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biology of amblyomma aureolatum (pallas, 1772) (acari: ixodidae) on some laboratory hosts in brazil.the ixodid amblyomma aureolatum is suspected to play a role in the epidemiology of wild life-cycle hemoparasites, which frequently infect dogs in rural and hunting areas in brazil. little is known about its bionomics. the objective of the present study was to evaluate some bionomic aspects of a. aureolatum ticks in brazil. one engorged female, collected from a dog (canis familiaris) in são sebastião das aguas claras, state of minas gerais, was used to establish a colony in the laboratory. subseq ...200212386709
the sex ratio of amblyomma cajennense (acari: ixodidae) with notes on the male feeding period in the laboratory.to evaluate the sex ratio of field collected nymphal amblyomma cajennense ticks, we collected 5326 engorged nymphs from naturally infested horses in pirassununga county and allowed them to molt to adults in the laboratory. they yielded a sex ratio of 1:1.83 (m:f). three and two engorged females were collected from horses pastured at pirassununga county and from tapirs pastured in sorocaba county, respectively. these females were allowed to oviposit and their progeny were reared until the adult s ...200211879968
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
amblyomma geochelone, a new species of tick (acari: ixodidae) from the madagascan ploughshare tortoise.the male and female of amblyomma geochelone n. sp. are described and illustrated by both scanning electron micrographs and line drawings. specimens of this new tick species were recovered from the endangered ploughshare tortoise, geochelone yniphora (vaillant), in northwestern madagascar. this relatively large tick is morphologically most similar to amblyomma nuttalli dönitz, which occurs in mainland sub-saharan africa where it mainly parasitizes other species of tortoises. however, several char ...200211931042
genetic identification of rickettsiae isolated from ticks in japan.following the description in japan of japanese spotted fever, caused by rickettsia japonica, a search for the vector of this disease led to the isolation of several rickettsiae from various tick species. sixty-three rickettsial isolates were obtained from six different tick species, and six type strains were described by pcr and monoclonal antibody testing. we identified these six strains by amplification and sequencing of the genes encoding 16s rrna and citrate synthase. we confirmed that the i ...200212037083
transcriptional analysis of the major antigenic protein 1 multigene family of cowdria ruminantium.the major antigenic protein 1 (map1) of the tick-borne rickettsial pathogen cowdria ruminantium is encoded by a multigene family containing conserved and variable genes. the part of a locus containing the map1 multigene family that was characterized contained three homologous, but non-identical map1 genes, designated map1-2, map1-1, and map1. reverse transcriptase-polymerase chain reaction was used to study the transcriptional activity of these genes in isolates of c. ruminantium grown in bovine ...200212039046
phylogenetic analysis of spotted fever group rickettsiae isolated from ticks in japan.eight spotted fever group (sfg) rickettsiae isolated from ticks in japan were classified by phylogenetic analysis based on the nucleotide sequences of both the citrate synthase-encoding gene (glta) and 190-kda antigen-encoding gene (rompa). in the phylogenetic tree of glta, strains dt-1 and fla-1 isolated from the dermacentor taiwanensis and haemaphysalis frava ticks, respectively, were placed as rickettsia japonica, and strains io-1, io-2, io-25, im-1 and ip-2 from genus ixodes ticks were place ...200212061626
evidence of spotted fever group rickettsiae in state of rio de janeiro, brazil.ticks were obtained from dogs from february to september of 1999 at weekly intervals, in the county of piraí, state of rio de janeiro. four hundred seventy four ixodids were taxonomically identified, 103 amblyomma cajennense, seven amblyomma ovale, 209 rhipicephalus sanguineus, and 155 amblyomma sp. an hemolymph test associated with giemsa's stain revealed two specimens in 163 ticks tested (r. sanguineus and amblyomma sp), containing rickettsia-like organisms. direct immunofluorescence verified ...200212163909
tick infestation of sika deer (cervus nippon) in the western part of yamaguchi prefecture, japan.ticks were collected from 94 sika deer (cervus nippon) hunted in the western part of yamaguchi prefecture, japan from august to november 1999, and march to july 2000. haemaphysalis longicornis and h. yeni were the dominant species from april to august, while h. flava and h. megaspinosa were dominant in october, november and march. this is the first report of h. yeni in the mainland of japan. small numbers of h. kitaokai, amblyomma testudinarium and ixodes ovatus were also recorded.200212185317
ixodid ticks on cattle belonging to small-scale farmers at 4 communal grazing areas in south africa.ixodid ticks were collected during the period september 1991 to august 1993 from cattle belonging to small-scale farmers utilising 4 communal grazing areas. three of these were in north west province and 1 in mpumalanga province, south africa. ten tick species were collected in north west province and 7 in mpumalanga. the adults of amblyomma hebraeum, rhipicephalus appendiculatus and rhipicephalus evertsi evertsi were most numerous in north west province, while in mpumalanga boophilus decoloratu ...200212515294
introduction of the exotic tick amblyomma hebraeum into florida on a human host.a resident of florida returned from a short visit to southern africa to find a male amblyomma hebraeum tick attached to the skin behind her knee. amblyomma hebraeum is a major vector of 2 pathogens that cause important diseases in southern africa, heartwater of ruminants and african tick-bite fever of humans. the tick was tested by polymerase chain reaction assay for evidence of infection with cowdria ruminantium and rickettsia africae (the causative agents of heart-water and african tick-bite f ...200212197136
ixodid ticks on indigenous goats owned by small-scale farmers in four communal grazing areas in south africa.indigenous goats belonging to small-scale farmers in 4 communal grazing areas in south africa were sampled for ixodid ticks during the period september 1991 to may 1993. three of these areas were in the north west province (rietgat, madinyane and bethany), and one in mpumalanga province (geluk). no tick control was practised unless requested by the owners. seven ixodid tick species, of which the majority were immature ticks, were collected from the goats in north west province. amblyomma hebraeu ...200212088070
