TitleAbstractYear(sorted descending)
conjunctival attachment of a tick: clinicopathologic report of a case.attachment by ticks to ocular surfaces is uncommon, but has been reported. the objective of this article is to describe a case of conjunctival tick attachment and a method for removal by conjunctival excision. a 39-year-old man presented to the emergency department with a complaint of foreign-body sensation in his right eye. he was found to have a live tick embedded in his conjunctiva. the tick was removed en bloc with surrounding conjunctiva by an ophthalmologist. the arthropod was identified a ...201118514466
antigen-presenting cells in draining lymph nodes of goats repeatedly infested by the cayenne tick amblyomma cajennense nymphs.resistance to tick feeding has been previously shown to be an acquired, immunologically mediated phenomenon in goats, associated with cutaneous basophilia to nymphs of amblyomma cajennense, the cayenne tick, after repeated infestations. on the other hand, it is well known that antigen-presenting cells (apcs) play an important role in the host immune reaction to tick infestations. the most able apcs for th cells are the well defined dendritic cells, mononuclear phagocytes and b-lymphocytes. immun ...201120596885
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
cattle and the natural history of rickettsia parkeri in mississippi.abstract cattle have been recognized as hosts for amblyomma maculatum, the gulf coast tick, for over 100 years. for nearly as long, a. maculatum have been known to harbor the spotted fever group rickettsia (sfgr), now known as rickettsia parkeri. however, human infection with r. parkeri was not documented until 2004. results presented herein describe a laboratory and a field study evaluating cattle and the natural history of a. maculatum and r. parkeri in mississippi. in the laboratory study, se ...201120846012
tick surveillance in great britain.the ability for public/veterinary health agencies to assess the risks posed by tick-borne pathogens is reliant on an understanding of the main tick vector species. crucially, the status, distribution, and changing trends in tick distribution and abundance are implicit requirements of any risk assessment; however, this is contingent on the quality of tick distribution data. since 2005 the health protection agency has promoted an enhanced tick surveillance program. through engagement with a variet ...201120849277
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
experimental primary and secondary infections of domestic dogs with ehrlichia this study, the infection dynamics of ehrlichia ewingii, causative agent of granulocytotropic ehrlichiosis in dogs and humans, was examined in experimentally infected dogs by using a combination of physical examination, hematologic and biochemical analyses, and molecular and serologic assays. for the experimental trials, blood from an e. ewingii-infected dog was inoculated intravenously into two na+»ve dogs and two dogs with prior experimental exposure to e. ewingii (both were negative for e. ...201121397411
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
case of tick bite with infestation of an extraordinary number of larval amblyomma testudinarium ticks. 201121434986
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
susceptibility of four tick species, amblyomma americanum, dermacentor variabilis, ixodes scapularis, and rhipicephalus sanguineus (acari: ixodidae), to nootkatone from essential oil of grapefruit.toxicity of nootkatone was determined in laboratory assays against unfed nymphs of amblyomma americanum l., dermacentor variabilis (say), ixodes scapularis say, and rhipicephalus sanguineus latreille. we determined the 50% lethal concentration (lc50) and 90% lethal concentration (lc90) of nootkatone by recording tick mortality 24 h after exposure in treated glass vials. nymphs were susceptible to nootkatone with lc50 values of 0.352, 0.233, 0.169, and 0.197 microg/cm2, and lc90 values of 1.001, ...201121485368
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
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
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
dermoscopy for tick bite: reconfirmation of the usefulness for the initial diagnosis.ticks transmit a variety of infectious diseases. diagnosis requires verification of a tick's presence. here, we describe a 61-year-old woman bitten by an eight-legged nymphal amblyomma testudinarium. we re-emphasize the usefulness of dermoscopy for identifying signs of the bite and determining the species of the biting tick.201121577370
coxiella symbionts in the cayenne tick amblyomma cajennense.members of the coxiella genus are intracellular bacteria that can infect a variety of animals including humans. a symbiotic coxiella was recently described in amblyomma americanum ticks in the northern hemisphere with no further investigations of other amblyomma species in other geographic regions. these ixodid ticks represent a group of important vectors for human infectious agents. in the present work, we have demonstrated that symbiotic coxiella (scox) are widespread, occurring in south ameri ...201121611689
