TitleAbstractYear(sorted ascending)
meteorological indicators for amblyomma cajennense and population dynamics in the tamaulipan biotic province in texas.we studied the population dynamics of free-living ticks in the tamaulipan biotic province in south texas from march, 2005 to november, 2008. we collected 70,873 ticks using carbon dioxide traps. amblyomma cajennense represented 93.6% of the ticks identified. a. cajennense is distributed from northern argentina to south texas in the tamaulipan biotic province. emergence of larval a. cajennense ticks was observed two to five weeks after significant rain events (p<0.0001) and had a strong negative ...201121635651
tick-borne bacteria in free-living jaguars (panthera onca) in pantanal, brazil.abstract tick-borne bacteria were investigated in 10 free-living jaguars and their ticks in the pantanal biome, brazil. jaguar sera were tested by indirect fluorescent antibody assays using rickettsia rickettsii, rickettsia parkeri, rickettsia amblyommii, rickettsia rhipicephali, rickettsia felis, rickettsia bellii, ehrlichia canis, and coxiella burnetii as crude antigens. all 10 jaguar sera reacted (titer ≥64) to at least one rickettsia species; 4 and 3 sera reacted with e. canis and c. burneti ...201121612532
first report of the isolation and molecular characterization of rickettsia amblyommii and rickettsia felis in central america.abstract during 2010, 15 adult ticks, identified as amblyomma cajennense, were collected from horses in cahuita and turrialba districts, whereas 7 fleas, identified as ctenocephalides felis, were collected from a dog in san jose city, costa rica. in the laboratory, three a. cajennense specimens, two from cahuita and one from turrialba, were individually processed for rickettsial isolation in cell culture, as was a pool of seven fleas. rickettsiae were successfully isolated and established in ver ...201121612539
suppression of host-seeking ixodes scapularis and amblyomma americanum (acari: ixodidae) nymphs after dual applications of plant-derived acaricides in new jersey.we evaluated the ability of dual applications of natural, plant-derived acaricides to suppress nymphal ixodes scapularis say and amblyomma americanum (l.) (acari: ixodidae) in a lyme disease endemic area of new jersey. an aqueous formulation of 2% nootkatone provided >90% control of i. scapularis through 7 d. control declined to 80.9% at 14 d, and a second application was made that provided >95% control through the remaining 4 wk of the nymphal season. nootkatone provided >90% control of a. amer ...201121510219
experimental infection of amblyomma aureolatum ticks with rickettsia rickettsii.we experimentally infected amblyomma aureolatum ticks with the bacterium rickettsia rickettsii, the etiologic agent of rocky mountain spotted fever (rmsf). these ticks are a vector for rmsf in brazil. r. rickettsii was efficiently conserved by both transstadial maintenance and vertical (transovarial) transmission to 100% of the ticks through 4 laboratory generations. however, lower reproductive performance and survival of infected females was attributed to r. rickettsii infection. therefore, bec ...201121529391
rickettsia rickettsii transmission by a lone star tick, north carolina.only indirect or circumstantial evidence has been published to support transmission of rickettsia rickettsii by amblyomma americanum (lone star) ticks in north america. this study provides molecular evidence that a. americanum ticks can function, although most likely infrequently, as vectors of rocky mountain spotted fever for humans.201121529399
rickettsia parkeri in gulf coast ticks, southeastern virginia, usa.we report evidence that amblyomma maculatum tick populations are well established in southeastern virginia. we found that 43.1% of the adult gulf coast ticks collected in the summer of 2010 carried rickettsia parkeri, suggesting that persons living in or visiting southeastern virginia are at risk for infection with this pathogen.201121529406
seasonal dynamics and hosts of amblyomma triste (acari: ixodidae) in argentina.the seasonal dynamics and host usage of amblyomma triste in argentina were analyzed. adults of a. triste were present from early winter to mid-summer, with the peak of abundance from late winter to mid-spring (august to october). larvae and nymphs were found from december to june, with the peak of abundance in summer. there were no differences among the biological parameters (pre-moult period of larvae and nymphs, pre-oviposition period of females, and minimum incubation period of eggs) of engor ...201121536384
efficacy of spinosad against acaricide-resistant and -susceptible rhipicephalus (boophilus) microplus and acaricide-susceptible amblyomma americanum and dermacentor variabilis.various acaricide-resistant strains of rhipicephalus (boophilus) microplus, representative of the major resistance mechanisms found in mexico and brazil, were exposed to spinosad using the food and agriculture organization of the united nations larval packet test and adult immersion test (ait). larvae of all strains tested were found to be susceptible to spinosad. conversely, spinosad did not show toxic activity toward engorged females used in the ait. in vitro tests against larvae, nymphs, and ...201121485374