ehrlichia ewingii infection in white-tailed deer (odocoileus virginianus).two closely related zoonotic ehrlichiae, ehrlichia chaffeensis and e. ewingii, are transmitted by amblyomma americanum, the lone star tick. because white-tailed deer (odocoileus virginianus) are critical hosts for all mobile stages of a. americanum and are important vertebrate reservoirs of e. chaffeensis, we investigated whether deer may be infected with e. ewingii, a cause of granulocytotropic ehrlichiosis in humans and dogs. to test for e. ewingii infection, we used polymerase chain reaction ...200212095432
the omp-1 major outer membrane multigene family of ehrlichia chaffeensis is differentially expressed in canine and tick hosts.sixteen of 22 omp-1 paralogs encoding 28-kda-range immunodominant outer membrane proteins of ehrlichia chaffeensis were transcribed in blood monocytes of dogs throughout a 56-day infection period. only one paralog was transcribed by e. chaffeensis in three developmental stages of amblyomma americanum ticks before or after e. chaffeensis transmission to naïve dogs.200212117987
transmission of hepatozoon americanum (apicomplexa: adeleorina) by ixodids (acari: ixodidae).american canine hepatozoonosis (ach) caused by hepatozoon americanum vincent-johnson, macintire, lindsay, lenz, baneth, and shkap is an emerging, often fatal, tick-borne protozoal disease of dogs in the united states of america. dogs acquire infection by ingesting ticks that contain oocysts. to understand the invertebrate (definitive) host range of h. americanum, experiments were carried out using four ixodids, rhipicephalus sanguineus (latreille), dermacentor variabilis say, amblyomma americanu ...200212144294
dermacentor variabilis and boophilus microplus (acari: ixodidae): experimental vectors of babesia equi to equids.the experimental vector competence of five laboratory-reared ixodid tick species representing three genera [amblyomma americanum (l.), boophilus microplus (canestrini), d. andersoni stiles, d. occidentalis marx, and d. variabilis (say)] for babesia equi (laveran 1901) was evaluated by delayed transfer of male ticks from infected to susceptible equids or by infesting the latter animals with adult ticks previously fed as nymphs on infected equids. after feeding for 5, 6, or 13 d on acquisition hos ...200212144301
identification and characterization of genes differentially expressed in the testis/vas deferens of the fed male tick, amblyomma hebraeum.most ixodid ticks must feed for at least a few days to complete gonad maturation. substances produced by the mature male gonad, and carried in the spermatophore, induce physiological changes in the female that lead to engorgement and oviposition. to begin defining the molecular phenotype at this stage of male development, we differentially cross-screened a cdna library made from the testis and vas deferens of fed ticks (amblyomma hebraeum koch) and isolated 35 genes that were putatively up-regul ...200212044495
horse resistance to natural infestations of anocentor nitens and amblyomma cajennense (acari: ixodidae).the objective of this study was to investigate some aspects of horse resistance to natural infestations of anocentor nitens and amblyomma cajennense over a 2-year period. free-living stages of a. nitens were used to evaluate the influence of season of the year on horse resistance. every 2 weeks, 10 selected engorged females, weighing 150-329 mg, were removed from naturally infested horses and were individually placed into glass tubes closed with a cotton stopper, and maintained in an incubator. ...200211812624
larval gulf coast ticks (amblyomma maculatum) [acari: ixodidae] as host for hepatozoon americanum [apicomplexa: adeleorina].laboratory-reared larval gulf coast ticks (gcts) (amblyomma maculatum) were exposed experimentally and found to acquire hepatozoon americanum infection while feeding on parasitemic dogs. these ticks supported gamogonic and sporogonic development of the apicomplexan, and oocysts from newly molted nymphs were infectious for a dog. other nymphs from this cohort that were allowed to feed on a blood-parasite naive sheep molted normally; the resulting adult ticks contained oocysts that were infectious ...200211750999
identity and synthesis of prostaglandins in the lone star tick, amblyomma americanum (l.), as assessed by radio-immunoassay and gas chromatography/mass spectrometry.high concentrations of pge(2) and pgf(2alpha) were identified by radio-immunoassay (ria) and/or gas chromatography/mass spectrometry (gc/ms) in the hemolymph, salivary glands and saliva of the lone star tick amblyomma americanum (l.). binding studies indicated that pge(2) was free and not bound to any proteins in the hemolymph. a small amount of 6-keto-pgf(1alpha) (breakdown product of pgi(2); prostacyclin) was also found in the salivary glands but not in the hemolymph or saliva. neither pgd(2) ...200211804805
developmental profiles of ecdysteroids, ecdysteroid receptor mrnas and dna binding properties of ecdysteroid receptors in the ixodid tick amblyomma americanum (l.).total body ecdysteroid titers were determined at specific stages during the larval and nymphal life of amblyomma americanum (l.). one ecdysteroid peak was observed following the completion of larval apolysis. however, two distinct ecdysteroid peaks occurred at a comparable stage in the nymphal molting cycle. the first occurred following apolysis and the second peak occurred at about the time of ecdysis. when whole body profiles of ecr and rxr mrnas were examined during the molting cycle using rt ...200211886781
ticks parasitizing dogs in northwestern georgia.from january 1998 through september 1999, 324 dogs in three northwestern georgia counties were examined for ticks. six species of ticks were recovered. the three most commonly collected ticks were the american dog tick, dermacentor variabilis (say) (310 male male, 352 female female; prevalence, 97%; mean intensity 2.1); the brown dog tick, rhipicephalus sanguineus (latreille) (118 male male, 119 female female, 38 nymphs; prevalence, 22%; mean intensity, 3.8); and the lone star tick, amblyomma am ...200211931241
a survey for nymphs of host-seeking ixodes scapularis and amblyomma americanum (acari: ixodidae) on tree trunks in deciduous forests.trunks of 83 trees in a mixed deciduous forests in maryland were sampled for the presence of nymphs of the blacklegged tick, ixodes scapularis say, and the lone star tick, amblyomma americanum (l.). although one or more nymphs of either i. scapularis or a. americanum was found in leaf litter and substrate < or = 1 m from the bases of 47% of the trees sampled, a total of 6 i. scapularis nymphs was found on the trunks of only five trees. no nymphs were found on the trunks of 12 dead trees. no a. a ...200211931264
parasitism of domestic swine (sus scrofa) by amblyomma ticks (acari: ixodidae) on a farm at monte negro, western amazon, brazil.abstract in january 2001, while conducting a survey of the tick fauna of the state of rondĵnia, brazil, a rural area within monte negro county was visited. on one farm within the county the producer maintained a herd of crossbred swine, sus scrofa l., that was reared under unconfined conditions, with unrestrained access to the pasture and adjacent native amazon equatorial forest. inspection of the swine herd produced a total of 77 ticks collected from eight adult pigs (mean, 9.6 ticks per pig) t ...200211931265
