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detection of ehrlichia chaffeensis in adult and nymphal amblyomma americanum (acari: ixodidae) ticks from long island, new york.the lone star tick, amblyomma americanum (l.), has increased in abundance in several regions of the northeastern united states, including areas of long island, ny. adult and nymphal stage a. americanum collected from several sites on long island were evaluated for infection with ehrlichia chaffeensis, the causative agent of human monocytic ehrlichiosis (hme), by using a nested polymerase chain reaction assay. fifty-nine (12.5%) of 473 adults and eight of 113 pools of five nymphs each (estimated ...200415605650
susceptibility of mice (mus musculus) to repeated infestation with amblyomma americanum (acari: ixodidae) ticks.laboratory mice, mus musculus (l.), balb/c strain, were assessed for their ability to develop resistance to repeated infestation by amblyomma americanum (l.) ticks. mice were infested five consecutive times with a. americanum nymphs. no decrease in tick viability was seen after five infestations, suggesting that balb/c mice do not develop immune-mediated resistance to a. americanum. in contrast, tick viability was significantly reduced in the second infestation of a new zealand white rabbit, a l ...200415605656
rickettsia parkeri: a newly recognized cause of spotted fever rickettsiosis in the united states.ticks, including many that bite humans, are hosts to several obligate intracellular bacteria in the spotted fever group (sfg) of the genus rickettsia. only rickettsia rickettsii, the agent of rocky mountain spotted fever, has been definitively associated with disease in humans in the united states. herein we describe disease in a human caused by rickettsia parkeri, an sfg rickettsia first identified >60 years ago in gulf coast ticks (amblyomma maculatum) collected from the southern united states ...200414999622
rickettsia species infecting amblyomma cooperi ticks from an area in the state of são paulo, brazil, where brazilian spotted fever is endemic.owing to the potential role of the tick amblyomma cooperi in the enzootic cycle of rickettsia rickettsii, the etiologic agent of brazilian spotted fever (bsf), this study evaluated infection by rickettsia species in a. cooperi ticks collected from an area in brazil where bsf is endemic. among a total of 40 a. cooperi adult ticks collected in an area of bsf endemicity in the state of são paulo, pcr analysis detected dna of rickettsia bellii in 16 ticks (40%), and 3 other ticks (7.5%) were positiv ...200414715737
two feeding-induced proteins from the male gonad trigger engorgement of the female tick amblyomma hebraeum.most female ixodid ticks, once mated, feed to repletion within 6-10 days. previous studies indicate that an engorgement factor (ef), passed to the female during copulation, may be the stimulus for engorgement. here, we show that extracts of the testis/vas deferens of fed (but not unfed) male amblyomma hebraeum contain ef bioactivity when injected into the hemocoel of feeding virgins. we have produced recombinant proteins (recproteins) from 28 feeding-induced genes in the male gonad and have iden ...200415069191
life cycle of amblyomma cooperi (acari: ixodidae) using capybaras (hydrochaeris hydrochaeris) as hosts.the life cycle of amblyomma cooperi was evaluated under laboratory conditions testing different host species. larval infestations were performed on chickens (gallus gallus) and capybaras (hydrochaeris hydrochaeris). nymphal infestations were performed on g. gallus, h. hydrochaeris, guinea pigs (cavia porcellus) and wild mice (calomys callosus). infestations by adult ticks were performed only on capybaras. all free-living stages were observed in darkness at 27 degrees c and rh 85%. capybaras were ...200415139274
first culture isolation of borrelia lonestari, putative agent of southern tick-associated rash illness.southern tick-associated rash illness (stari) is a lyme disease-like infection described in patients in the southeastern and south-central united states, where classic lyme disease is relatively rare. stari develops following the bite of a lone star tick (amblyomma americanum) and is thought to be caused by infection with an "uncultivable" spirochete tentatively named borrelia lonestari. in this study, wild lone star ticks collected from an area where b. lonestari is endemic were cocultured in a ...200415004069
how much pilocarpine contaminates pilocarpine-induced tick saliva?pilocarpine is often applied or injected into ticks to induce salivation, and the resulting saliva used to test for various pharmacological, biochemical and immunological activities. to measure the amount of pilocarpine in pilocarpine-induced tick saliva, an hplc-ms/ms method, based on capillary strong cation exchange chromatography online with an ion trap mass spectrometer, was used to measure pilocarpine in the pg to ng range. results indicate large concentrations of pilocarpine in ixodes scap ...200415009442
amblyomma americanum salivary glands: double-stranded rna-mediated gene silencing of synaptobrevin homologue and inhibition of pge2 stimulated protein secretion.protein secretion into the saliva from the tick salivary glands is due to exocytosis of vesicular membrane bound granular material regulated by snare complex proteins after salivary gland stimulation by pge2 [insect biochem. mol. biol. 32 (2002) 1711]. proteins associated with vesicles (v-snares) are essential components of the exocytotic process. synaptobrevin is a key v-snare in all secreting cells studied to date. a vesicle-associated synaptobrevin cdna fragment homologue from the salivary gl ...200415041024
ehrlichia ruminantium grows in cell lines from four ixodid tick genera.continuous cell lines from the ticks amblyomma variegatum, boophilus decoloratus, boophilus microplus, hyalomma anatolicum anatolicum, ixodes scapularis, ixodes ricinus and rhipicephalus appendiculatus were tested for ability to support growth of the rickettsial pathogen ehrlichia (previously cowdria) ruminantium. five e.ruminantium isolates, from west africa, south africa and the french west indies, were used. twelve tick cell lines were inoculated with e.ruminantium derived either from culture ...200415053931
occurrence of the gulf coast tick (acari: ixodidae) on wild and domestic mammals in north-central oklahoma.parasitic life stages of amblyomma maculatum koch were collected from domestic cattle and several species of wild mammals during a 3.5-yr study (may 1998-october 2001) in north-central oklahoma. adult ticks were the predominant life stage collected from cattle, white-tailed deer, coyotes, and raccoons, whereas only immature ticks were collected from cotton rats and white-footed mice. the prevalence of adult a. maculatum on white-tailed deer (n = 15) examined in june, july, and august 1998 was 80 ...200415061275