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
perspectives on canine and feline hepatozoonosis.two species of hepatozoon are currently known to infect dogs and cause distinct diseases. hepatozoon canis prevalent in africa, asia, southern europe, south america and recently shown to be present also in the usa causes infection mainly of hemolymphoid organs, whereas hepatozoon americanum prevalent in the southeastern usa causes myositis and severe lameness. h. americanum is transmitted by ingestion of the gulf coast tick amblyomma maculatum and also by predation on infected prey. h. canis is ...201121620568
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
prevalence and species composition of ixodid ticks infesting horses in three agroecologies in central oromia, ethiopia.a cross-sectional study was conducted to determine the species composition and prevalence of ixodid ticks infesting horses in three agroecological zones in central ethiopia. for this purpose, a total of 1,168 horses were examined for tick infestation. an overall prevalence of 39.04% of tick infestation on horses was recorded. a total of 917 adult ticks were collected from infested horses. amblyomma, boophilus, rhipicephalus, and hyalomma genera with the respective prevalence of 3.2%, 1.8%, 29.2% ...201121656133
tick infestation on wild snakes in northern part of western ghats of total, 167 individuals of 30 species of snakes belonging to 22 genera and five families were examined for tick infestation from november 2008 to march 2010. only two species of snakes, ptyas mucosa (l., 1758) (indian rat snake) and naja naja (l., 1758) (spectacled cobra), were found infested by ticks. all ticks collected were identified to be amblyomma gervaisi [previously aponomma gervaisi (lucas, 1847) 1. the average prevalence of these ticks on indian rat snakes (n=48) was 29.16%, with abu ...201121661308
distribution of spotted fever group rickettsiae in select tissues of experimentally infected and field-collected gulf coast ticks.salivary glands, midgut, malpighian tubules, and ovaries were dissected from infected, colony-derived amblyomma maculatum (gulf coast ticks) injected as nymphs with either rickettsia parkeri (a spotted fever group rickettsia [sfgr]; treatment) or phosphate-buffered saline (negative control). for comparison, similar tissues were dissected from hemolymph-positive, field-collected ticks. tissues were analyzed by indirect fluorescent antibody (ifa) tests. all phosphate-buffered saline-injected ticks ...201121661331
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
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, certifect™ (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
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
multi-locus sequence typing of ehrlichia ruminantium strains from geographically diverse origins and collected in amblyomma variegatum from uganda.abstract: background: the rickettsial bacterium ehrlichia ruminantium is the causative agent of heartwater in ruminants. a better understanding of the population genetics of its different strains is, however, needed for the development of novel diagnostic tools, therapeutics and prevention strategies. specifically, the development of effective vaccination policies relies on the proper genotyping and characterisation of field isolates. although multi-locus sequence typing (mlst) has been recently ...201121762509
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
salivary glands of amblyomma cajennense (acari: ixodidae): a histological and an ultrastructural overview.the present study on the salivary glands of semi-engorged amblyomma cajennense females has identified the various cell types present in this tissue and allowed its morphohistochemical characterization. marking techniques were applied to detect polysaccharides (pas), proteins (bromophenol blue), lipids (nile blue) and calcium (von kossa), as well as those of scanning electron microscopy (sem) and transmission electron microscopy (tem). the results obtained by tem showed and confirmed that these i ...201121301932
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
female ixodid ticks grow endocuticle during the rapid phase of engorgement.lees (proc zool soc lond 121:759-772, 1952) concluded that the ixodid tick ixodes ricinus grows endocuticle during the slow but not during the rapid, phase of engorgement, a conclusion supported by andersen and roepstorff (insect biochem mol biol 35:1181-1188, 2005) for the same species. in this study analysis of dimensional data and cuticle weight measurements from female ixodid ticks (amblyomma hebraeum) were used to test this hypothesis. both approaches showed that endocuticle growth continue ...201120711799
