Publications

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[ectoparasites of small wild mammals from the adjacent areas of itapecuru river and environmental preservation area of inhamum, state of maranhão, brazil].during fauna studies, thirty-six wild mammals were collected in adjacent areas of itapecuru river and environmental preservation area of inhamum, state of maranhão, brazil. they were sampled for ectoparasites. the following specimens of the order rodentia and its respective ectoparasites were identified: akodon sp. (androlaelaps sp. and laelaps sp.), oecomys sp. (androlaelaps sp. and amblyomma cajennense), oligoryzomys sp. (androlaelaps sp. laelaps sp. and amblyomma sp.) e oryzomys megacephalus ...200820059819
[seasonal dynamics of the free-living stages of amblyomma cajennense and amblyomma dubitatum (acari: ixodidae) in an endemic area for spotted fever in coronel pacheco region, minas gerais state].a study on the population behavior of amblyomma cajennense and amblyomma dubitatum larvae, nymphs and adult free-living stages was carried out in coronel pacheco county, minas gerais state, brazil, a spotted feverendemic area from may 2006 to april 2008. larvae of amblyomma sp. were collected from pasture using the technique of drag sampling with flannelette during may to october 2006, starting from february 2007 to november 2007 and starting from march 2008. well-defined peaks of populations oc ...200820059821
neuropeptide discovery in ixodoidea: an in silico investigation using publicly accessible expressed sequence tags.the ixodoidea (ticks) are important vectors in the transmission of many human diseases; for example, the blacklegged tick ixodes scapularis is the major vector in the transmission of lyme disease, the most frequently reported vector-borne illness in the united states. the development of expressed sequence tags (ests) for ixodoidean cdna libraries, and their public deposition, has generated a rich resource for protein discovery in members of this taxon, thereby providing an opportunity for better ...200818495123
failure by engorged stages of the lone star tick, amblyomma americanum, to react to assembly pheromone, guanine and uric acid.response to tick-exposed filter paper discs (tick excreta) by fed and non-fed stages of the lone star tick amblyomma americanum (l.) (acari: ixodidae) was examined from larva to adult. by contrast with engorged stages, each non-fed stage exhibited a classic arrestment response to assembly pheromone, characterized by lack of movement, retraction of legs and formation of small groups; this response was seen in approximately 75% of ticks that made contact with pheromone-treated surfaces. less prono ...200818498612
twelve-hour duration testing of cream formulations of three repellents against amblyomma americanum.the repellent efficacies of the u.s. military repellent 33% n,n-diethyl-3-methylbenzamide (deet), 10% and 20% (1s, 2's) 2-methylpiperidinyl-3-cyclohexene-1-carboxamide (ss220) and 10% and 20% 1-methyl-propyl-2-(hydroxyethyl)-1-piperidinecarboxylate (bayrepel) cream formulations on human volunteers against the lone star tick amblyomma americanum (l.) were evaluated in a simulated forest floor environment over a 12-h testing period. at 2-h intervals, volunteers, with repellent applied in a 5-cm-wi ...200818498614
immunomodulatory arsenal of nymphal ticks.ticks have developed their own immunomodulatory mechanisms to inhibit the host inflammatory response. one of them involves the ability to subvert the cytokine network at the site of tick feeding by secreting cytokine binding molecules. most studies have focused on the immunomodulatory prowess of adult female ticks. here we describe anti-cytokine activity in salivary gland extracts (sges) prepared from 2-day-fed nymphs of dermacentor reticulatus fabricius, ixodes ricinus l., rhipicephalus appendi ...200818498617
a quantitative real-time pcr assay for ehrlichia ruminantium using pcs20.heartwater is a tick borne disease that affects ruminants and wild animals in africa south of the sahara. it is caused by ehrlichia ruminantium and transmitted by the tick amblyomma hebraeum. the protocols currently used to detect heartwater take several days to complete. here, we describe the development of a pcs20 quantitative real-time pcr taqman probe assay to detect e. ruminantium in livestock blood and ticks from the field. the assay is based on the conserved pcs20 gene region of e. rumina ...200818511221
identification of residual blood proteins in ticks by mass spectrometry proteomics.mass spectrometry-based proteomics of individual ticks demonstrated persistence of mammalian host blood components, including alpha- and beta-globin chains, histones, and mitochondrial enzymes, in ixodes scapularis and amblyomma americanum ticks for months after molting. residual host proteins may identify sources of infection for ticks.200818680654
morphological changes in the salivary glands of amblyomma cajennense females (acari: ixodidae) in different feeding stages on rabbits at first infestation.this study examined salivary glands of unfed, partially engorged, and engorged females of the tick amblyomma cajennense on rabbits at first infestation using histological and histochemical techniques. in type i acini, no significant changes were observed among the three feeding conditions. in type ii acini of unfed females, c1, c2, and c4 cells were described for the first time in this species. in a comparison among the three feeding conditions, an increase in this acinus was observed, due to th ...200818685958
the effects of vegetation density and habitat disturbance on the spatial distribution of ixodid ticks (acari: ixodidae).larval, nymphal, and adult amblyomma americanum (l.), and adult dermacentor variabilis (say) ticks were collected using timed dragging techniques, in an attempt to examine how different habitat variables affect models that describe the distribution of ticks in virginia, usa. tick count data were modeled using two approaches: (i) habitat and edge, and (ii) habitat, edge, vegetation density and levels of disturbance. nymphs and adults tended to follow a forest edge distribution when analysed by ha ...200818686272
intracellular infection of tick cell lines by the entomopathogenic fungus metarhizium anisopliae.several fungal pathogens are able to enter and persist within eukaryotic cells as part of their infectious life cycle. metarhizium anisopliae is a saprophytic entomopathogenic fungus virulent towards numerous tick species, including those within the genera ixodes and amblyomma. infection of the target organism by this fungus proceeds via several steps, including adhesion and penetration of the host cuticle, proliferation within tissues and the haemolymph, and eventual eruption through the host c ...200818524924
identification of two genes essential for sperm development in the male tick amblyomma hebraeum koch (acari: ixodidae).in most ticks of the family ixodidae, gonad maturation and spermatogenesis are stimulated by the taking of a blood meal. previous work from this laboratory identified 35 genes that are up-regulated by feeding [weiss, b.l., stepczynski, j.m., wong, p., kaufman, w.r., 2002. identification and characterization of genes differentially expressed in the testis/vas deferens of the fed male tick, amblyomma hebraeum. insect biochemistry and molecular biology 32, 785-793]. the functions of most of these g ...200818549958