comparison of differentially expressed genes in the salivary glands of male ticks, amblyomma americanum and dermacentor andersoni.genes expressed differentially in the salivary glands of unfed and fed male ticks, amblyomma americanum (l.), were identified, cloned and sequenced, and some were compared with those expressed in the salivary glands of dermacentor andersoni. total protein and rna increased sixfold in the salivary glands of fed male a. americanum, while in fed male d. andersoni salivary glands, rna increased approximately 3.5 times. feeding d. andersoni in the presence of females increased total rna by 25% over t ...200212020839
analysis of serum and whole blood values in relation to helminth and ectoparasite infections of feral pigs in texas.in the summers of 1996 and 1997, 60 wild pigs (sus scrofa) were necropsied from three sites in south texas (usa) to test the hypothesis that serum and whole blood parameters vary significantly (p < or = 0.05) with the prevalence and intensity of parasites infecting wild pigs. we found ten parasite species: five nematodes (metastrongylus salmi, metastrongylus pudentotectus, stephanurus dentatus, oesophagostomum dentatum, and physocephalus sexalatus); four ixodid ticks (amblyomma cajennense, ambly ...200212038138
control of ixodes scapularis and amblyomma americanum through use of the '4-poster' treatment device on deer in maryland.deer self-treatment devices ('4-posters') were evaluated for their efficacy in reducing populations of blacklegged ticks, ixodes scapularis, and lone star ticks, amblyomma americanum. at each of three locations in maryland, 25 '4-posters' were operated in study areas of approximately 5.18 km2. populations of host-seeking ticks were monitored by flagging of treated areas and similar untreated control areas without '4-posters.' from 1998 to 2002 the percent mortalities achieved were 69, 75.8 and 8 ...200214570143
how specific are host-produced kairomones to host-seeking ixodid ticks?ixodid ticks respond to host-produced substances (kairomones) that influence the ticks' host-finding behavior. in the laboratory adult blacklegged ticks, ixodes scapularis say, lone star ticks, amblyomma americanum l., and american dog ticks, dermacentor variabilis (say) became akinetic on residues rubbed from their principal hosts (deer for the former two species and dogs for the latter). however, arrestment also occurred when adults of these species were tested using the same method bioassay, ...200214570126
quantification of vitellogenesis and its control by 20-hydroxyecdysone in the ixodid tick, amblyomma hebraeum.ovaries of the ixodid tick, amblyomma hebraeum koch, grew rapidly after engorgment as a result of yolk uptake. at 26 degrees c, oviposition began by day 10 post-engorgement, plateaued on days 16-18, and ended by day 38. vitellin (vt) was partially purified from ovaries of day 10 engorged ticks by gel filtration and ion exchange chromatography. this vt comprises seven major and several minor polypeptides. two polypeptides (211 and 148 kd) from haemolymph of engorged female ticks corresponded to m ...200212770055
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 ...200214570118
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
identification of ctenocephalides felis fleas as a host of rickettsia felis, the agent of a spotted fever rickettsiosis in yucatań, mexico.in search for the vector of the recently recognized spotted fever rickettsiosis of the yucatán, ticks, fleas, and lice were collected from vegetation and dogs in localities where seropositive persons had been found. the arthropods were examined by polymerase chain reaction (pcr) using primers for the genus-specific 17-kda protein gene followed by restriction fragment length polymorphism (rflp) and dna sequencing. eleven (20%) of 54 pools of ctenocephalides felis fleas contained dna of rickettsia ...200212653300
gynandromorphism in amblyomma cajennense and rhipicephalus sanguineus (acari: ixodidae).during a survey of ticks on horses in november 2000, at the university of são paulo farm in pirassununga county, são paulo, brazil, 1 gynandromorph of amblyomma cajennense was collected from a naturally infested horse. in another survey on dogs in march 2001, in the urban area of monte negro, rondônia, brazil, a gynandromorph of rhipicephalus sanguineus was collected from a naturally infested dog. both specimens are described and classified as perfect bipartite protogynanders.200212197141
infection rates of amblyomma americanum and dermacentor variabilis by ehrlichia chaffeensis and ehrlichia ewingii in southwest missouri.both ehrlichia chaffeensis and ehrlichia ewingii are causative agents of human ehrlichiosis. both pathogens are transmitted to humans through the bite of an infected lone star tick (amblyomma americanum). since missouri has a high incidence of human monocytic ehrlichiosis, we investigated the prevalence of e. chaffeensis- and e. ewingii-infected a. americanum and dermacentor variabilis (american dog tick) ticks to help assess the relative risk for humans exposed to these vectors. we used a neste ...200212653298
effect of deer exclusion by fencing on abundance of amblyomma americanum (acari: ixodidae) on fire island, new york, usa.the effects of deer exclusion on northern populations of lone star ticks, amblyomma americanum, were tested at the lighthouse tract, fire island, ny, usa, where densities of this species have increased recently. game fencing was erected to exclude deer from two sites of roughly one ha each, and populations of nymphal and adult a. americanum within were compared with those at control sites outside the exclosures. percent control of nymphs within vs. outside the exclosures averaged 48.4% in the fo ...200212546457
search for borrelia sp. in ticks collected from potential reservoirs in an urban forest reserve in the state of mato grosso do sul, brazil: a short report.a total of 128 ticks of the genus amblyomma were recovered from 5 marsupials (didelphis albiventris) - with 4 recaptures - and 17 rodents (16 bolomys lasiurus and 1 rattus norvegicus) captured in an urban forest reserve in campo grande, state of mato grosso do sul, brazil. of the ticks collected, 95 (78.9%) were in larval form and 22 (21.1%) were nymphs; the only adult (0.8%) was identified as a. cajennense. viewed under dark-field microscopy in the fourth month after seeding, 9 cultures prepare ...200212219124
characterization of protective antigens from the midgut of amblyomma variegatum ticks.separation of midgut membrane proteins from the tick, ambylomma variegatum, using a nonionic detergent (triton x-114), resulted in two protein fractions, namely det (detergent) and aq (aqueous). in immunoblotting analysis with polyclonal antibodies against these fractions, 4 proteins (mr approximately 27,000, 67,000, 86,000 and 95,000,) and 2 proteins (m, approximately 54,000 and 67,000) were detected in the det and aq fractions, respectively. three of the det fraction proteins mr approximately ...200212475080
