PMID(sorted ascending)
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
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
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
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
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
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
the diagnostic usefulness of dermoscopy for identifying six-legged larval ticks.ticks are vectors of a variety of diseases such as lyme disease and japanese spotted fever. we examined an 87-year-old female with multiple tick bites by at least 236 larval amblyomma testudinarium infestations. numerous tick bites are generally caused by the six-legged larvae, which were verified in this case by dermoscopy. the present case indicates the diagnostic usefulness of dermoscopy for six-legged larval tick bites.201021771529
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
[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
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
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
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
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
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
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
Displaying items 1701 - 1744 of 1744