secretory process of salivary glands of female amblyomma cajennense (acari: ixodidae) ticks fed on resistant rabbits.ticks have great economic and health importance since infested animals have reduced milk and meat production, and, besides that, they are expensive ectoparasites to control. while feeding, ticks can transmit to their hosts a large amount of pathogens, including rickettsia rickettsii responsible for the "spotted fever" or "fever of the mountains." it is known that animals infested with ticks or artificially immunized with their salivary gland extracts develop resistance, which is related to a dec ...201120711802
rickettsia monteiroi sp. nov., infecting the tick amblyomma incisum in adult amblyomma incisum ticks were collected in an atlantic rainforest area at intervales state park, state of s+úo paulo, brazil. from an a. incisum specimen, rickettsiae were successfully isolated in vero cell culture by the shell vial technique. rickettsial isolation was confirmed by optical microscopy, transmission electron microscopy, and pcrs targeting portions of the rickettsial genes glta, htra, rrs, and sca1 on infected cells. fragments of 1,089, 457, 1,362, and 443 nucleoti ...201121685169
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
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
Effect of Forest Fragmentation on Tick Infestations of Birds and Tick Infection Rates by Rickettsia in the Atlantic Forest of Brazil.Habitat loss and modifications affect biodiversity, potentially contributing to outbreaks of infectious diseases. We evaluated if the patch sizeinfragmented areas of Atlantic Forest in southeastern Brazil influences the diversity of forest birds and consequently the prevalence of ticks on birds and the rickettsial infection of these ticks. During 2 years, we collected ticks from birds in 12 sites: four small forest patches (80-140 ha), four large ones (480-1,850 ha), and four forest control area ...201122173291
Development of multiple-locus variable-number tandem-repeat analysis for rapid genotyping of Ehrlichia ruminantium and its application to infected Amblyomma variegatum collected in heartwater endemic areas in Uganda.SUMMARYThe rickettsial bacterium Ehrlichia ruminantium is the causative agent of heartwater, a serious tick-borne disease in ruminants. The genetic diversity of organisms in the field will have implications for cross-protective capacities of any vaccine developed, and for an effective vaccine design strategy proper genotyping and understanding of existing genetic diversity in the field is necessary. We searched for variable-number tandem-repeat (VNTR) loci for use in a multi-locus VNTR analysis ...201122008706
Coxiella burnetii in Western Barred Bandicoots (Perameles bougainville) from Bernier and Dorre Islands in Western Australia.The aim of this work is to investigate the presence of Coxiella burnetii in Perameles bougainville and their ticks on two islands off Western Australia. Haemaphysalis humerosa, Haemaphysalis ratti, and Haemaphysalis lagostrophi were collected from P. bougainville on Bernier and Dorre Islands from 2005 to 2007; only Amblyomma limbatum was collected from humans over the same interval. One of 13 tick samples and 1 of 12 P. bougainville fecal samples were positive for C. burnetii DNA using quantitat ...201122167449
Detection of Rickettsia parkeri and Candidatus Rickettsia andeanae in Amblyomma maculatum Gulf Coast Ticks Collected from Humans in the United States.Abstract Rickettsia parkeri, a spotted fever group (SFG) rickettsia recently found to be pathogenic to humans, causes an eschar-associated febrile illness. The R. parkeri rickettsiosis, Tidewater spotted fever, has been misdiagnosed as Rocky Mountain spotted fever due to serologic cross reactivity and the lack of specific diagnostic methods. Candidatus Rickettsia andeanae, also a SFG rickettsia, is a recently described agent of unknown pathogenicity originally identified in ticks collected fro ...201122022815
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
a novel rickettsia infecting amblyomma dubitatum ticks in brazil.a total of 130 adult free-living ticks of amblyomma cajennense and 9 free-living amblyomma dubitatum were collected in the surroundings of the pampulha lake, within belo horizonte city, state of minas gerais, south-eastern brazil. each adult tick was tested for rickettsial infection by pcr protocols targeting the rickettsial genes glta, htra, and ompa. all the 130 a. cajennense ticks were negative by pcr. in contrast, all 9 a. dubitatum ticks were shown to contain rickettsial dna. pcr products w ...201122108014
in vitro propagation of candidatus rickettsia andeanae isolated from amblyomma maculatum.candidatus rickettsia andeanae was identified during an investigation of a febrile outbreak in northwestern peru (2002). dna sequencing from two ticks (amblyomma maculatum, ixodes boliviensis) collected during the investigation revealed a novel rickettsia agent with similarity to the spotted fever group rickettsiae. since then, candidatus r. andeanae has been detected in a. maculatum ticks collected in the southeastern and southcentral united states, argentina, and peru. to date, candidatus r. a ...201122098316