life-cycle and host specificity of amblyomma tigrinum (acari: ixodidae) under laboratory conditions.biological data of three generations of amblyomma tigrinum in the laboratory are reported and the suitability of different host species for immature ticks are compared. grouping the three generations, infestations by both the larval and nymphal stages were performed on chickens (gallus gallus), wistar rats (rattus norvegicus), rabbits (orytolagus cuniculus), wild mice (calomys callosus), dogs (canis familiaris) and opossums (didelphis albiventris). only dogs were used for infestations by adult t ...200212475081
notes on parasitism by amblyomma humerale (acari: ixodidae) in the state of rondônia, western amazon, brazil.the tick amblyomma humerale koch is endemic to south america. all host records refer to the adult stage parasitizing tortoises, mostly yellow-footed tortoise, geochelone denticulata (l.), and red-footed tortoise, geochelone carbonaria (spix). the current study reports the presence of a. humerale in the state of rondônia, brazil. a total of 215 adult ticks (201 males, 14 females) was collected from six g denticulata in an indian reserve and nine geochelone sp. in rural monte negro county, giving ...200212495177
the prevalence of cowdria ruminantium in free-living adult amblyomma hebraeum collected at a communal grazing area and in 2 wildlife reserves in south africa.in order to detect the prevalence of cowdria ruminantium in the vector tick, amblyomma hebraeum, free-living, unfed adult ticks were collected with the aid of pheromone/co2 traps. ticks were collected at the rietgat communal grazing area, as well as in the southwestern kruger national park and in the songimvelo game reserve, all located in heartwater-endemic areas of south africa. the presence of c. ruminantium in these ticks was determined by polymerase chain reaction (pcr) analysis. ticks from ...200212515301
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
a ten-year study of tick biting in mississippi: implications for human disease transmission.to determine exactly which tick species bit people in mississippi, information was gathered on ticks involved in human biting cases for the ten-year period, january 1, 1990-december 31, 1999. specimens were identified by the author and, in most cases, confirmed by personnel at the institute of arthropodology and parasitology, georgia southern university. a total of 119 ticks were recovered from 73 humans during the study period. seven tick species were represented; most common included the lone ...200212853269
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
eradication of the tropical bont tick in the caribbean: is the caribbean amblyomma program in a crisis?the progress and problems in the caribbean amblyomma program (cap) are reviewed since its inception in 1995. during 1998, there were funding and administrative management problems. usda resolved the acute funding crisis, and after three years of negotiation, the cap has now secured an additional euro 1.5 million from the european community. changes in administration in 1998 included the withdrawal of iica from the program, and the transition during the decentralization of administrative and fina ...200212381609
a new subfamily, bothriocrotoninae n. subfam., for the genus bothriocroton keirans, king & sharrad, 1994 status amend. (ixodida: ixodidae), and the synonymy of aponomma neumann, 1899 with amblyomma koch, 1844.evidence suggesting polyphyly of the traditionally recognised tick genus aponomma neumann, 1899 is summarized. continued recognition of this genus in its current concept leaves a polyphyletic genus aponomma and a paraphyletic genus amblyomma koch, 1844. to improve the correlation between our understanding of phylogenetic relationships in metastriate ticks and their classification, a few changes in classification are proposed. the members of the 'indigenous australian aponomma' group (sensu kaufm ...200212386418
avgi, an index of genes transcribed in the salivary glands of the ixodid tick amblyomma variegatum.random clones from a cdna library made from mrna purified from dissected salivary glands of feeding female amblyomma variegatum ticks were subjected to single pass sequence analysis. a total of 3992 sequences with an average read length of 580 nucleotides have been used to construct a gene index called avgi that consists of 2109 non-redundant sequences. a provisional gene identity has been assigned to 39% of the database entries by sequence similarity searches against a non-redundant amino acid ...200212392910
ixodid ticks feeding on humans in south africa: with notes on preferred hosts, geographic distribution, seasonal occurrence and transmission of pathogens.this paper records the identities of 558 ixodid ticks feeding on 194 humans in south africa. these ticks belonged to 20 species in six genera and those most frequently encountered were amblyomma hebraeum, haemaphysalis leachi, hyalomma marginatum rufipes, hyalomma truncatum, rhipicephalus appendiculatus, rhipicephalus gertrudae and rhipicephalus simus. with the exception of the larvae of r. appendiculatus, the incidents of these ticks feeding on humans correlated well with their seasonal occurre ...200212593517
increasing risks of introduction of heartwater onto the american mainland associated with animal movements.opportunities to introduce heartwater onto the american mainland through animal movements include importation from africa of tick-infested reptiles and of subclinically infected wild ungulates and importation of livestock from islands in the caribbean infested with amblyomma variegatum ticks. measures to control importation of heartwater vectors on reptiles include importation bans of infested species, treatment of imported reptiles, and eradication of established infestations on the american ma ...200212381604
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
ticks associated with armadillo (euphractus sexcinctus) and anteater (myrmecophaga tridactyla) of emas national park, state of goias, brazil.this study was conducted in october 1998 and november 1999 in the emas national park (131,868 ha), a savanna-type cerrado region situated in the far south of goias state, brazil, near the geographic center of south america (15 degrees -23 degrees s; 45 degrees -55 degrees w). animals were captured with the aid of nets and anesthetized (15 mg/kg ketamine + 1 mg/kg xylasine) in order to collect ticks for identification and to establish laboratory colonies. they included giant anteaters (myrmecopha ...200212381607
