TitleAbstractYear(sorted descending)
[search for the spirochete borrelia burgdorferi sensu lato by polymerase chain reaction in wild chilean ticks].lyme disease is a tick-borne human disease caused by the spirochete borrelia burgdorferi. main vectors of lyme disease are ticks of the ixodes and amblyomma genera. cases with clinical manifestations of lyme disease and favorable responses to antimicrobial agents have been reported in chile, some of them with erythema migrans, the hallmark of b burgdorferi infection.200111372294
borrelia lonestari dna in adult amblyomma americanum ticks, alabama.polymerase chain reaction analysis of 204 amblyomma americanum and 28 a. maculatum ticks collected in august 1999 near the homes of patients with southern tick-associated rash illness and in control areas in choctaw county, alabama, showed borrelia lonestari flagellin gene sequence from two adult a. americanum. the presence of b. lonestari in a. americanum ticks from alabama suggests that this suspected pathogen may be widespread in the southeastern united states.200111384533
reduction in mortality from heartwater in cattle, sheep and goats exposed to field challenge using an inactivated vaccine.inactivated vaccines for heartwater prepared with the commercially acceptable montanide isa 50 (isa 50) adjuvant were field tested in boer goats in botswana, angora goats in south africa, and merino sheep in zambia and zimbabwe. two vaccines, one made using the zimbabwean mbizi isolate and the other using the respective local field isolate (sunnyside in botswana; bathurst in south africa; lutale in zambia), were tested at each site, except in zimbabwe where only the mbizi vaccine was tested. com ...200111390083
entomogenous fungi as promising biopesticides for tick control.when ticks were sealed in nylon tetrapacks and infected with the entomogenous fungi, beauveria bassiana and metarizium anisopliae and maintained in potted grass in the field, the fungal oil formulations (10(9) conidia per ml) induced 100% mortality in larvae of rhipicephalus appendiculatus and amblyomma variegatum, whereas mortalities in nymphs varied between 80-100% and in adults 80-90%. the aqueous formulations (10(9) conidia per ml) induced mortalities of 40-50% and reductions in egg hatchabi ...200011354619
cowdria ruminantium antibodies in acaricide-treated and untreated cattle exposed to amblyomma variegatum ticks in the indirect enzyme-linked immunosorbent assay (elisa), based on the major antigenic protein i fragment b (mapi-b) of cowdria ruminantium, was used to assess seroprevalence in cattle in the gambia. two groups of 20 n'dama and 20 gobra zebu cattle were monitored for 12 months with flumethrin treatment and for another 10 months without acaricidal treatment. two groups of 20 n'dama and 20 gobra cattle served as untreated controls. during the period of acaricidal treatment, the cumulative proportions ...200011354623
collection of free-living nymphs and adults of amblyomma hebraeum (acari: ixodidae) with pheromone/carbon dioxide traps at 5 different ecological sites in heartwater endemic regions of south africa.the capture of free-living adults and nymphs of amblyomma hebraeum, the main vector of heartwater in domestic and wild ruminants in south africa, by means of attraction-aggregation-attachment-pheromone/carbon dioxide traps at five endemic localities in south africa is described. although the traps were used successfully at each of the localities, no determination of their efficiency in relation to the actual abundance of ticks at a particular site was made. this study confirmed that the traps co ...200011354624
amblyomma tigrinum (acari: ixodidae) in relation to phytogeography of central-northern argentina with notes on hosts and seasonal distribution.the findings of amblyomma tigrinum in continental argentina north of 40 degrees s are presented according to phytogeographic domains (andean-patagonic, amazonian and chaco) and the seasonal distribution is depicted on a monthly basis. a total of 718 adult ticks and four nymphs were found. a. tigrinum ticks were present in all domains. adult ticks were found all year round but they were more abundant during the summer. most ticks were found on domestic dogs but the survey has a bias to domestic h ...200011354625
ultrastructure studies on post-oocyst development of the lizard hemogregarine hemolivia mariae in the tick amblyomma limbatum.the ultrastructural features of the development of hemolivia mariae, a blood parasite of the australian lizard, tiliqua rugosa, from sporokinetes to sporozoites in their vector tick amblyomma limbatum are described. sporokinetes, released from oocysts, re-establish themselves in tick-gut epithelial cells within a parasitophorous vacuole, the wall of which becomes evaginating and anastomosing and is underlined extensively by endoplasmic reticulum. the sporozoites forming within the encysting spor ...200010894472
range expansion of the tick amblyomma triguttatum triguttatum, an australian vector of q fever.the tick amblyomma triguttatum triguttatum has previously been reported from western australia, queensland and new south wales. a viable population of this species, including all developmental stages, has now been discovered on the southern end of yorke peninsula, south australia. species determination was carried out morphologically and using 18s and 16s rrna. the data for 16s rrna are the first published for this species. amblyomma t. triguttatum is significant through its involvement in the n ...200010899523
amblyomma americanum: specific uptake of immunoglobulins into tick hemolymph during feeding.the passage of immunoglobulins in the blood meal into hemolymph prompts development of vaccines against internal antigens of ticks, but little is known about kinetics and specificity of the immunoglobulin uptake. we used capillary feeding of adult amblyomma americanum hard ticks to introduce compounds into the midgut and then examined the hemolymph after various times for their presence and concentration. immunoglobulins of different sources, albumin, choramphenicol acetyltransferase, inulin, an ...200011162374
ticks and tick-borne disease systems in space and from space.analyses within geographical information systems (giss) indicate that small- and large-scale ranges of hard tick species (ixodidae) are determined more by climate and vegetation than by host-related factors. spatial distributions of ticks may therefore be analysed by statistical methods that seek correlations between known tick presence/absence and ground- or remotely-sensed (rs) environmental factors. in this way, local habitats of amblyomma variegatum in the caribbean and ixodes ricinus in eur ...200010997208
ticks associated with wild animals in the nhecolândia pantanal, brazil.a study of ticks associated with wild animals was carried out from september 1996 to april 1998 at the fazenda alegria (21,000 ha), in the nhecolândia pantanal, state of mato grosso do sul, brazil, a sunken plain bordering the upper paraguay river, located 19 x 08's; 56 x 46'w. a total of 81 wild animals (13 species, 6 orders) were captured with the aid of nets, and ticks were found on 63 (78%). tick species identified included boophilus microplus (canestrini), amblyomma cajennense (f.), a. parv ...200011193635
