fecundity and development of the lone star tick on woodlot-pastured braford and hereford heifers. 19807430489
ectoparasites collected from bobwhite quail in the southeastern united states.twenty-one species of ectoparasites representing 19 genera were collected from 481 bobwhite quail (colinus virginianus) from nine areas in four southeastern states. sixteen species, amblyomma americanum, haemaphysalis chordeilis, haemaphysalis leporispalustris, eutrombicula alfreddugesi alfreddugesi, neoschoengastia americana, boydaia colini, pterolichus sp., colinophilus wilsoni, megninia sp., apionacarus wilsoni, colinoptes cubanensis, menacanthus pricei, colinicola numidiana, gonoides ortygis ...19807463603
activity of repellents applied to skin for protection against amblyomma americanum and ixodes scapularis ticks (acari: ixodidae).twenty-nine repellents were tested on human skin for duration of activity as protectants against nymphal lone star ticks (amblyomma americanum) and against black-legged or deer ticks (ixodes scapularis say). eleven of these repellents, including deet, provided > 2 h of protection against the lone star tick. one repellent, 1-(3-cyclohexenyl-ylcarbonyl) piperidine, was effective > or = 4 h. four repellents (2 pyridines and 2 piperidines with protection lasting 2.3-3 h) showed acaricidal activity t ...19957616181
experimental transmission of ehrlichia chaffeensis (rickettsiales: ehrlichieae) among white-tailed deer by amblyomma americanum (acari: ixodidae).ehrlichia chaffeensis anderson, dawson & wilson, causative agent of human (predominantly monocytic) ehrlichiosis, was successfully transmitted experimentally by amblyomma americanum (l.) to white-tailed deer, odocoileus virginianus (zimmerman). deer were needle-exposed intravenously to e. chaffeensis in tissue-culture canine macrophage (dh82) cells, and 11 d later were exposed to laboratory-reared a. americanum larvae, nymphs, and adults for acquisition feeding. three months after this feeding, ...19957616529
ehrlichiosis in a golf-oriented retirement community.ehrlichiosis due to ehrlichia chaffeensis usually occurs sporadically or in small clusters, with an annual incidence estimated at 3 to 5 cases per 100,000 population in areas of endemic disease. the putative principal vector is the lone star tick (amblyomma americanum). we investigated an outbreak of ehrlichiosis that occurred in june 1993 among members of a golf-oriented retirement community (community a) in tennessee. the community is densely wooded and borders a wildlife-management area where ...19957616991
epidemiologic and diagnostic studies of patients with suspected early lyme disease, missouri, 1990-1993.a retrospective case-control study investigated 45 missouri outpatients with annular rashes meeting a surveillance case definition for erythema migrans and with onset in 1990-1991. risk factors included being male, living near a body of water, and hunting. twenty patients (44%) associated their rash with the bite of a tick; of these, 5 described an adult amblyomma americanum. a typical rash was described as expanding over time and measuring 8 cm in diameter at 4 days after onset. mild constituti ...19957622891
biosynthesis of salivary prostaglandins in the lone star tick, amblyomma americanum.dopamine-induced saliva from ticks fed [3h]arachidonic acid contained the radiolabelled prostaglandins e2, f2 alpha, d2, and b2, the latter probably derived from pge2 owing to the alkalinity of tick saliva. prostaglandin synthetase (pgs) activity in the salivary gland homogenate from the lone star tick, amblyomma americanum, could not be detected by standard radiometric methodologies successfully employed for tissues from many animal species, including numerous arthropods. modifications to the a ...19957627205
evaluation of ixodes scapularis, amblyomma americanum, and dermacentor variabilis (acari: ixodidae) from georgia as vectors of a florida strain of the lyme disease spirochete, borrelia burgdorferi.the ability of three common tick species from georgia to maintain and transmit the causative agent of lyme disease, borrelia burgdorferi, was compared under laboratory conditions. a b. burgdorferi cotton rat isolate (mi-6) from florida was selected as a strain from the south, and the sh2-82 isolate from new york was used as a positive control. amblyomma americanum (l.) and dermacentor variabilis (say) did not transmit the mi-6 isolate from inoculated hamsters to naive laboratory mice, and nympha ...19957650697