acaricide resistance profiles of single- and multi-host ticks from communal and commercial farming areas in the eastern cape and north-west provinces of south africa.a field study (february 2000 to august 2001) was conducted on communal and commercial farms in the eastern cape and north-west provinces of south africa to detect the levels of tick resistance to commonly used acaricides. the larvae obtained from engorged females of the one-host tick boophilus decoloratus, the two-host tick rhipicepalus evertsi evertsi and the three-host ticks amblyomma hebraeum and rhipicephalus appendiculatus were tested against various concentrations of amitraz, chlorfenvinph ...200212234005
studies on seasonal dynamics of ticks of ogaden cattle and individual variation in resistance to ticks in eastern 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
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
immunogenicity of ehrlichia ruminantium grown in tick cell lines.ehrlichia (previously cowdria) ruminantium, the pathogen which causes heart-water in domestic and wild ruminants, can now be propagated in cell lines from one vector (amblyomma variegatum) and five non-vector (ixodes scapularis, i. ricinus, boophilus decoloratus, b. microplus and rhipicephalus appendiculatus) tick species. e. ruminantium isolates from west and south africa and the caribbean vary in their cell line preference, growth patterns and immunogenic capability. in laboratory trials, cert ...200214570129
progress towards the eradication of amblyomma variegatum from the caribbean.progress in the caribbean amblyomma program (cap) is reviewed since its inception in 1995 when regional eradication activities for amblyomma variegatum ticks were initiated using bayticol pour-on. technical achievements in the various islands were slow initially, and showed a wide diversity in attaining eradication targets. st. kitts, considered as a model program. eliminated the tropical bont tick (tbt) from most of the island in less than 3 years. however, the elimination of very low numbers o ...200214570141
the argasidae, ixodidae and nuttalliellidae (acari: ixodida): a world list of valid tick names.the world's argasid tick fauna comprises 183 species in four genera, namely argas, carios, ornithodoros and otobius in the family argasidae. the ixodid tick fauna consists of 241 species in the genus ixodes and 442 species in the genera amblyomma, anomalohimalaya, bothriocroton, cosmiomma, dermacentor, haemaphysalis, hyalomma, margaropus, nosomma, rhipicentor and rhipicephalus in the family ixodidae, with the genus boophilus becoming a subgenus of the genus rhipicephalus. the family nuttallielli ...200214570115
an inhibitor of thrombin-stimulated blood platelet aggregation from the salivary glands of the hard tick amblyomma variegatum (acari: ixodidae).the tropical bont tick, amblyomma variegatum can cause intense skin irritation and inflammation and bites that often develop into septic wounds or abscess in their host. crude salivary gland extract (sge) of partially engorged a. variegatum females as well as sge protein fractions purified by three-step reverse phase hplc procedure were tested for their anti-aggregatory effect on isolated human blood platelets stimulated with thrombin and compared with the effect of recombinant hirudin. at conce ...200214570120
the relationship between 'critical weight' and 20-hydroxyecdysone in the female ixodid tick, amblyomma hebraeum.the feeding cycle of adult female ticks (acari: ixodidae) is divided into preparatory, slow and rapid feeding phases. at the transition from slow to rapid feeding, amblyomma hebraeum (koch) females reach a 'critical weight' (cw; approx. 10x the unfed weight) that is characterized by several behavioural and physiological changes. five of these changes were used as criteria to establish a more precise estimate of cw than we have to date. the cw as defined by re-attachment to the host was 9x the un ...200112770177
ticks (acari: ixodidae) associated with domestic dogs in franca region, são paulo, brazil.ticks on 140 domestic dogs from both urban and rural areas of franca region in são paulo state were identified with 102 dogs from urban areas and 38 from rural areas. of urban dogs, 27.5% were infested exclusively by rhipicephalus sanguineus ticks. of the rural dogs, 36.8% were infested with the following tick species: r. sanguineus, boophilus microplus, amblyomma ovale and a. cajennense. mixed infestations included a dog hosting a. cajennense and a. ovale and another with b. microplus and r. sa ...200112455880
borrelia lonestari infection after a bite by an amblyomma americanum tick.erythematous rashes that are suggestive of early lyme disease have been associated with the bite of amblyomma americanum ticks, particularly in the southern united states. however, borrelia burgdorferi, the causative agent of lyme disease, has not been cultured from skin biopsy specimens from these patients, and diagnostic serum antibodies usually have not been found. borrelia lonestari sp nov, an uncultured spirochete, has been detected in a. americanum ticks by dna amplification techniques, bu ...200111372036
the distribution of ixodid ticks (acari: ixodidae) in central ethiopia.ixodid ticks were collected from domestic animals, mainly cattle, in 11 administrative zones covering 84 districts in central ethiopia over a period of 2 years (july 1996 to june 1998). nineteen tick species were identified. four of these belonged to the genus amblyomma, one to boophilus, two to haemaphysalis, three to hyalomma and nine to rhipicephalus. amblyomma variegatum and rhipicephalus evertsi evertsi were present in all 11 administrative zones and, with the exception of afar, boophilus d ...200112026058
tick infestation of borana cattle in the borana province of ethiopia.a study was conducted to identify and determine burdens of ticks infesting borana cattle in the borana province of ethiopia. rhipicephalus pulchellus, rhipicephalus pravus, rhipicephalus muhsamae, rhipicephalus praetextatus, rhipicephalus evertsi evertsi, amblyomma gemma, amblyomma variegatum, amblyomma cohaerens, amblyomma lepidum, hyalomma truncatum, hyalomma marginatum rufipes and boophilus decoloratus were identified on the cattle. their burdens ranged from 658-1,554 with a mean of 1,205 tic ...200111403429
reduction in mortality from heartwater in cattle, sheep and goats exposed to field challenge using an inactivated vaccine.inactivated vaccines for heartwater prepared with the commercially acceptable montanide isa 50 (isa 50) adjuvant were field tested in boer goats in botswana, angora goats in south africa, and merino sheep in zambia and zimbabwe. two vaccines, one made using the zimbabwean mbizi isolate and the other using the respective local field isolate (sunnyside in botswana; bathurst in south africa; lutale in zambia), were tested at each site, except in zimbabwe where only the mbizi vaccine was tested. com ...200111390083