rickettsia species infecting amblyomma ticks from an area endemic for brazilian spotted fever in brazil.this study reports rickettsial infection in amblyomma cajennense and amblyomma dubitatum ticks collected in an area of the state of minas gerais, brazil, where brazilian spotted fever is considered endemic. for this purpose, 400 adults of a. cajenennse and 200 adults of a. dubitatum, plus 2,000 larvae and 2,000 nymphs of amblyomma spp. were collected from horses and from the vegetation. the ticks were tested for rickettsial infection through polymerase chain reaction (pcr) protocols targeting po ...201122166385
[surveillance of rickettsia sp. infection in capybaras (hydrochoerus hydrochaeris) a potential model of epidemiological alert in endemic areas].introduction. capybaras (hydrochoerus hydrochaeris) are considered amplifying hosts of rickettsia sp. these rodents are usually parasitized by the tick vector, amblyomma cajennense, the main vector of rickettsioses in humans and animals in south america. capybaras can be used as sentinels in detection of circulation of rickettsiae. objective. antibodies to rickettsiae of spotted fever group were detected in capybaras in a rural area of cordoba province, northern colombia. materials and methods. ...201122159538
essential oils of cupressus funebris, juniperus communis, and j. chinensis (cupressaceae) as repellents against ticks (acari: ixodidae) and mosquitoes (diptera: culicidae) and as toxicants against mosquitoes.juniperus communis leaf oil, j. chinensis wood oil, and cupressus funebris wood oil (cupressaceae) from china were analyzed by gas chromatography and gas chromatography-mass spectrometry. we identified 104 compounds, representing 66.8-95.5% of the oils. the major components were: α-pinene (27.0%), α-terpinene (14.0%), and linalool (10.9%) for j. communis; cuparene (11.3%) and δ-cadinene (7.8%) for j. chinensis; and α-cedrene (16.9%), cedrol (7.6%), and β-cedrene (5.7%) for c. funebris. the essen ...201122129397
relationships between tick counts and coat characteristics in nguni and bonsmara cattle reared on semiarid rangelands in south africa.indigenous nguni cattle are adapted to the semiarid rangeland and appear to be resistant to ticks; however, the mechanism for tick resistance is yet to be established. to understand tick resistance in cattle, relationships among skin thickness, hair length, coat score, and tick counts were estimated in nguni (n=12) and bonsmara (n=12) heifers on semiarid rangelands of south africa. the tick species observed to infest the heifers were rhipicephalus (boophilus) decoloratus (frequency: 76%), rhipic ...201121890073
tick cell lines for study of crimean-congo hemorrhagic fever virus and other arboviruses.abstract continuous cell lines derived from many of the vectors of tick-borne arboviruses of medical and veterinary importance are now available. their role as tools in arbovirus research to date is reviewed and their potential application in studies of tick cell responses to virus infection is explored, by comparison with recent progress in understanding mosquito immunity to arbovirus infection. a preliminary study of propagation of the human pathogen crimean-congo hemorrhagic fever virus (cc ...201121955214
acaricidal effect of an isolate from hoslundia opposita vahl against amblyomma variegatum (acari: ixodidae).hoslundia opposita vahl. (lamiaceae), a common local shrub in ghana, is traditionally known not only for its pharmacological benefits but also for its insecticidal properties. its acaricidal property, however, has not been investigated.201122022167
Southern Tick-Associated Rash Illness (STARI) in the North: STARI following a tick bite in Long Island, New York.The most common clinical manifestation of Lyme disease is the characteristic rash, erythema migrans (EM). In the 1980s EM-like eruptions were reported in Missouri and other southeastern states. The EM-like eruptions, which were of unknown etiology, often followed the bite of the Lone Star tick (Amblyomma americanum) and the rash is called STARI (southern tick-associated rash illness). Although the Lone Star tick is found in the Lyme disease-endemic areas of New England and Mid-Atlantic regions o ...201121940418
experimental infection of the tick amblyomma cajennense, cayenne tick, with rickettsia rickettsii, the agent of rocky mountain spotted the laboratory, amblyomma cajennense (acari: ixodidae) (fabricius) larvae, nymphs and adults were exposed to rickettsia rickettsii by feeding on needle-inoculated animals, and thereafter reared on uninfected guinea pigs or rabbits. regardless of the tick stage that acquired the infection, subsequent tick stages were shown to be infected (confirming transstadial and transovarial transmissions) and were able to transmit r. rickettsii to uninfected animals, as demonstrated by serological and mol ...201122007869