[amblyomma tigrinum in the municipality of lages, sc, and biology observations under laboratory conditions].to study the biological features of amblyomma tigrinum, samples of engorged females collected from dogs in the city of lages, sc, brazil, were maintained in petri dishes into an incubator at 27+/-1 degrees c and 80+/-10% rh, for egg laying. for the development of the subsequent experimental phases, artificial infestations were performed in rabbits using the technique of the cotton bag glued to the ear's base. the mean period of hatch, feeding and larval molt were 11.67, 5.93 and 10.96 days, resp ...200818554444
ticks, amblyomma rotundatum (acari: ixodidae), on toads, chaunus schneideri and chaunus granulosus (anura: bufonidae), in northern argentina.this communication provides notes on 2 species of toads, chaunus schneideri and chaunus granulosus, infested with ixodid ticks, amblyomma rotundatum, from the provinces of corrientes and formosa in northern argentina. chaunus schneideri is a new amphibian host record for a. rotundatum, a species previously reported to parasitize other anurans and also reptiles. we examined 74 ticks on 5 toads. all ticks were a. rotundatum; all adults were females, and all developmental stages were randomly attac ...200818564766
amblyomma triste koch, 1844 (acari: ixodidae): hosts and seasonality of the vector of rickettsia parkeri in uruguay.amblyomma triste koch, 1844, the tick species most frequently involved in human bites in uruguay, has been implicated as a vector of human rickettsiosis. seasonal abundance of adult a. triste was examined by standard flagging at three sites where human tick bites and cases of the disease have been reported. adult tick activity occurred from august to february (end of winter to mid summer in the southern hemisphere) with a peak in spring. activity declined in step with decreasing temperatures and ...200818565680
reliminary survey of ticks (acari: ixodidae) on cattle in central equatoria state, southern sudan.in a preliminary survey conducted in 2005, the species composition and seasonality of ticks infesting cattle in central equatoria state, southern sudan was determined. three locations were selected (gumbo, khor rumla and nyaing) and surveyed every 3 months. two cattle herds in each of the three locations were visited four times during the study period. total body collections of ticks were made from each of five cattle (nilotic zebu breed) kept in six different herds. four tick genera and ten spe ...200818575063
distribution, hosts, 16s rdna sequences and phylogenetic position of the neotropical tick amblyomma parvum (acari: ixodidae).the hosts, distribution, intraspecific genetic variation and phylogenetic position of amblyomma parvum (acari: ixodidae) have recently been re-assessed. data on this tick's hosts and distribution were obtained not only from existing literature but also from unpublished records. sequences of the ticks' mitochondrial 16s ribosomal dna (rdna) were used to evaluate genetic variation among specimens of a. parvum from different localities in argentina and brazil, and to explore the phylogenetic relati ...200818577332
failure of ivermectin and eprinomectin to control amblyomma parvum in goats: characterization of acaricidal activity and drug pharmacokinetic disposition.the therapeutic efficacies of ivermectin (subcutaneous injection) and eprinomectin (topical treatment) given at two different dosage levels to goats naturally infested with amblyomma parvum were assessed. treatments included subcutaneous injection of ivermectin at 0.2 and 0.4mg/kg and extra-label pour-on administration of eprinomectin at 0.5 and 1mg/kgb.w. ivermectin and eprinomectin failed to control amblyomma parvum on goats. treatment with ivermectin resulted in a low number of engorged femal ...200818584966
aspects of the life cycle of amblyomma parvum (acari: ixodidae) under natural conditions.monthly samplings of the rodent galea musteloides (caviidae) were carried out from january 2005 to december 2006 in quilino, córdoba province, argentina, to determine the seasonal distribution of immature stages of amblyomma parvum. in the same locality, cattle and goats were also monthly examined to asses the seasonality of the females of this species. engorged ticks collected on their natural hosts were maintained in the laboratory at 25 degrees c and 83-86% relative humidity to study biologic ...200818620813
effect of 20-hydroxyecdysone and haemolymph on oogenesis in the ixodid tick amblyomma hebraeum.earlier work from our laboratory indicated that injection of 20-hydroxyecdysone (20e) into non-vitellogenic female amblyomma hebraeum ticks stimulates the synthesis of vitellogenin (vg), but not its uptake into oocytes [friesen, k., kaufman, w.r., 2004. effects of 20-hydroxyecdysone and other hormones on egg development, and identification of a vitellin-binding protein in the ovary of the tick, amblyomma hebraeum. journal of insect physiology 50, 519-529]. in contrast, thompson et al. [thompson, ...200818634796
ticks (acari: ixodidae) infesting wild birds in an atlantic forest area in the state of são paulo, brazil, with isolation of rickettsia from the tick amblyomma longirostre.during field work in nazaré paulista, state of são paulo, brazil, we found 13 (56.5%) of 23 birds (mostly passeriformes) to be infested by 28 larvae and 1 nymph of amblyomma spp. two larvae were reared to the adult stage, being taxonomically identified as amblyomma parkeri fonseca and aragio, whereas five larvae and one nymph were identified as amblyomma longirostre koch. all six a. longirostre specimens were shown to be infected by rickettsia, as demonstrated by polymerase chain reaction (pcr) ...200818714882
laboratory maintenance of ehrlichia chaffeensis and ehrlichia canis and recovery of organisms for molecular biology and proteomics studies.tick-borne illnesses are emerging as a major concern for human health in recent years. these include the human monocytic ehrlichiosis caused by the amblyomma americanum tick-transmitted bacterium, ehrlichia chaffeensis; human ewingii ehrlichiosis caused by ehrlichia ewingii (also transmitted by a. americanum ticks); and human granulocytic anaplasmosis caused by the ixodes scapularis tick-transmitted pathogen, anaplasma phagocytophilum. likewise, tick-borne rickettsial pathogens are also a major ...200818770537
rickettsia parkeri rickettsiosis and its clinical distinction from rocky mountain spotted fever.rickettsia parkeri rickettsiosis, a recently identified spotted fever transmitted by the gulf coast tick (amblyomma maculatum), was first described in 2004. we summarize the clinical and epidemiological features of 12 patients in the united states with confirmed or probable disease attributable to r. parkeri and comment on distinctions between r. parkeri rickettsiosis and other united states rickettsioses.200818808353
exotic grass invasion reduces survival of amblyomma americanum and dermacentor variabilis ticks (acari: ixodidae).exotic plants often invade areas of high human activity, such as along trails, roads, and forest edges, and in disturbed riparian areas. these same habitat types are also favored by ticks. this convergence suggests that habitat modifications caused by exotic plant invasions may mediate disease vector habitat quality, indirectly affecting human disease risk at the local spatial scale. we tested the hypothesis that experimental invasions of japanese stiltgrass, microstegium vimineum (trin.) a. cam ...200818826028