ticks (acari: ixodidae) spread by the international trade in reptiles and their potential roles in dissemination of diseases.the international trade in live reptiles has grown dramatically in the last decade. since many of these reptiles are infested with ticks, the number of ticks introduced to new exotic locations has also increased. this is causing concern in importing countries such as the united states because some of the reptilian ticks are known to be vectors of diseases of veterinary and economic importance, such as heartwater. rational measures to control these tick species and to eradicate new introductions ...200111354992
[search for the spirochete borrelia burgdorferi sensu lato by polymerase chain reaction in wild chilean ticks].lyme disease is a tick-borne human disease caused by the spirochete borrelia burgdorferi. main vectors of lyme disease are ticks of the ixodes and amblyomma genera. cases with clinical manifestations of lyme disease and favorable responses to antimicrobial agents have been reported in chile, some of them with erythema migrans, the hallmark of b burgdorferi infection.200111372294
efficacy of granular deltamethrin against ixodes scapularis and amblyomma americanum (acari: ixodidade) nymphs.a single barrier application of granular deltamethrin to the woodland edges of a forested residential community in late spring significantly reduced the abundance of ixodes scapularis say nymphs. the application also suppressed the population of amblyomma americanum (l.) nymphs, which recently became established in the study area. the efficacy of deltamethrin is compared with other commonly used acaricides.200111296847
host associations of ticks parasitizing rodents at borrelia burgdorferi enzootic sites in south carolina.a total of 237 rodents was collected in 4 regions of south carolina from july 1994 through december 1995. eight species were collected, including cotton mouse, hispid cotton rat, eastern woodrat, marsh rice rat, white-footed mouse, eastern harvest mouse, golden mouse, and black rat. of the 1,514 ticks recovered from these hosts, ixodes minor neumann, including larvae, nymphs, and adults, was the most abundant species, representing 54% of the total. only immature stages of other tick species were ...200111780825
risk of lyme disease: perceptions of residents of a lone star tick-infested community.lone star ticks (amblyomma americanum) have been suggested as a vector of the agent of lyme disease (borrelia burgdorferi sensu lato) in the usa, based on associations with an infection manifesting mainly as erythema migrans. in laboratory experiments, however, they failed to transmit b. burgdorferi sensu stricto.200111693973
detection and identification of spotted fever group rickettsiae and ehrlichiae in african ticks.rickettsia africae, a recently identified pathogen, was detected for the first time in amblyomma ticks from niger, mali, burundi, and sudan, and "r. mongolotimonae" was identified for the first time in africa. rickettsiae of unknown pathogenicity and two new ehrlichiae of the ehrlichia canis group were identified in ticks from mali and niger.200111747731
identification and characterization of a homologue of the pro-inflammatory cytokine macrophage migration inhibitory factor in the tick, amblyomma americanum.studying tick feeding and digestion, we discovered in a cdna library from partially fed amblyomma americanum ticks the first known arthropod homologue of a human cytokine, the pro-inflammatory macrophage migration inhibitory factor (mif). the tick origin of the mif cdna clone was confirmed by sequencing a genomic fragment that contained the full-length tick mif gene with two introns. antiserum to a tick mif-specific peptide as well as antiserum to complete tick mif revealed the expression of tic ...200111520355
prevalence of infection by the protozoan hemolivia mariae in ticks.this paper considers the prevalence of natural infections of the protozoan hemolivia mariae, in its hosts the australian sleepy lizard, tiliqua rugosa, and the ixodid tick species, amblyomma limbatum. we investigate whether the protozoan may be influencing the tick population in the field, by comparing the observed prevalence of infection in ticks with the prevalence expected from known transmission dynamics. the prevalence of infection in nymphs was similar to the expected prevalence, but the o ...200111206116
antibody responses to map 1b and other cowdria ruminantium antigens are down regulated in cattle challenged with tick-transmitted heartwater.serological diagnosis of heartwater or cowdria ruminantium infection has been hampered by severe cross-reactions with antibody responses to related ehrlichial agents. a map 1b indirect enzyme-linked immunosorbent assay that has an improved specificity and sensitivity for detection of immunoglobulin g (igg) antibodies has been developed to overcome this constraint (a. h. m. van vliet, b. a. m. van der zeijst, e. camus, s. m. mahan, d. martinez, and f. jongejan, j. clin. microbiol. 33:2405-2410, 1 ...200111238227
first records of tick-borne pathogens, borrelia, and spotted fever group rickettsiae in okinawajima island, japan.in early april 2000, tick-borne pathogens were surveyed in the northern area of okinawajima island, okinawa prefecture, which is the southernmost area of japan. borrelia valaisiana, a lyme disease spirochete, was isolated from a field mouse mus calori, and unidentified rickettsiae of the spotted fever group were isolated from all stages of amblyomma testudinarium. these are the first reports of these pathogens on okinawajima island.200111293483
effects of selected meterological factors on diurnal questing of ixodes scapularis and amblyomma americanum (acari: ixodidade).the diurnal questing behavior of adult ixodes scapularis say and amblyomma americanum (l.) were monitored in the field to determine whether ticks would be collected with greater frequency during certain times of the day and under certain ambient meteorological conditions. temperature and relative humidity explained a significant amount of the total variation in tick collections. although both species were collected during every period, i. scapularis adults tended to quest earlier and later in th ...200111296842
ultrastructure of developmental stages of hemolivia mariae (apicomplexa: haemogregarinidae), natural parasite of the australian sleepy lizard, in experimentally infected deviant hosts.mabuya vitatta (olivier) (scincidae) and agama stellio (l.) (agamidae) were infected with hemolivia mariae smallridge et paperna, 1997 by ingestion of tick viscera from amblyomma limbatum neumann, fed as nymphs on naturally infected australian sleepy lizards, tiliqua rugosa gray. the unnatural infection apparently interfered with the developmental schedule of the parasites. transmission electron microscopic images of merogonic stages were obtained, as well as images of early developing gametocyt ...200111817448