laboratory evaluation of pathogenicity of entomogenous nematodes to african tick species.five strains of entomogenous nematodes, steinernema carpocapsae strains dd, mexican, sr, and heterorhabditis bacteriophora strains 1s5 and hp88, were tested for their pathogenicity to various developmental stages of five african tick species namely; rhipicephalus appendiculatus, r. evertsi, amblyomma variegatum, a. gemma, and boophilus decoloratus. in engorged female r. appendiculatus, all nematodes at a concentration of 1,000 infective juveniles (ij)/dish, except s. carpocapsae mexican strain, ...200011193637
tropical bont tick (amblyomma variegatum) eradication in the caribbean. the st. kitts experience.the tropical bont tick (tbt) was first identified in st. kitts in 1978. initially, infestation was observed on cattle that developed a severe dermatitis. over a period of seven years, the tbt spread to most areas of the island, affecting cattle, sheep, and goats. the ruminant livestock population declined from, 6,000, 9,000, and 7,000 cattle, sheep, and goats, respectively, in 1984 to an estimated 400, 800, and 1,000, cattle, sheep, and goats in 1990. a project to control the tropical bont tick ...200011193641
laboratory and field evaluation of entomogenous fungi for tick control.aqueous and oil-based formulations of two entomogenous fungi, beauveria bassiana and metarhizium anisopliae were tested for their efficacy against the three major species of african ticks; namely, amblyomma variegatum, rhipicephalus apendiculatus, and boophilus decoloratus. both fungal species and formulations were observed to induce high mortalities, especially in the larvae. the oil-based formulation was found to be more effective than the aqueous formulation. monthly application of aqueous fo ...200011193673
american canine hepatozoonosis. an emerging disease in the new world.hepatozoon canis was first described from dogs in 1905 in india and rhipicephalus sanguineus was identified as the vector. dogs on the texas gulf coast were recognized in 1978 to have hepatozoonosis, and it was thought that h. canis had entered the new world. later, it was realized that american canine hepatozoonosis (ach) is more debilitating than its old world counterpart, often resulting in death. when the malady and parasite were characterized, a new species, h. americanum, was described, in ...200011193705
the effect of male ticks on the feeding performance of immature stages of rhipicephalus sanguineus and amblyomma americanum (acari: ixodidae).a unique group of immunoglobulin-binding proteins (igbps), produced by ixodid male ticks during the latter half of their prolonged feeding period, improves the feeding performance of co-feeding females. as a follow-up to this observation, we investigated whether male tick feeding also affects the feeding of other developmental stages. immature stages of rhipicephalus sanguineus (latreeille) and amblyomma americanum (l.) were fed on rabbits in the presence or absence of conspecific males. the mea ...200011201360
ectoparasites of dogs belonging to people in resource-poor communities in north west province, south africa.a total of 344 dogs belonging to people in resource-poor communities in north west province, south africa, was examined for ectoparasites, and all visible arthropods were collected from the left side of each dog. by doubling these numbers it was estimated that the dogs harboured 14,724 ixodid ticks, belonging to 6 species, 1,028 fleas, belonging to 2 species, and 26 lice. haemaphysalis leachi accounted for 420 and rhipicephalus sanguineus for 14,226 of the ticks. pure infestations of h. leachi w ...200011205167
influence of temperature and relative humidity on the moulting success of amblyomma limbatum and aponomma hydrosauri (acari: ixodidae) larvae and nymphs.this study compared the duration of the moulting periods of engorged larvae and nymphs of the ixodid ticks, amblyomma limbatum and aponomma hydrosauri, at different temperature/relative humidity regimes, and examined the relationships between the engorged weight of ticks and their weights after moulting. the results showed that for each species, there was a significant relationship between the weights of unfed nymphs and engorged larvae, and the weights of unfed adults and engorged nymphs. the w ...200010980285
attempted transmission of ehrlichia chaffeensis among white-tailed deer by amblyomma maculatum.a deer was needle-exposed intravenously to ehrlichia chaffeensis (rickettsiales: ehrlichieae) in canine macrophage (dh82) cells and 7 days later was infested with laboratory-reared amblyomma maculatum (koch) (acari:ixodidae) nymphs for acquisition feeding. after molting, the adult ticks were allowed to feed on a naive deer. the organism was reisolated from the needle-exposed deer by cell culture and e. chaffeensis dna was detected in the deer's blood by pcr. similar isolation/recovery techniques ...200010941753
ectoparasites and gastrointestinal helminths of southern flying squirrels in southeast georgia.southern flying squirrels (glaucomys volans) from southeastern georgia were examined for ectoparasites and gastrointestinal helminths. ten species of ectoparasites were recovered, including 3 species of sucking lice (hoplopleura trispinosa, microphthirus uncinatus, and neohaematopinus sciuropteri), 1 species of flea (orchopeas howardi), 2 species of ticks (amblyomma maculatum and ixodes scapularis), 3 species of mesostigmatid mites (androlaelaps casalis, a. fahrenholzi, and haemogamasus ambulans ...200011128479
evidence of cowdria ruminantium infection (heartwater) in amblyomma sparsum ticks found on tortoises imported into florida.amblyomma marmoreum and a. sparsum ticks were collected from tortoises imported into florida from africa and were tested for cowdria ruminantium infection using a c. ruminantium-specific pcs20 polymerase chain reaction assay. in i shipment imported from zambia, 15 of the 38 a. sparsum male ticks collected from the leopard tortoises (geochelone pardalis) were found to be positive for infection with c. ruminantium. in contrast, all 148 a. marmoreum tested were negative for c. ruminantium infection ...200011128494
host association and seasonal activity of amblyomma americanum (acari: ixodidae) in missouri.from june 1993 through june 1996, 2,260 adult, 4,426 nymphal, and 2,178 larval lone star ticks amblyomma americanum (l.) were collected in missouri from vertebrate hosts and by dragging a cloth over vegetation. prevalence, mean intensity, and relative abundance of each stage varied among hosts. the relative abundance of adult lone star ticks was highest on white-tailed deer, but this stage was also collected from raccoons, opossum, red fox, coyotes, and wild turkey. nymphs were collected from gr ...200011128501
production of pheromones by artificially fed males of the tick amblyomma maculatum (acari: ixodidae).aggregation-attachment pheromones are produced only by male ticks of the genus amblyomma that have imbibed blood for at least 8 d from their mammalian hosts. this report demonstrates that production and release of aggregation-attachment pheromones by amblyomma maculatum (koch) males can be induced in vitro by using nonblood media, artificially introduced through capillary tubes, into the male ticks. the presence of these pheromones is demonstrated by using both biological observations on bovine ...200011004791
ticks (acari: ixodidae) associated with rural dogs in uruará, eastern amazon, brazil.a survey of 124 dogs for ticks was conducted from august to november 1998 in 68 small farms of uruará municipality in eastern amazon-brazil. we collected 55 ticks from 18 dogs (14.5%). amblyomma oblongoguttatum koch, amblyomma ovale koch, and amblyomma cajennense (f.) were found on nine, six, and one dog, respectively. fourteen small farms (20.5%) had at least one dog with ticks.200011004794