comparative activity of deet and ai3-37220 repellents against the ticks ixodes scapularis and amblyomma americanum (acari: ixodidae) in laboratory bioassays.the repellents n,n-diethyl-3-methylbenzamide (deet) and racemic 2-methylpiperidinyl-3-cyclohexene-1-carboxamide (ai3-37220) were evaluated using two different laboratory bioassays to determine their relative effectiveness against host-seeking nymphs of the blacklegged tick, ixodes scapularis say, and the lone star tick, amblyomma americanum (l.). in a petri dish bioassay, ticks were released within a ring of repellent on a horizontal filter paper disk. in the second bioassay, ticks were allowed ...200415061285
a monitoring study on the prevalence of dermatophilosis and parafilariosis in cattle in a smallholder semi-arid farming area in zimbabwe.the prevalences of dermatophilosis and parafilariosis were monitored for one year in cattle in sanyati, a semi-arid smallholder farming area in zimbabwe. the prevalence of dermatophilosis differed (p < 0.05) with season and among calves, cows, oxen and bulls. in bulls and cows, dermatophilosis lesions were localized mainly to the inguinal regions and between the front limbs. the prevalence and morbidity of dermatophilosis infection were significantly higher (p < 0.05) during the wet season than ...200415080537
species of ticks on camels and their seasonal population dynamics in eastern ethiopia.a study was conducted to identify the species of ticks found on camels (camelus dromedarius) and their seasonal population dynamics in eastern ethiopia. collection and identification of the ticks were undertaken at 2-month intervals from december 1997 to august 1999. on each occasion, all the visible adult ticks were collected from one side of the body of each of the same 17 camels. the most abundant species of ticks on the camels were rhipiephalus pulchellus (85.2%), hyalomma dromedarii (5.9%), ...200415080539
detection of pathogenic ehrlichia in ticks collected at acquisition sites of human ehrlichiosis in missouri.we collected 385 ticks from sites in missouri associated with human monocytic ehrlichiosis. using pcr, we detected e. chaffeensis or e. ewingii in 2 of 19 pools of adult amblyomma americanum, 0 of 32 pools of dermacentor variabilis, and 6 (18%) of 39 pools of unspeciated nymphal ticks from 3 of 6 sites associated with disease and one site not associated with disease. we also detected a variant of a. phagocytophila in one nymph pool.200415119113
the distribution and ecological 'preferences' of the tick amblyomma cajennense (acari: ixodidae), an ectoparasite of humans and other mammals in the americas.the distribution and ecological 'preferences', in the nearctic and neotropical regions, of the prominent, pathogen-carrying tick amblyomma cajennense (fabricius) were reviewed, on the basis of the published literature, satellite imagery, and the examination of several tick collections. the tick has been collected from the southern u.s.a. (texas and florida) to northern argentina, but is probably absent from uruguay and southern brazil (the few records of the species in these areas probably repre ...200415119974
glycerophosphodiester phosphodiesterase gene (glpq) of borrelia lonestari identified as a target for differentiating borrelia species associated with hard ticks (acari:ixodidae).a glpq ortholog was identified in dna from borrelia lonestari-positive amblyomma americanum, providing further evidence that b. lonestari is more closely related to the relapsing fever group spirochetes than to borreliae that cause lyme disease. this finding provides a basis for developing diagnostic assays to differentiate species of borrelia transmitted by hard ticks.200415131225
disease survey of free-ranging grey brocket deer (mazama gouazoubira) in the gran chaco, bolivia.samples from 17 free-ranging hunter-killed grey brocket deer (mazama gouazoubira) in the gran chaco, bolivia, were collected during june-august 1999. all 17 deer appeared to be in good condition at the time of death. gross necropsies were performed, serum was collected for serologic evaluation of selected infectious disease agents, and feces and ectoparasites were collected for evaluation of internal and external parasites. serologic tests were positive for antibodies against bovine respiratory ...200415137493
monthly dynamics of ticks (acari:ixodida) infesting n'dama cattle in the republic of guinea.the occurrence of ixodid ticks on n'dama cattle was studied in the republic of guinea between june 1994 and may 1995. monthly tick collections were performed on 80 animals from 14 villages located in dabola, kouroussa and dinguiraye prefectures. a total of 19,804 ticks was collected and classified using standard taxonomic keys. the following tick species were identified: amblyomma variegatum, hyalomma marginatum rufipes, hyalomma trunctum, hyalomma nitidum, rhipicephalus lunulatus, rhipicephalus ...200415139086
ehrlichia ruminantium seroprevalence in domestic ruminants in ghana; i. longitudinal survey in the greater accra region.serum samples collected monthly over a 34-month period from cattle, sheep and goats in the greater accra region of ghana were tested for antibodies to ehrlichia (previously cowdria) ruminantium, the causative agent of heartwater, by polyclonal competitive elisa (pc-elisa). maternal antibodies, detected in about half of animals followed from under 1 month old, declined to negative levels within 2-4 months. amblyomma variegatum tick vectors were present on livestock in rural areas throughout the y ...200415145496
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.partially fed adult female amblyomma hebraeum ticks were injected with 20-hydroxyecdysone (20e; up to 43 microg/g body weight (bw)), juvenile hormone iii (jh iii; up to 100 microg/g bw), bovine insulin (up to 2000 mu/g bw), or triiodothyronine (up to 200 ng/g bw) in an attempt to stimulate vitellogenesis. of these, only 20e stimulated synthesis and release of vitellogenin (vg). immunoblot analysis revealed that vg-synthesis occurred in the fat body. however, consistent with earlier observations ...200415183281