factors associated to theileria equi in equids of two microregions from rio de janeiro, brazil.serum samples from 714 equids of itaguaí and serrana microregions, rio de janeiro, southeastern brazil, were examined by indirect fluorescent antibody test (titer 1:80) for theileria equi. the prevalence in the microregions and factors associated with seropositivity were evaluated and the prevalence ratio (pr) calculated. the overall prevalence of t. equi infection was 81.09% (n = 579), with higher prevalence (p < 0.05) in the itaguaí (85.43%) when compared to serrana microregion (76.92%). the g ...201121961755
A new typing technique for the Rickettsiales Ehrlichia ruminantium: Multiple-locus variable number tandem repeat analysis.Ehrlichia ruminantium (ER) is a member of the order Rickettsiales transmitted by Amblyomma ticks. This obligatory intracellular bacterium is the causative agent of a fatal disease in ruminants, named heartwater. It represents a constraint on breeding development in sub-Saharan Africa and in the Caribbean. The genetic diversity of the strains of ER, which could be a limiting factor to obtain effective vaccines, needs to be better characterized. For this purpose, we developed a molecular typing te ...201122143037
Seroprevalence and risk factors to Ehrlichia spp. and Rickettsia spp. in dogs from the Pantanal Region of Mato Grosso State, Brazil.Sera of 320 dogs from urban and rural areas of a Pantanal region of Brazil were evaluated for rickettsial (Rickettsia rickettsii, R. parkeri, R. amblyommii, R. rhipicephali, R. felis, and R. bellii) and ehrlichial (Ehrlichia canis) infection by the immunofluorescence assay (IFA). Risk factors for ehrlichiosis or rickettsiosis were also evaluated. Positive reaction against Ehrlichia spp. was detected in 227 (70.9%) dogs, 119 (74.3%) from an urban area and 108 (67.5%) from rural areas (P>0.05). Fo ...201122108015
amblyomma dissimile koch (acari: ixodidae) attacking primolius maracana vieillot (psittaciformes: psittacidae) in the amazon region, state of pará, brazil.the tick amblyomma dissimile koch feeds preferentially on reptiles (squamata), although amphibians (anura) also seem to be important hosts. we report an a. dissimile nymph infesting a blue-winged macaw, primolius maracana, held in captivity in the mangal das garças park, state of pará, brazil. environmental observations suggest that free-living iguanas (iguana iguana), which used to walk on the bird enclosure in the park, were the source of the a. dissimile tick that infested the blue-winged mac ...201121952971
high rates of rickettsia parkeri infection in gulf coast ticks (amblyomma maculatum) and identification of "candidatus rickettsia andeanae" from fairfax county, virginia.the gulf coast tick, amblyomma maculatum, is a vector of rickettsia parkeri, a recently identified human pathogen that causes a disease with clinical symptoms that resemble a mild form of rocky mountain spotted fever. because the prevalence of r. parkeri infection in geographically distinct populations of a. maculatum is not fully understood, a. maculatum specimens collected as part of a tick and pathogen surveillance system in fairfax county, virginia, were screened to determine pathogen infect ...201121867421
Infection prevalences of common tick-borne pathogens in adult lone star ticks (Amblyomma americanum) and American dog ticks (Dermacentor variabilis) in Kentucky.Rocky Mountain spotted fever, Lyme disease, and ehrlichiosis are tick-borne diseases that are reported annually in Kentucky. We conducted a survey to describe infection prevalence of tick-borne pathogens in Amblyomma americanum and Dermacentor variabilis ticks collected in Kentucky. During 2007-2008, we collected 287 ticks (179 D. variabilis and 108 A. americanum) from canine, feral hog, horse, raccoon, white-tailed deer, and human hosts in six counties in Kentucky. Ticks were screened for Ricke ...201121976578
rickettsia parkeri in amblyomma maculatum ticks, north carolina, usa, 2009-2010.we detected rickettsia parkeri in 20%-33% of amblyomma maculatum ticks sampled in north carolina. results highlight the high frequencies of r. parkeri-infected ticks in the state with the highest annual incidence of rocky mountain spotted fever. epidemiologic studies are needed to definitively link r. parkeri to cases of spotted fever rickettsiosis.201122172164
Study of infection by Rickettsiae of the spotted fever group in humans and ticks in an urban park located in the City of Londrina, State of Paraná, Brazil.Spotted fevers are emerging zoonoses caused by Rickettsia species in the spotted fever group (SFG). Rickettsia rickettsii is the main etiologic agent of Brazilian spotted fever (BSF)and it is transmitted by Amblyomma spp. ticks.201121901874