a case of gynandromorphism in amblyomma oblongoguttatum (acari: ixodidae).during a survey conducted from august to november 1998 to ticks associated with dogs in the rural area of uruará, in the state of para, eastern amazon region of brazil, we collected one gynandromorph specimen out of 18 amblyomma oblongoguttatum koch specimens collected from dogs. it is a perfect bipartite gynandromorph, reported in this species for the first time.200011004795
analysis of the expressed genome of the lone star tick, amblyomma americanum (acari: ixodidae) using an expressed sequence tag expressed sequence tag (est) approach was used to study the genome of two developmental stages of the lone star tick, amblyomma americanum. cdna libraries were constructed from the larval and adult stages of a. americanum. in total, 1942 ests were sequenced (1462 adult ests and 480 larval ests) and analyzed using bioinformatic programs. contig assembly using the capii program revealed 11% and 15% redundancy of sequences in the larval and adult ests, respectively. of the 1942 ests, 1738 sequen ...200011087176
detection of ehrlichia chaffeensis dna in amblyomma americanum ticks in connecticut and rhode island.ehrlichia chaffeensis, the causative agent of human monocytic ehrlichiosis, is transmitted by amblyomma americanum ticks, which are most abundant in the southern united states. because serologic evidence suggests that residents of connecticut are exposed to e. chaffeensis, a. americanum ticks were collected in connecticut and rhode island for pcr analysis to detect e. chaffeensis dna. eight of 106 (7.6%) a. americanum ticks from connecticut and 6 of 52 (11.5%) from rhode island contained e. chaf ...200011101616
chemical composition of lipophylic compounds from the body surface of unfed adult ixodes persulcatus ticks (acari: ixodidae).chemical compositions of ethereal extracts of the body surface of unfed male and female ixodes persulcatus ticks (acari: ixodidae) were studied by gas chromatography using mass-spectrometric detection. more than 100 different organic compounds were detected. the predominant components were saturated fatty hydrocarbons, saturated and unsaturated fatty acids, aldehydes, squalene, cholesterol and cholesterol derivatives. a number of compounds found in i. persulcatus are known as components of phero ...200011108395
what's eating you? amblyomma ticks (amblyomma americanum). 200011109142
does geographic range affect the attractant-aggregation-attachment pheromone of the tropical bont tick, amblyomma variegatum?the tropical bont tick, amblyomma variegatum, transmits heartwater in sub-saharan africa and in the caribbean. this species has a broad geographic distribution, ranging from madagascar and other islands in the indian ocean through most of sub-saharan africa, to several islands in the eastern caribbean sea. blood fed male a. variegatum secrete an attraction-aggregation-attachment (aaa) pheromone which, combined with co2, excites host finding and formation of feeding clusters of these ticks. howev ...200011110239
a review of the ticks (acari, ixodida) of brazil, their hosts and geographic distribution - 1. the state of rio grande do sul, southern brazil.a review of the ticks (acari, ixodida) of the state of rio grande do sul, southern brazil, was completed as a step towards a definitive list (currently indicated as 12) of such species, their hosts and distribution. the ticks: argas miniatus (poultry), ixodes loricatus (opossums), amblyomma aureolatum (dogs), a. calcaratum (anteaters), a. cooperi (capybaras), a. nodosum (anteaters), a. tigrinum (dogs) (neotropical) and rhipicephalus sanguineus (dogs) (introduced, cosmopolitan, afrotropical) were ...200010904399
the '4-poster' passive topical treatment device to apply acaricide for controlling ticks (acari: ixodidae) feeding on white-tailed deer.a '4-poster' device that attracts white-tailed deer to a bait source, and as they feed, allows a self-application of a pesticide to the head, ears, and neck to control ticks was designed, constructed, and tested. the device consists of a central bin containing bait to attract deer and two feeding and application stations. these stations each have one bait port and two vertical pesticide-impregnated applicator rollers. this design allows unrestricted vertical retraction of the head to minimize in ...200010916301
distribution of ehrlichia chaffeensis (rickettsiales: rickettsiaeceae) in amblyomma americanum in southern indiana and prevalence of e. chaffeensis--reactive antibodies in white-tailed deer in indiana and ohio in continue monitoring the prevalence and distribution of ehrlichia chaffeensis (rickettsiales: rickettsiaeceae) in southern indiana, a total of 498 amblyomma americanum (l.) ticks (262 adults and 292 nymphs) was collected from five southern indiana counties during may and june 1998. ticks were pooled and examined for the presence of e. chaffeensis using nested polymerase chain reaction and primers specific for the 16s rrna gene of e. chaffeensis. the average minimum infection rate for adult tic ...200010916302
new host and distribution record of amblyomma javanense (acari: ixodidae) in thailand.amblyomma javanense (supino) was collected from a malayan pangolin (manis javanica desmarest) and a wild boar (sus scrofa l.) from tak province on the western boundary of thailand along the myanmar (burma) border. to date, this tick species has not been recorded from this area and from a wild boar.200010916309
a state-by-state survey of ticks recorded from humans in the united states.based on tick specimens accessioned into the u.s. national tick collection, the species of ticks recorded as ectoparasites of humans are documented and compared for 49 u.s. states. a total of 44 tick species was recorded as parasites of humans, consisting of 11 species of soft ticks (argasidae) and 33 species of hard ticks (ixodidae). four of the hard tick species are not native to the u.s. and were removed from travelers returning from foreign destinations. therefore, we record 40 of the 84 spe ...200010925803
ultrastructure of hemolivia mariae gamonts in the blood of the lizard tiliqua rugosa and their development to oocyst stage in the tick amblyomma limbatum.the ultrastructural features of the development of hemolivia mariae from intra-erythrocytic gamonts in their host, the australian lizard tiliqua rugosa, to oocysts containing sporokinetes in their vector, the tick amblyomma limbatum, are described. mature intra-erythrocytic gamonts, as well as gamonts ingested by the tick were encased in a thick (30 nm) capsule with distinct suture sites at each of the two apices. in the only image of a presumed syzygy, both partners were still encased. further ...200010935907
prevalence and intensity of the blood parasite hemolivia mariae in a field population of the skink tiliqua rugosa.the impacts of virulent parasites on humans or domestic animals are well documented. less is known of the impact of parasites in natural host-parasite associations. a population of the australian sleepy lizard tiliqua rugosa is infected with the blood microparasite hemolivia mariae, which is transmitted by the ectoparasitic tick amblyomma limbatum. in most infected lizards a very small proportion, usually < 1%, of red blood cells are infected. a study of the prevalence of the microparasite in th ...200010952265