development of a novel self-medicating applicator for control of internal and external parasites of wild and domestic animals.four trials, three in the united states and one in south africa, were conducted to evaluate the potential value of a novel self-medicating applicator in the passive control of gastrointestinal nematodes in cattle and deer, and of files and ticks on cattle using oil-based treatments. the results of the trials demonstrated that this applicator is an effective and practical device for the passive treatment of both deer and cattle for trichostrongyle infections using the endectocide, moxidectin (cyd ...200415185574
a proteomics approach to characterizing tick salivary secretions.the saliva of ticks contains a complex mixture of bioactive molecules including proteins that modulate host responses ensuring successful feeding. the limited amount of saliva that can be obtained from ticks has hampered characterization of salivary proteins using traditional protein chemistry. recent improvements in two-dimensional gel electrophoresis, mass spectrometry, and bioinformatics provide new tools to characterize small amounts of protein. these methods were employed to characterize sa ...200415198089
cutaneous hypersensitivity induced in rabbits by extracts of the tick amblyomma cajennense (acari: ixodidae).the cutaneous hypersensitivity test was used to correlate host resistance to ticks and type of reactions elicited by aomblyomma cajennense (fabricius, 1787) tick extract in rabbits. rabbits were divided into 3 groups of 2 animals each: naive, pre-infested and control. cutaneous hypersensitivity was induced by intradermal inoculation of 25 microg extract in 0.03 ml of phosphate buffered saline (pbs) in rabbit ears. control rabbits were inoculated with pbs only. the ear thickness was measured with ...200415214693
cross-reactivity between antigens from amblyomma cajennense and a. hebraeum (acari: ixodidae).laboratory animals exposed to feeding ticks develop resistance which is reflected by a decline in tick engorgement weight, egg-laying by adults and reduced egg viability. serum antibodies from these hosts and their reaction with tick antigens have been detected by different methods, including precipitation techniques, immunofluorescent techniques, elisa and western blots. however, little is known about the effects of antibodies on ticks that engorge on resistant hosts, or which tissues of the ti ...200415214694
spotted fever group rickettsiae from ticks captured in sudan.ticks were collected from ruminants in various areas of sudan in 1998 and 2000. primer pairs of rickettsial citrate synthase gene (glta) and a spotted fever group (sfg) rickettsial 190-kda surface antigen gene (rompa), respectively, were used for identification. polymerase chain reaction (pcr)-positive products were used for dna sequencing. the glta gene was detected in 55% of the ticks examined (57/104). among the 57 ticks studied, 19 were positive for the rompa gene. thus, 18% of the ticks exa ...200415218219
human otoacariasis: a retrospective study from an area of sri lanka.intra-aural ticks were present in 870 (15.2%) of 5714 patients who reported with ear-related complaints to the ear, nose and throat ward at ratnapura hospital, sabaragamuwa province, sri lanka, from january 2000 to december 2001. a retrospective study of 383 of these otoacariasis cases showed that the majority (70.8%) of surgically-removed ticks were nymphal amblyomma integrum, together with nymphal and adult rhipicephalus haemaphysaloides, r. sanguineus, hyalomma brevipunctata, h. marginatum, a ...200415186938
ectoparasites of gray squirrels in two different habitats and screening of selected ectoparasites for bartonellae.gray squirrels, sciurus carolinensis, were livetrapped in 2 different habitat types, woodland (67 squirrels) and parkland (53 squirrels), in southeastern georgia. ectoparasites were recovered from anesthetized squirrels and compared between hosts from the 2 habitats. because of the absence of low vegetation in parkland habitats, it was hypothesized that the ectoparasite fauna, especially ticks and chiggers, would be more diverse on woodland squirrels. the results were generally in agreement with ...200415270090
ticks (acari: ixodidae) parasitizing wild carnivores in phu khieo wildlife sanctuary, thailand.ixodid ticks were collected and identified from 8 wild carnivore species in phu khieo wildlife sanctuary, northeastern thailand. six tick species belonging to 4 genera were recovered and identified from 132 individuals. these included amblyomma testudinarium (n = 36), haemaphysalis asiatica (n = 58), h. hystricis (n = 31), h. semermis (n = 3), rhipicephalus haemaphysaloides (n = 3), and ixodes granulatus (n = 1). leopard cats (prionailurus bengalensis) (n = 19) were infested with 4 tick species, ...200415270119
first record of immature stages of amblyomma tigrinum (acari: ixodidae) on wild birds in chile.for the first time, larvae and nymphs of amblyomma tigrinum ticks were found on three species of wild birds (zenaida auriculata, callipepla californica and nothoprocta perdicaria) in chile. a significant higher number of a. tigrinum was found on fledglings of z. auriculata and n. perdicaria than on adults of these species of birds. a significant higher number was also observed on n. perdicaria living in non-irrigated areas as compared with irrigated areas. infestation levels were 6.5, 6.3 and 10 ...200415285147
disease agents in amblyomma americanum from northeastern georgia.amblyomma americanum (lone star tick) is known or suspected to vector several organisms that are implicated as human pathogens, including ehrlichia chaffeensis, e. ewingii, and borrelia lonestari. these three agents have also been detected in white-tailed deer (odocoileus virginianus). because northeastern georgia has a high abundance of both lone star ticks and white-tailed deer, and one of these organisms, e. chaffeensis, is already known to be endemic in the area, we assayed individual adult ...200415311471
ehrlichia prevalence in amblyomma americanum, central texas. 200415338551
water relations in eggs of the lone star tick, amblyomma americanum, with experimental work on the capacity for water vapor absorption.this study shows that water stress is not countered in eggs of the lone star tick, amblyomma americanum (l.), using water vapor, and suggests involvement of liquid water as a developmental cue. eggs fail to maintain an equilibrium water content in subsaturated air, hence, gain not equal to loss, with net water losses occurring at relative humidities near saturation and these eggs exhibit a three-fold drop in viability, but not incubation period, as compared to eggs held in saturated air. amblyom ...200415347026