rickettsia rickettsii (rickettsiales: rickettsiaceae) in amblyomma americanum (acari: ixodidae) from kansas.the role of lone star ticks as vectors for rocky mountain spotted fever (rmsf) remains poorly described. we compared the entomological inoculation rates (eirs) for rickettsia spp. for representative sites in missouri and kansas, states that frequently report rmsf each year. host-seeking ticks were collected during 2006 and pooled tick homogenates analyzed by polymerase chain reaction to detect probable r. rickettsii, with confirmation for multiple gene targets performed on individual ticks from ...201121485390
ehrlichia ruminantium in amblyomma variegatum and domestic ruminants in the caribbean.the highly sensitive nested pcs20 polymerase chain reaction assay for ehrlichia ruminantium was negative on 506 amblyomma variegatum from caribbean islands where clinical heartwater has not been reported, mainly the united states virgin islands (18), dominica (170), montserrat (5), nevis (34), st. kitts (262), and st. lucia (17). positive results were obtained with positive controls (crystal springs strain) and a. variegatum from countries in africa where infections are endemic, mainly tanzania ...201121485394
failure of the amblyomma cajennense nymph to become infected by theileria equi after feeding on acute or chronically infected horses.tick-borne diseases in horses are caused by the intraerythrocytic protozoan parasites theileria equi and babesia caballi. although t. equi is highly endemic in latin america, the new world vector of this important parasite is controversial. the aim of this study was to test the ability of nymph amblyomma cajennense ticks acquire infection by t. equi following feeding on infected horses. three experiments were performed: tick acquisition of t. equi from an experimentally infected horse, tick acqu ...201121501609
infection by spotted fever rickettsiae in people, dogs, horses and ticks in londrina, parana state, brazil.spotted fever is a disease caused by bacteria from the genus rickettsia of the spotted fever group (sfg). rickettsia rickettsii is likely the main agent of brazilian spotted fever (bsf). with the objective of gathering information on the circulation of sfg rickettsiae in londrina, parana state, ticks from dogs and horses and also blood from dogs, horses and humans were collected in a neighbourhood of the city which presented potential for circulation of rickettsiae between hosts and vectors. amb ...201121824336
comparative analysis of hemocyte phagocytosis between six species of arthropods as measured by flow cytometry.phagocytosis of pathogens by hemocytes is a rapid-acting immune response and represents a primary means of limiting microbial infection in some species of arthropods. to survey the relative capacity of hemocyte phagocytosis as a function of the arthropod immune response, we examined the extent of phagocytosis among a wide taxonomic range of arthropod species including a decapod crustacean (litopenaeus vannamei), three ixodid tick species (amblyomma americanum, dermacentor variabilis, and ixodes ...201121843526
rickettsia parkeri rickettsiosis, argentina.rickettsia parkeri, a recently identified cause of spotted fever rickettsiosis in the united states, has been found in amblyomma triste ticks in several countries of south america, including argentina, where it is believed to cause disease in humans. we describe the clinical and epidemiologic characteristics of 2 patients in argentina with confirmed r. parkeri infection and 7 additional patients with suspected r. parkeri rickettsiosis identified at 1 hospital during 2004-2009. the frequency and ...201121762568
efficacy of dry ice-baited traps for sampling amblyomma americanum (acari: ixodidae) varies with life stage but not habitat.the carbon dioxide-baited trap is the most common and effective method for sampling vector life-stage amblyomma americanum (l.) (acari: ixodidae), although confounding environmental variables are rarely considered. a mark-recapture experiment was designed to compare recapture proportions of a. americanum nymphs and adults between two habitat types: old field and oak-hickory forest. powdered fluorescent dye was used to mark a. americanum ticks released in 1-m increments from carbon dioxide-baited ...201121661336
case of tick bite with infestation of an extraordinary number of larval amblyomma testudinarium ticks. 201121434986
distribution and habitat utilization of the gopher tortoise tick ( amblyomma tuberculatum ) in southern mississippi.abstract the distribution of the gopher tortoise tick ( amblyomma tuberculatum ) has been considered intrinsically linked to the distribution of its primary host, gopher tortoises ( gopherus polyphemus ). however, the presence of g. polyphemus does not always equate to the presence of a. tuberculatum . there is a paucity of data on the ecology, habitat preferences, and distribution of a. tuberculatum . the goals of this study were to assess the distribution of a. tuberculatum in southern mississ ...201121506776