lower temperature limits for activity of several ixodid ticks (acari: ixodidae): effects of body size and rate of temperature change.uncoordinated activity threshold temperature, the temperature below which ticks can no longer seek a host in a coordinated manner, and the activity threshold temperature, when all activity ceases, were examined for three species of ticks found in coastal sections of new york. the mean uncoordinated activity threshold and activity threshold temperatures were determined for nymphal, female and male ixodes scapularis say, nymphal, female, and male amblyomma americanum (l.), and for female and male ...19957650705
regulation of free arachidonic acid levels in isolated salivary glands from the lone star tick: a role for important regulatory step for prostaglandin synthesis is the availability of the precursor, free arachidonic acid (aa). in isolated salivary glands of the lone star tick, amblyomma americanum (l.), the level of free aa appears to depend on higher phospholipase a2 (pla2) activity rather than decreased rates of re-esterification by lysophosphatide acyl transferase (lat). this conclusion is supported by experiments where inhibition of lat with merthiolate was without effect, while the calcium io ...19957655056
borrelia burgdorferi in eastern virginia: comparison between a coastal and inland virginia, borrelia burgdorferi was more prevalent in a site along the atlantic ocean, near maryland, than in an inland site near williamsburg and yorktown. at the coastal site on assateague island, b. burgdorferi was isolated from 4.2% of 475 animals sampled, including four species of small mammals. serologic tests indicated that 25-37% of the small rodents assayed had been exposed to b. burgdorferi. immunofluorescence antibody assays specific for b. burgdorferi showed spirochete infection in ...19957677212
origin of arachidonic acid in the salivary glands of the lone star tick, amblyomma, americanum.the contribution of synthesis and dietary sequestration to the high arachidonate content of the lone star tick, amblyomma americanum, salivary glands was investigated by assessing the salivary metabolites of various radiolabeled fatty acid substrates administered to partially fed females. a portion of each of the fatty acids studied was incorporated into the fatty acid moiety of the phospholipid fraction. [14c]acetate was metabolized only into myristic, palmitic, palmitoleic, steric, and oleic a ...19957711753
uptake, incorporation and redistribution of arachidonic acid in isolated salivary glands of the lone star tick.the ability of isolated salivary glands from the lone star tick, amblyomma americanum, to take up, incorporate and redistribute [3h]arachidonic acid was examined. uptake of arachidonic acid was concentration dependent--a single salivary gland incorporated up to approximately 2.8 micrograms arachidonic acid in 60 min. over 90% of the [3h]arachidonate entering the glands was esterified and found only in the phospholipid (approximately 80%) and triglyceride (approximately 10%). essentially no radio ...19957742831
ectoparasites of opossums and raccoons in southeastern georgia.twelve species of ectoparasites (four fleas, three ticks, three chiggers, one macronyssid mite, and one atopomelid mite) were recovered from 42 opossums, didelphis virginiana kerr, live-trapped from september 1992 through april 1994 in southeastern georgia. the fleas, ctenocephalides felis (bouché) (prevalence = 19%) and polygenis gwyni (c. fox) (36%); the ticks, dermacentor variabilis (say) (40%) and ixodes scapularis say (19%); and the macronyssid mite, ornithonyssus wernecki (fonseca) (21%), ...19947815408
cytosystematics of five north american amblyomma (acarina: ixodidae) species.the karyotypes of 5 species of amblyomma ticks found in north america were examined for the presence and location of constitutive heterochromatin (c-bands). all specimens examined had 20 autosomes and an xx:xo sex-determining system, with the x being the largest element in the karyotype. except as noted in text, the autosomes of all species were acrocentric and heterochromatin was restricted to the centromeric region. the third largest autosome in 4 of the 5 species displayed a consistent band o ...19957876973
integrated management strategies for amblyomma americanum (acari: ixodidae) on pastured beef on tick control and knowledge of the damage caused to beef cattle by tick feeding were incorporated into a computerized dynamic life table model (lstsim) for amblyomma americanum (l.). simulations were made to determine economically feasible, 5-yr integrated pest management (ipm) strategies for a. americanum in forage areas utilized by bos taurus, bos indicus, and crossbred cattle (b. taurus x b. indicus). the effects of host resistance, pasture rotation, habitat conversion, topical acarici ...19947932604