susceptibility of mosquito and tick cell lines to infection with various flaviviruses.the genus flavivirus consists of more than 70 virus species and subtypes, the majority of which are transmitted by mosquitoes or ticks, although some have no known vector (nkv). the ability of these viruses to infect cultured cells derived from mosquito or tick species offers a useful insight into the suitability of such vectors to harbour and replicate particular viruses. we undertook a comparative study of the susceptibility of mammalian vero cells, a clonal mosquito cell line (c6/36) and rece ...200415347394
detection of rickettsia africae in patients and ticks along the coastal region of cameroon.rickettsia africae was identified in seven (6%) of 118 patients with acute fevers of unknown etiology proven not to be malaria or typhoid fever from clinics along the coastal region of cameroon by polymerase chain reaction (pcr) amplification and sequencing of the citrate synthase (glta) and outer membrane protein a (ompa) genes of rickettsia. the majority (71%) of the patients were female. clinical manifestations included fever (100%), headache (71%), myalgia (71%), arthralgia (43%), pulmonary ...200415381820
rickettsiosis caused by rickettsia conorii in uruguay.the first three human cases of rickettsiosis caused by rickettsia conorii in montevideo, uruguay were described in 1990. all of them showed an initial papulosquamous lesion on the scalp from a canine tick bite (amblyomma triste). at the same time, fever and regional adenopathies were observed. serological diagnosis was made by the indirect igm immunofluorescent technique on glass smears of r. conorii (biomerieux laboratories, france). all patients had a benign disease course after been treated w ...200312860638
persistence of hepatozoon americanum (apicomplexa: adeleorina) in a naturally infected dog.to determine the persistence of hepatozoon americanum in a naturally infected dog, skeletal muscle biopsies were performed at approximately 6-mo intervals over a period of 5.5 yr, and the samples were examined for presence of lesions of american canine hepatozoonosis (ach). nymphal amblyomma maculatum (gulf coast tick) were allowed to feed to repletion on the dog periodically over the 5.5-yr period, and adult ticks were dissected and examined for presence of h. americanum oocysts. with 3 excepti ...200312880267
amblyomma aureolatum (pallas, 1772) and amblyomma ovale koch, 1844 (acari: ixodidae): hosts, distribution and 16s rdna sequences.dna sequences of amblyomma aureolatum (pallas, 1772) and amblyomma ovale koch, 1844 were obtained to determine genetic differences between these tick species. collections of these species are discussed in relation to distribution and hosts. seven ticks collections (four from brazil, one from argentina, one from uruguay and one from usa) house a total of 1272 a. aureolatum (224 males, 251 females, 223 nymphs and 574 larvae) and 1164 a. ovale (535 males, 556 females, 66 nymphs and 7 larvae). the l ...200312719142
exotic ticks introduced into the united states on imported reptiles from 1962 to 2001 and their potential roles in international dissemination of diseases.since 1962, a total of 29 species of exotic ticks have been introduced into the united states on imported reptiles, with 17 species from the genus amblyomma, 11 from the genus aponomma and one from the genus hyalomma. in the absence of measures to control introduction of these importations, some exotic tick species will develop breeding colonies and become established as indigenous species and some tickborne diseases may be introduced to wreak havoc among susceptible native populations. however, ...200312719143
effect of fast protein liquid chromatography fractionated salivary gland extracts from different ixodid tick species on interleukin-8 binding to its cell receptors.interleukin-8 plays a critical role in inflammatory processes. hence generation of molecules with anti-il-8 activity is likely to be important for successful feeding and for survival of the ticks. anti-il-8 activity was studied in saliva of three ixodid tick species--dermacentor reticulatus (fabricius, 1794), rhipicephalus appendiculatus neumann, 1901, and amblyomma variegatum (fabricius, 1794). the greatest activity was shown in saliva prepared from d. reticulatus. the activity was attributed t ...200312735728
[relative abundance of amblyomma spp. (acari: ixodidae) in bovines (bos taurus and b. indicus) from costa rica].the research describe the big amount of ticks of the amblyomma genus, found on bovines through monthly samplings carried out in ten farms in eight ecological zones (ez) of costa rica. ticks larger than 4 mm were picked up from the right side of the animals during the visit. the study compiled meteorological information for some farms located in the experiment, showing that the most fluctuant variable is rainfall. the most important amblyomma species found was a. cajennense. amblyomma nymphs were ...200315162737
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
amblyomma aureolatum and ixodes auritulus (acari: ixodidae) on birds in southern brazil, with notes on their ecology.between january 1999 and december 2000, 876 bird specimens were captured in three different ecological environments from the reinhard maack park, curitiba, state of paraná, southern brazil. a total of 142 birds (16.2%) were infested with amblyomma aureolatum (pallas 1772) (n=699) and/or ixodes auritulus neumann, 1904 (n=18) ticks. questing a. aureolatum nymphs (n=2) and adults (n=5) were also collected from the soil and the vegetation. none of the i. auritulus were collected off-host. we collect ...200314974693
larval behavioral diapause regulates life cycle of amblyomma cajennense (acari: ixodidae) in southeast brazil.previous studies have determined that amblyomma cajennense (f.) produces one generation per year in southeastern brazil. larvae predominate from april to july, nymphs from july to october, and adults from october to march. in the current study, we observed engorged females, their eggs, and respective larvae in the field. engorged females were released in grass plots under natural conditions, at monthly intervals, from october 2000 to march 2001. preoviposition periods lasted 1-2 wk, and mean egg ...200312693845
ecological analysis of acari recovered from coprolites from archaeological site of northeast brazil.coprolite samples of human and animal origin from the excavations performed at the archaeological site of furna do estrago, at brejo da madre de deus in the state of pernambuco, brazil and sent to the paleoparasitology laboratory at escola nacional de saúde pública-fiocruz, rio de janeiro, were analyzed for mites. after rehydratation and sedimentation of the coprolites, the alimentary contents and the sediments were examined and the mites collected and prepared in definitive whole mounts, using ...200312687780
