PMID(sorted ascending)
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
temporal and spatial dynamics of a parapatric boundary between two australian reptile ticks.two tick species aponomma hydrosauri and amblyomma limbatum that infest large reptiles have an abrupt parapatric boundary near mt mary in south australia. a previous model has suggested that the boundary is maintained at population density troughs resulting from habitat heterogeneity along a gradual environmental gradient. this paper describes the dynamics of the boundary on three transects over 17 years, 1982-98. over the last seven years of that period there has been a significant increase in ...200111298975
risk factors to tick infestations and their occurrence on horses in the state of são paulo, brazil.from december 1998 to march 1999, 40 stud farms were studied in the state of são paulo, brazil. during visits to farms, horses reared under grazing conditions were examined for the presence of ticks. on each farm visit, horse pastures were closely inspected and a questionnaire was given to the farm supervisor with the purpose of gaining information about ecological and management variables (independent variables) that could be associated with the presence and infestation levels of ticks on the f ...200111337122
entomogenous fungi as promising biopesticides for tick control.when ticks were sealed in nylon tetrapacks and infected with the entomogenous fungi, beauveria bassiana and metarizium anisopliae and maintained in potted grass in the field, the fungal oil formulations (10(9) conidia per ml) induced 100% mortality in larvae of rhipicephalus appendiculatus and amblyomma variegatum, whereas mortalities in nymphs varied between 80-100% and in adults 80-90%. the aqueous formulations (10(9) conidia per ml) induced mortalities of 40-50% and reductions in egg hatchabi ...200011354619
cowdria ruminantium antibodies in acaricide-treated and untreated cattle exposed to amblyomma variegatum ticks in the indirect enzyme-linked immunosorbent assay (elisa), based on the major antigenic protein i fragment b (mapi-b) of cowdria ruminantium, was used to assess seroprevalence in cattle in the gambia. two groups of 20 n'dama and 20 gobra zebu cattle were monitored for 12 months with flumethrin treatment and for another 10 months without acaricidal treatment. two groups of 20 n'dama and 20 gobra cattle served as untreated controls. during the period of acaricidal treatment, the cumulative proportions ...200011354623
collection of free-living nymphs and adults of amblyomma hebraeum (acari: ixodidae) with pheromone/carbon dioxide traps at 5 different ecological sites in heartwater endemic regions of south africa.the capture of free-living adults and nymphs of amblyomma hebraeum, the main vector of heartwater in domestic and wild ruminants in south africa, by means of attraction-aggregation-attachment-pheromone/carbon dioxide traps at five endemic localities in south africa is described. although the traps were used successfully at each of the localities, no determination of their efficiency in relation to the actual abundance of ticks at a particular site was made. this study confirmed that the traps co ...200011354624
amblyomma tigrinum (acari: ixodidae) in relation to phytogeography of central-northern argentina with notes on hosts and seasonal distribution.the findings of amblyomma tigrinum in continental argentina north of 40 degrees s are presented according to phytogeographic domains (andean-patagonic, amazonian and chaco) and the seasonal distribution is depicted on a monthly basis. a total of 718 adult ticks and four nymphs were found. a. tigrinum ticks were present in all domains. adult ticks were found all year round but they were more abundant during the summer. most ticks were found on domestic dogs but the survey has a bias to domestic h ...200011354625
ticks (acari: ixodidae) spread by the international trade in reptiles and their potential roles in dissemination of diseases.the international trade in live reptiles has grown dramatically in the last decade. since many of these reptiles are infested with ticks, the number of ticks introduced to new exotic locations has also increased. this is causing concern in importing countries such as the united states because some of the reptilian ticks are known to be vectors of diseases of veterinary and economic importance, such as heartwater. rational measures to control these tick species and to eradicate new introductions ...200111354992
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
[search for the spirochete borrelia burgdorferi sensu lato by polymerase chain reaction in wild chilean ticks].lyme disease is a tick-borne human disease caused by the spirochete borrelia burgdorferi. main vectors of lyme disease are ticks of the ixodes and amblyomma genera. cases with clinical manifestations of lyme disease and favorable responses to antimicrobial agents have been reported in chile, some of them with erythema migrans, the hallmark of b burgdorferi infection.200111372294
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
reduction in mortality from heartwater in cattle, sheep and goats exposed to field challenge using an inactivated vaccine.inactivated vaccines for heartwater prepared with the commercially acceptable montanide isa 50 (isa 50) adjuvant were field tested in boer goats in botswana, angora goats in south africa, and merino sheep in zambia and zimbabwe. two vaccines, one made using the zimbabwean mbizi isolate and the other using the respective local field isolate (sunnyside in botswana; bathurst in south africa; lutale in zambia), were tested at each site, except in zimbabwe where only the mbizi vaccine was tested. com ...200111390083
tick infestation of borana cattle in the borana province of ethiopia.a study was conducted to identify and determine burdens of ticks infesting borana cattle in the borana province of ethiopia. rhipicephalus pulchellus, rhipicephalus pravus, rhipicephalus muhsamae, rhipicephalus praetextatus, rhipicephalus evertsi evertsi, amblyomma gemma, amblyomma variegatum, amblyomma cohaerens, amblyomma lepidum, hyalomma truncatum, hyalomma marginatum rufipes and boophilus decoloratus were identified on the cattle. their burdens ranged from 658-1,554 with a mean of 1,205 tic ...200111403429