introduction of potential heartwater vectors and other exotic ticks into florida on imported reptiles.following the discovery of establishment of the african tortoise tick amblyomma marmoreum in florida, the present study was undertaken to determine the extent of introduction of exotic ticks into florida on imported reptiles. exotic ticks were identified on 29 (91%) of 32 reptile premises in 18 counties of florida. the ticks, found on a variety of imported tortoises, snakes, and monitor lizards, belonged to 4 amblyomma species (a. marmoreum, amblyomma nuttalli, amblyomma sabanerae, and amblyomma ...200010958443
prevalence of ehrlichia ewingii in amblyomma americanum in north carolina. 200010979750
detection of the agent of heartwater, cowdria ruminantium, in amblyomma ticks by pcr: validation and application of the assay to field ticks.we have previously reported that the pcs20 pcr detection assay for cowdria ruminantium, the causative agent of heartwater disease of ruminants, is more sensitive than xenodiagnosis and the pcs20 dna probe for the detection of infection in the vector amblyomma ticks. here, we further assessed the reliability of the pcr assay and applied it to field ticks. the assay detected dna of 37 isolates of c. ruminantium originating from sites throughout the distribution of heartwater and had a specificity ...200010747140
tick infestations of birds in coastal georgia and alabama.mist-netted birds were examined for ticks on jekyll island, glynn co., georgia (32 bird species) in 1996-1998, and at fort morgan, baldwin co., alabama (36 species) in 1998 during fall migration. sixty-two (14.7%) of 423 birds from jekyll island and 22 (13.3%) of 165 birds from fort morgan were infested with ticks. the mean number of ticks per infested bird was 2.0 on jekyll island and 6.3 at fort morgan. ten species of birds were infested with ticks on jekyl1 island where 87% of all ticks were ...200010780541
short report: study on the efficacy of a new long-acting formulation of n, n-diethyl-m-toluamide (deet) for the prevention of tick attachment.the beneficial effects of n, n-diethyl-m-toluamide (deet) against biting insects of human and animals appear to last <6 hr after a single application to the skin. to prolong the repellent effects of deet, recently we developed a new long-acting formulation of deet called lipodeet. this preparation was retained in the skin for a longer duration of time with minimal systemic absorption. in this study, we have evaluated the protective effect of three compounds (deet, lipodeet, and morpel 220) again ...200010813468
competence of the african tortoise tick, amblyomma marmoreum (acari: ixodidae), as a vector of the agent of heartwater (cowdria ruminantium).the ability of the african tortoise tick, amblyomma marmoreum, to acquire and transmit cowdria ruminantium infection was investigated experimentally with transmission trials and with a c. ruminantium-specific polymerase chain reaction (pcr) detection assay. laboratory-reared a. marmoreum larvae and nymphs were fed on small ruminants with clinical heartwater. after molting, the resultant nymphs were fed on cowdria ruminantium-naive sheep (n = 3), and the adults were ground and inoculated intraven ...200010864237
isolation and molecular cloning of a secreted immunosuppressant protein from dermacentor andersoni salivary gland.a 36-kda immunosuppressant protein (da-p36) was isolated from salivary glands of feeding female ixodid ticks dermacentor andersoni, using its affinity for ultralink biosupport medium (pierce, rockford, illinois)/protein complexes. using a nested set of forward degenerate oligonucleotide primers corresponding to da-p36 n-terminal amino acids, a cdna encoding the immunosuppressant protein was isolated by 3' rapid amplification of cdna ends. the resulting 772-base pair cdna encodes a novel protein ...200010864249
identification of ehrlichia chaffeensis by nested pcr in ticks from southern china.a total of 717 ticks collected from southern china were examined by nested pcr for the presence of ehrlichia chaffeensis. sixteen (55. 2%) of 29 adult amblyomma testudinarium ticks and 28 (11.7%) of 240 adult and at least 4.2% of 215 nymphal (pooled specimens) haemaphysalis yeni ticks tested positive. four other species of ticks were negative. selected positive amplicons were confirmed by dna sequencing.200010878087
responses of the tropical bont tick, amblyomma variegatum (fabricius), to its aggregation-attachment pheromone presented in an air stream on a servosphere.male amblyomma variegatum ticks feeding on a host release a mixture of o-nitrophenol and methyl salicylate which serves to attract conspecifics. the behavioural responses of a. variegatum on a servosphere to these volatiles presented in an air stream are detailed here. in still air, ticks walked on all eight legs, but with long halts. in contrast, the air stream caused continuous walking and induced a reaching response where the forelegs actively sampled the air. such reaching increased the angu ...200010659046
prostaglandin e(2)-stimulated secretion of protein in the salivary glands of the lone star tick via a phosphoinositide signaling pathway.previous studies identified a prostaglandin e(2) (pge(2)) receptor in the salivary glands of partially fed female lone star ticks, amblyomma americanum (l.). in the present studies, protein secretion from dispersed salivary gland acini was shown to be specific for pge(2), as compared with pgf(2alpha) or the thromboxane analog u-46619, in accordance with their respective binding affinities for the pge(2) receptor. furthermore, the selective pge(2) ep1 receptor agonist, 17-phenyl trinor pge(2), wa ...200010989297
invasion of west african cattle by the tick amblyomma variegatum.studies in cameroon and burkina faso examined the invasion process of cattle by adult amblyomma variegatum fabricius (acari: ixodidae) ticks. nearly all the ticks picked up in the pasture during grazing were found on the limb ends, near the hooves, where they temporarily attached. then when the cattle lay down, the ticks moved from the feet towards the predilection sites, where they attached definitively. many ticks disappeared during this displacement. all the female ticks and approximately 70% ...200011129703
diversity of ectoparasites in sheep flocks in são paulo, brazil.the occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. sheep production used to be a predominantly family activity in the state of são paulo (brazil), but it began to become a commercial activity in the past decade. thus, information about the ectoparasites existing in sheep flocks has become necessary. the present data were obtained by means of questionnaires sent to all sheep breeders belonging to the 'associação paulista de criadores de ovinos' (aspaco; ...200011020945
feasibility of controlling ixodes scapularis ticks (acari: ixodidae), the vector of lyme disease, by parasitoid augmentation.a theoretical analysis of the feasibility of controlling tick populations (ixodidae) by the release of reared ixodiphagus parasitoids in tick ecosystems yielded promising results. the analysis suggested that if reasonable progress could be made in mass-rearing the parasitoids, it would be possible to control the blacklegged tick, ixodes scapularis (say), the vector of lyme disease, by this biological control procedure. lyme disease has become the most important vector-borne disease in the united ...200011004774