evidence supporting the presence of borrelia burgdorferi in missouri.although lyme disease is commonly seen in the southcentral united states, the epidemiology of the disease is poorly defined there. the purpose of this study was to document the presence of borrelia burgdorferi in ticks collected in southeastern missouri and around the city of st. louis. spirochetes were detected and identified as b. burgdorferi by immunofluorescent antibody (ifa) tests using the monoclonal antibody h5332 in 1.9% of amblyomma americanum and 2.0% of dermacentor variabilis ticks co ...19947943575
origin, accumulation and mobilization of salivary prostaglandin precursors in the lone star tick. 19947958372
ticks (acari: ixodidae) collected from small and medium-sized kansas species of hard-bodied ticks were collected from 20 species of small and medium-sized mammals in kansas; amblyomma americanum l., dermacentor variabilis (say), haemaphysalis leporispalustris (packard), ixodes cookei packard, i. kingi bishopp, i. sculptus neumann, and i. texanus banks. dermacentor variabilis was found statewide, a. americanum only in the eastern one-third of the state, and the ixodes spp. and h. leporispalustris were widely scattered. the most common tick found was d. varia ...19948057327
distribution of arachidonic acid among phospholipid subclasses of lone star tick salivary glands.the subclass composition of choline- and ethanolamine-containing phospholipids was determined by analysis of acyl-linked fatty acids released by base hydrolysis of diradylglycerobenzoates formed from lone star tick salivary gland diacyl, alkylacyl and alkenylacyl phospholipids. the diacyl subclass comprises 87% of all choline-containing phospholipids, while th alkylacyl subclass comprises c. 9% and the alkenylacyl subclass c. 4%. the diacyl subclass comprises 72-77% of ethanolamine-containing ph ...19948069331
genome size and organization in the ixodid tick amblyomma americanum (l.).we used dna reassociation kinetics to determine genome size and organization in the ixodid tick amblyomma americanum. we calculated the genome size of a. americanum to be approximately 1.08 pg or 1.04 x 10(9) base pairs and to consist of 35.8% unique dna, 4.2% foldback sequences, 17.9% highly repetitive sequences, and 42.1% moderately repetitive sequences. comparison of the reassociation kinetics of long and short fragments revealed repetitive sequences to be distributed in a pattern of long per ...19948069417
seasonal and annual abundance of amblyomma americanum (acari: ixodidae) in central georgia.seasonal and annual changes in the abundance of amblyomma americanum (l.) larvae, nymphs, and adults were monitored over a 5-yr period in the piedmont physiographic region of georgia. tick abundance was monitored with cloth drags (all life stages) and co2-baited cloth panels (nymphs and adults) monthly during march through september from 1987 through 1991. larvae appeared in substantial numbers in july and were most numerous in august and september. small numbers of unfed larvae apparently overw ...19948158632
influence of annual and biennial prescribed burning during march on the abundance of amblyomma americanum (acari: ixodidae) in central georgia.a 5-yr study to evaluate the influence of annual and biennial prescribed burning in march on the abundance of amblyomma americanum (l.) was conducted on oconee wildlife management area in the piedmont physiographic region of georgia. tick abundance on plots embedded in larger burned and unburned areas were monitored with cloth drags and co2-baited cloth panels monthly during march through september from 1987 through 1991. annual and biennial prescribed burning from 1988 to 1991 significantly red ...19948158633
prevalence of borrelia (spirochaetaceae) spirochetes in texas ticks.between 1990 and 1992, ticks from eight texas parks were collected and analyzed to determine the prevalence of spirochete-infected ticks. borrelia spirochetes were detected in 1.03% of 5,141 amblyomma americanum (l.) adults examined, a species texas residents often encounter. no spirochetes were observed in the other tick species tested.19948189421
new version of lstsim for computer simulation of amblyomma americanum (acari: ixodidae) population dynamics.a previous version of lone star tick simulation model (lstsim) for a wildlife ecosystem was revised and expanded to include a beef cattle forage area and improved handling of tick-host-habitat interactions. relationships between environmental and biological variables were also refined in the new version. general validity of the revised model was established by comparing simulated and observed host-seeking populations of amblyomma americanum (l.) at five geographic locations, three in oklahoma an ...19938254630