resistance of leopard tortoises and helmeted guineafowl to cowdria ruminantium infection (heartwater).experimental infection trials were conducted to investigate susceptibility of leopard tortoises (geochelone pardalis) and helmeted guineafowl (numida meleagris) to infection with cowdria ruminantium, the causative agent of heartwater, a tickborne disease of domestic and wild ruminants. ten guineafowl were inoculated intravenously with a virulent dose of c. ruminantium derived from bovine endothelial cell cultures, and four leopard tortoises were exposed to c. ruminantium infection by the feeding ...200111423187
1-octen-3-ol isolated from bont ticks attracts amblyomma variegatum.volatiles from various life-stages of the bont ticks amblyomma variegatum and a. hebraeum were collected by using solid-phase microfibers and charcoal traps. an octenol isomer was found to be a major constituent of most of the tick material sampled and was identified as 1-octen-3-ol by gas chromatography-mass spectrometry and by using antenna of the tsetse fly glossina brevipalpis in gas chromatography-linked antennogram detection. release of this compound increased during molt to adulthood and ...200111441439
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
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
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
investigation of blood parasites in livestock infested with argasid and ixodid ticks in egypt.nineteen species and subspecies of ixodid and argasid ticks, hyalomma dromedarii, h. impeltatum, h. anatolicum excavatum, h. a. anatolicum, h. truncatum, h. m. marginatum, h. m. rufipes, h. m. turanicum, boophilus annulatus, rhipicephalus sanguineus, r. turanicus, r. guilhoni, r. camicasi, amblyomma lipidum, a. marmoreum, a. vareigatum, argas persicus, a. hermanii and a. arboreus were collected from different localities in five governorates, giza, sharkia, ismailia, el beheira and sinai. hyalomm ...200111478436
ultrastructure of developmental stages of hemolivia stellata (apicomplexa: haemogregarinidae) in the cane toad bufo marinus and in its vector tick amblyomma rotondatum.the fine structure of the hemogregarine hemolivia stellata petit, landau, baccam and lainson, 1990 developmental stages in the cane toad bufo marinus l. and the vector tick amblyomma rotondatum koch, 1844 are described. in the liver of the toad, merozoites bound by a pellicle were located free and in the cytoplasm, and young and encased mature polynucleated meronts were located in a parasitophorous vacuole (pv). premature gametocytes in the erythrocytes were bound by a bilayered membranous wall ...200111510993
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
evidence for the utility of the bm86 antigen from boophilus microplus in vaccination against other tick species.the bm86 antigen, as originally identified in boophilus microplus, is the basis of commercial tick vaccines against this tick species. the potential for using this antigen or homologues of the antigen in vaccination against other tick species has been assessed. we have conducted vaccine trials in cattle using the b. microplus-derived recombinant bm86 vaccine (tickgard) using pairs of vaccinated calves and control calves. these were infested with b. microplus and boophilus decoloratus larvae simu ...200111523920
dermatophilus congolensis infection in goats in tanzania.when goats in eastern tanzania were screened for skin diseases, dermatophilus congolensis was isolated from the skin lesions in 8 of 484 animals examined. in one severely affected case, the disease was also characterized by histological studies (gram stain, giemsa stain and routine he studies) and electron microscopy. the histological picture was characterized by hyperkeratosis, parakeratosis, acanthosis, folliculitis and an inflammatory cellular reaction involving the epidermis. gram stain and ...200111556616
transmission of cowdria ruminantium by amblyomma gemma from infected african buffalo (syncerus caffer) and eland (taurotragus oryx) to sheep.two african buffalo (syncerus caffer), an eland (taurotragus oryx) and a waterbuck (kobus defassa) were intravenously inoculated with cowdria ruminantium (kiswani). amblyomma gemma nymphs were fed on the animals at 3 weekly intervals. jugular blood was also collected at 3 weekly intervals and inoculated into sheep. nymphal ticks that fed on one buffalo on days 16 and 37 and on the other buffalo on day 58 after infection transmitted the disease as adults to sheep. nymphs that were applied to the ...200111556617
new distribution records of amblyomma hebraeum in the sandveld region of botswana. 200111563715
ixodes rubicundus nymphs are short-day diapause-induced ticks with thermolabile sensitivity and desiccation resistance.the karoo paralysis tick, ixodes rubicundus neumann (acari: ixodidae), is a semi-voltine ixodid that survives stressful environmental conditions using morphogenetic diapause (eggs and engorged nymphs) and desiccation resistance. both photoperiod and temperature influence diapause induction in the engorged nymph. ixodes rubicundus nymphs are typical long-day photoperiodic organisms. the critical photoperiod is approximately 13.5 h light, 10.5 h dark, and they display a thermolabile response. the ...200111583453
parasites of domestic and wild animals in south africa. xl. ticks on dogs belonging to people in rural communities and carnivore ticks on the vegetation.ixodid ticks were collected at weekly intervals from february 1999 to april 2000 from domestic dogs belonging to people in rural communities in north-eastern kwazulu-natal. seven ticks were identified to species level and adult haemaphysalis leachi followed by immature amblyomma hebraeum and adult rhipicephalus simus were the most prevalent. infestation with adult h. leachi was most intense during february and march 1999 and from january to april 2000, and least intense during october 1999. infe ...200111585091
anti-interleukin-8 activity of tick salivary gland extracts.interleukin-8 (il-8) is one of many mammalian chemokines (chemotactic cytokines) that direct mammalian inflammatory and immune cells to sites of injury and infection. chemokines are produced locally and act on leucocytes through selective receptors. the principal role of il-8 is to control the movement and activity of neutrophils. to date, several tick species have been shown to modulate the production or activity of certain cytokines but none of these are chemokines. using an il-8 specific elis ...200111589777
