltamethrin against ixodes scapularis and amblyomma americanum (acari: ixodidade) nymphs.a single barrier application of granular deltamethrin to the woodland edges of a forested residential community in late spring significantly reduced the abundance of ixodes scapularis say nymphs. the application also suppressed the population of amblyomma americanum (l.) nymphs, which recently became established in the study area. the efficacy of deltamethrin is compared with other commonly used acaricides.200111296847
serodiagnosis of human granulocytic ehrlichiosis by using novel combinations of immunoreactive recombinant proteins.a panel of seven recombinant antigens, derived from ehrlichia phagocytophila (the agent of human granulocytic ehrlichiosis), was evaluated by class-specific enzyme-linked immunosorbent assays (elisas) for utility in the diagnosis of the infection. fourteen genomic fragments, obtained by serologic expression screening, contained open reading frames (orfs) encoding 16 immunodominant antigens. eleven of these antigens were members of the major surface protein (msp) multigene family. alignment of th ...200111427556
animal model of fatal human monocytotropic ehrlichiosis.human monocytotropic ehrlichiosis caused by ehrlichia chaffeensis is a life-threatening, tick-borne, emerging infectious disease for which no satisfactory animal model has been developed. strain hf565, an ehrlichial organism closely related to e. chaffeensis isolated from ixodes ovatus ticks in japan, causes fatal infection of mice. c57bl/6 mice became ill on day 7 after inoculation and died on day 9. the liver revealed confluent necrosis, ballooning cell injury, apoptosis, poorly formed granulo ...200111159213
amblyomma americanum: specific uptake of immunoglobulins into tick hemolymph during feeding.the passage of immunoglobulins in the blood meal into hemolymph prompts development of vaccines against internal antigens of ticks, but little is known about kinetics and specificity of the immunoglobulin uptake. we used capillary feeding of adult amblyomma americanum hard ticks to introduce compounds into the midgut and then examined the hemolymph after various times for their presence and concentration. immunoglobulins of different sources, albumin, choramphenicol acetyltransferase, inulin, an ...200011162374
the effect of male ticks on the feeding performance of immature stages of rhipicephalus sanguineus and amblyomma americanum (acari: ixodidae).a unique group of immunoglobulin-binding proteins (igbps), produced by ixodid male ticks during the latter half of their prolonged feeding period, improves the feeding performance of co-feeding females. as a follow-up to this observation, we investigated whether male tick feeding also affects the feeding of other developmental stages. immature stages of rhipicephalus sanguineus (latreeille) and amblyomma americanum (l.) were fed on rabbits in the presence or absence of conspecific males. the mea ...200011201360
a survey for nymphs of host-seeking ixodes scapularis and amblyomma americanum (acari: ixodidae) on tree trunks in deciduous forests.trunks of 83 trees in a mixed deciduous forests in maryland were sampled for the presence of nymphs of the blacklegged tick, ixodes scapularis say, and the lone star tick, amblyomma americanum (l.). although one or more nymphs of either i. scapularis or a. americanum was found in leaf litter and substrate < or = 1 m from the bases of 47% of the trees sampled, a total of 6 i. scapularis nymphs was found on the trunks of only five trees. no nymphs were found on the trunks of 12 dead trees. no a. a ...200211931264
molecular and antigenic comparison of ehrlichia canis isolates from dogs, ticks, and a human in venezuela.we previously culture isolated a strain of ehrlichia canis, the causative agent of canine ehrlichiosis, from a human in venezuela. in the present study, we examined whether dogs and ticks are infected with e. canis in venezuela and, if so, whether this is the same strain as the human isolate. pcr analysis using e. canis-specific primers revealed that 17 of the 55 dog blood samples (31%) and all three pools of four rhipicephalus sanguineus ticks each were positive. an ehrlichial agent (venezuelan ...200111473993
identity and synthesis of prostaglandins in the lone star tick, amblyomma americanum (l.), as assessed by radio-immunoassay and gas chromatography/mass spectrometry.high concentrations of pge(2) and pgf(2alpha) were identified by radio-immunoassay (ria) and/or gas chromatography/mass spectrometry (gc/ms) in the hemolymph, salivary glands and saliva of the lone star tick amblyomma americanum (l.). binding studies indicated that pge(2) was free and not bound to any proteins in the hemolymph. a small amount of 6-keto-pgf(1alpha) (breakdown product of pgi(2); prostacyclin) was also found in the salivary glands but not in the hemolymph or saliva. neither pgd(2) ...200211804805
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