ticks (acari: ixodidae) infesting medium-sized wild mammals in southwestern species of ixodid ticks (n = 2,661) were found on medium-sized wild mammals (n = 295) during a 13-mo study in shelby county, tennessee. the seven tick species collected were dermacentor variabilis (say), amblyomma americanum (l.), rhipicephalus sanguineus (latreille), ixodes texanus (banks), i. cookei (packard), i. scapularis (say), and haemaphysalis leporispalustris (packard). the raccoon had the greatest tick species diversity in all of the aforementioned ticks except h. leporispalustris ...19938254637
changes in lipids of the salivary glands of the lone star tick, amblyomma americanum, during feeding.the lipid composition of salivary glands from male and female lone star ticks, amblyomma americanum, was investigated at progressive stages of tick feeding. the amounts of fatty acids from both phospholipid and neutral lipid fractions increased dramatically during the initial stage of feeding and peaked in partially fed females weighing 100-250 mg. percentage compositions of myristic (14:0) and palmitic acid (16:0) decreased, but stearic (18:0), oleic (18:1), linoleic (18:2), and arachidonic aci ...19938277375
analysis of lipids in the salivary glands of amblyomma americanum (l.): detection of a high level of arachidonic acid.analysis of lipids in salivary glands of the lone star tick, amblyomma americanum, demonstrated that arachidonic acid (20:4, n-6) comprises 8% of all fatty acids identified by gas chromatography. the occurrence of arachidonic acid and other c20 polyunsaturated fatty acids in tick salivary glands was confirmed by gas chromatography-mass spectrometry. arachidonate is located entirely in the phospholipid fraction and is associated exclusively with phosphatidylcholine (pc) and phosphatidylethanolami ...19938324244
isolation and transmission of the lyme disease spirochete from the southeastern united states.the isolation of the lyme disease spirochete (borrelia burgdorferi) from the southeastern united states is reported. three isolates, two from cotton mice (peromyscus gossypinus) and one from the black-legged tick (ixodes scapularis), were recovered from sapelo island, georgia, in july and september 1991. the spirochetes were characterized by indirect fluorescent antibody assay using a battery of five monoclonal antibodies, by sodium dodecyl sulfate/polyacrylamide gel electrophoresis (sds/page) o ...19938346258
amblyomma americanum: a potential vector of human ehrlichiosis.polymerase chain reaction primers specific for ehrlichia chaffeensis were used to amplify dna from extracts of pooled ticks. amplification was performed on extracts from 140 pools (1,579 total ticks) consisting of three tick genera collected from five states. the characteristic 389-basepair product was observed after amplification of extracts from seven different pools of adult amblyomma americanum (117 pools, 1,462 ticks), but not from pools of nymphs. no specific product was observed after amp ...19938357086
implications of selection and hybridization studies on the mode of inheritance of photoperiodically induced developmental diapause in laboratory strains of the lone star tick (acari: ixodidae).selection of lone star ticks, amblyomma americanum (l.), that were reared in the laboratory under short-day photoperiods of 10:14 (l:d) h resulted in third generation (f3) diapause versus f3 nondiapause strain replete nymphs having significantly different mean molting times (days from detachment to ecdysis) of 100.9 versus 54.7 d, respectively; whereas, the f7 unselected laboratory control strain had an even smaller, significantly different mean molting time of 49.5 d. two hybrid crosses of f2 n ...19938433316
computer-controlled olfactometer system for studying behavioral responses of ticks to carbon olfactometer system that consisted of a laptop computer, a carbon dioxide analyzer, and an apparatus to control gas flows was designed to study ixodid tick behavioral responses to varying carbon dioxide (co2) concentrations. the system provided a method to regulate and measure stimulatory co2 concentrations (1-99 ppm) above ambient co2 background levels. adult amblyomma americanum (l.) and dermacentor variabilis (say) demonstrated behavioral responses to co2 concentrations as low as 9 ppm abo ...19938510116
a new borrelia infecting lone star ticks. 19968531586
physiological and nutritional responses of steers infested with varying densities of amblyomma americanum (acari: ixodidae).the effects of varying densities of lone star tick, amblyomma americanum (l.), on measured physiological parameters of beef cattle in a controlled environment was determined. steers were infested with either 0, 20, 60, or 120 pairs of adult ticks. heart rate, respiration, rectal temperature, fecal and urine excretions, and water and feed consumption were monitored daily. blood samples were taken every 3rd d to measure cortisol, total proteins, urea nitrogen, and glucose levels. hematocrits were ...19958537543