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
detection and identification of spotted fever group rickettsiae and ehrlichiae in african ticks.rickettsia africae, a recently identified pathogen, was detected for the first time in amblyomma ticks from niger, mali, burundi, and sudan, and "r. mongolotimonae" was identified for the first time in africa. rickettsiae of unknown pathogenicity and two new ehrlichiae of the ehrlichia canis group were identified in ticks from mali and niger.200111747731
larval gulf coast ticks (amblyomma maculatum) [acari: ixodidae] as host for hepatozoon americanum [apicomplexa: adeleorina].laboratory-reared larval gulf coast ticks (gcts) (amblyomma maculatum) were exposed experimentally and found to acquire hepatozoon americanum infection while feeding on parasitemic dogs. these ticks supported gamogonic and sporogonic development of the apicomplexan, and oocysts from newly molted nymphs were infectious for a dog. other nymphs from this cohort that were allowed to feed on a blood-parasite naive sheep molted normally; the resulting adult ticks contained oocysts that were infectious ...200211750999
ticks from a morelet's crocodile in belize.parasitism of crocodilians by ticks has rarely been reported, and to our knowledge only seven published accounts exist. on 3 july 1999, we collected four ticks from a subadult morelet's crocodile (crocodylus moreletii) captured in northern belize. these were identified as amblyomma dissimile (one female), and amblyomma sp. (two nymphs, one larva). the crocodile was captured on land approximately 100 m from water, and all four ticks were attached to loose skin on the lateral surface of the tail. ...200111763751
host associations of ticks parasitizing rodents at borrelia burgdorferi enzootic sites in south carolina.a total of 237 rodents was collected in 4 regions of south carolina from july 1994 through december 1995. eight species were collected, including cotton mouse, hispid cotton rat, eastern woodrat, marsh rice rat, white-footed mouse, eastern harvest mouse, golden mouse, and black rat. of the 1,514 ticks recovered from these hosts, ixodes minor neumann, including larvae, nymphs, and adults, was the most abundant species, representing 54% of the total. only immature stages of other tick species were ...200111780825
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
horse resistance to natural infestations of anocentor nitens and amblyomma cajennense (acari: ixodidae).the objective of this study was to investigate some aspects of horse resistance to natural infestations of anocentor nitens and amblyomma cajennense over a 2-year period. free-living stages of a. nitens were used to evaluate the influence of season of the year on horse resistance. every 2 weeks, 10 selected engorged females, weighing 150-329 mg, were removed from naturally infested horses and were individually placed into glass tubes closed with a cotton stopper, and maintained in an incubator. ...200211812624
ultrastructure of developmental stages of hemolivia mariae (apicomplexa: haemogregarinidae), natural parasite of the australian sleepy lizard, in experimentally infected deviant hosts.mabuya vitatta (olivier) (scincidae) and agama stellio (l.) (agamidae) were infected with hemolivia mariae smallridge et paperna, 1997 by ingestion of tick viscera from amblyomma limbatum neumann, fed as nymphs on naturally infected australian sleepy lizards, tiliqua rugosa gray. the unnatural infection apparently interfered with the developmental schedule of the parasites. transmission electron microscopic images of merogonic stages were obtained, as well as images of early developing gametocyt ...200111817448
seasonal epidemiology of ticks and aspects of cowdriosis in n'dama village cattle in the central guinea savannah of côte d' the central guinea savannah of côte d'ivoire, cattle breeding started only approximately 30 years ago. the impact of parasitism on the overall health status and productivity of the trypanotolerant n'dama cattle in this area is unknown. in close collaboration with national veterinary institutions and local farmers, we studied spectrum, burden and seasonal dynamics of ticks (including aspects of cowdriosis) on n'dama village cattle. in a longitudinal study, three randomly selected cattle herds ...200211821134
heterogeneity in the effect of different ixodid tick species on human natural killer cell activity.tick saliva plays a vital role in blood-feeding, including manipulation of the host response to tick infestation. furthermore, a diverse number of tick-borne pathogens are transmitted to vertebrate hosts via tick saliva, some of which exploit the immunomodulatory activities of their vector's saliva. we report that salivary gland extracts (sge) derived from dermacentor reticulatus adult ticks induce a decrease in the natural killer (nk) activity of effector cells obtained from healthy human blood ...200211856443
seasonal dynamics of ticks (acari: ixodidae) on horses in the state of são paulo, brazil.natural tick infestations were assessed every 14 days on horses over a 2-year period. amblyomma cajennense adult ticks were counted individually, without detachment from the horses. larvae and nymphs of a. cajennense were collected using a rubber scraper that scratched engorged immature ticks from the host. adult females of anocentor nitens larger than 4mm length were counted on the horses. blood samples were also obtained from the horses every 14 days and macroclimatic data were obtained for th ...200211879967
the sex ratio of amblyomma cajennense (acari: ixodidae) with notes on the male feeding period in the evaluate the sex ratio of field collected nymphal amblyomma cajennense ticks, we collected 5326 engorged nymphs from naturally infested horses in pirassununga county and allowed them to molt to adults in the laboratory. they yielded a sex ratio of 1:1.83 (m:f). three and two engorged females were collected from horses pastured at pirassununga county and from tapirs pastured in sorocaba county, respectively. these females were allowed to oviposit and their progeny were reared until the adult s ...200211879968