new epidemiological data on brazilian spotted fever in an endemic area of the state of são paulo, brazil.the present work evaluated rickettsial infection in dogs and their ticks in an area endemic for brazilian spotted fever (bsf) in the metropolitan area of são paulo, brazil, where the tick amblyomma aureolatum was presumed to be the vector of the disease. ticks were collected on dogs from 185 houses, encompassing single infestations by rhipicephalus sanguineus, amblyomma aureolatum, amblyomma longirostre, or amblyomma sp. in dogs from 60 (32.4%), 77 (41.6%), 2 (1.1%), and 25 (13.5%) houses, respe ...200818847319
molecular and biological characterization of the amblyomma americanum organic anion transporter polypeptide.the organic anion transporting polypeptides (oatps in rodents and other organism; oatps in human) are na(+)-independent transporters that shuttle a wide range of endogenous and xenobotic amphipathic compounds across plasma membranes. we previously discovered an amblyomma americanum tick (aam) oatp cdna among genes that were upregulated or induced in ticks that were stimulated to start feeding. in this study, we have characterized a 2860 bp full-length cdna that encode a 724 amino acid putative p ...200818931313
experimental infection of opossums didelphis aurita by rickettsia rickettsii and evaluation of the transmission of the infection to ticks amblyomma cajennense.the present study evaluated the infection of opossums (didelphis aurita) by rickettsia rickettsii and their role as amplifier hosts for horizontal transmission of r. rickettsii to amblyomma cajennense ticks. three groups of opossums were evaluated: on day 0, group 1 (g1) was inoculated intraperitoneally with r. rickettsii; group 2 (g2) was infested by r. rickettsii-infected ticks; and group 3 (g3) was the uninfected control group. opossum rectal temperature was measured daily. blood samples were ...200818945194
rickettsial spotted fever in capoeirão village, itabira, minas gerais, brazil.the present study investigated the infection by spotted fever rickettsia in an endemic area for brazilian spotted fever (bsf; caused by rickettsia rickettsii) in minas gerais state, brazil. human, canine and equine sera samples, and amblyomma cajennense adult ticks collected in a rural area of itabira city, minas gerais state were tested for rickettsial infection. through immunofluorescence assay (ifa) we demonstrated the presence of antibodies anti-r. rickettsii in 8.2%, 81.3% and 100% of the h ...200818949349
defining the immune response to ehrlichia species using murine models.pathogenic bacteria belonging to the family anaplasmataceae include species of the genera ehrlichia and anaplasma. ehrlichia chaffeensis, first known as the causative agent of human monocytic ehrlichiosis, also infects several vertebrate hosts including white-tailed deer, dogs, coyotes and goats. e. chaffeensis is transmitted from the bite of an infected hard tick, such as amblyomma americanum. e. chaffeensis and other tick-transmitted pathogens have adapted to both the tick and vertebrate host ...200819028013
comparative susceptibility of larval stages of amblyomma aureolatum, amblyomma cajennense, and rhipicephalus sanguineus to infection by rickettsia rickettsii.the current study compared the susceptibility of larval stages of amblyomma cajennense (f.), amblyomma aureolatum (pallas), and rhipicephalus sanguineus (latreille) to infection by a brazilian strain of rickettsia rickettsii. guinea pigs experimentally infected by r. rickettsii were simultaneously infested by larvae of the three tick species. recovered engorged larvae were allowed to molt to nymphs and held in an incubator at 23 degrees c and 85-90% rh. subsequent flat nymphs were tested for ric ...200819058642
amblyomma variegatum ticks and heartwater on three caribbean islands.amblyomma variegatum tick infestation, tick infection by ehrlichia ruminantium (er), and er genetic diversity were studied in the caribbean islands of guadeloupe, marie-galante, and antigua between 2003 and 2005. nested pcr for pcs20 was used to detect er, while er strains were characterized by sequencing or by restriction fragment length polymorphism (rflp) profiles of map-1 pcr products. in 2003 in guadeloupe, the prevalence of tick-infested herds was 35.6%. in marie-galante 79.1% of herds in ...200819120208
field collection and genetic classification of tick-borne rickettsiae and rickettsiae-like pathogens from south texas: coxiella burnetii isolated from field-collected amblyomma cajennense.we are reporting the first known isolation of the q-fever agent coxiella burnetii from field-collected cayenne ticks amblyomma cajennense in north america. q-fever affects a number of domestic ungulates where it can lead to abortion in sheep and goats. there is far less known about the disease's effects on wild species, primarily because of the tendency of the disease to self resolve and to provide long-term immunity to subsequent infections. the first recovery of c. burnetii in north america wa ...200819120212
cutaneous basophilia in the resistance of goats to amblyomma cajennense nymphs after repeated infestations.the acquisition of resistance in goats against amblyomma cajennense after repeated infestations and the role of inflammatory cells in this mechanism were investigated. ten naive goats aged 6 months were distributed into two groups: test (n= 5), infested thrice at 30-day intervals; and control (n= 5), infested once. nymphs (n= 115 per animal per infestation) were released inside alimentary chambers glued to the animal's dorsum and the following biological parameters were evaluated: yielding rate, ...200819120216
guinea pigs develop cutaneous basophilia after repeated infestations by nymphs of the tick amblyomma triste.this study investigated the development of resistance in guinea pigs to nymphs of amblyomma triste ticks after repeated infestations. guinea pigs were infested thrice, at 30-day intervals, with 30 nymphs of a. triste per animal per infestation. acquisition of resistance was evaluated by determining: nymph yielding rate, engorgement period, and weight. skin biopsies of tick bite sites were collected at 24, 48, and 96 h after tick attachment for inflammatory cell counts. engorged nymphs weighed 5. ...200819120217
effect of amblyomma cajennense ticks on the immune response of balb/c mice and horses.this work evaluated the effect of the amblyomma cajennense tick on the immune response of balb/c mice and on horse lymph node cell proliferation. we observed that mice do not develop resistance to nymphs of this tick species and that lymphocyte proliferation of this host is inhibited by tick saliva, nymphal extract, or infestations. horse lymph node cell proliferation is inhibited by tick saliva as well. mice lymphocytes under the effect of tick saliva, nymphal extract, or infestations display a ...200819120218
viral association with the elusive rickettsia of viper plague from ghana, west africa.we previously reported a rickettsial heartwater-like disease in vipers from ghana that resembled heartwater in its gross lesions, was apparently transmitted by ticks (aponomma and amblyomma), and responded clinically favorably to early treatment with tetracycline. cell culture showed consistent cytopathic effects in bovine endothelial cells, viper cells, and mouse cells, and inhibition of cytopathic effect by tetracycline in vitro. a type d retrovirus was observed in vacuoles in all infected cel ...200819120239
