Publications

case of tick bite with infestation of an extraordinary number of larval amblyomma testudinarium ticks.		2011	21434986
the relevance of tick bites to the production of ige antibodies to the mammalian oligosaccharide galactose-a-1,3-galactose.	in 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.	2011	21453959
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 ...	2011	21460018
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, ...	2011	21485368
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 ...	2011	21485374
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 ...	2011	21485390
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 ...	2011	21485394
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 ...	2011	21501609
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 ...	2011	21506776
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 ...	2011	21510219
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 ...	2011	21529391
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.	2011	21529399
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.	2011	21529406
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 ...	2011	21536384
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.	2011	21577370
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 ...	2011	21611689
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 ...	2011	21612532
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 ...	2011	21612539
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 ...	2011	21620568
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 ...	2011	21635651
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% ...	2011	21656133
tick infestation on wild snakes in northern part of western ghats of india.	in 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 ...	2011	21661308
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 ...	2011	21661331
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 ...	2011	21661336
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 ...	2011	21794986
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 ...	2011	21777734
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 ...	2011	21762568
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 ...	2011	21762509
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 ...	2011	21270002
amblyomma americanum (l.) (acari: ixodidae) tick salivary gland serine protease inhibitor (serpin) 6 is secreted into tick saliva during tick feeding.	in 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 ...	2011	21270316
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 ...	2011	21286933
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 ...	2011	21301932
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 ...	2011	21337954
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 ...	2011	21350849
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 ...	2011	21353392
rickettsia monteiroi sp. nov., infecting the tick amblyomma incisum in brazil.	free-living 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 ...	2011	21685169
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 ...	2011	21824336
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 ...	2011	21843526
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 ...	2011	21723081
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 ...	2011	20846012
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 ...	2011	20849277
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 ...	2011	20711799
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 ...	2011	20711802
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.	2011	21192865