developmental profiles of ecdysteroids, ecdysteroid receptor mrnas and dna binding properties of ecdysteroid receptors in the ixodid tick amblyomma americanum (l.).total body ecdysteroid titers were determined at specific stages during the larval and nymphal life of amblyomma americanum (l.). one ecdysteroid peak was observed following the completion of larval apolysis. however, two distinct ecdysteroid peaks occurred at a comparable stage in the nymphal molting cycle. the first occurred following apolysis and the second peak occurred at about the time of ecdysis. when whole body profiles of ecr and rxr mrnas were examined during the molting cycle using rt ...200211886781
amblyomma geochelone, a new species of tick (acari: ixodidae) from the madagascan ploughshare tortoise.the male and female of amblyomma geochelone n. sp. are described and illustrated by both scanning electron micrographs and line drawings. specimens of this new tick species were recovered from the endangered ploughshare tortoise, geochelone yniphora (vaillant), in northwestern madagascar. this relatively large tick is morphologically most similar to amblyomma nuttalli dönitz, which occurs in mainland sub-saharan africa where it mainly parasitizes other species of tortoises. however, several char ...200211931042
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
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
parasitism of domestic swine (sus scrofa) by amblyomma ticks (acari: ixodidae) on a farm at monte negro, western amazon, brazil.abstract in january 2001, while conducting a survey of the tick fauna of the state of rondĵnia, brazil, a rural area within monte negro county was visited. on one farm within the county the producer maintained a herd of crossbred swine, sus scrofa l., that was reared under unconfined conditions, with unrestrained access to the pasture and adjacent native amazon equatorial forest. inspection of the swine herd produced a total of 77 ticks collected from eight adult pigs (mean, 9.6 ticks per pig) t ...200211931265
evaluation of three commercial tick removal evaluate three commercially available tick removal tools against medium-tipped nontissue tweezers.199811990185
comparison of differentially expressed genes in the salivary glands of male ticks, amblyomma americanum and dermacentor andersoni.genes expressed differentially in the salivary glands of unfed and fed male ticks, amblyomma americanum (l.), were identified, cloned and sequenced, and some were compared with those expressed in the salivary glands of dermacentor andersoni. total protein and rna increased sixfold in the salivary glands of fed male a. americanum, while in fed male d. andersoni salivary glands, rna increased approximately 3.5 times. feeding d. andersoni in the presence of females increased total rna by 25% over t ...200212020839
the distribution of ixodid ticks (acari: ixodidae) in central ethiopia.ixodid ticks were collected from domestic animals, mainly cattle, in 11 administrative zones covering 84 districts in central ethiopia over a period of 2 years (july 1996 to june 1998). nineteen tick species were identified. four of these belonged to the genus amblyomma, one to boophilus, two to haemaphysalis, three to hyalomma and nine to rhipicephalus. amblyomma variegatum and rhipicephalus evertsi evertsi were present in all 11 administrative zones and, with the exception of afar, boophilus d ...200112026058
genetic identification of rickettsiae isolated from ticks in japan.following the description in japan of japanese spotted fever, caused by rickettsia japonica, a search for the vector of this disease led to the isolation of several rickettsiae from various tick species. sixty-three rickettsial isolates were obtained from six different tick species, and six type strains were described by pcr and monoclonal antibody testing. we identified these six strains by amplification and sequencing of the genes encoding 16s rrna and citrate synthase. we confirmed that the i ...200212037083
analysis of serum and whole blood values in relation to helminth and ectoparasite infections of feral pigs 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
transcriptional analysis of the major antigenic protein 1 multigene family of cowdria ruminantium.the major antigenic protein 1 (map1) of the tick-borne rickettsial pathogen cowdria ruminantium is encoded by a multigene family containing conserved and variable genes. the part of a locus containing the map1 multigene family that was characterized contained three homologous, but non-identical map1 genes, designated map1-2, map1-1, and map1. reverse transcriptase-polymerase chain reaction was used to study the transcriptional activity of these genes in isolates of c. ruminantium grown in bovine ...200212039046
identification and characterization of genes differentially expressed in the testis/vas deferens of the fed male tick, amblyomma hebraeum.most ixodid ticks must feed for at least a few days to complete gonad maturation. substances produced by the mature male gonad, and carried in the spermatophore, induce physiological changes in the female that lead to engorgement and oviposition. to begin defining the molecular phenotype at this stage of male development, we differentially cross-screened a cdna library made from the testis and vas deferens of fed ticks (amblyomma hebraeum koch) and isolated 35 genes that were putatively up-regul ...200212044495
phylogenetic analysis of spotted fever group rickettsiae isolated from ticks in japan.eight spotted fever group (sfg) rickettsiae isolated from ticks in japan were classified by phylogenetic analysis based on the nucleotide sequences of both the citrate synthase-encoding gene (glta) and 190-kda antigen-encoding gene (rompa). in the phylogenetic tree of glta, strains dt-1 and fla-1 isolated from the dermacentor taiwanensis and haemaphysalis frava ticks, respectively, were placed as rickettsia japonica, and strains io-1, io-2, io-25, im-1 and ip-2 from genus ixodes ticks were place ...200212061626