survey of ticks collected in mississippi for rickettsia, ehrlichia, and borrelia species.from november 1999 through october 2000, we tested ticks collected from vegetation as well as from deer, dogs, and humans for spotted fever group (sfg) rickettsiae, ehrlichia chaffeensis, and borrelia spp. spirochetes. a total of 149 adult ticks representing four species was collected from 11 collection sites from southwestern to northern mississippi. amblyomma americanum was most commonly collected (n=68), followed by ixodes scapularis (n=53). the bird tick, ixodes brunneus (usually rare), was ...200314714667
evaluation of a prototype ehrlichia chaffeensis surveillance system using white-tailed deer (odocoileus virginianus) as natural sentinels.the natural history of ehrlichia chaffeensis, the causative agent of human monocytotropic ehrlichiosis, includes the lone star tick (lst, amblyomma americanum) as a vector and white-tailed deer (wtd; odocoileus virginianus) as both a natural reservoir of e. chaffeensis and a major host of lst. the goal of the current study was to implement and evaluate a prototype surveillance system to delineate the geographic distribution of e. chaffeensis using wtd as natural sentinels. to accomplish this goa ...200314733672
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
evaluation of transovarial transmission and transmissibility of ehrlichia chaffeensis (rickettsiales: anaplasmataceae) in amblyomma americanum (acari: ixodidae).it has long been assumed that ehrlichia chaffeensis (anderson, dawson & wilson), is not transmitted transovarially in the lone star tick vector amblyomma americanum (l.). to test this hypothesis, three beagle dogs, canis familiaris (l.) (carnivora: canidae), were subcutaneously infected with e. chaffeensis (arkansas strain). uninfected nymphal lone star ticks were placed on the infected dogs and allowed to feed to repletion. these nymphal ticks were allowed to molt, and five of five adult female ...200314765684
hosts and distribution of amblyomma auricularium (conil 1878) and amblyomma pseudoconcolor aragão, 1908 (acari: ixodidae).collections of amblyomma auricularium (conil 1878) and a. pseudoconcolor aragão, 1908 are discussed in relation to distribution and hosts. three tick collections (two from argentina and a third from the usa) house a total of 574 a. auricularium (307 males, 162 females, 73 nymphs and 32 larvae) and 179 a. pseudoconcolor (96 males, 74 females, 4 nymphs and 5 larvae). apart from an adult a. pseudoconcolor found on a bird, nothura maculosa temminck, 1815, all ticks were found on mammals. the great m ...200314580065
experimental infection of lone star ticks, amblyomma americanum (l.), with rickettsia parkeri and exposure of guinea pigs to the agent.the maculatum agent, rickettsia parkeri (a member of the spotted fever group rickettsiae), was inoculated into a colony of the lone star tick, amblyomma americanum, and followed for two tick generations. in addition, guinea pigs were exposed to the agent by direct injection and by feeding infected ticks on them. eighty (53%) of 150 nymphal a. americanum that were inoculated with suspensions of r. parkeri were positive by hemolymph test and fluorescent antibody test for rickettsial infection when ...200314596284
a cautionary note: survival of nymphs of two species of ticks (acari: ixodidae) among clothes laundered in an automatic washer.host-seeking ticks often remain on clothing of persons returning home from work or recreation in tick habitats, and can pose at least a temporary risk to people and pets in these homes. laundering clothing has been one of the recommendations to reduce tick exposure. host-seeking lone star tick, amblyomma americanum (l.), and blacklegged tick, ixodes scapularis say, nymphs confined in polyester mesh packets, were included with laundry in cold, warm, and hot wash cycles of an automatic clothes was ...200314596290
ticks (ixodida: ixodidae) parasitising humans in uruguay.during routine collections between november 1999 and november 2002, three species of tick (amblyomma tigrinum, amblyomma triste and rhipicephalus sanguineus) were found on humans in southern uruguay. the finding of r. sanguineus and a. triste on humans is of particular concern because these tick species may be involved in the transmission of the pathogens causing human rickettsioses, a type of disease already known to occur in uruguay.200314613636
comparing the detection of exposure to ehrlichia ruminantium infection on a heartwater-endemic farm by the pcs20 polymerase chain reaction assay and an indirect map1-b enzyme linked immunosorbent assay.detection of heartwater is not always easy especially because all the serological assays so far available either have poor sensitivity or specificity. the indirect map-1b elisa has been reported to be the most specific test for heartwater, although it does also detect antibodies to some closely related ehrlichial agents. this study was undertaken to compare two methods for the detection of heartwater infection caused by the ehrlichial agent ehrlichia (cowdria) ruminantium. fifteen cattle on a he ...200314621319
acquired resistance of horses to amblyomma cajennense (fabricius, 1787) ticks.acquired immunity of horses to larvae, nymphs and adults of the amblyomma cajennense tick was evaluated through three consecutive experimental infestations of tick-bite naïve hosts. data from these infestations were compared to those from field-sensitized horses and donkeys. it was observed that tick-bite naïve horses developed a low level of resistance after two infestations as shown by a significant decrease in larval yield and a tendency for lower engorged weight of nymphs during third infest ...200314637029
in vitro assays for repellents and deterrents for ticks: differing effects of products when tested with attractant or arrestment stimuli.most in vivo and in vitro tests with repellents or deterrents against ticks have not considered which sensory channel is being targeted. we have recorded the responses of two hard tick species (acari: ixodidae) in vitro to determine if such products can disrupt the perception of an attractant in a repellent assay or the perception of an arrestment stimulus in a deterrent assay. ethyl butylacetylaminopropionate (ebaap), n,n-diethyl-methyl-benzamide (deet), permethrin and indalone were chosen to t ...200314651650