parasites of domestic and wild animals in south africa. xl. ticks on dogs belonging to people in rural communities and carnivore ticks on the vegetation.ixodid ticks were collected at weekly intervals from february 1999 to april 2000 from domestic dogs belonging to people in rural communities in north-eastern kwazulu-natal. seven ticks were identified to species level and adult haemaphysalis leachi followed by immature amblyomma hebraeum and adult rhipicephalus simus were the most prevalent. infestation with adult h. leachi was most intense during february and march 1999 and from january to april 2000, and least intense during october 1999. infe ...200111585091
ticks from a morelet's crocodile in belize.parasitism of crocodilians by ticks has rarely been reported, and to our knowledge only seven published accounts exist. on 3 july 1999, we collected four ticks from a subadult morelet's crocodile (crocodylus moreletii) captured in northern belize. these were identified as amblyomma dissimile (one female), and amblyomma sp. (two nymphs, one larva). the crocodile was captured on land approximately 100 m from water, and all four ticks were attached to loose skin on the lateral surface of the tail. ...200111763751
dermatophilus congolensis infection in goats in tanzania.when goats in eastern tanzania were screened for skin diseases, dermatophilus congolensis was isolated from the skin lesions in 8 of 484 animals examined. in one severely affected case, the disease was also characterized by histological studies (gram stain, giemsa stain and routine he studies) and electron microscopy. the histological picture was characterized by hyperkeratosis, parakeratosis, acanthosis, folliculitis and an inflammatory cellular reaction involving the epidermis. gram stain and ...200111556616
transmission of cowdria ruminantium by amblyomma gemma from infected african buffalo (syncerus caffer) and eland (taurotragus oryx) to sheep.two african buffalo (syncerus caffer), an eland (taurotragus oryx) and a waterbuck (kobus defassa) were intravenously inoculated with cowdria ruminantium (kiswani). amblyomma gemma nymphs were fed on the animals at 3 weekly intervals. jugular blood was also collected at 3 weekly intervals and inoculated into sheep. nymphal ticks that fed on one buffalo on days 16 and 37 and on the other buffalo on day 58 after infection transmitted the disease as adults to sheep. nymphs that were applied to the ...200111556617
new distribution records of amblyomma hebraeum in the sandveld region of botswana. 200111563715
ticks (acari: ixodidae) and spirochetes (spirochaetaceae: spirochaetales) recovered from birds on a georgia barrier island.from september 1997 through july 1999, 300 individuals and 46 species of birds were mist-netted and screened for ticks and spirochetes on st. catherine's island, liberty county, ga. seventy-six (25%) of the birds were parasitized by a meal intensity of 4.6 ticks. seasonally, more birds were infested with ticks during the summer (50% in 1998, 34% in 1999) than in spring (15% in 1998, 11% in 1999) or fall (21% in 1997, 20% in 1998), mainly because of severe infestations on some birds by immature s ...200111296828
ixodes rubicundus nymphs are short-day diapause-induced ticks with thermolabile sensitivity and desiccation resistance.the karoo paralysis tick, ixodes rubicundus neumann (acari: ixodidae), is a semi-voltine ixodid that survives stressful environmental conditions using morphogenetic diapause (eggs and engorged nymphs) and desiccation resistance. both photoperiod and temperature influence diapause induction in the engorged nymph. ixodes rubicundus nymphs are typical long-day photoperiodic organisms. the critical photoperiod is approximately 13.5 h light, 10.5 h dark, and they display a thermolabile response. the ...200111583453
resistance of leopard tortoises and helmeted guineafowl to cowdria ruminantium infection (heartwater).experimental infection trials were conducted to investigate susceptibility of leopard tortoises (geochelone pardalis) and helmeted guineafowl (numida meleagris) to infection with cowdria ruminantium, the causative agent of heartwater, a tickborne disease of domestic and wild ruminants. ten guineafowl were inoculated intravenously with a virulent dose of c. ruminantium derived from bovine endothelial cell cultures, and four leopard tortoises were exposed to c. ruminantium infection by the feeding ...200111423187
1-octen-3-ol isolated from bont ticks attracts amblyomma variegatum.volatiles from various life-stages of the bont ticks amblyomma variegatum and a. hebraeum were collected by using solid-phase microfibers and charcoal traps. an octenol isomer was found to be a major constituent of most of the tick material sampled and was identified as 1-octen-3-ol by gas chromatography-mass spectrometry and by using antenna of the tsetse fly glossina brevipalpis in gas chromatography-linked antennogram detection. release of this compound increased during molt to adulthood and ...200111441439
investigation of blood parasites in livestock infested with argasid and ixodid ticks in egypt.nineteen species and subspecies of ixodid and argasid ticks, hyalomma dromedarii, h. impeltatum, h. anatolicum excavatum, h. a. anatolicum, h. truncatum, h. m. marginatum, h. m. rufipes, h. m. turanicum, boophilus annulatus, rhipicephalus sanguineus, r. turanicus, r. guilhoni, r. camicasi, amblyomma lipidum, a. marmoreum, a. vareigatum, argas persicus, a. hermanii and a. arboreus were collected from different localities in five governorates, giza, sharkia, ismailia, el beheira and sinai. hyalomm ...200111478436
anti-interleukin-8 activity of tick salivary gland extracts.interleukin-8 (il-8) is one of many mammalian chemokines (chemotactic cytokines) that direct mammalian inflammatory and immune cells to sites of injury and infection. chemokines are produced locally and act on leucocytes through selective receptors. the principal role of il-8 is to control the movement and activity of neutrophils. to date, several tick species have been shown to modulate the production or activity of certain cytokines but none of these are chemokines. using an il-8 specific elis ...200111589777
ultrastructure of developmental stages of hemolivia stellata (apicomplexa: haemogregarinidae) in the cane toad bufo marinus and in its vector tick amblyomma rotondatum.the fine structure of the hemogregarine hemolivia stellata petit, landau, baccam and lainson, 1990 developmental stages in the cane toad bufo marinus l. and the vector tick amblyomma rotondatum koch, 1844 are described. in the liver of the toad, merozoites bound by a pellicle were located free and in the cytoplasm, and young and encased mature polynucleated meronts were located in a parasitophorous vacuole (pv). premature gametocytes in the erythrocytes were bound by a bilayered membranous wall ...200111510993
evidence for the utility of the bm86 antigen from boophilus microplus in vaccination against other tick species.the bm86 antigen, as originally identified in boophilus microplus, is the basis of commercial tick vaccines against this tick species. the potential for using this antigen or homologues of the antigen in vaccination against other tick species has been assessed. we have conducted vaccine trials in cattle using the b. microplus-derived recombinant bm86 vaccine (tickgard) using pairs of vaccinated calves and control calves. these were infested with b. microplus and boophilus decoloratus larvae simu ...200111523920