ixodid ticks on indigenous goats owned by small-scale farmers in four communal grazing areas in south africa.indigenous goats belonging to small-scale farmers in 4 communal grazing areas in south africa were sampled for ixodid ticks during the period september 1991 to may 1993. three of these areas were in the north west province (rietgat, madinyane and bethany), and one in mpumalanga province (geluk). no tick control was practised unless requested by the owners. seven ixodid tick species, of which the majority were immature ticks, were collected from the goats in north west province. amblyomma hebraeu ...200212088070
ehrlichia ewingii infection in white-tailed deer (odocoileus virginianus).two closely related zoonotic ehrlichiae, ehrlichia chaffeensis and e. ewingii, are transmitted by amblyomma americanum, the lone star tick. because white-tailed deer (odocoileus virginianus) are critical hosts for all mobile stages of a. americanum and are important vertebrate reservoirs of e. chaffeensis, we investigated whether deer may be infected with e. ewingii, a cause of granulocytotropic ehrlichiosis in humans and dogs. to test for e. ewingii infection, we used polymerase chain reaction ...200212095432
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
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
dermacentor variabilis and boophilus microplus (acari: ixodidae): experimental vectors of babesia equi to equids.the experimental vector competence of five laboratory-reared ixodid tick species representing three genera [amblyomma americanum (l.), boophilus microplus (canestrini), d. andersoni stiles, d. occidentalis marx, and d. variabilis (say)] for babesia equi (laveran 1901) was evaluated by delayed transfer of male ticks from infected to susceptible equids or by infesting the latter animals with adult ticks previously fed as nymphs on infected equids. after feeding for 5, 6, or 13 d on acquisition hos ...200212144301
evidence of spotted fever group rickettsiae in state of rio de janeiro, brazil.ticks were obtained from dogs from february to september of 1999 at weekly intervals, in the county of piraí, state of rio de janeiro. four hundred seventy four ixodids were taxonomically identified, 103 amblyomma cajennense, seven amblyomma ovale, 209 rhipicephalus sanguineus, and 155 amblyomma sp. an hemolymph test associated with giemsa's stain revealed two specimens in 163 ticks tested (r. sanguineus and amblyomma sp), containing rickettsia-like organisms. direct immunofluorescence verified ...200212163909
tick infestation of sika deer (cervus nippon) in the western part of yamaguchi prefecture, japan.ticks were collected from 94 sika deer (cervus nippon) hunted in the western part of yamaguchi prefecture, japan from august to november 1999, and march to july 2000. haemaphysalis longicornis and h. yeni were the dominant species from april to august, while h. flava and h. megaspinosa were dominant in october, november and march. this is the first report of h. yeni in the mainland of japan. small numbers of h. kitaokai, amblyomma testudinarium and ixodes ovatus were also recorded.200212185317
introduction of the exotic tick amblyomma hebraeum into florida on a human host.a resident of florida returned from a short visit to southern africa to find a male amblyomma hebraeum tick attached to the skin behind her knee. amblyomma hebraeum is a major vector of 2 pathogens that cause important diseases in southern africa, heartwater of ruminants and african tick-bite fever of humans. the tick was tested by polymerase chain reaction assay for evidence of infection with cowdria ruminantium and rickettsia africae (the causative agents of heart-water and african tick-bite f ...200212197136
gynandromorphism in amblyomma cajennense and rhipicephalus sanguineus (acari: ixodidae).during a survey of ticks on horses in november 2000, at the university of são paulo farm in pirassununga county, são paulo, brazil, 1 gynandromorph of amblyomma cajennense was collected from a naturally infested horse. in another survey on dogs in march 2001, in the urban area of monte negro, rondônia, brazil, a gynandromorph of rhipicephalus sanguineus was collected from a naturally infested dog. both specimens are described and classified as perfect bipartite protogynanders.200212197141
evaluation of safety and efficacy of acaricides for control of the african tortoise tick (amblyomma marmoreum) on leopard tortoises (geochelone pardalis).nine acaricides (amitraz, carbaryl, chlorpyrifos, cyfluthrin, fipronil, lindane, permethrin, phenothrin, and pyrethrins) were studied for their efficacy in killing the african tortoise tick (amblyomma marmoreum). only four of the acaricides (chlorpyrifos, cyfluthrin, lindane, and permethrin) produced 100% mortality within 24 hr of application, and only two (cyfluthrin and permethrin) continued to cause 100% mortality when diluted to as low as 1:10,000. five of the acaricides (amitraz, carbaryl, ...200212216793
attraction of the tropical bont tick, amblyomma variegatum, to human breath and to the breath components acetone, no and co2.ticks are of medical and veterinary importance and employ several cues in search of a host. olfaction is one modality by which ticks locate a blood-meal and breath is the major vent of gaseous and volatile metabolites from the host that could contribute to this search. we studied the responses of a hunter tick, amblyomma variegatum, to diluted human breath and five of its components (acetone, co2, no, isoprene and nh3) while walking in an air stream on a locomotion compensator. diluted breath el ...200212216862
search for borrelia sp. in ticks collected from potential reservoirs in an urban forest reserve in the state of mato grosso do sul, brazil: a short report.a total of 128 ticks of the genus amblyomma were recovered from 5 marsupials (didelphis albiventris) - with 4 recaptures - and 17 rodents (16 bolomys lasiurus and 1 rattus norvegicus) captured in an urban forest reserve in campo grande, state of mato grosso do sul, brazil. of the ticks collected, 95 (78.9%) were in larval form and 22 (21.1%) were nymphs; the only adult (0.8%) was identified as a. cajennense. viewed under dark-field microscopy in the fourth month after seeding, 9 cultures prepare ...200212219124
amblyomma hebraeum is a vector of rickettsia africae and not r. conorii. 200112219911