alteration of arachidonate levels in tick salivary glands by dietary modification of host blood lipids.tick saliva contains prostaglandins of the 2-series, believed to facilitate bloodmeal acquisition. because ticks cannot synthesize the prostaglandin precursor, arachidonic acid, investigations were undertaken to study the uptake, incorporation, and distribution of arachidonic acid in the salivary glands of the lone star tick in vitro and in vivo. uptake of [3h]arachidonate by isolated salivary glands was reduced in the presence of low concentrations of arachidonic or eicosapentaenoic acids, but ...19968541571
prostaglandin biosynthesis and subcellular localization of prostaglandin h synthase activity in the lone star tick, amblyomma americanum.we report on prostaglandin (pg) biosynthesis in the lone star tick, amblyomma americanum. in vitro preparations of whole female ticks and internal tissues were competent to biosynthesize four pgs: pga2/pgb2, pgd2, pge2, pgf2 alpha. pga2/pgb2 was the major product under optimal conditions. pg biosynthesis by whole tick and internal tissues were sensitive to incubation conditions including, protein concentration, time, temperature, ph, and presence of a co-factor cocktail composed of reduced gluta ...19958541884
field evaluation of deet and a piperidine repellent (ai3-37220) against amblyomma americanum (acari: ixodidae).repellent efficacy of deet (n,n-diethyl-3-methylbenzamide) and a piperidine, ai3-37220, was evaluated topically on human volunteers against lone star tick, amblyomma americanum (l.), nymphs and adults in the field. ai3-37220, at 0.5 mg/cm2, provided > 90% repellency against adult and nymphal ticks over a 6-h test period and showed significantly better repellent efficacy than deet. deet, at the same concentration, provided 85% repellency at 0 h and deteriorated to 55% repellency at 6 h.19958551512
serologic diagnosis of human monocytic ehrlichiosis by immunoblot analysis.human monocytic ehrlichiosis is caused by ehrlichia chaffeensis, an intracellular bacterium probably transmitted by the tick amblyomma americanum in the united states. despite its lack of specificity in discriminating among infections by closely related ehrlichia spp., immunofluorescence assay (ifa) is the most frequently used serological diagnostic method. to improve the specificity of the serological diagnosis, we compared antigenic profile of e. canis and e. chaffeensis antigen with homologou ...19948556515
hemocytic rickettsia-like organisms in ticks: serologic reactivity with antisera to ehrlichiae and detection of dna of agent of human granulocytic ehrlichiosis by pcr.ixodid ticks were collected from connecticut, massachusetts, missouri, pennsylvania, rhode island, and british columbia (canada) during 1991 to 1994 to determine the prevalence of infection with hemocytic (blood cell), rickettsia-like organisms. hemolymph obtained from these ticks was analyzed by direct and indirect fluorescent antibody (fa) staining methods with dog, horse, or human sera containing antibodies to ehrlichia canis, ehrlichia equi, or rickettsia rickettsii. of the 693 nymphal and a ...19958567911
identification of an uncultivable borrelia species in the hard tick amblyomma americanum: possible agent of a lyme disease-like illness.bites from the hard tick amblyomma americanum are associated with a lyme disease-like illness in the southern united states. to identify possible etiologic agents for this disorder, a. americanum ticks were collected in missouri, texas, new jersey, and new york and examined microscopically. uncultivable spirochetes were present in approximately 2% of the ticks. borrelia genus-specific oligonucleotides for the flagellin and 16s rrna genes were used for amplification of dna. products were obtained ...19968568302
temporal association of amblyomma americanum with the presence of ehrlichia chaffeensis reactive antibodies in white-tailed deer.from 1981 through 1993, tick infestations and serum antibodies reactive to ehrlichia chaffeensis, the causative agent of human ehrlichiosis, were monitored among white-tailed deer (odocoileus virginianus) at whitehall experimental forest, clarke county, georgia (usa). neither ticks nor e. chaffeensis antibodies were detected during the first two years of the study. infestations of the lone star tick (amblyomma americanum), a suspected vector of e. chaffeensis, first were noted on deer in 1983. p ...19958583627