seasonal and spatial dynamics of ectoparasite infestation of a threatened reptile, the tuatara (sphenodon punctatus).the conservation of threatened vertebrate species and their threatened parasites requires an understanding of the factors influencing their distribution and dynamics. this is particularly important for species maintained in conservation reserves at high densities, where increased contact among hosts could lead to increased rates of parasitism. the tuatara (sphenodon punctatus) (reptilia: sphenodontia) is a threatened reptile that persists at high densities in forests (approximately 2700 tuatara/ ...200819120965
microbial communities and interactions in the lone star tick, amblyomma americanum.to quantify microbial composition and interactions, we identified prokaryotic communities in the lone star tick (amblyomma americanum) based on 16s rrna gene sequences and direct probing. the lone star tick is the vector of emerging diseases and host to additional symbionts of unknown activity, and is representative of other blood-sucking arthropods. we evaluated the potential for vertical (transovarial) transmission by molecular analysis of microbial symbionts from egg and larval clutches. dire ...200819378409
rickettsia parkeri in argentina.clinical reports of an eschar-associated rickettsiosis in the paraná river delta of argentina prompted an evaluation of amblyomma triste ticks in this region. when evaluated by pcr, 17 (7.6%) of 223 questing adult a. triste ticks, collected from 2 sites in the lower paraná river delta, contained dna of rickettsia parkeri.200819046514
molecular detection of ehrlichia chaffeensis in amblyomma parvum ticks, argentina. 200819046533
ixodid ticks infesting domestic goats in communal land areas of zimbabwe.the purpose of this study was to determine the species spectrum of ticks infesting goats owned by resource-limited farmers in the state-owned communal land areas of zimbabwe. ticks were collected from goats at a single locality within each of 5 communal land areas, and a total of 14 ixodid tick species was recovered. the most numerous tick was rhipicephalus evertsi evertsi, which was present in all areas at each sampling, and a rhipicephalus sp. (near r. punctatus), which was most abundant on go ...200819244819
artificial feeding of amblyomma cajennense (acari: ixodidae) fasting females through capillary tube technique.the present study aimed to adjust the artificial feeding technique through capillaries and to verify its influence over the biology of amblyomma cajennense females. five groups of 20 female ticks were formed. females were starved for 45 days and then fed with citrated bovine blood using capillary tubes in different periods of time. females were divided in five experimental groups with 20 individuals each and fed as follows: groups uninterruptedly fed for 12, 24, and 48 hours and groups fed 2 and ...200819245757
tick-borne ehrlichiosis infection in human beings.human monocytic ehrlichiosis is a tick-borne infectious disease transmitted by several tick species, especially amblyomma spp caused by ehrlichia chaffeensis. e. chaffeensis is an obligatory intracellular, tick-transmitted bacterium that is maintained in nature in a cycle involving at least one and perhaps several vertebrate reservoir hosts. two additional ehrlichia spp, anaplasma (formerly ehrlichia) phagocytophila (the agent of human granulocytic ehrlichiosis [hge]) and e. ewingii (a cause of ...200819248653
[characterization of ectoparasites on dogs in the nucleus of urban expansion of juiz de fora, minas gerais, brazil].the present work studied the characterization of ectoparasites on dogs in the nucleus of urban expansion of juiz de fora, minas gerais, brazil. the collections were conducted from july to september 2003, examining 101 dogs of no defined breed. the ectoparasites were collected through visual and tactile inspection of the animals' bodies, and were then placed in bottles with 70 degrees gl ethanol and identified under a stereomicroscope. specimens were clarified and mounted on slides for analysis u ...200819265575
[ticks of genus amblyomma (acari: ixodidae) and their relationship with hosts in endemic area for spotted fever in the state of são paulo].seven species of mammals and 36 of birds were investigated to determine the tick prevalence and intensity of infestation. the study was conducted at the esalq/usp in piracicaba municipality, state of são paulo. it was collected 52 mammals and 158 birds parasitized by 12,418 ticks. adult ticks (n= 7,343) were found on capybaras, while the immature were mainly collected on small mammals and birds. the main hosts for immatures in descending order were opossums (69.1%), capybara (24.4%) and black vu ...200819265580
ticks infesting amphibians and reptiles in pernambuco, northeastern brazil.ticks infesting amphibians and reptiles in the state of pernambuco are reviewed, based on the current literature and new collections recently carried out by the authors. to date, three tick species have been found on amphibians and reptiles in pernambuco. amblyomma fuscum appears to be exclusively associated with boa constrictor, its type host. amblyomma rotundatum has a relatively low host-specificity, being found on toads, snakes, and iguana. amblyomma dissimile has been found on a lizard and ...200819265581
a borreliacidal factor in amblyomma americanum saliva is associated with phospholipase a2 activity.previous work in our laboratory described the in vitro killing of borrelia burgdorferi when co-cultured with saliva from adult amblyomma americanum. borreliacidal activity was not evident using ixodes scapularis saliva. mixing trypsin with saliva eliminated the borreliacidal activity of a. americanum saliva, while incorporating a trypsin inhibitor restored all borreliacidal activity, indicating this factor was of protein or peptide origin. one-dimensional page indicated at least 7 major protein ...200919271281
transcriptome analysis of the salivary glands of the female tick amblyomma americanum (acari: ixodidae).ticks infest a wide range of hosts while bypassing their immune, inflammatory and haemostatic responses during their extended feeding, which may last for more than two weeks. here, we present a transcriptome analysis of 3868 expressed sequence tags (ests) from three cdna libraries generated from the salivary glands of adult female ambyomma americanum ticks at different stages of feeding. we applied a normalization step for one library, significantly decreasing the abundance of mitochondrial sequ ...200919320755
francisella-like endosymbiont dna and francisella tularensis virulence-related genes in brazilian ticks (acari: ixodidae).ticks are vectors of a variety of pathogens, including francisella tularensis. bacteria in the genus francisella have been identified mostly in the northern hemisphere and include tick endosymbionts. francisella has never been described in brazil, where amblyomma spp. ticks are known as the vector of many bacterial zoonotic pathogens. in the present work, we have identified bacterial dna sequences with identity to francisella genes in amblyomma dubitatum neumann dermacentor nitens (neumann), and ...200919351090
gastrointestinal parasites and ectoparasites of bradypus variegatus and choloepus hoffmanni sloths in captivity from costa rica.sloths may serve as host to a wide range of parasites. however, there is little information available on the types of parasites that affect costa rica's sloth population. during a 1-yr period, 65 specimens of costa rican sloth species (choloepus hoffmanni; n = 56) and bradypus variegates; n = 9) from a local zoo were sampled. fecal samples were evaluated using two different diagnostic techniques, sheather's flotation and sedimentation. concurrently, these sloths were examined for ectoparasites. ...200919368244