amblyomma testudinarium tick bite: one case of engorged adult and a case of extraordinary number of larval tick infestation.this paper reports two recent cases of tick bite due to amblyomma testudinarium. the first case was an 86-year-old farmer infested with a fully engorged adult tick attached on his inguinal region. the second case was a 57-year-old male infested with an extraordinarily large number of larval ticks (> 100 larvae). the ticks were identified as a. testudinarium based on morphological characteristics. to our knowledge, the latter case is the eleventh case of larval tick bites among all tick species a ...200011211793
naturally occurring and experimentally transmitted hepatozoon americanum in coyotes from oklahoma.twenty free-ranging coyotes (canis latrans) in oklahoma (usa) were examined for the presence of naturally occurring infections with hepatozoon americanum and to determine if bone lesions attributable to h. americanum were present. although eight of the 20 free-ranging coyotes were found to be naturally infected with h. americanum, no bone lesions were detected. in addition, two coyote pups were exposed to h. americanum oocysts collected from experimentally infected ticks and the course of the re ...200010682757
comparison of efficacy of american and african amblyomma ticks as vectors of heartwater (cowdria ruminantium) infection by molecular analyses and transmission trials.the ability of amblyomma americanum, amblyomma cajennense, amblyomma maculatum, and amblyomma variegatum to acquire and transmit cowdria ruminantium infection was investigated. uninfected nymphs were fed on clinically reacting c. ruminantium-infected sheep and then analyzed for infection by specific dna detection assays and by tick transmission trials. by polymerase chain reaction (pcr), the mean infection prevalence of a. maculatum ticks (50.7%) was similar to that of a. variegatum, elevage str ...200010701562
prevalence of ehrlichia chaffeensis (rickettsiales: rickettsiaceae) in amblyomma americanum (acari: ixodidae) from the georgia coast and barrier islands.human monocytic ehrlichiosis is an emerging zoonosis caused by infection with ehrlichia chaffeensis anderson, dawson, jones & wilson, which is transmitted to mammals by ixodid ticks. prevalence of infected ticks and distribution of infection foci indicate relative risk of human exposure to ehrlichiosis and may be influenced by factors such as geographic isolation, human disturbance, and the availability of suitable mammalian reservoir hosts. to test, this, individual and pooled lone star ticks, ...200010730500
first record of amblyomma auricularium (acari: ixodidae) in the united states.amblyomma auricularium (conil) was collected from an armadillo in glades county, fl. two females and 11 males were collected. this is the first record of this species in the united states.200011126562
ticks (acari: ixodidae) associated with wild animals in the pantanal region of brazil.this paper describes the identification of ticks from wild animals of the pantanal region in brazil as part of a comprehensive study about established and emerging tick-host relationships and related pathological aspects. eighty-one animals were captured (representing 13 species, six orders), and ticks were found on 63 (78%). tick species identified included boophilus microplus (canestrini), amblyomma cajennense (f.), amblyomma parvum aragão, amblyomma pseudoconcolor aragão, amblyomma scalpturat ...200011126563
population dynamics of the free-living stages of amblyomma cajennense (fabricius, 1787) (acari: ixodidae) on pastures of pedro leopoldo, minas gerais state, brazil.a study on the population behavior of amblyomma cajennense larvae, nymphs and adult free-living stages was carried out in pedro leopoldo county, minas gerais state, brazil, from july 1995 to july 1997. larvae were collected from pasture from april to october using the technique of drag sampling with flannelette. the maximal larval population was observed during autumn (may) representing, respectively, 48 and 82% of the total numbers recovered during the first and the second years of the experime ...200010996741
new and earlier records of ticks (acari: ixodidae, argasidae) from guinea-bissau.ticks were collected from pastures and domestic and wild vertebrates during the rainy seasons of 1994 and 1996 in guinea-bissau. we collected the following species: from pastures rhipicephalus lunulatus neumann, r. muhsamae morel & vassiliades, r. senegalensis koch, and r. sulcatus neumann; from reptiles amblyomma nuttalli dönitz and aponomma flavomaculatum (lucas); and from mammals amblyomma paulopunctatum neumann, amblyomma splendidum giebel, amblyomma variegatum (f.), hyalomma truncatum koch, ...200011126561
parasitism by ixodes didelphidis and i. loricatus (acari: ixodidae) on small wild mammals from an atlatic forest in the state of sao paulo, brazil.from january 1995 to june 1996, ticks were studied in a fragment of atlantic forest in a residential area in the city of itapevi, state of sao paulo, brazil. cases of human lyme disease-like illness were registered in this area during the spring of 1992. the monthly relative density of ticks was determined and the influence of seasonal climatic conditions was evaluated as well as the relationship between ticks and hosts. ticks (n = 88) were collected from small mammals captured (n = 134) in mont ...200011185614
eradication and surveillance of the tropical bont tick in the caribbean. an international approach.the caribbean amblyomma program (cap) is a multidonor funded effort involving several technical organizations and national governments in the eradication of the tropical bont tick. the food and agriculture organization (fao) is the lead technical agency, providing both technical and administrative support to the cap regional coordination unit (rcu) based in barbados. all collaborating agencies, donors, and national representatives are members of the amblyomma program council (apc), the overall g ...200011193618
effects of granular carbaryl application on sympatric populations of ixodes scapularis and amblyomma americanum (acari: ixodidae) nymphs.a single application of granular carbaryl approaching the lowest recommended rate to the shrub layer of a forested area in late spring significantly reduced the abundance of ixodes scapularis say nymphs throughout their peak activity period, but had little effect on amblyomma americanum l. nymphs. factors influencing the efficacy of the application are discussed. the possible explanations for the lack of efficacy of granular carbaryl against a. americanum, including behavior, formulation, and ap ...200015218915
ehrlichia chaffeensis (rickettsiales: ehrlichieae) infection in amblyomma americanum (acari: ixodidae) at aberdeen proving ground, maryland.human monocytic ehrlichiosis (hme) is a sometimes fatal, emerging tick-borne disease caused by the bacterium ehrlichia chaffeensis. it is frequently misdiagnosed because its symptoms mimic those of the flu. current evidence indicates that amblyomma americanum (l.), the lone star tick, is the major vector of hme. to determine if e. chaffeensis is present in ticks at aberdeen proving ground, md, questing a. americanum ticks were collected from 33 sites. nucleic acid was extracted from 34 adult and ...200015535577
seasonal distribution and abundance of ticks (acari: ixodidae) in northwestern florida.a 2-yr study was conducted in a northwestern florida state park and recreation area to determine tick species composition, seasonal abundance, and spatial distribution. risk of tick attachment to park visitors was also assessed relative to tick abundance from several habitats. tick collections consisted of weekly cloth drag samples obtained from ground and emergent vegetation along a deer trail, a walking trail located in a 3-mo-old control burned area of forest, a nonburned walking trail, picni ...200015535590