acaricide resistance profiles of single- and multi-host ticks from communal and commercial farming areas in the eastern cape and north-west provinces of south africa.a field study (february 2000 to august 2001) was conducted on communal and commercial farms in the eastern cape and north-west provinces of south africa to detect the levels of tick resistance to commonly used acaricides. the larvae obtained from engorged females of the one-host tick boophilus decoloratus, the two-host tick rhipicepalus evertsi evertsi and the three-host ticks amblyomma hebraeum and rhipicephalus appendiculatus were tested against various concentrations of amitraz, chlorfenvinph ...200212234005
studies on seasonal dynamics of ticks of ogaden cattle and individual variation in resistance to ticks in eastern this study the dominant tick species identified were amblyomma cohaerens 52.2%, rhipicephaluspravus 19.3% and a. variegatum 14.6%. a. cohaerens occurred throughout the sampling period and showed a peak during march. their number declined significantly (p < 0.01) from august to december. r. pravus occurred from july to december only and peaking in september (p < 0.01). a. variegatum occurred in low numbers throughout the study period with a marked seasonal variation (p < 0.01) and abundant num ...200212241029
simultaneous detection of anaplasma and ehrlichia species in ruminants and detection of ehrlichia ruminantium in amblyomma variegatum ticks by reverse line blot hybridization.the detection of anaplasma and ehrlichia species is usually based on species-specific pcr assays, since no assay is yet available which can detect and identify these species simultaneously. to this end, we developed a reverse line blot (rlb) assay for simultaneous detection and identification of anaplasma and ehrlichia species in domestic ruminants and ticks. in a pcr the hypervariable v1 region of the 16s ribosomal rna (rrna) gene was amplified with a set of primers unique for members of the ge ...200212243899
development of resistance to nymphs of amblyomma cajennense ticks (acari:ixodidae) in dogs.ticks have long been regarded as constraints to humans and domestic animals, but hosts often develop resistance to ticks after repeated infestations. the purpose of this investigation was to study the possible acquisition of immunity in domestic dogs to nymphs of a. cajennense by determining the tick alimentary performance after successive controlled infestations. mean engorged weight of nymphs was not significantly different among the three infestations; molting rate from nymph to adult ticks, ...200212381587
hypersensitivity induced in dogs by nymphal extract of amblyomma cajennense ticks (acari:ixodidae).in general, hosts develop resistance to ticks after repeated infestations; nevertheless, several studies on naturally occurring host-tick interactions were unable to detect resistance of hosts to ticks even after repeated infestations. the purpose of this investigation was to study the type of cutaneous hypersensitivity to unfed nymphal extract of a. cajennense in dogs, which, unlike guinea pigs, do not develop resistance. a first, but no second, peak in skin reaction was observed, suggesting th ...200212381588
increasing risks of introduction of heartwater onto the american mainland associated with animal movements.opportunities to introduce heartwater onto the american mainland through animal movements include importation from africa of tick-infested reptiles and of subclinically infected wild ungulates and importation of livestock from islands in the caribbean infested with amblyomma variegatum ticks. measures to control importation of heartwater vectors on reptiles include importation bans of infested species, treatment of imported reptiles, and eradication of established infestations on the american ma ...200212381604
ticks associated with armadillo (euphractus sexcinctus) and anteater (myrmecophaga tridactyla) of emas national park, state of goias, brazil.this study was conducted in october 1998 and november 1999 in the emas national park (131,868 ha), a savanna-type cerrado region situated in the far south of goias state, brazil, near the geographic center of south america (15 degrees -23 degrees s; 45 degrees -55 degrees w). animals were captured with the aid of nets and anesthetized (15 mg/kg ketamine + 1 mg/kg xylasine) in order to collect ticks for identification and to establish laboratory colonies. they included giant anteaters (myrmecopha ...200212381607
control and eradication of chelonian tick infestations, with particular reference to vectors of heartwater.studies using the african tortoise tick (amblyomma marmoreum) and leopard tortoises (geochelone pardalis) demonstrated that cyfluthrin and permethrin were safe and efficacious acaricides for control of amblyomma ticks on tortoises. a protocol was developed that successfully eradicated an a. sparsum infestation from a tortoise breeding facility in florida. it involved treatment of all tortoises with a permethrin formulation, followed by treatment of the premises with a cyfluthrin formulation. sen ...200212381608
eradication of the tropical bont tick in the caribbean: is the caribbean amblyomma program in a crisis?the progress and problems in the caribbean amblyomma program (cap) are reviewed since its inception in 1995. during 1998, there were funding and administrative management problems. usda resolved the acute funding crisis, and after three years of negotiation, the cap has now secured an additional euro 1.5 million from the european community. changes in administration in 1998 included the withdrawal of iica from the program, and the transition during the decentralization of administrative and fina ...200212381609
prevalence of ectoparasites in a population of feral cats from north central florida during the summer.ectoparasites are a common and important cause of skin disorders in cats. ectoparasites are capable of disease transmission and can cause life-threatening anemia in young or debilitated animals. the objective of this study was to determine the potential feline ectoparasites in domestic cats by using a cohort of feral cats from north central florida that have not received veterinary care and have no known exposure to insecticide application. a total of 200 feral cats were randomly selected for th ...200212383632