evidence of borrelia lonestari dna in amblyomma americanum (acari: ixodidae) removed from humans.we used a nested pcr with borrelia flagellin gene (flab) primers and dna sequencing to determine if borrelia lonestari was present in amblyomma americanum ticks removed from military personnel and sent to the tick-borne disease laboratory of the u.s. army center for health promotion and preventive medicine. in our preliminary investigation, we detected borrelia sequences in 19 of 510 a. americanum adults and nymphs from ft. a. p. hill, va. during the 2001 tick season, the flab primers were used ...200314662940
meteorologically mediated diurnal questing of ixodes scapularis and amblyomma americanum (acari: ixodidae) nymphs.questing ixodes scapularis say and amblyomma americanum (l.) nymphs were collected in the field by drag sampling to determine whether ticks would be collected in greater numbers during certain times of the day and under certain ambient meteorological conditions. ticks were collected hourly for 16 h on 4 d and counts were contrasted with simultaneous measurements of ambient temperature and relative humidity, and with similar measurements made within the leaf litter. peak numbers of questing i. sc ...200314680102
transstadial transfer of west nile virus by three species of ixodid ticks (acari: ixodidae).larvae and/or nymphs of four species of ixodid ticks, ixodes scapularis say, amblyomma americanum (l.), dermacentor andersoni stiles, and dermacentor variabilis say, were fed to completion on laboratory hamsters or mice which had been inoculated with a west nile (wn) virus isolate from culex pipiens l. captured in connecticut usa. maximum titers in mice and hamsters were approximately 5 and two logs, respectively, lower than recorded (10 logs) in a naturally infected american crow, corvus brachy ...200314680122
dna evidence of borrelia lonestari in amblyomma americanum (acari: ixodidae) in southeast missouri.amblyomma americanum collected near lake wappapello, missouri, tested positive for borrelia lonestari using polymerase chain reaction and sequence analyses of b. lonestari 16s rrna and flagellin (flab) genes. twelve pools containing a total of 214 nymph or adult ticks contained evidence of infection with b. lonestari (minimum prevalence 5.6%). these data suggest that persons in southeast missouri are at risk for exposure to b. lonestari after a. americanum tick bite, a possible cause of erythema ...200314680133
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
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
ixodid tick species recovered from domestic dogs in japan.the species of ixodid ticks (acari: ixodidae) recovered from domestic dogs in japan between september to november 2000 and april to june 2001 were identified. a total of 4122 ticks, including 1624 larvae, 1200 nymphs, 1016 females and 282 males were removed from 1221 dogs during these periods. haemaphysalis longicornis (neumann) was the most frequently found (40.3% of dogs), followed by h. flava (neumann) (16.1% of dogs), rhipicephalus sanguineus (latreille) (4.8% of dogs) and ixodes ovatus (neu ...200312680923
detection of ehrlichia spp., anaplasma spp., rickettsia spp., and other eubacteria in ticks from the thai-myanmar border and vietnam.a total of 650 ticks, including 13 species from five genera, were collected from animals, from people, or by flagging of the vegetation at sites on the thai-myanmar border and in vietnam. they were tested by pcr to detect dna of bacteria of the order rickettsiales: three anaplasma spp. were detected in ticks collected in thailand, including (i) anaplasma sp. strain anda465, which was considered a genotype of anaplasma platys (formerly ehrlichia platys) and which was obtained from dermacentor aur ...200312682151
molecular evidence for novel tick-associated spotted fever group rickettsiae from thailand.ticks are of considerable medical and veterinary importance because they directly harm the host through their feeding action and indirectly through vectoring many bacterial pathogens. despite many ticks being known from thailand, very little is known about the bacteria they may harbor. we report here the results of a survey of tick-associated bacteria in thailand. a total of 334 individuals representing 14 species of ticks in five genera were collected from 10 locations in thailand and were exam ...200312693853
repellent efficacy of deet and kbr 3023 against amblyomma hebraeum (acari: ixodidae).the bont tick, amblyomma hebraeum koch, is the principal vector of rickettsia africae, the agent of african tick bite fever, in southern africa. in contrast to most other hard ticks, members of the genus amblyomma exhibit a characteristic attack host-seeking behavior. the efficacy of topically applied 20% lotions of deet (diethyl-3-methylbenzamide), the currently considered reference repellent substance, and kbr 3023, a recently developed piperidine compound, was evaluated against laboratory-rea ...200312693855
rna interference in ticks: a study using histamine binding protein dsrna in the female tick amblyomma americanum.rna interference (rnai), a gene silencing process, has been recently exploited to determine gene function by degrading specific mrnas in several eukaryotic organisms. we constructed a double stranded rna (dsrna) from a previously cloned putative amblyomma americanum histamine binding protein (hbp) to test the significance of using this methodology in the assessment of the function and importance of gene products in ectoparasitic ticks. the female salivary glands incubated in vitro with hbp dsrna ...200312752664
efficacy of two 65% permethrin spot-on formulations against induced infestations of ctenocephalides felis (insecta: siphonaptera) and amblyomma americanum (acari: ixodidae) on beagles.the efficacy of two formulations of a topically applied 65% permethrin spot-on (defend exspot treatment for dogs, schering-plough animal health) was evaluated against experimental infestations of the cat flea ctenocephalides felis and the lone star tick amblyomma americanum in dogs. eighteen dogs were randomly assigned to treatment with 65% permethrin in either diethylene glycol monomethyl ether (dgme; original formulation) or propylene glycol monomethyl ether (pgme) or to be untreated as a cont ...200312756635
spotted fever group rickettsiae in ticks from the masai mara region of kenya.we have identified for the first time rickettsia africae, and the ticks that harbored them, in kenya. a total of 5,325 ticks were collected from vegetation, livestock, and wild animals during two field trips to southwestern kenya. most were immature forms (85.2%) belonging to the genera amblyomma or rhipicephalus. the adults also included representatives from the genus boophilus. ticks were assessed for rickettsial dna by a polymerase chain reaction (pcr) using primers for the spotted fever grou ...200312812343