molecular individuality: polymorphism of salivary gland proteins in three species of ixodid tick.pooled tissue samples are frequently used in biochemical studies involving parasites in order to ensure that there is sufficient material for experimentation. a pooled sample is considered to represent the overall phenotypic characteristics of the investigated population. however, this will not be the case if there is a significant degree of molecular polymorphism among individuals in the sampled population. here we demonstrate marked differences in the protein profile of salivary glands among i ...199910737731
profile of the ecdysteroid hormone and its receptor in the salivary gland of the adult female tick, amblyomma hebraeum.we examined the hemolymph ecdysteroid titer (by radioimmunoassay) and profile of the ecdysteroid receptor (ecr/usp; by [3h]ponasterone a binding, gel mobility shift assay, western blot) in the salivary gland of the ixodid tick, amblyomma hebraeum koch (acari: ixodidae) throughout the tick feeding period and first 6 days post-engorgement. throughout the slow phase of feeding, the hemolymph ecdysteroid titer was approximately 18 pg/microliter. the titer peaked at approximately 52 pg/microliter dur ...199910070743
molecular cloning of camp-dependent protein kinase catalytic subunit isoforms from the lone star tick, amblyomma americanum (l.).the salivary glands of ixodid ticks are central to tick feeding and to survival during off-host periods. they produce and secrete a number of molecules critical to maintaining the complex host-vector interface and to maintaining osmotic balance. we have previously shown that a cyclic amp-dependent protein kinase (capk) is involved in the mechanism of salivary gland secretion. we have now cloned cdnas encoding three isoforms of the catalytic subunit (capk-c) of the capk from amblyomma americanum, ...199910070744
novel ehrlichia organism (rickettsiales: ehrlichieae) in white-tailed deer associated with lone star tick (acari: ixodidae) parasitism.polymerase chain reaction (pcr) evidence of a novel ehrlichia organism was found recently in wild white-tailed deer, odocoileus virginianus zimmermann, and lone star ticks, amblyomma americanum l., from the southeastern united states. to evaluate whether lone star tick parasitism was associated with the presence of this novel ehrlichia organism in deer, 2 retrospective studies were conducted using specific nested pcr to test archived deer serum samples. the 1st study of 150 serum samples collect ...199910083757
molecular cloning and characterization of the ehrlichia chaffeensis variable-length pcr target: an antigen-expressing gene that exhibits interstrain variation.a clone expressing an immunoreactive protein with an apparent molecular mass of 44 kda was selected from an ehrlichia chaffeensis arkansas genomic library by probing with anti-e. chaffeensis hyperimmune mouse ascitic fluid. nucleotide sequencing revealed an open reading frame (orf) capable of encoding a 198-amino-acid polypeptide. the orf contained four imperfect, direct, tandem 90-bp repeats. the nucleotide and deduced amino acid sequences did not show close homologies to entries in the molecul ...199910203503
[experimental transmission of crimean-congo hemorrhagic fever virus: role of 3 vector species in the maintenance and transmission cycles in senegal].in this article, we published the role of three species of ticks amblyomma variegatum (fabricius, 1974), hyalomma marginatum rufipes (koch, 1844) and hyalomma truncatum (koch, 1844) in the maintenance and transmission of the cchf virus. the imagos of these species were infected by intracoelomic route. vertical transmission (transtasial and transovarial) and horizontal transmission for different stases were studied by isolation on newborn mice, polymerase chain reaction, indirect immunofluorescen ...199910229934
responses of three species of adult ticks (acari: ixodidae) to chemicals in the coats of principal and minor laboratory bioassays, host-seeking adult blacklegged ticks, ixodes scapularis say, lone star ticks, amblyomma americanum (l.), and american dog ticks, dermacentor variabilis (say), were exposed to substances from the pelage of dogs and white-tailed deer, odocoileus virginianus (zimmermann). male a. americanum exhibited an arrestant response to all samples of deer tarsal gland substances tested, whereas female a. americanum, female i. scapularis, and male and female d. variabilis responded to ...199910337091
attachment sites of four tick species (acari: ixodidae) parasitizing humans in georgia and south carolina.from june 1995 through january 1998, 677 tick specimens were submitted by 521 humans from 14 states. analysis was limited to specimens originating in georgia and south carolina, representing 87.3% of total submissions. attachment sites were specified in 367 specimens (62.3%). the american dog tick, dermacentor variabilis (say), a vector of the agent of rocky mountain spotted fever, favored the head and neck in 59% of attached specimens. the lone star tick, amblyomma americanum (l.), a strongly i ...199910337108
palp-splaying behavior and a specific mouthpart site associated with active water vapor uptake in amblyomma americanum (acari: ixodidae).ticks actively absorb water vapor from unsaturated air via their mouthparts. a wax technique was used to cover select areas of the mouthparts of the lone star tick, amblyomma americanum (l.), to examine whether a specific site is involved in uptake. covering dorsal, ventral, and distal regions failed to inhibit uptake, whereas wax applied to the proximal region, specifically the hypostome-cheliceral junction, blocked water absorption. a novel occurrence of a palp-splaying behavior was observed d ...199910337109
population dynamics of ticks on indigenous cattle in a pastoral dry to semi-arid rangeland zone of uganda.studies on seasonality and population dynamics of ticks on indigenous cattle and their crosses (calves) were carried out in buruli ranching scheme, nabiswera, luwero district of uganda on three treatment groups of animals: group 1 (twice a week dipping), group 2 (once a month dipping) and group 3 (no tick control). during this study, four major species of ticks of economic importance were recorded in decreasing order of abundance: rhipicephalus appendiculatus, rhipicephalus evertsi evertsi, ambl ...199910353189
evaluation of 16s, map1 and pcs20 probes for detection of cowdria and ehrlichia species.a panel of 16s ribosomal rna gene probes has been developed for the study of the epidemiology of heartwater; five of these detect different cowdria genotypes, one detects five distinct genotypes; one detects any group iii ehrlichia species other than cowdria and one detects any group ii ehrlichia species. these probes have been used on pcr-amplified rickettsial 16s rrna genes from over 200 amblyomma hebraeum ticks. control ticks were laboratory-reared and either uninfected or fed on sheep experi ...199910355799
the life cycle of amblyomma neumanni ribaga, 1902 (acari: ixodidae) in the laboratory.a colony of amblyomma neumanni was started with engorged females collected from cattle in the province of salta (24 degrees 51's, 65 degrees 33'w), argentina. the larvae and nymphs were fed on rabbits and the adults on calves. the non-parasitic stages were maintained in darkness at 27 +/- 1 degrees c and 83-86% rh. the life cycle (pre-feeding period not tested) had a mean duration of 205.7 days. the mean time (days) for the different phases of the cycle were as follows: feeding of females 8.8, p ...199910356766