a new subfamily, bothriocrotoninae n. subfam., for the genus bothriocroton keirans, king & sharrad, 1994 status amend. (ixodida: ixodidae), and the synonymy of aponomma neumann, 1899 with amblyomma koch, 1844.evidence suggesting polyphyly of the traditionally recognised tick genus aponomma neumann, 1899 is summarized. continued recognition of this genus in its current concept leaves a polyphyletic genus aponomma and a paraphyletic genus amblyomma koch, 1844. to improve the correlation between our understanding of phylogenetic relationships in metastriate ticks and their classification, a few changes in classification are proposed. the members of the 'indigenous australian aponomma' group (sensu kaufm ...200212386418
lack of parthenogenesis by amblyomma cajennense (acari: ixodidae).some reproductive parameters of adult stages of amblyomma cajennense ticks were studied. the capacity of virgin females to reproduce by parthenogenesis was evaluated, during an experimental infestation, in absence of males, on a horse (equus cabalus). ticks were spread either completely free or in limited sites on the body of the animal. the engorged virgin females showed longer feeding periods and lighter body weights than those that had been fertilized. some of these unmated females produced s ...200212386707
biology of amblyomma aureolatum (pallas, 1772) (acari: ixodidae) on some laboratory hosts in brazil.the ixodid amblyomma aureolatum is suspected to play a role in the epidemiology of wild life-cycle hemoparasites, which frequently infect dogs in rural and hunting areas in brazil. little is known about its bionomics. the objective of the present study was to evaluate some bionomic aspects of a. aureolatum ticks in brazil. one engorged female, collected from a dog (canis familiaris) in são sebastião das aguas claras, state of minas gerais, was used to establish a colony in the laboratory. subseq ...200212386709
avgi, an index of genes transcribed in the salivary glands of the ixodid tick amblyomma variegatum.random clones from a cdna library made from mrna purified from dissected salivary glands of feeding female amblyomma variegatum ticks were subjected to single pass sequence analysis. a total of 3992 sequences with an average read length of 580 nucleotides have been used to construct a gene index called avgi that consists of 2109 non-redundant sequences. a provisional gene identity has been assigned to 39% of the database entries by sequence similarity searches against a non-redundant amino acid ...200212392910
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
identification of snare and cell trafficking regulatory proteins in the salivary glands of the lone star tick, amblyomma americanum (l.).prostaglandin e(2) (pge(2)) stimulates secretion of tick salivary gland proteins via a phosphoinositide signaling pathway and mobilization of intracellular ca(2+) (). highly conserved intracellular snare (soluble nsf attachment protein receptors) complex proteins are associated with the mechanism of protein secretion in vertebrate and invertebrate neuronal and non-neuronal cells. proteins in the salivary glands of partially fed female lone star ticks cross-react individually with antibodies to s ...200212429123
introduced ticks and tick-borne diseases: the threat and approaches to eradication.exotic tick species and tick-borne diseases are serious threats to live-stock, companion animals, and wildlife in the united states. recurring introductions of exotic tick species into the united states are a significant indicator of the degree of risk. successful tick-eradication campaigns, such as the national program that eradicated boophilus annulatus and b. microplus from the united states, the cattle fever tick eradication program of the us department of agriculture's veterinary services t ...200212442574
babesiosis and heartwater: threats without boundaries.suppose one of your clients from southern florida starts talking about cattle egrets while you are vaccinating her cat. it seems she found a nearly dead egret near the cattle pen a few days ago, picked it up, and noticed a number of what looked like small ticks on the legs. or, suppose you are called out to a small dairy in central texas to look at some cows that are feverish and anemic. the first animal you examine has a few brown ticks attached just under the tail. finally, perhaps you are loo ...200212442575
ticks (acari: ixodidae) associated with domestic dogs in franca region, são paulo, brazil.ticks on 140 domestic dogs from both urban and rural areas of franca region in são paulo state were identified with 102 dogs from urban areas and 38 from rural areas. of urban dogs, 27.5% were infested exclusively by rhipicephalus sanguineus ticks. of the rural dogs, 36.8% were infested with the following tick species: r. sanguineus, boophilus microplus, amblyomma ovale and a. cajennense. mixed infestations included a dog hosting a. cajennense and a. ovale and another with b. microplus and r. sa ...200112455880
characterization of protective antigens from the midgut of amblyomma variegatum ticks.separation of midgut membrane proteins from the tick, ambylomma variegatum, using a nonionic detergent (triton x-114), resulted in two protein fractions, namely det (detergent) and aq (aqueous). in immunoblotting analysis with polyclonal antibodies against these fractions, 4 proteins (mr approximately 27,000, 67,000, 86,000 and 95,000,) and 2 proteins (m, approximately 54,000 and 67,000) were detected in the det and aq fractions, respectively. three of the det fraction proteins mr approximately ...200212475080
life-cycle and host specificity of amblyomma tigrinum (acari: ixodidae) under laboratory conditions.biological data of three generations of amblyomma tigrinum in the laboratory are reported and the suitability of different host species for immature ticks are compared. grouping the three generations, infestations by both the larval and nymphal stages were performed on chickens (gallus gallus), wistar rats (rattus norvegicus), rabbits (orytolagus cuniculus), wild mice (calomys callosus), dogs (canis familiaris) and opossums (didelphis albiventris). only dogs were used for infestations by adult t ...200212475081