amblyomma hebraeum is a vector of rickettsia africae and not r. conorii. 200112219911
sensitive detection of ehrlichia chaffeensis in cell culture, blood, and tick specimens by reverse transcription-pcr.ehrlichia chaffeensis is an obligatory intracellular bacterium of monocytes and macrophages and the etiologic agent of human monocytic ehrlichiosis, an emerging zoonosis. the lone star tick (amblyomma americanum) has been implicated as the primary vector of e. chaffeensis. the present study examined the sensitivity of the nested reverse transcription (rt)-pcr based on the 16s rrna gene relative to that of the nested pcr for detection of e. chaffeensis in infected dh82 cells, experimentally infec ...200111158090
lone star tick-infecting borreliae are most closely related to the agent of bovine borreliosis.although borrelia theileri, the agent of bovine borreliosis, was described at the turn of the century (in 1903), its relationship with borreliae causing lyme disease or relapsing fever remains undescribed. we tested the previously published hypothesis that spirochetes infecting lone star ticks (amblyomma americanum) may comprise b. theileri by analyzing the 16s ribosomal dnas (rdnas) and flagellin genes of these spirochetes. b. theileri, the amblyomma agent, and b. miyamotoi formed a natural gro ...200111158095
interdigital gland substances of white-tailed deer and the response of host-seeking ticks (acari: ixodidae).host-seeking male and female blacklegged ticks, ixodes scapularis say, exhibited an arrestant response when contacting substances from front and rear interdigital glands of male and female white-tailed deer, odocoileus virginianus (zimmermann). female i. scapularis responded positively to substances from interdigital glands on the fore legs and hind legs of female deer, whereas male i. scapularis responded only to samples from the fore legs of does. these results showed that previously reported ...200111268681
preliminary survey of ticks (acari: ixodidae) parasitizing wild turkeys (aves: phasianidae) in eastern kansas.during the spring and fall turkey hunting seasons of 1999, hunters and kansas department of wildlife and parks field personnel examined wild turkeys, meleagris gallopavo l., for ticks and submitted them to us for identification. from springtime hunting, we received 113 ticks from 12 turkeys killed in nine counties, all in the eastern one-third of kansas. collectors reported examining three additional wild turkeys on which no ticks were found. all ticks were nymphal lone star ticks, amblyomma ame ...200111268682
prevalence of infection in ticks submitted to the human tick test kit program of the u.s. army center for health promotion and preventive medicine.in 1997, ticks removed from humans and received alive by the tick-borne disease laboratory of the u.s. army center for health promotion and preventive medicine (usachppm) were tested for pathogens by polymerase chain reaction (pcr). thirty-three of 222 (15%) amblyomma americanum (l.) dnas produced amplicons of the expected size of ehrlichia chaffeensis anderson, dawson & wilson and 26/222 (12%) produced amplicons indicating borrelia burgdorferi johnson, schmid, hyde, steigalt & brenner. five (2% ...200111268694
mating strategies and spermiogenesis in ixodid ticks.mate-seeking and sperm-transfer in the ixodid hard ticks, which include important vectors of zoonotic pathogens, generally reflect their peculiarly prolonged pattern of feeding. the metastriate ticks, including dermacentor, amblyomma, and rhipicephalus, invariably attain sexual maturity and mate solely on their hosts. the more primitive prostriate ixodes ticks, however, may copulate both in the absence of hosts and while the female engorges. these expanded opportunities for insemination complica ...200111112167
temporal and spatial dynamics of a parapatric boundary between two australian reptile ticks.two tick species aponomma hydrosauri and amblyomma limbatum that infest large reptiles have an abrupt parapatric boundary near mt mary in south australia. a previous model has suggested that the boundary is maintained at population density troughs resulting from habitat heterogeneity along a gradual environmental gradient. this paper describes the dynamics of the boundary on three transects over 17 years, 1982-98. over the last seven years of that period there has been a significant increase in ...200111298975
risk factors to tick infestations and their occurrence on horses in the state of são paulo, brazil.from december 1998 to march 1999, 40 stud farms were studied in the state of são paulo, brazil. during visits to farms, horses reared under grazing conditions were examined for the presence of ticks. on each farm visit, horse pastures were closely inspected and a questionnaire was given to the farm supervisor with the purpose of gaining information about ecological and management variables (independent variables) that could be associated with the presence and infestation levels of ticks on the f ...200111337122
hepatozoon canis infection associated with dog ticks of rural areas of rio de janeiro state, brazil.hepatozoon canis is a tick-borne protozoan that infects dogs and has been reported throughout the world. manifestation of h. canis infection varies from being sub-clinical in apparently healthy dogs to severe illness. the main vector of the infection is the dog tick, rhipicephalus sanguineus although other species may also transmit this agent. h. canis has been reported previously in brazil, but mostly as an occasional finding during laboratory exams and always associated with other diseases. th ...200111113545
borrelia lonestari dna in adult amblyomma americanum ticks, alabama.polymerase chain reaction analysis of 204 amblyomma americanum and 28 a. maculatum ticks collected in august 1999 near the homes of patients with southern tick-associated rash illness and in control areas in choctaw county, alabama, showed borrelia lonestari flagellin gene sequence from two adult a. americanum. the presence of b. lonestari in a. americanum ticks from alabama suggests that this suspected pathogen may be widespread in the southeastern united states.200111384533
ixodid ticks on white-tailed deer and feral swine in florida.a state-wide survey was conducted in florida during the 1997-99 hunting seasons to examine white-tailed deer (odocoileus virginianus) and feral swine (sus scrofa) for potential indigenous vectors of the rickettsial agent of heartwater, cowdria ruminantium. a total of 504 white-tailed deer and 166 feral swine was examined from 30 wildlife management areas across the state. amblyomma maculatum, an experimental vector of c. ruminantium, was common on both deer and feral swine throughout the state. ...200111469190
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