notes on populational dynamics of amblyomma ticks (acari: ixodidae) in brazil.previous populational dynamics data generated for amblyomma parvum aragão and amblyomma cajennense (fabricius) in argentina and southeastern brazil have indicated that these ticks complete 1 generation per yr, with larvae predominating in autumn, nymphs in winter, and adults mostly during spring and summer. the present study reports populational dynamics data for free-living amblyomma spp. ticks in northern brazil (amazon forest, latitude 10os), and for amblyomma spp. ticks collected on birds in ...200919256723
influence of prescribed burns on the abundance of amblyomma americanum (acari: ixodidae) in the missouri ozarks.the increasingly widespread use of prescribed burns to manage oak (quercus spp.)-hickory (carya spp.) forests in the missouri ozarks, usa, has considerable potential to alter the abundance of amblyomma americanum (l.) (acari: ixodidae), the lone star tick, an important vector of several emerging pathogens. in particular, responses of important tick hosts, primarily white-tailed deer (odocoileus virginianus), to fire management and the resultant changes in the distribution and abundance of a. ame ...200919769033
ticks (acari: ixodidae) infesting birds in an atlantic rain forest region of brazil.brazil has the third richest bird diversity of the world; however, there are few data concerning ticks (acari: ixodidae) parazitizing birds. the aim of the study was to report tick infestations on wild birds from an atlantic rain forest region of brazil. during 2 yr, ticks were collected from birds and from the environment in 12 forest sites. a total of 1,725 birds were captured representing 80 species from 24 families. in total, 223 (13%) birds were found infested by immature stages of amblyomm ...200919769058
sensitivity of host-seeking nymphal lone star ticks (acari: ixodidae) to immersion in heated water.host-seeking nymphal amblyomma americanum (l.) (acari: ixodidae) were placed into heated water, and their survival or their torpidity was recorded as a function of exposure time. exposures were determined that either kill the nymphs or affect their mobility. all nymphs died when exposed for a minute or more to a temperature > 51 degrees c. nearly all nymphs remained motionless for a period of time when exposed for 3 min to a temperature > 44 degrees c.200919769061
morphological description of amblyomma brasiliense aragão, 1908 (acari: ixodidae) larvae and nymphs.the immature stages of neotropical ticks are poorly known and in many cases have not been described. tis work presents a morphological description of amblyomma brasiliense larvae (f1) and a redescription of nymphs (f1). a. brasiliense is reported as one of the most aggressive ticks to humans in brazil. immature ticks obtained from a laboratory colony initiated from adult specimens collected in the parque estadual intervales (24 degrees 18 degrees s and 48 degrees 24' w), são paulo, brazil, were ...200919772770
ticks on domestic animals in pernambuco, northeastern brazil.the objective of this article was to discuss some aspects of ticks associated with domestic animals in the state of pernambuco, northeastern brazil, based on a literature review and present new data obtained from recent tick collections carried out in this northeastern brazilian state. from august 2007 to june 2008, 1,405 ticks were collected and five species were identified: amblyomma cajennense (fabricius, 1787), amblyomma ovale koch, 1844, dermacentor nitens neumann, 1897, rhipicephalus (boop ...200919772771
ectoparasite infestation on rural dogs in the municipality of são vicente férrer, pernambuco, northeastern brazil.this article presents the results of a study on ectoparasites infesting rural dogs in pernambuco, northeastern brazil. forty-one dogs from a rural community of pernambuco were examined and 70.7% were infested by ectoparasites. the prevalence rates of infestation by ticks, fleas, and lice were 58.5, 43.9 and 22%, respectively. of 24 dogs parasitized by ticks, 15 were exclusively infested by rhipicephalus sanguineus (latreille) (32 females, 66 males, 9 nymphs; prevalence, 48.8%; mean intensity, 5. ...200919772781
anaplasmosis and ehrlichiosis - maine, 2008.anaplasmosis and ehrlichiosis are rickettsial tickborne diseases that have had at least a twofold increase in prevalence in the united states since 2000. despite similar clinical presentations, the causative organisms are carried by different ticks with distinct geographic and ecologic associations. surveillance efforts are complicated by ambiguous terminology and serologic testing with antibody cross-reactivity. although anaplasmosis historically has been reported in maine, ehrlichiosis has bee ...200919779398
salivary gland degeneration and vitellogenesis in the ixodid tick amblyomma hebraeum: surpassing a critical weight is the prerequisite and detachment from the host is the trigger.the normal engorged body weight of female ixodid ticks (acari: ixodidae) is about 100x the unfed weight. virgin female amblyomma hebraeum normally do not feed beyond 10x the unfed weight. however, about 10-20% of a population of virgins will feed to perhaps 20x the unfed weight, but not much beyond that. in a. hebraeum, when females surpass about 10x the unfed weight, the following changes in physiology occur if they are removed from the host: (a) they will not reattach if given the opportunity, ...200919555693
rickettsial infection in amblyomma nodosum ticks (acari: ixodidae) from brazil.the rickettsial infections in 174 amblyomma nodosum found on passeriform birds in the atlantic forest, eastern brazil, have recently been evaluated. rickettsiae were successfully isolated from two ticks, using cultures of vero cells. both isolates were molecularly characterised, using the rickettsial genes glta and htra and, when possible, also ompa and ompb. portions of the glta and htra genes from one of the rickettsial isolates were found be closely match the corresponding genbank sequences f ...200919583912
babesia spp. infection in dogs from rural areas of são paulo state, brazil.the status of babesia spp. infection in dogs from rural areas of são paulo state, brazil was studied. for this, 150 animals were examined by blood smears and by pcr; the presence of tick infestation was also investigated. by the blood smear examination, 3 animals (2%) were detected positive and by pcr for babesia spp. 12 (8%) were positive, with bands visualized in 450 bp. rhipicephalus sanguineus or amblyomma spp. were found on 36 (24%) of the 150 dogs. amblyomma species found were a. cajennens ...200919602312
[occurrence of ticks (acari: ixodidae) in the municipality of goiatins, tocantins].due to a suspected human case of brazilian lyme-like disease in the city of goiatins, tocantins state, an epidemiological survey was carried out in eight counties in this region during september 2007 and february 2008, where 1,890 ticks were collected from domestic animals and from the environment. a total of eight tick species were identified: rhipicephalus sanguineus, rhipicephalus (boophilus) microplus, dermacentor nitens, amblyomma cajennense, amblyomma oblongoguttatum, amblyomma ovale, ambl ...200919602318
noncompetitive inhibitor of thrombin. 200919644995