Life-cycle and host preference of Amblyomma ovale (Acari: Ixodidae) under laboratory conditions.This study evaluated for the first time the life cycle of Amblyomma ovale in the laboratory. For this purpose, larvae and nymphs were exposed to Gallus gallus (chickens), Cavia porcellus (guinea pigs), Rattus norvegicus (wistar rats), Oryctolagus cuniculus (domestic rabbits), Calomys callosus (vesper mouse), and Didelphis albiventris (white-eared opossum). Nymphs were also exposed to Nectomys squamipes (South American water rat). Adult ticks were fed on dogs. The life-cycle of A. ovale in labora ...201122113779
Global gene expression profiling of Ehrlichia ruminantium at different stages of development.Ehrlichia ruminantium (ER), the causative agent of heartwater on ruminants, is an obligate intracellular bacterium transmitted by ticks of the genus Amblyomma. Previous studies have shown that early stages of development may be critical for Ehrlichia pathogenicity. To gain insights into the biology of intracellular ER, we determined the genome-wide transcriptional profile of ER replicating inside bovine aortic endothelial cells using DNA microarrays. At intermediate and late stages of infection ...201122098128
evaluation of 4-poster acaricide applicators to manage tick populations associated with disease risk in a tennessee retirement 1993, four residents of a retirement community in middle tennessee were hospitalized with symptoms of ehrlichiosis causing community managers to implement mitigation methods to reduce tick numbers. for the past four years, managers have utilized 4-poster acaricide applicators that aim to reduce disease risk to residents by killing ticks that feed on deer. to determine the efficacy of this technique, we assessed amblyomma americanum abundance in the vicinity of the devices by dragging 400 m ve ...201122129412
equine piroplasmosis associated with amblyomma cajennense ticks, texas, usa.we report an outbreak of equine piroplasmosis in southern texas, usa, in 2009. infection prevalence reached 100% in some areas (292 infected horses). amblyomma cajennense was the predominant tick and experimentally transmitted theileria equi to an uninfected horse. we suggest that transmission by this tick species played a role in this outbreak.201122000367
spotted fever group rickettsia infecting ticks (acari: ixodidae) in the state of santa catarina, brazil.during 2006-2008, a total of 260 adult ticks were collected from domestic and wild animals in different regions of the state of santa catarina (sc), brazil, including areas where human cases of brazilian spotted fever have been reported. collected ticks belonging to nine species (amblyomma aureolatum, amblyomma cajennense, amblyomma dubitatum, amblyomma longirostre, amblyomma ovale, amblyomma tigrinum, dermacentor nitens, rhipicephalus microplus and rhipicephalus sanguineus) were tested by polym ...201122241112
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
the action of amblyomma cajennense tick saliva in compounds of the hemostatic system and cytotoxicity in tumor cell lines.ticks are blood-feeding arthropods that secrete anticoagulant molecules to maintain the fluidity of the blood during its feeding. tick saliva has many compounds with biological activities that interact directly with host systems, such as blood clotting, platelet aggregation, cell death, among others. some reports show that there are proteins with anticancer properties in tick saliva. this paper reports some of the biological roles of the amblyomma cajennense tick saliva, including factor xa and ...201121723081
nymphs of the genus amblyomma (acari: ixodidae) of brazil: descriptions, redescriptions, and identification key.together with the larval stage, the nymphal stage of ticks of the genus amblyomma are the most aggressive ticks for humans entering areas inhabited by wildlife and some domestic animals in brazil. however, due to the absence of morphological descriptions of the nymphal stage of most brazilian amblyomma species, plus the lack of an identification key, little or nothing is known about the life history of amblyomma spp. nymphs in the country. in the present study, morphological description of the n ...201021771514
a case of amblyomma testudinarium tick bite in a korean woman.a case of tick bite was found in the inguinal region of a 74-year-old korean woman. she was attacked by the tick while working in her vegetable garden in the vicinity of mountain located in suncheon city, the southern coastal area of the korean peninsula. on admission she complained of mild discomfort and itching around the bite area. the causative tick was 23 mm long and had slender pedipalps. the scutum was quite ornate and had eyes at the edge. the genital aperture was located anterior to the ...201021234234
veterinary extension on sampling techniques related to heartwater research.heartwater, a tick-borne disease caused by ehrlichia ruminantium, is considered to be a significant cause of mortality amongst domestic and wild ruminants in south africa. the main vector is amblyomma hebraeum and although previous epidemiological studies have outlined endemic areas based on mortalities, these have been limited by diagnostic methods which relied mainly on positive brain smears. the indirect fluorescent antibody test (ifa) has a low specificity for heartwater organisms as it cros ...201021247042