Geographical distribution and prevalence of selected Borrelia, Ehrlichia, and Rickettsia infections in Amblyomma americanum (Acari: Ixodidae) in New Jersey.We used published accounts to describe the known statewide distribution of the lone star tick, Amblyomma americanum, in New Jersey and field surveys to characterize the geographical range of A. americanum and selected A. americanum-transmitted pathogens in Monmouth County, the hypothesized northern limit of the species distribution. Ticks were collected using standardized methods from 50 widely dispersed public access areas within 18 municipalities to produce estimates of relative abundance amon ...201122017087
restricted application of insecticides: a promising tsetse control technique, but what do the farmers think of it?restricted application of insecticides to cattle is a cheap and safe farmer-based method to control tsetse. in western africa, it is applied using a footbath, mainly to control nagana and the tick amblyomma variegatum. in eastern and southern africa, it might help controlling the human disease, i.e., rhodesian sleeping sickness as well. the efficiency of this new control method against ticks, tsetse and trypanosomoses has been demonstrated earlier. the invention, co-built by researchers and farm ...201121858241
gotch ear: a poorly described, local, pathologic condition of livestock associated primarily with the gulf coast tick, amblyomma maculatum.gotch ear is a condition in animals in which the ear is swollen, deformed, curled, drooped, possibly necrotic, and is usually associated with attachment by the gulf coast tick, amblyomma maculatum. little is known of the etiology or epidemiology of gotch ear in livestock. reports generally describe the condition in cattle, but it has also been reported in horses and mules and more recently in a goat. this review explores the history and etymology of the term "gotch ear" and reports on current st ...201122047764
acaricidal activity of thymol on larvae and nymphs of amblyomma cajennense (acari: ixodidae).the aim of the present study was to evaluate the acaricidal efficacy of thymol on unengorged and engorged larvae and engorged nymphs of amblyomma cajennense. to perform the test for unengorged larvae, the larval packet technique was employed and mortality was evaluated 24h after the test, while for engorged larvae and engorged nymphs the immersion technique was employed and mortality was evaluated after 15 days. in all the experiments, the following concentrations of thymol were tested: 2.5, 5.0 ...201121794986
efficacy of a novel topical combination of fipronil, amitraz and (s)-methoprene for treatment and control of induced infestations with four north american tick species (dermacentor variabilis, ixodes scapularis, amblyomma americanum and amblyomma maculatum) on dogs.five laboratory studies were conducted to confirm that a single topical dose of the novel combination of fipronil, amitraz and (s)-methoprene, certifectâ„¢ (merial limited, ga, usa), is efficacious for the rapid control of pre-existing infestations and the prevention of new infestations with ixodes scapularis, dermacentor variabilis, amblyomma americanum and amblyomma maculatum for at least 28 days on dogs. in each study, 8 male and 8 female purpose-bred, laboratory beagles were randomly assigned ...201121777734
induction of complete courtship ritual in amblyomma cajennense using 2,6-dichlorophenol at female-equivalent order to clarify the role of 2,6-dichlorophenol (2,6-dcp) in the courtship of amblyomma cajennense, sexually mature males that had previously fed on rabbits were tested in bioassays. the males were released onto dummies treated with whole female extract or synthetic 2,6-dcp at a concentration of two female equivalents, or with hexane (control), and their responses were observed. in the presence of both the extract and 2,6-dcp, excitation was observed among the males, expressed in the form of ...201122166393
Ehrlichia chaffeensis transcriptome in mammalian and arthropod hosts reveals differential gene expression and post transcriptional regulation.Human monocytotropic ehrlichiosis is an emerging life-threatening zoonosis caused by obligately intracellular bacterium, Ehrlichia chaffeensis. E. chaffeensis is transmitted by the lone star tick, Amblyomma americanum, and replicates in mononuclear phagocytes in mammalian hosts. Differences in the E. chaffeensis transcriptome in mammalian and arthropod hosts are unknown. Thus, we determined host-specific E. chaffeensis gene expression in human monocyte (THP-1) and in Amblyomma and Ixodes tick ce ...201121915290
structure of thymidylate kinase from ehrlichia chaffeensis.the enzyme thymidylate kinase phosphorylates the substrate thymidine 5'-phosphate (dtmp) to form thymidine 5'-diphosphate (dtdp), which is further phosphorylated to dttp for incorporation into dna. ehrlichia chaffeensis is the etiologic agent of human monocytotropic erlichiosis (hme), a potentially life-threatening tick-borne infection. hme is endemic in the united states from the southern states up to the eastern seaboard. hme is transmitted to humans via the lone star tick amblyomma americanum ...201121904055