detection and identification of rickettsial agents in ticks from domestic mammals in eastern panama.several outbreaks of rocky mountain spotted fever have occurred in recent years in colombian communities close to the border with panama. however, little is known about rickettsiae and rickettsial diseases in eastern panamanian provinces, the darien province and the kuna yala, located north of the endemic area in colombia. in 2007, 289 ticks were collected in several towns from dogs, horses, mules, cows, and pigs. dna was extracted from 124 dermacentor nitens, 64 rhipicephalus sanguineus, 43 amb ...200919645289
evidence for the presence of francisella and spotted fever group rickettsia dna in the tick amblyomma fimbriatum (acari: ixodidae), northern territory, australia.ticks (n = 252) were collected from five wild-caught reptile species during routine trapping in the djukbinj national park and fogg dam reserve, northern territory, australia. pooling of ticks (one to four ticks per pool), according to sex or host animal, resulted in 187 samples used for screening for the presence of rickettsia species via molecular methods. rickettsia dna was detected via the amplification of the glta, ompa, and ompb genes in 57 (34%) of the 187 tick samples, all of which conta ...200919645299
new approaches to detection and identification of rickettsia africae and ehrlichia ruminantium in amblyomma variegatum (acari: ixodidae) ticks from the caribbean.imported from africa in the 1700s and despite frequent modern eradication efforts, amblyomma variegatum (f.) spread through the caribbean by cattle transport, small ruminants, and migrating birds. a. variegatum is a vector for rickettsia africae, the causative agent of african tick bite fever, and ehrlichia ruminantium, the causative agent of heartwater. we examined 95 a. variegatum and six rhipicephalus (boophilus) microplus (canestrini) collected from cattle at an abattoir in antigua. engorged ...200919645301
community-based prevention of lyme disease and other tick-borne diseases through topical application of acaricide to white-tailed deer: background and rationale.this series of articles describes the first large-scale experiment designed to explore the efficacy of reducing the risk of tick-borne disease in highly endemic communities of the northeastern and mid-atlantic united states through deployment of a self-application device that treats white-tailed deer with acaricide to prevent feeding by adult ixodes scapularis ticks and all stages of amblyomma americanum ticks where both species occur. the results of the multicenter study are reported in the acc ...200919650729
effectiveness of the 4-poster passive topical treatment device in the control of ixodes scapularis and amblyomma americanum (acari: ixodidae) in new jersey.twenty-five "4-poster" feeders were placed throughout a 5.2 km(2) study area within a secured military facility situated in a hyperendemic area for lyme disease in central monmouth county, new jersey. calculated levels of control, relative to untreated areas, peaked at 82.7%, 77.3%, and 94.2% for of host-seeking ixodes scapularis say larvae, nymphs, and adults, respectively, within 5 years of deployment. control of host-seeking amblyomma americanum (l.) peaked at 99.2%, 89.5%, and 96.9% for larv ...200919650733
the impact of 4-poster deer self-treatment devices at three locations in maryland.from 1998-2002 twenty-five deer self-treatment devices (4-posters), using 2% amitraz, were operated at three locations in maryland to determine their effectiveness in controlling blacklegged ticks, ixodes scapularis say, and lone star ticks, amblyomma americanum (l.). each treatment site was approximately 518 ha and paired with a similar site lacking 4-posters. locations varied in deer density, tick abundance, and land use. flagging for host-seeking ticks showed declines in tick populations at a ...200919650735
sustained control of gibson island, maryland, populations of ixodes scapularis and amblyomma americanum (acari: ixodidae) by community-administered 4-poster deer self-treatment bait stations.in 1998, twenty-five 4-poster deer treatment bait stations were deployed on gibson island (gi), maryland, as part of the u.s. department of agriculture (usda) northeast area-wide tick control project. treatments concluded in june 2002, having achieved 80% and 99.5% control of blacklegged ticks, ixodes scapularis, and lone star ticks, amblyomma americanum, respectively. no area-wide tick control was attempted again on the island until 2003, when 15 dandux-manufactured 4-posters were purchased by ...200919650736
the united states department of agriculture's northeast area-wide tick control project: summary and conclusions.from 1997 to 2002, the u.s. department of agriculture's northeast area-wide tick control project used acaricide-treated 4-poster deer treatment bait stations in five eastern states to control ticks feeding on white-tailed deer. the objectives of this host-targeted technology were to reduce free-living blacklegged (ixodes scapularis say) and lone star (amblyomma americanum [l.]) tick populations and thereby to reduce the risk of tick-borne disease. during 2002 to 2004, treatments were suspended, ...200919650739
cloning and characterization of rhipicephalus appendiculatus voraxinalpha and its effect as anti-tick vaccine.male tick-derived voraxinalpha and voraxinbeta, a pair of testicular proteins, are transferred to female via copulation to stimulate female blood feeding in the tick amblyomma hebraeum (a. hebraeum). immunized animals with recombinant (r-)voraxinalpha and voraxinbeta have been shown as highly resistant to the tick infestation. in this study, we describe the cloning and characterization of voraxinalpha homologue from the tick rhipicephalus appendiculatus (r. appendiculatus), the major vector for ...200919665610
current management of human granulocytic anaplasmosis, human monocytic ehrlichiosis and ehrlichia ewingii ehrlichiosis.anaplasma phagocytophilum, ehrlichia chaffeensis and ehrlichia ewingii are emerging tick-borne pathogens and are the causative agents of human granulocytic anaplasmosis, human monocytic ehrlichiosis and e. ewingii ehrlichiosis, respectively. collectively, these are referred to as human ehrlichioses. these obligate intracellular bacterial pathogens of the family anaplasmataceae are transmitted by ixodes spp. or amblyomma americanum ticks and infect peripherally circulating leukocytes to cause inf ...200919681699
[survey of rickettsia spp in the ticks amblyomma cajennense and amblyomma dubitatum in the state of são paulo].the presence of rickettsial infection was surveyed in 3,545 amblyomma cajennense ticks and 2,666 amblyomma dubitatum ticks. using the hemolymph test, polymerase chain reaction and isolation of rickettsia in cell cultures, all of the amblyomma cajennense were negative, whereas 634 (23.8%) of the amblyomma dubitatum ticks were shown to be infected with rickettsia bellii.200919684990
ehrlichia chaffeensis infections in drosophila melanogaster.ehrlichia chaffeensis is an obligate, intracellular bacterium, transmitted by the tick amblyomma americanum, and is the causative agent of human monocytic ehrlichiosis infections. we previously demonstrated that e. chaffeensis is capable of growing in drosophila s2 cells. therefore, we tested the hypothesis that e. chaffeensis can infect adult drosophila melanogaster. adult drosophila organisms were experimentally challenged with intra-abdominal injections of bacteria. ehrlichia-infected flies s ...200919687202