comparison of two methods for collecting free-living ticks in the amazonian the present study, we compared 2 methods for collecting ixodid ticks on the verges of animal trails in a primary amazon forest area in northern brazil. (i) dragging: this method was based on passing a 1-m(2) white flannel over the vegetation and checking the flannel for the presence of caught ticks every 5-10 m. (ii) visual search: this method consisted of looking for questing ticks on the tips of leaves of the vegetation bordering animal trails in the forest. a total of 103 adult ticks belon ...201021771528
refuge sharing network predicts ectoparasite load in a in social groups facilitates cross-infection by parasites. however, empirical studies on indirect transmission within wildlife populations are scarce. we investigated whether asynchronous overnight refuge sharing among neighboring sleepy lizards, tiliqua rugosa, facilitates indirect transmission of its ectoparasitic tick, amblyomma limbatum. we fitted 18 neighboring lizards with gps recorders, observed their overnight refuge use each night over 3 months, and counted their ticks every fort ...201020802788
absence of rickettsia rickettsii and occurrence of other spotted fever group rickettsiae in ticks from tennessee.rocky mountain spotted fever (rmsf) is the most common tick-borne illness in tennessee. little is known about the occurrence of r. rickettsii, the causative agent, in ticks in tennessee. to better understand the prevalence and distribution of rickettsial agents in ticks, we tested 1,265 amblyomma, dermacentor, and ixodes adult and nymphal ticks. additionally, we tested 231 amblyomma americanum larvae. ticks were collected from 49 counties from humans, wild animals, domestic canines, and flannel ...201020810834
detection of theileria and babesia in brown brocket deer (mazama gouazoubira) and marsh deer (blastocerus dichotomus) in the state of minas gerais, brazil.intraerythrocytic protozoan species of the genera theileria and babesia are known to infect both wild and domestic animals, and both are transmitted by hard-ticks of the family ixodidae. the prevalences of hemoprotozoa and ectoparasites in 15 free-living mazama gouazoubira, two captive m. gouazoubira and four captive blastocerus dichotomus from the state of minas gerais, brazil, have been determined through the examination of blood smears and the use of nested polymerase chain reaction (npcr). t ...201021354704
population genetics of amblyomma americanum (acari: ixodidae) collected from arkansas.lone star ticks, amblyomma americanum l. (acari: ixodidae),infest multiple hosts such as birds, and mammals of various sizes (rodents to white-tailed deer) and can harbor human pathogens such as borrelia lonestari and ehrlichiosis chaffeensis. the population structure of 251 a. americanum ticks, collected from canines and two white-tailed deer in six arkansas ecoregions, was examined using dna sequences of a 247-bp region of the mitochondrial dna ribosomal rna 16s gene. of the 247 nucleotide cha ...201020380295
bacterial diversity in amblyomma americanum (acari: ixodidae) with a focus on members of the genus rickettsia.the lone star tick, amblyomma americanum (acari: ixodidae), is commonly reported from people and animals throughout the eastern u.s. and is associated with transmission of a number of emerging diseases. to better define the microbial communities within lone star ticks, 16s rrna gene based analysis using bacteria-wide primers, followed by sequencing of individual clones (n = 449) was used to identify the most common bacterial operational taxonomic units (otus) present within colony-reared and wil ...201020380308
repellent activity of deet against amblyomma cajennense (acari: ixodidae) nymphs submitted to different laboratory bioassays.this study was developed to evaluate the repellent activity of n,n-diethyl-3-methylbenzamide (deet) against amblyomma cajennense nymphs. two repellent bioassays were compared and the effective concentration and repellent time were calculated. the fingertip test was accomplished to evaluate in vivo four concentrations of the compound (0.200; 0.100; 0.050 and 0.025⁻²) and the filter-paper bioassay to evaluate in vitro the two highest concentrations.the compound provided repellence higher tha ...201020385054
rickettsiae in gulf coast ticks, arkansas, determine the cause of spotted fever cases in the southern united states, we screened gulf coast ticks (amblyomma maculatum) collected in arkansas for rickettsiae. of the screened ticks, 30% had pcr amplicons consistent with rickettsia parkeri or candidatus rickettsia amblyommii.201020409375
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