ixodid ticks from panthers and bobcats in florida.ixodid ticks were present in all 189 samples examined from 53 florida panthers (felis concolor coryi, 104 collections) and 85 bobcats (felis rufus floridana) in florida (usa) between 1974 and 1991. we identified 3,251 ticks from panthers and 918 from bobcats. specimens of dermacentor variabilis, ixodes scapularis, i. affinis, amblyomma maculatum, and a. americanum were present on 49, 39, 17, seven, and two of the 53 florida panthers, respectively, and comprised 36%, 55%, 7%, 1%, and < 1% of the ...19958592378
dietary modification of host blood lipids affect reproduction in the lone star tick, amblyomma americanum(l.).the feeding and reproductive performance of female lone star ticks (amblyomma americanum (l.)) infesting guinea pigs on diets containing 15% fish oil (fo) or safflower oil (so) were investigated. replete ticks fed on fo-fed guinea pigs weighed approximately 30% less than those on the so-fed guinea pigs. the lower engorged weight resulted in a similar decrease in the mass and number of eggs laid and number of larvae hatching. no effect of host dietary treatment was observed upon the reproductive ...19968604084
ehrlichia-like 16s rdna sequence from wild white-tailed deer (odocoileus virginianus).the reservoir hosts of ehrlichia chaffeensis, etiologic agent of human ehrlichiosis are unknown. initially, white-tailed deer (wtd) were serologically implicated as possible reservoirs of e. chaffeensis. subsequent studies showed that wtd were susceptible to infection with e. chaffeensis and that deer-to-deer transmission by a tick vector, amblyomma americanum, is possible under experimental conditions. to determine if wild wtd were infected with e. chaffeensis, whole blood was collected from 10 ...19968627501
ticks parasitizing humans in georgia and south carolina.from 1990 through 1995, 913 ticks removed from 460 human patients in georgia or south carolina were identified and recorded. the majority of these specimens (758, 83.0%) were lone star ticks, amblyomma americanum. one hundred and four (11.4%) american dog ticks dermacentor variabilis, 36 (3.9%) blacklegged ticks ixodes scapularis, 9 (1.0%) gulf coast ticks amblyomma maculatum, and 6 (0.7%) brown dog ticks rhipicephalus sanguineus were also recovered. all active stages (larvae, nymphs, and adults ...19968636862
systemic treatment of white-tailed deer with ivermectin-medicated bait to control free-living populations of lone star ticks (acari:ixodidae).whole-kernel corn was treated with 10 mg ivermectin per 0.45 kg corn and fed at rate of approximately .45 kg/deer per day to white-tailed deer confined in the treatment pasture, whereas deer in an adjacent control pasture received a similar ration of untreated corn. treatments were dispensed from february through september of 1992 and 1993, and free-living populations of lone star ticks. amblyomma americanum (l.), were monitored in both pastures using dry-ice traps to quantify nymphs and adults ...19968667385
molecular cloning of delta 9 fatty acid desaturase from the protozoan tetrahymena thermophila and its mrna expression during thermal membrane response to a decrease in its growth temperature, the protozoan tetrahymena is known to increase the level of unsaturated fatty acids in its membrane phospholipids so as to maintain the correct physical state (fluidity) of the membranes. in this organism, synthesis of unsaturated fatty acids is initiated by delta 9 acyl-coa desaturase. our previous studies have shown that, during cold adaptation, the activity of microsomal palmitoyl- and stearoyl-coa desaturase increases, reaching a maximal l ...19968694777
salivary gland changes and host antibody responses associated with feeding of male lone star ticks (acari:ixodidae).the goal of this study was to demonstrate that male lone star ticks, amblyomma americanum (l.), actively feed on rabbits during attachment and that the host is capable of mounting an immune response against male salivary gland proteins. during attachment, it was shown that male ticks salivary glands hypertrophy. an enzyme-linked immunosorbent assay was used to detect rabbit serum proteins in the midgut of previously attached male ticks. sds-polyacrylamide gel electrophoresis showed that the prot ...19968699458
cold-hardiness of a laboratory colony of lone star ticks (acari: ixodidae).the cold-hardiness of a lone star tick, amblyomma americanum (l.), laboratory colony was characterized. fed and unfed larvae, fed and unfed nymphs, and unfed adults did not survive exposure to -17 degrees c for 7 d. after an 8-d exposure to -10 degrees c, adults tolerated cold better than immatures and unfed specimens fared better than fed ticks. exposing unfed 6-wk-old (postmolt) adult males and females to -15 degrees c for increasing intervals up to 2 h suggests that males were more tolerant t ...19968699473