role of the lone star tick, amblyomma americanum (l.), in human and animal diseases.we reviewed scientific literature pertaining to known and putative disease agents associated with the lone star tick, amblyomma americanum. reports in the literature concerning the role of the lone star tick in the transmission of pathogens of human and animal diseases have sometimes been unclear and even contradictory. this overview has indicated that a. americanum is involved in the ecology of several disease agents of humans and other animals, and the role of this tick as a vector of these di ...200919054615
a redescription of haemogregarina fitzsimonsi dias, 1953 and some comments on haemogregarina parvula dias, 1953 (adeleorina: haemogregarinidae) from southern african tortoises (cryptodira: testudinidae), with new host data and distribution records.blood films were examined from 154 wild and captive tortoises from four provinces of south africa, including gauteng, kwazulu-natal, north west and western cape. the five species ofchelonians studied were chersina angulata (schweigger), kinixys belliana belliana (gray), k. lobatsiana power, k. natalensis hewitt, and stigmochelys pardalis (bell). two species of haemogregarines, previously reported from mozambique, were identified in blood films, namely haemogregarina fitzsimonsi dias, 1953 and ha ...200919827360
seasonal distribution of larvae and nymphs of amblyomma tigrinum koch, 1844 (acari: ixodidae).the seasonality of immature stages of amblyomma tigrinum was studied in an area of the chaco phytogeographical province in córdoba, argentina by monthly collection of larvae from ground feeding birds and sigmodontinae rodents, and nymphs from caviidae rodents from may 2005 to april 2007. an apparent peak of abundance was found from december to may but differences with other months of the year were not significant (p>0.05). these and previous results suggest that the parasitic stages of a. trigri ...200919833442
alternate pathway of infection with hepatozoon americanum and the epidemiologic importance of predation.the range of american canine hepatozoonosis (ach) is expanding from the southern usa northward. transmission of hepatozoon americanum occurs by ingestion of infected gulf coast ticks, amblyomma maculatum. the source of the protozoan for the tick remains undetermined; infected dogs are unusual hosts for the tick.200919709355
development of the immature stages of amblyomma lepidum (acari: ixodidae) under field conditions.according to this study, the effect of seasonality on the development of larvae and nymphs of amblyomma lepidum was highly significant (p< or =0.001). the moulting of larvae was only possible in the rainy season, where means of 76.8 and 73.1% were recorded in the first and the second year, respectively. nymphs, in the same period, achieved 68.8 and 71.8% moult. in winter, only 11.8 and 12.2% of nymphs succeeded to moult in the first and the second year, respectively. males outnumbered females, b ...200919709816
detection of theileria parva antibodies in the african buffalo (syncerus caffer) in the livestock-wildlife interface areas of zambia.a serolocigical survey was conducted for the detection of theileria parva antibodies in 176 african buffaloes (syncerus caffer) sampled between 1996 and 2005 in livestock-wildlife interface areas of zambia. rhipicephalus appendiculatus, rhipicephalus species, and amblyomma variegatum were the most abundant tick species identified on buffaloes. t. parva sero-positives were reported in buffaloes sampled from game management areas at mlanga and nanzhila bordering the kafue national parks and in the ...200919733007
efficacy of a topical ectoparasiticide containing dinotefuran, pyriproxyfen, and permethrin against amblyomma americanum (lone star tick) and amblyomma maculatum (gulf coast tick) on dogs.amblyomma americanum (lone star tick) and amblyomma maculatum (gulf coast tick) are important disease vectors for both dogs and humans. this article describes two studies conducted to evaluate the efficacy of a new topical spot-on ectoparasiticide containing dinotefuran, permethrin, and pyriproxyfen (vectra 3d, summit vetpharm) against a. maculatum and a. americanum in dogs. dogs were treated on day 0 and infested on days -1, 7, 14, 21, and 28 with approximately 40 ticks each day. live tick coun ...200919742444
rickettsia parkeri in amblyomma americanum ticks, tennessee and georgia, usa.to determine the geographic distribution of the newly recognized human pathogen rickettsia parkeri, we looked for this organism in ticks from tennessee and georgia, usa. using pcr and sequence analysis, we identified r. parkeri in 2 amblyomma americanum ticks. this rickettsiosis may be underdiagnosed in the eastern united states.200919788817
pathogen prevalence and blood meal identification in amblyomma ticks as a means of reservoir host determination for ehrlichial pathogens. 200919793129
comparative efficacy of bioud to other commercially available arthropod repellents against the ticks amblyomma americanum and dermacentor variabilis on cotton cloth.bioud is an arthropod repellent that contains the active ingredient 2-undecanone originally derived from wild tomato plants. repellency of bioud was compared with five commercially available arthropod repellents against the ticks amblyomma americanum (l.) and dermacentor variabilis say in two-choice bioassays on treated versus untreated cotton cheesecloth. overall mean percentage repellency against both species was greatest for and did not differ significantly between bioud (7.75% 2-undecanone) ...200919815887
distribution of antibodies reactive to borrelia lonestari and borrelia burgdorferi in white-tailed deer (odocoileus virginianus) populations in the eastern united states.southern tick-associated rash illness is a lyme-like syndrome that occurs in the southern states. borrelia lonestari, which has been suggested as a possible causative agent of southern tick-associated rash illness, naturally infects white-tailed deer (wtd; odocoileus virginianus) and is transmitted by the lone star tick (amblyomma americanum). to better understand the prevalence and distribution of borrelia exposure among wtd, we tested wtd from 21 eastern states for antibodies reactive to b. lo ...200919874183
innovative approach for transcriptomic analysis of obligate intracellular pathogen: selective capture of transcribed sequences of ehrlichia ruminantium.whole genome transcriptomic analysis is a powerful approach to elucidate the molecular mechanisms controlling the pathogenesis of obligate intracellular bacteria. however, the major hurdle resides in the low quantity of prokaryotic mrnas extracted from host cells. our model ehrlichia ruminantium (er), the causative agent of heartwater, is transmitted by tick amblyomma variegatum. this bacterium affects wild and domestic ruminants and is present in sub-saharan africa and the caribbean islands. be ...200920034374
possible acquired resistance of dogs successively infested by amblyomma cajennense (fabricius, 1787) (acari: ixodidae) nymphs.the present study aimed to evaluate the occurrence of immune resistance in dogs successively infested with amblyomma cajennense nymphs. five animals were submitted to four consecutive infestations with a. cajennense nymphs, at fourteen-day intervals. for each infestation, 50 nymphs were used per animal and data on the parasitic and non-parasitic periods were recorded. the average recovering rate of engorged nymphs in the successive infestations were 52.0, 29.2, 9.6 and 12.8%, respectively, with ...200920040189