beauveria bassiana (ascomycota: hypocreales) as a management agent for free-living amblyomma americanum (acari: ixodidae) in ohio.unfed adult amblyomma americanum were exposed to the entomopathogenic fungus beauveria bassiana and placed in the field. ticks exposed to the fungus experienced higher mortality than those in the control group (p = 0.001). it is recommended that for inclusion in a tick management program, the fungus be applied in the late evening during the months march through june as this is when ticks are most active and conditions suitable for fungal activity occur.201120607363
emergence of rickettsia africae, oceania.we detected rickettsia africae, the agent of african tick-bite fever (atbf), by amplification of fragments of glta, ompa, and ompb genes from 3 specimens of amblyomma loculosum ticks collected from humans and birds in new caledonia. clinicians who treat persons in this region should be on alert for atbf.201121192865
ecology and dynamics of the blood parasite, hepatozoon tuatarae (apicomplexa), in tuatara (sphenodon punctatus) on stephens island, new zealand.we explored infection patterns and temporal dynamics of the protozoan blood parasite hepatozoon tuatarae (apicomplexa) infecting the tuatara (sphenodon punctatus), a protected reptile living on stephens island, new zealand. in march 2006, we surveyed tuatara in five study sites to examine spatial variation in infection prevalence, and four times, from may 2005 to november 2006, we recaptured marked individuals within three study sites to examine the temporal dynamics of infection. we also examin ...201121270002
amblyomma americanum (l.) (acari: ixodidae) tick salivary gland serine protease inhibitor (serpin) 6 is secreted into tick saliva during tick order to successfully feed and transmit disease agents, ticks are thought to inject serine protease inhibitors (serpins) into the host to modulate host defense responses to tick feeding, such as inflammation, the complement activation pathway and blood coagulation. in this study, we show that amblyomma americanum (aam) serpin (s) 6 is putatively injected into the host during tick feeding, in that the antibody to recombinant (r) aams6 specifically reacted with the expected ~43/45 kda aams6 pro ...201121270316
cross-mating experiments with geographically different populations of amblyomma cajennense (acari: ixodidae).the present study evaluated the reproductive compatibility of the crosses between adult ticks of the following three geographically different populations of amblyomma cajennense: state of são paulo (sp), southeastern brazil; state of rondônia (ro), northern brazil; and colombia (co). in addition, crosses between a. cajennense ticks from argentina (ar) and sp ticks were also performed. the argentinean population (ar) was compatible with sp because their crosses resulted in high % egg hatching (me ...201121286933
a further insight into the sialome of the tropical bont tick, amblyomma variegatum.ticks--vectors of medical and veterinary importance--are themselves also significant pests. tick salivary proteins are the result of adaptation to blood feeding and contain inhibitors of blood clotting, platelet aggregation, and angiogenesis, as well as vasodilators and immunomodulators. a previous analysis of the sialotranscriptome (from the greek sialo, saliva) of amblyomma variegatum is revisited in light of recent advances in tick sialomes and provides a database to perform a proteomic study ...201121362191
an acarologic survey and amblyomma americanum distribution map with implications for tularemia risk in the united states, tickborne diseases occur focally. missouri represents a major focus of several tickborne diseases that includes spotted fever rickettsiosis, tularemia, and ehrlichiosis. our study sought to determine the potential risk of human exposure to human-biting vector ticks in this area. we collected ticks in 79 sites in southern missouri during june 7-10, 2009, which yielded 1,047 adult and 3,585 nymphal amblyomma americanum, 5 adult amblyomma maculatum, 19 adult dermacentor variab ...201121363979
gotch ear in a goat: a case report.abstract a 1-year-old castrated male saanen goat was observed to have drooping and edema of the left ear consistent with published accounts of gotch ear in cattle associated with a tick bite. the goat's left ear was edematous from the tip of the pinna to the base of the ear. no signs of trauma or infectious processes were observed. three engorged gulf coast ticks (amblyomma maculatum) were observed attached inside the ear. ticks were removed and the ear biopsied at tick attachment sites. the aff ...201121395411
tick paralysis caused by amblyomma maculatum on the mexican pacific coast.tick paralysis is a rare entity in which it is necessary to identify the cause and remove the arthropod to have a rapid remission of symptoms. in the absence of an early diagnosis, the outcome can be fatal, as toxins are released from the tick's saliva as it feeds. to the best of the authors' knowledge, this is the first clinical report of the disease in mexico and latin america. a 22-year-old man from a rural area, who was in contact with cattle, developed ascending flaccid paralysis secondary ...201121395426
first reports of ectoparasites collected from wild-caught exotic reptiles in florida.we collected ectoparasites from 27 of 51 wild-caught, free-ranging exotic reptiles examined in florida from 2003 to 2008. sampled animals represented eight species, five of which yielded ectoparasites. reported new parasite distribution records for the united states include the following: the first collection of the african tick amblyomma latum (koch) from a wild-caught animal [ball python, python regius (shaw)] in the united states; the first collection of the lizard scale mite hirstiella stami ...201121337954