immune responses to dermatophilus congolensis infections.complex mechanisms underly the establishment of dermatophilosis, an exudative and proliferative skin disease of ruminants. this multicomponent system involves the bacterium dermatophilus congolensis, transmission by various routes including flies, host genetic factors and immunosuppression by amblyomma variegatum ticks. here, nick ambrose and colleagues summarize recent evidence for an association between a. variegatum and severe chronic dermatophilosis in cattle. breed-based differences in resi ...199910377534
canine hepatozoonosis: comparison of lesions and parasites in skeletal muscle of dogs experimentally or naturally infected with hepatozoon americanum.we report previously undescribed, early lesions in skeletal muscle of dogs experimentally infected with hepatozoon americanum by ingestion of laboratory-reared, infected amblyomma maculatum. the earliest muscle lesion was recognized at the first interval of examination 3 weeks following exposure. the lesion consisted of a large, modified host cell whose cytoplasm frequently contained a demonstrable parasite. in skeletal muscle, the cell was consistently located between muscle fibers or in loose ...199910384901
susceptibility and carrier status of impala, sable, and tsessebe for cowdria ruminantium infection (heartwater).three species of wild african ruminants, impala (aepyceros melampus), sable (hippotragus equinus), and tsessebe (damaliscus lunatus), were experimentally inoculated with in vitro culture-derived cowdria ruminantium organisms, the tick-borne causative agent of heartwater in domestic ruminants, to determine their susceptibility to infection. no clinical disease was observed in any of the ruminants. however, c. ruminantium was detected in the sable by the transmission of heartwater to susceptible s ...199910386439
tick-borne rickettiosis in guadeloupe, the french west indies: isolation of rickettsia africae from amblyomma variegatum ticks and serosurvey in humans, cattle, and goats.twenty-seven rickettsiae were isolated and/or detected from 100 amblyomma variegatum ticks collected on guadeloupe in the french west indies. in this study, the polymerase chain reaction procedure appeared to be more sensitive in detecting rickettsiae in ticks than the shell-vial technique. sequencing a portion of the outer membrane protein a-encoding gene showed that these rickettsiae appeared to be identical to rickettsia africae, a member of the spotted fever group rickettsiae recently descri ...199910403315
seroepidemiologic studies on babesia equi and babesia caballi infections in brazil.horses from six stud farms representing the most frequent types of horse breeding in brazil were tested for babesia antibodies by the ifa test. the farms are located at the tropic of capricorn at an altitude of 472-715 m where temperatures below 0 degrees c may occur. horses of conventional stud farms were infested with dermacentor nitens, amblyomma cajennense, and boophilus microplus. infestation with bo. microplus was associated with direct or indirect contact of horses with cattle, and was no ...199910447188
theileria sp. infections associated with bovine fatalities in the united states confirmed by small-subunit rrna gene analyses of blood and tick samples.theileria sp.-specific small subunit (ssu) rrna gene amplification confirmed the presence of the organism in cattle and in amblyomma americanum and dermacentor variabilis ticks collected from a cattle herd in missouri. blood from the index animal had type a and type d theileria ssu rrna genes. the type d gene was also found in blood from two cohort cattle and tick tissues. the type a ssu rrna gene was previously reported from bovine theileria isolates from texas and north carolina; the type d ge ...199910449501
evidence of rickettsial spotted fever and ehrlichial infections in a subtropical territory of jujuy, argentina.between november 1993 and march 1994, a cluster 6 pediatric patients with acute febrile illnesses associated with rashes was identified in jujuy province, argentina. immunohistochemical staining of tissues confirmed spotted fever group rickettsial infection in a patient with fatal disease, and testing of serum of a patient convalescing from the illness by using an indirect immunofluorescence assay (ifa) demonstrated antibodies reactive with spotted fever group rickettsiae. a serosurvey was condu ...199910463693
comparison of methods for introducing and producing artificial infection of ixodid ticks (acari: ixodidae) with ehrlichia chaffeensis.only 29.5 +/- 8.91% of engorged amblyomma americanum (l.) nymphs that we inoculated with ehrlichia chaffeensis molted successfully to adults compared with 75.8 +/- 7.46% of engorged nymphs that were not inoculated. however, 65.4 +/- 6.02% of unfed nymphs of this species were exposed for 2 h to e. chaffeensis suspension introduced to them through glass capillaries gained weight. these nymphs were placed on rabbits, and approximately 50% of them completed their feeding and molted successfully to a ...199910467766
squalene: a naturally abundant mammalian skin secretion and long distance tick-attractant (acari: ixodidae).squalene is a naturally occurring lipid on mammalian skin and is an attractant to the lone star tick, amblyomma americanum (l.). in this study, we compared squalene to the standard tick-attractants, benzaldehyde, isobutyric acid, methyl salicylate, nonanoic acid, and o-nitrophenol identified as active ingredients of tick aggregation-attachment pheromones and determined its effectiveness in field and laboratory settings at varying distances. squalene was detected from 1/4 m greater than the stand ...199910467784
toxicity of neem seed oil (azadiracta indica) against the larvae of amblyomma variegatum a three-host tick in cattle.the in vitro toxicity of neem seed oil (azadiracta indica, family: meliaceae, 'dogon yaro' in hausa -language) was tested against the larvae of a three-host tick, amblyomma variegatum (family: ixodidae or hard tick) parasitic to cattle commonly found in nigeria. undiluted neem oil (100% concentration) was found to kill all (100% mortality) the larvae after 48 h. the toxicity was concentration and time dependent.199910479769
cowdria ruminantium infection in ticks in the kruger national amblyomma hebraeum ticks, the principle vector of heartwater (cowdriosis) of domestic ruminants in southern africa, were collected in pheromone traps placed in kruger national park, an exclusively wildlife sanctuary in south africa. these ticks transmitted cowdria ruminantium, the rickettsial agent causing heartwater, to a susceptible goat, resulting in acute, fatal disease. c ruminantium was isolated in bovine endothelial cell culture from the plasma of this animal during the febrile stag ...199910515616
[african rickettsia infections].epidemiology: african rickettsiasis is transmitted by rickettsia africae, a cattle tick. amblyomma spp. is an emerging rickettsiasis in sub-sehalian afric described in 1992. seroepidemiology studies conducted in africa show that it is probably the most widespread rickettsiasis in the sorld. in addition, the development of tourist activities in southern african countries has led to an increase in the number of reported cases in subjects returning from endemic areas. a high serprevalence of anti r ...199910518970