notes on parasitism by amblyomma humerale (acari: ixodidae) in the state of rondônia, western amazon, brazil.the tick amblyomma humerale koch is endemic to south america. all host records refer to the adult stage parasitizing tortoises, mostly yellow-footed tortoise, geochelone denticulata (l.), and red-footed tortoise, geochelone carbonaria (spix). the current study reports the presence of a. humerale in the state of rondônia, brazil. a total of 215 adult ticks (201 males, 14 females) was collected from six g denticulata in an indian reserve and nine geochelone sp. in rural monte negro county, giving ...200212495177
ixodid ticks on cattle belonging to small-scale farmers at 4 communal grazing areas in south africa.ixodid ticks were collected during the period september 1991 to august 1993 from cattle belonging to small-scale farmers utilising 4 communal grazing areas. three of these were in north west province and 1 in mpumalanga province, south africa. ten tick species were collected in north west province and 7 in mpumalanga. the adults of amblyomma hebraeum, rhipicephalus appendiculatus and rhipicephalus evertsi evertsi were most numerous in north west province, while in mpumalanga boophilus decoloratu ...200212515294
the prevalence of cowdria ruminantium in free-living adult amblyomma hebraeum collected at a communal grazing area and in 2 wildlife reserves in south order to detect the prevalence of cowdria ruminantium in the vector tick, amblyomma hebraeum, free-living, unfed adult ticks were collected with the aid of pheromone/co2 traps. ticks were collected at the rietgat communal grazing area, as well as in the southwestern kruger national park and in the songimvelo game reserve, all located in heartwater-endemic areas of south africa. the presence of c. ruminantium in these ticks was determined by polymerase chain reaction (pcr) analysis. ticks from ...200212515301
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
survey of ixodid tick species on domestic cats in japan.various species of ixodid ticks, attached to domestic cats in japan, were identified in spring (april to june) and autumn (september to november). in the spring, a total of 282 ticks, including 61 larvae, 70 nymphs, 127 females and 24 males were collected from 126 cats. of these, 264 were identified up to the species level. in the spring, haemaphysalis longicornis was the most frequently (39.7%, 50/126) found tick species on feline hosts, followed by ixodes ovatus (35.0%, 44/126), ixodes nippone ...200312531297
effect of deer exclusion by fencing on abundance of amblyomma americanum (acari: ixodidae) on fire island, new york, usa.the effects of deer exclusion on northern populations of lone star ticks, amblyomma americanum, were tested at the lighthouse tract, fire island, ny, usa, where densities of this species have increased recently. game fencing was erected to exclude deer from two sites of roughly one ha each, and populations of nymphal and adult a. americanum within were compared with those at control sites outside the exclosures. percent control of nymphs within vs. outside the exclosures averaged 48.4% in the fo ...200212546457
ticks (acari: ixodidae) on wild animals from the porto-primavera hydroelectric power station area, brazil.from june 2000 to june 2001, a total of 741 ticks were collected from 51 free-living wild animals captured at the porto-primavera hydroelectric power station area, located alongside an approximately 180 km course of the paran river, between the states of s o paulo and mato grosso do sul, comprising 9 species of 3 genera: ambly-omma (7 species), boophilus (1) and anocentor (1). a total of 421 immature amblyomma ticks were reared in laboratory until the adult stage, allowing identification of the ...200312563479
brazilian distribution of amblyomma varium koch, 1844 (acari: ixodidae), a common parasite of sloths (mammalia: xenarthra).amblyomma varium, commonly known in brazil as the "carrapato-gigante-da-pregui a" (sloth's giant tick) is found from southern central america to argentina. the present study adds information on the geographical distribution of a. varium, as well as on their hosts, based on material deposited in the main brazilian collections and on the available literature. eighty-two vials, containing 191 adult specimens, deposited in five acari collections between 1930 and 2001, were examined. these vials incl ...200312563481
ixodid ticks feeding on humans in south africa: with notes on preferred hosts, geographic distribution, seasonal occurrence and transmission of pathogens.this paper records the identities of 558 ixodid ticks feeding on 194 humans in south africa. these ticks belonged to 20 species in six genera and those most frequently encountered were amblyomma hebraeum, haemaphysalis leachi, hyalomma marginatum rufipes, hyalomma truncatum, rhipicephalus appendiculatus, rhipicephalus gertrudae and rhipicephalus simus. with the exception of the larvae of r. appendiculatus, the incidents of these ticks feeding on humans correlated well with their seasonal occurre ...200212593517
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
infection rates of amblyomma americanum and dermacentor variabilis by ehrlichia chaffeensis and ehrlichia ewingii in southwest missouri.both ehrlichia chaffeensis and ehrlichia ewingii are causative agents of human ehrlichiosis. both pathogens are transmitted to humans through the bite of an infected lone star tick (amblyomma americanum). since missouri has a high incidence of human monocytic ehrlichiosis, we investigated the prevalence of e. chaffeensis- and e. ewingii-infected a. americanum and dermacentor variabilis (american dog tick) ticks to help assess the relative risk for humans exposed to these vectors. we used a neste ...200212653298
identification of ctenocephalides felis fleas as a host of rickettsia felis, the agent of a spotted fever rickettsiosis in yucatań, search for the vector of the recently recognized spotted fever rickettsiosis of the yucatán, ticks, fleas, and lice were collected from vegetation and dogs in localities where seropositive persons had been found. the arthropods were examined by polymerase chain reaction (pcr) using primers for the genus-specific 17-kda protein gene followed by restriction fragment length polymorphism (rflp) and dna sequencing. eleven (20%) of 54 pools of ctenocephalides felis fleas contained dna of rickettsia ...200212653300
Displaying items 901 - 1000 of 1744