response of nkedi zebu and ankole cattle to tick infestation and natural tick-borne, helminth and trypanosome infections in uganda.a cross-sectional study was conducted in soroti district of uganda to establish important traits of nkedi zebu and ankole cattle regarding their production performance responses to natural infections of trypanosomes, gastrointestinal nematodes, theileria parva, babesia bigemina, anaplasma marginale and tick infestations. over four visits between october 2006 to august 2007, tick counts were performed and blood, faecal samples and sera were collected from the nkedi zebu (295) and ankole (165) cat ...201121350849
life cycle of the tick amblyomma parvum aragão, 1908 (acari: ixodidae) and suitability of domestic hosts under laboratory conditions.amblyomma parvum is a widespread neotropical tick found on several domestic animals and is known to harbor a rickettsia species of yet unknown pathogenicity. however its life cycle on, and suitability of, several of these hosts has not been described. in this work the biology of a. parvum is presented when fed on seven domestic hosts (chicken, dog, rabbit, horse, guinea pig, cattle and goat). the complete life cycle of the tick varied from 96.8 to 102 days. highest engorgement weight of larvae w ...201121353392
the relevance of tick bites to the production of ige antibodies to the mammalian oligosaccharide galactose-a-1, 2009, we reported a novel form of delayed anaphylaxis to red meat that is related to serum ige antibodies to the oligosaccharide galactose-a-1,3-galactose (alpha-gal). most of these patients had tolerated meat for many years previously. the implication is that some exposure in adult life had stimulated the production of these ige antibodies.201121453959
risk factors for african tick-bite fever in rural central africa.african tick-bite fever is an emerging infectious disease caused by the spotted fever group rickettsia, rickettsia africae, and is transmitted by ticks of the genus amblyomma. to determine the seroprevalence of exposure to r. africae and risk factors associated with infection, we conducted a cross-sectional study of persons in seven rural villages in distinct ecological habitats of cameroon. we examined 903 plasma samples by using an indirect immunofluorescence assay for antibodies to r. africae ...201121460018
anointing chemicals and hematophagous arthropods: responses by ticks and mosquitoes to citrus (rutaceae) peel exudates and monoterpene components.some birds and mammals roll on or wipe themselves with the fruits or leaves of citrus spp. or other rutaceae. these anointing behaviors, as with anointing in general, are thought to function in the topical acquisition of chemicals that deter consumers, including hematophagous arthropods. we measured avoidance and other responses by nymphal lone star ticks (amblyomma americanum) and adult female yellow fever mosquitoes (aedes aegypti) to lemon peel exudate and to 24 volatile monoterpenes (racemat ...201121409496
distribution and molecular characterization of wolbachia endosymbionts and filarial nematodes in maryland populations of the lone star tick (amblyomma americanum).the lone star tick amblyomma americanum is host to a wide diversity of endosymbiotic bacteria. we identified a novel wolbachia symbiont infecting a. americanum. multilocus sequence typing phylogenetically placed the endosymbiont in the increasingly diverse f supergroup. we assayed a total of 1031 ticks (119 females, 78 males and 834 nymphs in 89 pools) from 16 maryland populations for infection. infection frequencies in the natural populations were approximately 5% in females and <2% (minimum in ...201121410491
colonization of grande comore island by a lineage of rhipicephalus appendiculatus ticks.union of the comoros suffered a severe east coast fever epidemic in 2004. rhipicephalus appendiculatus was probably involved in pathogen transmission as this competent tick species, although previously absent from comoros, was sampled on 4 animals on one geographical site during the epidemic. we carried out an entomological survey on all three islands of union of the comoros to establish cattle tick species distribution with a special emphasis on r. appendiculatus. we investigated r. appendicula ...201121414194
plant extracts, isolated phytochemicals, and plant-derived agents which are lethal to arthropod vectors of human tropical diseases--a review.the recent scientific literature on plant-derived agents with potential or effective use in the control of the arthropod vectors of human tropical diseases is reviewed. arthropod-borne tropical diseases include: amebiasis, chagas disease (american trypanosomiasis), cholera, cryptosporidiosis, dengue (hemorrhagic fever), epidemic typhus (brill-zinsser disease), filariasis (elephantiasis), giardia (giardiasis), human african trypanosomiasis (sleeping sickness), isosporiasis, leishmaniasis, lyme di ...201121432748
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