a self-medicating applicator for control of ticks on deer.a self-medicating applicator for killing ticks on deer and domestic ungulates by passive transfer of acaricides during feeding is described. the applicator consists of a barrel divided into a food bin (above) and a sealed self-contained acaricide reservoir (below) with a vertical, centrally-located ceramic column that extends from the reservoir into the food bin. acaricide is drawn up the column from the sealed reservoir by absorption. animals attracted to the food in the device acquire the acar ...19968744707
effects of pyriproxyfen on engorged females and newly oviposited eggs of the lone star tick (acari:ixodidae).engorged females and 1- to 3-d-old eggs of the lone star tick, amblyomma americanum (l), were exposed to 9 treatments of pyriproxyfen (4, 8, and 16 micrograms/cm2) in glass vials at exposure periods of 7 d, 14 d, and continuous at each dosage level. treatment of newly engorged females did not affect the number of females ovipositing, but the number of eggs oviposited decreased as dosage and exposure time increased. complete inhibition of egg hatch occurred at all treatment levels except that of ...19968840677
survival and water-balance characteristics of unfed adult amblyomma cajennense (acari: ixodidae).off-host survival, water balance, and cold tolerance of unfed adult, cayenne ticks, amblyomma cajennense (f.), were examined to evaluate species characteristics important to zoogeography and off-host ecology. survivorship decreased when males and females were subjected to progressively drier constant environmental conditions. average maximum survival was 641.2 and 682.5 d at 85% rh and 23 degrees c (2.98 mm hg) for males and females, respectively. mean survival in both sexes was progressively le ...19968906907
seasonal activity and relative abundance of amblyomma americanum in mississippi.ecological investigations of the lone star tick, amblyomma americanum (l.), were conducted in 3 adjacent 60-m2 plots, located in noxubee national wildlife refuge, noxubee county, mississippi. ticks were collected weekly from july 1992 to july 1993 by flagging randomly selected lanes. during the year, larval ticks were collected first in early july, with peak numbers in september, and they were collected no later than late october. nymphal ticks were collected from mid-march to late october, with ...19968906916
site-specific geographic association between amblyomma americanum (acari: ixodidae) infestations and ehrlichia chaffeensis-reactive (rickettsiales: ehrlichieae) antibodies in white-tailed deer.serum samples from white-tailed deer, odocoileus virginianus zimmermann, collected from 1982 through 1992 from the southeastern united states were tested for antibodies reactive to ehrlichia chaffeensis anderson, dawson, jones, & wilson, the causative agent of human ehrlichiosis. results were compared between areas based on known infestations of the lone star tick, amblyomma americanum l., a suspected vector of e. chaffeensis. one hundred and twenty-five of 300 (41.7%) deer tested positive (> or ...19968906920
tick avoidance behaviors associated with a decreased risk of anti-tick salivary gland protein antibody seropositivity in military personnel exposed to amblyomma americanum in arkansas.during april through september 1990, 399 military personnel who originated from either fort chaffee, arkansas (n = 236) or fort wainwright, alaska (n = 163) were studied during maneuvers in tick-infested areas at fort chaffee. study subjects completed a questionnaire and had pre- and post-maneuvers serum specimens analyzed for antibodies to several rickettsial and ehrlichial agents and to amblyomma americanum (lone star tick) salivary gland proteins (anti-tick saliva antibodies [atsa], a biologi ...19968916798
human ehrlichiosis--maryland, 1994.ehrlichiosis is an emerging tickborne infectious disease caused by obligate intracellular, gram-negative rickettsia that infect leukocytes. human monocytic ehrlichiosis (hme) is caused by ehrlichia chaffeensis and is believed to be transmitted by amblyomma americanum (the lone star tick). most hme cases have been reported in southeastern and south-central states. during may-july 1994, five cases of serologically confirmed hme were identified among residents of maryland. all five persons lived ne ...19968926996