ticks and antibodies to borrelia burgdorferi from mammals at cape hatteras, nc and assateague island, md and va.results of a survey for ixodid ticks and/or serum antibodies to borrelia burgdorferi from 14 species of small to large mammals from eastern coastal areas of the united states are presented. most samples were obtained from july 1987 through june 1989 (excluding december-march) at 3 locales: assateague is. national seashore, worcester co., md., and accomack co., va. (approximately 38 degrees 05' n 75 degrees 10' w), and cape hatteras national seashore, dare co., nc (approximately 35 degrees 30' n ...199910534951
prevalence of cowdria ruminantium infection in amblyomma hebraeum ticks from heartwater-endemic areas of zimbabwe.analysis of the transmission dynamics of cowdria ruminantium, the tick-borne rickettsial agent of heartwater in ruminants, requires accurate measures of infection in vector populations. to obtain these, amblomnia hebraeum ticks were collected at two heartwater-endemic locations in the lowveld and highveld regions of zimbabwe and assessed for c. ruminantium infection with specific polymerase chain reaction (pcr) and dna probe detection assays. at the lowveld site, 11.2% (50/446) of adult ticks an ...199910579452
ticks feeding on humans: a review of records on human-biting ixodoidea with special reference to pathogen this article, literature records of argasid and ixodid ticks feeding on humans worldwide are provided in view of increased awareness of risks associated with tick bites. ticks can cause paralyses, toxicoses, allergic reactions and are vectors of a broad range of viral, rickettsial, bacterial and protozoan pathogens. approximately 12 argasid species (argas and ornithodos) are frequently found attached to humans who intrude into tick-infested caves and burrows. over 20 ixodid tick species are o ...199910581710
infection rates of amblyomma americanum (acari: ixodidae) by ehrlichia chaffeensis (rickettsiales: ehrlichieae) and prevalence of e. chaffeensis-reactive antibodies in white-tailed deer in southern indiana, monitor the percentage and stability of ehrlichia chaffeensis-infected ticks in southern indiana over time, pools of amblyomma americanum (l.) ticks were screened for infection in southern indiana for a 2nd time. nested polymerase chain reaction (with 6% dmso included only in the 2nd reaction) was performed on 920 ticks in pools of 5 individuals from 9 sites (5 sites previously examined and 4 new ones) in 6 counties. the average minimum infection rate for all sites for 1997 was 1.6%, lower th ...199910593071
parasites in cross-bred pigs in the upper east region of ghana.a cross-sectional study was carried out in the upper east region (uer) of ghana in order to estimate the prevalence of parasitic infections in local cross-bred pigs. out of 60 villages with a human population of 200-1000 inhabitants, 10 villages were randomly selected for the study. the number of pigs varied from 50 to 200 pigs per village. in total 259 faecal samples from growers were collected and examined. ninety-one percent of the animals excreted parasite eggs. among these the prevalence of ...199910628701
parasites of domestic and wild animals in south africa. xxxvii. ixodid ticks on cattle on kikuyu grass pastures and in valley bushveld in the eastern cape province.individual calves, exposed to infestation for 14 d on dry-land kikuyu grass pastures on the coast near alexandria, were slaughtered at approximately monthly intervals over a period of 2 years and examined for ticks. although seven species were recovered total tick burdens were for the most part low. changing the acaricide with which other cattle on the farm, but not the survey calves, were treated from an organophosphate-based compound to a synthetic pyrethroid resulted in a marked sustained red ...199910631707
the occurrence of theileria and cowdria parasites in african buffalo (syncerus caffer) and their associated amblyomma hebraeum ticks.the polymerase chain reaction and oligonucleotide probing were used to detect theileria and cowdria species in dna extracted from blood and ticks recovered from 24 african buffalo during a gamecapture operation in the kruger national park, south africa. species-specific probing indicated that all but one of the buffalo were carrying at least one theileria species. indirect fluorescent antibody (ifa) serology indicated that all animals had been exposed to theileria parva infection but only 33% we ...199910631711
naturally occurring hepatozoonosis in coyotes from oklahoma.nine of 16 free-ranging coyotes (canis latrans) from central oklahoma (usa) had naturally acquired infections of hepatozoon americanum. infections were confirmed by recognition of tissue stages closely resembling h. americanum in skeletal and cardiac muscle. at the time coyotes were collected they were infested with a variety of ticks, including adult gulf coast ticks (amblyomma maculatum). we propose that the high prevalence of h. americanum in this small sample of free-ranging coyotes and the ...199910073352
serologic study of the prevalence of rickettsiosis in yucatán: evidence for a prevalent spotted fever group rickettsiosis.because of the discovery of a spotted fever group rickettsiosis with signs and symptoms similar to dengue fever in yucatan, mexico, immunofluorescence assay (ifa) serology was performed on sera from 390 persons selected from a representative geographic distribution of rural yucatan to detect antibodies reactive with rickettsia rickettsii, r. akari, a thai strain (tt-118) that is most closely related to a rickettsia identified in amblyomma cajennense ticks in southern texas, and r. typhi. the ifa ...199910497980
transmission of the blood parasite hemolivia mariae between its lizard and tick hosts.the haemogregarine hemolivia mariae is found in the erythrocytes of a natural population of the lizard tiliqua rugosa. it infects two tick species, amblyomma limbatum and aponomma hydrosauri, which parasitise lizards. in laboratory experiments, engorged amb. limbatum nymphs from infected lizards transmitted the haemogregarine to uninfected lizards significantly more often than engorged ap. hydrosauri nymphs. dissections of larvae and nymphs of both species fed on the same infected hosts showed t ...199910494815
wild birds as hosts of amblyomma cajennense (fabricius, 1787) (acari: ixodidae).we evaluated the prevalence, mean intensity and relative density of ticks in 467 wild birds of 67 species (12 families) from forest and cerrado habitats at two protected areas of minas gerais, between march and september 1997. ticks collected (n=177) were identified as larvae and nymphs of amblyomma cajennense and four other species of amblyomma. we report for the first time 28 bird species as hosts of the immature stages of a. cajennense, demonstrating the lack of host specificity of the larvae ...199910419381
phylogeny of the hard ticks (ixodidae) inferred from 18s rrna indicates that the genus aponomma is paraphyletic.we examined the phylogeny of ticks (acari:parasitiformes:ixodida) and their closest known mite relatives (acari:parasitiformes:mesostigmata and holothyrida) using 18s rrna sequences. in our analyses, we included sequences from 36 taxa. sequences for 13 hard ticks (family ixodidae), 5 soft ticks (family argasidae), and 2 mesostigmatid mites were obtained from the genbank database and we generated sequences for 15 hard ticks and 1 holothyrid mite. ten of these tick species were endemic to australi ...199910191073
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