a method for extraction and analysis of high quality genomic dna from ixodid ticks.currently, no published methods describe the extraction of high molecular weight genomic dna from ixodid ticks (acari: ixodidae) and commonly used methods of extraction are not well adapted for use with members of this family. a method for extraction of minimally degraded genomic dna from ixodid ticks that can be completed in one or two days is described. the method produces dna which is of sufficient size (>24 kb) for use in southern analysis and which is readily digestible by restriction endon ...200312823841
seasonal fluctuation of parasitic infestation in donkeys (equus asinus) in oodi village, kgatleng district, botswana.during the period march to september 2000, a study was conducted in oodi village, kgatleng district, botswana, to investigate the seasonal fluctuation of internal, external and blood parasites of donkeys. twelve adult donkeys were randomly selected from a farmer with a herd of 15 donkeys. monthly visits were made to the farmer when the donkeys were examined for parasites. the only ectoparasites recovered from the donkeys were instars of various tick species. the most prevalent tick was rhipiceph ...200312836744
endocannabinoids and related fatty acid amides, and their regulation, in the salivary glands of the lone star tick.the salivary glands and saliva from the lone star tick amblyomma americanum (l.) were analyzed for the presence of the two endogenous agonists of cannabinoid receptors, n-arachidonoylethanolamine (anandamide) and 2-arachidonoylglycerol (2-ag), as well as of the anandamide congener, n-palmitoylethanolamine (pea), an anti-inflammatory and analgesic mediator that is inactive at cannabinoid receptors. two very sensitive mass-spectrometric techniques were used for this purpose. both 2-ag and pea, as ...200312842196
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
ehrlichiae and ehrlichial diseases in china.the various ticks collected from different areas of china were examined for the existence of ehrlichial agents by polymerase chain reaction (pcr) with genus- or species-specific primers designed on the basis of ehrlichial 16s rrna genes and sequence analyses. in southern china, e. chaffeensis was detected in amblyomma testudinarium ticks from infested cattle, haemaphysalis yeni ticks from hare, and ixodes ovatus ticks from muntiacus reevesi. e. canis was identified in rhipicephalus sanguineus ti ...200312860598
rickettsia honei: a spotted fever group rickettsia on three continents.rickettsia honei (also known as strain tt-118) has been detected on three continents. originally isolated in thailand in 1962 (and confirmed in 2001), it has also been detected on flinders island (australia) in 1993 and in texas (usa) in 1998. on each continent it has been associated with a different species of tick. the original isolate (thai tick typhus strain tt-118) was from a pool of larval ixodes and rhipicephalus ticks. later it was detected in i. granulatus from rattus rattus. its pathog ...200312860601
phylogenetic relationships among ehrlichia ruminantium isolates.ehrlichia ruminantium, the causative agent of heartwater, is a tick-borne pathogen infecting ruminants throughout sub-saharan africa and on some caribbean islands. the most reliable test for e. ruminantium is pcr-based, but this gives positive results in some areas free of clinical heartwater and of the known amblyomma spp. tick vectors. to investigate the molecular basis for this finding we have sequenced and carried out phylogenetic analysis of a range of genes from a number of e. ruminantium ...200312860707
selection assisted by a bola-dr/dq haplotype against susceptibility to bovine dermatophilosis.bovine dermatophilosis is a severe skin infection of tropical ruminants inducing a severe loss in productivity and a 15% mortality rate. this disease is caused by the actinomycete bacterium dermatophilus congolensis associated with the tick amblyomma variegatum. currently there are no prospects for a vaccine, and acaricide or antibiotic control is hampered by the development of chemoresistance. animal breeders have observed that dermatophilosis susceptibility seems to be determined genetically, ...200312927091
african tick bite fever.african tick bite fever is an acute febrile illness that is frequently accompanied by headache, prominent neck muscle myalgia, inoculation eschars, and regional lymphadenitis. the disease is caused by rickettsia africae, a recently identified spotted fever group rickettsia, which is transmitted by ungulate ticks of the amblyomma genus in rural sub-saharan africa and the french west indies. whereas reports on african tick bite fever in indigenous populations are scarce, the number of reported cas ...200312954562
detection by two enzyme-linked immunosorbent assays of antibodies to ehrlichia ruminantium in field sera collected from sheep and cattle in ghana.two serological tests for detection of antibodies to ehrlichia (previously cowdria) ruminantium, the causative agent of heartwater, were compared by using field sera collected from sheep and cattle as part of serosurveys in ghana. sera selected as either negative or positive by a new polyclonal competitive enzyme-linked immunosorbent assay (pc-elisa) were tested by the indirect map1-b elisa. cutoff values of 14 percent positivity (14 pp) for both ruminant species were obtained for the map1-b eli ...200312965927
ixodid ticks of angora and boer goats, grysbok, common duikers, kudus and scrub hares in valley bushveld in the eastern cape province, south africa.at monthly intervals from february 1983 to january 1984 two angora goats, two boer goats, one grysbok, raphicerus melanotis, one common duiker, sylvicapra grimmia, one greater kudu, tragelaphus strepsiceros, and four scrub hares, lepus saxatilis, were killed on a farm in valley bushveld in the eastern cape province, south africa and examined for ticks. seven ixodid tick species were collected, of which rhipicephalus glabroscutatum followed by amblyomma hebraeum and rhipicephalus oculatus were th ...200312967172
parasites of domestic and wild animals in south africa. xli. arthropod parasites of impalas, aepyceros melampus, in the kruger national park.ectoparasites were collected from impalas, aepyceros melampus, at four localities within the kruger national park, namely skukuza, in the biyamiti region, crocodile bridge and pafuri. animals were also examined at skukuza during a severe drought and at skukuza and pafuri towards the end of a second drought. parasite burdens were analysed in relation to locality, sex, age class, month and drought. the impalas were infested with 13 ixodid ticks species, including two that were identified only to g ...200312967174