cloning and sequence of a gene for a homologue of the c subunit of the v-atpase from the salivary gland of the tick amblyomma americanum (l).a 1084 base pair partial cdna showing similarity to the c subunit of the vacuolar atpase (v-atpase) was isolated on a clone from a cdna library made from salivary glands from 3-day-old feeding adult amblyomma americanum (l.) female ticks. the 5' end was completed using primer extension and the two pieces joined to form a complete cdna of 1373 bp. this mrna is expressed in embryos and the salivary glands of unfed adults and adult females at all stages of feeding. specific inhibitors of the v-atpa ...19979013257
tick-raccoon associations and the potential for lyme disease spirochete transmission in the coastal plain of north carolina.raccoons (procyon lotor) were live-trapped and examined for ticks from july 1990 to july 1993 in the coastal plain of north carolina on marine corps base, camp lejeune, north carolina (usa). five species of ixodid ticks were found on 351 (78%) of 449 raccoons. amblyomma americanum was the most abundant tick found on raccoons. dermacentor variabilis, ixodes texanus, and ixodes scapularis were frequently collected, while ixodes cookei were rarely collected from raccoons. tick burdens were not affe ...19979027688
identification and characterization of anticoagulant activities in the saliva of the lone star tick, amblyomma americanum (l.).anticoagulant activities against both the extrinsic and intrinsic coagulation pathways were identified in the saliva of partially fed female lone star ticks, amblyomma americanum (l.). the activities of factor xa and thrombin in the common pathway of the coagulation cascade were inhibited by tick saliva. the greatest anticoagulant activities were found in the saliva of ticks weighing more than 200 mg. the anticoagulant activities in tick saliva could be detected without preincubation of tick sal ...19979057694
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
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 ...19979103758
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
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
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. ...19979151505
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.19979194851
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 ...19979195722
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 ...19979196173
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 ...19979219365
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 ...19979220680
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.19979230803
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 ...19979272444
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 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 ...19979287955
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 ...19979326887
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. ...19979379294
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 ...19989431909
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 ...19979439115
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 ...19979491364
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 ...19979501418
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 ...19989509259
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.19979531233
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 ...19989574696
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 ...19989596710
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 ...19989620365
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 ...19989620368
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
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 ...19989650514
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 ...19989668486
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 ...19989673934
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
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
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 ...19989701935
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
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 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.19989705425
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.19989708212
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 ...19989715947
physician-diagnosed erythema migrans and erythema migrans-like rashes following lone star tick differentiate cases of physician-diagnosed erythema migrans and erythema migrans-like rashes associated with lone star tick (amblyomma americanum) bites.19989722725
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 ...19989738027
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 ...19989775620
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.19989790445
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