prevalence of equine piroplasmosis and its association with tick infestation in the state of são paulo, brazil.serum samples were collected from 582 horses from 40 stud farms in the state of são paulo and tick (acari: ixodidae) infestations were evaluated on them. serum samples were subjected to the complement fixation test (cft) and a competitive inhibition elisa (celisa) for babesia caballi and theileria equi. logistic regression analyses were performed to construct multivariate models that could explain the dependent variable (horses positive for b. caballi or t. equi) as a function of the independent ...200920040201
notes on population dynamics of amblyomma ticks (acari: ixodidae) in brazil.previous population dynamics data, generated for amblyomma parvum aragão and amblyomma cajennense (fabricius) in argentina and southeastern brazil, have indicated that these ticks complete 1 generation per year, with larvae predominating in autumn, nymphs in winter, and mostly adults during spring and summer. the present study reports population dynamics data for free-living amblyomma spp. ticks in northern brazil (amazon forest, latitude 10 degrees s, 63 degrees w), and for amblyomma spp. ticks ...200920050009
histopathology and ultrastructure features of the midgut of adult females of the tick amblyomma cajennense fabricius, 1787 (acari: ixodidae) in various feeding stages and submitted to three infestations.the digestive tube of the tick amblyomma cajennense is responsible for the digestion during feeding on the host. this study analyzed the midgut of unfed, partially engorged, and fully engorged fed females as well as three infestations in rabbits. in a. cajennense, the digestive tube is long and from the midgut, two pairs of diverticula ramify and lead to a blind end. in some midgut regions were observed for the first time in ticks, structures termed here "nodules." the midgut of unfed females po ...200919929171
ectoparasites (sucking lice, fleas and ticks) of small mammals in southeastern kenya.during 1998-2000, at least 14 species (n = 309) of small mammals were live-trapped and examined for ectoparasites in moist forests of the taita and shimba hills and drier savannah habitats of nguruman, southeastern kenya. ectoparasites were recorded from 11 species of mammals. five species of sucking lice [hoplopleura inexpectans johnson, h. intermedia kellogg & ferris, polyplax reclinata (nitzsch), p. waterstoni bedford and schizophthirus graphiuri ferris], six species of fleas (ctenophthalmus ...200919941604
whartonacarus floridensis sp. nov. (acari: trombiculidae), with a taxonomic review and the first record of whartonacarus chiggers in the continental united states.among several unusual species collected during surveillance of ectoparasites on wildlife hosts in the southeastern united states and caribbean region, the larvae of a new species of whartonacarus were encountered in 2003 on a cattle egret, bubulcus ibis (l.), in the florida keys. this is the first record for a member of whartonacarus in the continental united states. the mite is described and named as whartonacarus floridensis mertins, and the possible significance of this discovery with respect ...200919960669
effects of photoperiod on reproduction, nymphal developmental timing, and diapause in amblyomma maculatum (acari: ixodidae).female engorgement weight, oviposition, and molting times of larvae and nymphs of amblyomma maculatum koch (acari: ixodidae) were studied at various photoperiods under constant humidity and temperature in the laboratory. ticks were held at photoperiods of 0:24, 10:14, 12:12, or 14:10 (l:d) h from egg through unfed nymphal stage and then at either the same or a different regime from fed nymphs to adults. no significant effects were observed on oviposition, female engorgement weights, survival, or ...200919960673
influence of photoperiod and temperature on the larval behavioral diapause of amblyomma cajennense (acari: ixodidae).larval behavioral diapause was shown to be the major factor controlling the 1-yr generation pattern of amblyomma cajennense (f.) (acari: ixodidae) in brazil. during fieldwork, this behavior was shown to coincide with long daylength (>12 h) and high mean ground temperature (approximately =25 degrees c), which prevail during spring-summer in brazil. the current study evaluated biological parameters of engorged females, their eggs, and the resultant larvae inside plastic pots planted with the grass ...200919960674
strains of ehrlichia chaffeensis in southern indiana, kentucky, mississippi, and north carolina.rates of infection of amblyomma americanum (l.) by ehrlichia chaffeensis were compared in 100 ticks collected from sites in each of four states: indiana, north carolina, kentucky, and mississippi. the overall infection rates were similar among sites, ranging from 1 to 4%. because pathogenic differences may exist between e. chaffeensis strains, nested polymerase chain reaction (pcr) amplification of the variable-length pcr target (vlpt), and sequencing of the amplicons were performed to different ...200919960699
surveys for ectoparasites on wildlife associated with amblyomma variegatum (acari: ixodidae)-infested livestock in st. croix, u.s. virgin islands.surveys in 2001, 2005, and 2006 attempted to determine the role of wildlife in maintenance and dissemination of the tropical bont tick, amblyomma variegatum (f.) (acari: ixodidae), in st. croix, u.s. virgin islands. small mammals; birds; white-tailed deer, odocoileus virginianus (zimmermann); and feral cattle, bos taurus l., were examined at nine premises, in mountainous rain forest, and in surrounding areas in western st. croix, an area including and central to all known bont tick-infested prem ...200919960701
ticks and tick-borne pathogens and putative symbionts of black bears (ursus americanus floridanus) from georgia and florida.ticks were collected from 38 black bears (ursus americanus floridanus) from northwestern florida (n = 18) from 2003 to 2005 and southern georgia (n = 20) in 2006. five species (amblyomma americanum, a. maculatum, dermacentor variabilis, ixodes scapularis, and i. affinis) were collected from florida bears, and 4 species (a. americanum, a. maculatum, d. variabilis, i. scapularis) were collected from bears in georgia. ixodes scapularis was the most frequently collected tick, followed by d. variabil ...200919413369
new developments in canine hepatozoonosis in north america: a review.abstract : canine hepatozoonosis is caused by hepatozoon canis and hepatozoon americanum, apicomplexan parasites transmitted to dogs by ingestion of infectious stages. although the two agents are phylogenetically related, specific aspects, including characteristics of clinical disease and the natural history of the parasites themselves, differ between the two species. until recently, h. canis infections had not been clearly documented in north america, and autochthonous infection with h. america ...200919426444
ecology of amblyomma neumanni (acari: ixodidae).the life cycle of amblyomma neumanni was described studying the seasonal distribution of free-living stages and parasitic phases during two consecutive years. development periods of engorged ticks under different photoperiod conditions were recorded. larvae of a. neumanni have the peak of abundance in autumn. nymphs reach the peak in winter. females were collected on cattle from autumn to late spring. the seasonal distribution pattern of females showed a bimodal curve, with a peak in autumn and ...200919427299
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