american canine hepatozoonosis.american canine hepatozoonosis (ach) is a tick-borne disease that is spreading in the southeastern and south-central united states. characterized by marked leukocytosis and periosteal bone proliferation, ach is very debilitating and often fatal. dogs acquire infection by ingesting nymphal or adult gulf coast ticks (amblyomma maculatum) that, in a previous life stage, ingested the parasite in a blood meal taken from some vertebrate intermediate host. ach is caused by the apicomplexan hepatozoon a ...200314557294
life cycle and host specificity of amblyomma triste (acari: ixodidae) under laboratory conditions.we report biological data of two generations of amblyomma triste in laboratory and compared the suitability of different host species. infestations by larval and nymphal stages were performed on guinea pigs (cavia porcellus), chickens (gallus gallus), rats (rattus norvegicus), rabbits (oryctolagus cuniculus), wild mice (calomys callosus), dogs (canis familiaris) and capybaras (hydrochaeris hydrochaeris). infestations by adult ticks were performed on dogs, capybaras and rabbits. tick developmenta ...200314756395
attraction of amblyomma variegatum (ticks) to the attraction-aggregation-attachment-pheromone with or without carbon dioxide.the responses of adult amblyomma variegatum ticks released from various distances to different doses of the synthetic attraction-aggregation-attachment pheromone (aaap) (made up of orthonitrophenol, methyl salicylate and nonanoic acid in paraffin oil), dispensed from the center of circular field plots, were studied in the presence or absence of elevated levels of co2. up to 90% of the ticks released were attracted to the pheromone source in the presence of co2 within 3h. co2 alone was unattracti ...200314580064
modulation of human lymphocyte proliferation by salivary gland extracts of ixodid ticks (acari: ixodidae): effect of feeding stage and sex.ixodid ticks remain attached to their hosts for several days to weeks. during this extended feeding process new proteins involved in the modulation of host immune responses are expressed in tick salivary glands. in our study a stimulatory or inhibitory effect of salivary gland extracts (sge) of unfed and partially fed female ixodes ricinus (linnaeus, 1758), female and male amblyomma variegatum (fabricius, 1794) and rhipicephalus appendiculatus neumann, 1901 ticks on human lymphocyte proliferatio ...200314971600
a survey for spotted fever group rickettsiae and ehrlichiae in amblyomma variegatum from st. kitts and nevis.eighty-nine amblyomma variegatum ticks were collected from the islands of st. kitts and nevis in the caribbean and preserved in 70% ethanol or local rum. after being washed in sterile water, their dna was extracted and analyzed by a polymerase chain reaction (pcr) for dna of spotted fever group rickettsiae and ehrlichiae. none of the tested ticks was positive in a pcr assay using the primers 16s ehrd and 16s ehrr for the 16s rrna gene of ehrlichia spp.. forty-one percent of the a. variegatum (36 ...200312932098
ticks (acari: ixodidae) on wild marsh-deer (blastocerus dichotomus) from southeast brazil: infestations before and after habitat loss.the lake from porto-primavera hydroelectric power station inundated an area of 2,200 km2 at the border of são paulo and mato-grosso do sul states, brazil. infestations by ticks were evaluated on 135 marsh deer, blastocerus dichotomus (illiger), captured before and after inundation. ticks were collected for identification, and infestation level of animals was assessed by scoring. deer were divided into four groups according to capture location and temporal relation to the inundation. groups 1, 2, ...200312943103
climate change decreases habitat suitability for some tick species (acari: ixodidae) in south africa.models predicting current habitat availability for four prominent tick species in africa (boophilus decoloratus, amblyomma hebraeum, rhipicephalus appendiculatus and hyalomma truncatum) were constructed using remotely sensed information about abiotic variables and a point-to-point similarity metric. year-to-year variations in the forecasted habitat suitability over the period 1983-2000 show a clear decrease in habitat availability, which is attributed primarily to increasing temperature in the r ...200312967169
american canine hepatozoonosis.american canine hepatozoonosis is an emerging, tick-transmitted infection of domestic dogs caused by a recently recognized species of apicomplexan parasite, hepatozoon americanum. the known definitive host of the protozoan is the gulf coast tick, amblyomma maculatum. presently recognized intermediate hosts include the domestic dog and the coyote, canis latrans. laboratory-reared larval or nymphal a. maculatum can be infected readily by feeding to repletion on a parasitemic intermediate host; spo ...200312885206
american canine hepatozoonosis.hepatozoon americanum infection is an emerging tickborne disease in the southern united states. this organism causes a very different and much more severe disease than does hepatozoon canis, the etiologic agent of canine hepatozoonosis in the rest of the world. h americanum is transmitted through ingestion of the definitive host, amblyomma maculatum (the gulf coast tick). clinical signs of american canine hepatozoonosis tend to wax and wane over time and may include lameness, weakness, pain, mus ...200312910749
seasonal dynamics of the cayenne tick, amblyomma cajennense on horses in brazil.the population dynamics of all stages of the cayenne tick, amblyomma cajennense (fabricius) (acari: ixodidae) on horses was evaluated over a period of 2 years in the district of pedro leopoldo, state of minas gerais, brazil. every 14 days, the left side of 20 horses was brushed for collection of immature stages; counts of adults were also undertaken. infestation by larvae was detected from april to august, whereas nymphs were observed from june to october. infestation by adults was detected thro ...200314651655
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
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
studies on seasonal dynamics of ticks of ogaden cattle and individual variation in resistance to ticks in eastern ethiopia.in 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
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