Publications

TitleAbstractYear
Filter
PMID
Filter
hemorrhagic disease in dogs infected with an unclassified intraendothelial piroplasm in southern brazil.a hemorrhagic disease affecting dogs in brazil, referred to popularly as "nambiuvú" (bloody ears) and believed to be transmitted by ticks, has been observed in animals infected with an organism described originally in 1910 as a piroplasm, and known locally as rangelia vitalii. in this series of 10 cases, the disease was characterized by anaemia, jaundice, fever, spleno- and lymphadenomegaly, hemorrhage in the gastrointestinal tract, and persistent bleeding from the nose, oral cavity and tips, ma ...200516153781
ehrlichial infection in cameroonian canines by ehrlichia canis and ehrlichia ewingii.ehrlichia chaffeensis and ehrlichia ewingii are agents of emerging human ehrlichioses in north america and are transmitted primarily by amblyomma americanum ticks, while ehrlichia canis is the globally distributed cause of canine monocytic ehrlichiosis (cme) and is transmitted by the brown dog tick, rhipicephalus sanguineus. although e. canis and ehrlichia ruminantium are endemic in africa, the presence of ehrlichial agents in dogs and ticks in cameroon has not been investigated. the objective o ...200516181750
geographic distribution of ticks (acari: ixodidae) in iowa with emphasis on ixodes scapularis and their infection with borrelia burgdorferi.in iowa, public concern regarding lyme disease has increased markedly over the last decade. in response to these concerns, a statewide surveillance program was initiated in 1990 based on ticks received by the department of entomology at iowa state university. ticks were received from health care professionals, state government agencies, and the general public. a total of 5,343 ticks from all 99 iowa counties were identified during the 12 years of this study. dermacentor variabilis was the most n ...200516187889
experimental infection of adult and juvenile coyotes with domestic dog and wild coyote isolates of hepatozoon americanum (apicomplexa: adeleorina).each of five adult and four juvenile coyotes (canis latrans) was exposed to an oral dose of 50 hepatozoon americanum oocysts recovered from amblyomma maculatum ticks that previously fed on either naturally infected domestic dogs (canis familiaris) or naturally infected wild coyotes. all coyotes exposed to h. americanum became infected, regardless of isolate source, and all exhibited mild to moderate clinical disease that simulated american canine hepatozoonosis in naturally infected dogs. at 100 ...200516244069
detection of babesia caballi in amblyomma variegatum ticks (acari: ixodidae) collected from cattle in the republic of guinea.a reverse line blot hybridisation (rlb) assay was applied to screen amblyomma variegatum adult ticks (n = 504) collected from n'dama cattle in the republic of guinea. in a pcr, the v1 hypervariable region of the 16s ribosomal rna (rrna) gene was amplified with a set of primers unique for species of the genera anaplasma and ehrlichia, and the v4 hypervariable region of the 18s rrna gene was amplified with primers specific for members of the genera theileria and babesia. amplified pcr products fro ...200516252481
factors influencing in vitro infectivity and growth of rickettsia peacockii (rickettsiales: rickettsiaceae), an endosymbiont of the rocky mountain wood tick, dermacentor andersoni (acari, ixodidae).rickettsia peacockii, a spotted fever group rickettsia, is a transovarially transmitted endosymbiont of rocky mountain wood ticks, dermacentor andersoni. this rickettsia, formerly known as the east side agent and restricted to female ticks, was detected in a chronically infected embryonic cell line, dae100, from d. andersoni. we examined infectivity, ability to induce cytopathic effect (cpe) and host cell specificity of r. peacockii using cultured arthropod and mammalian cells. aposymbiotic dae1 ...200516288906
characterization of stages of hepatozoon americanum and of parasitized canine host cells.american canine hepatozoonosis is caused by hepatozoon americanum, a protozoan parasite, the definitive host of which is the tick, amblyomma maculatum. infection of the dog follows ingestion of ticks that harbor sporulated h. americanum oocysts. following penetration of the intestinal mucosa, sporozoites are disseminated systemically and give rise to extensive asexual multiplication in cells located predominantly in striated muscle. the parasitized canine cells in "onion skin" cysts and in granu ...200516301575
the molecular and biological analysis of ixodid ticks histamine release factors.we previously described a dermacentor varibialis (dv) cdna that encodes a ubiquitously expressed and tick saliva-secreted functional histamine release factor (hrf) homolog. in this study gene specific primers based on dvhrf open reading frame nucleotide sequence were utilized to amplify three orthologs, from the wood tick, d. andersoni (da), the black legged tick, the southern cattle tick, boophilus microplus (bm) and the lone star tick, amblyomma americanum (aa). at nucleotide level, sequence c ...200516323052
histopathology of tick-bite lesions in naturally infested capybaras (hydrochoerus hydrochaeris) in brazil.in the present work features of tick-bite lesions were evaluated in capybaras naturally infested with amblyomma cajennense and amblyomma dubitatum ticks. gross appearance of tick bite site was characterized by a mild swelling and erythema. microscopic examination revealed the cement cone, a tube-like homogenous eosinophilic mass penetrating deep into the dermis. this structure was surrounded in the dermis by a cellular infiltrate and free eosinophilic granules and was associated to edema of vari ...200516323054
orally active acaricidal peptide toxins from spider venom.numerous species of ticks and mites (collectively known as acarines) are serious pests of animals, humans, and crops. there are few commercially available acaricides and major classes of these chemicals continue to be lost from the marketplace due to resistance development or deregistration by regulatory agencies. there is consequently a pressing need to isolate new and safe acaricidal compounds. in this study, we show that two families of peptide neurotoxins isolated from the venom of the austr ...200616330063
ehrlichia under our noses and no one notices.ehrlichia chaffeensis, an obligately intracellular bacterium, resides within a cytoplasmic vacuole in macrophages, establishes persistent infection in natural hosts such as white-tailed deer and canids, and is transmitted transstadially and during feeding by ticks, particularly amblyomma americanum. ehrlichial cell walls contain glycoproteins and a family of divergent 28 kda proteins, but no peptidoglycan or lipopolysaccharide. the dense-cored ultrastructural form preferentially expresses certai ...200516358425
capillary tube feeding system for studying tick-pathogen interactions of dermacentor variabilis (acari: ixodidae) and anaplasma marginale (rickettsiales: anaplasmataceae).a capillary tube feeding (ctf) system was adapted for studying the interaction between dermacentor variabilis (say) and the rickettsial cattle pathogen anaplasma marginale theiler. a. marginale undergoes a complex developmental cycle in ticks that begins in midguts and ends by transmission from salivary glands. in this ctf system, male d. variabilis were fed a. marginale-infected blood or cultured tick cells. ticks that fed on highly rickettsemic calves developed midgut and salivary gland infect ...200516366000
human skin lesions in east central state, nigeria due to the larvae of amblyomma variegatum (fabricius, 1794). 197316366347
distribution of borreliae among ticks collected from eastern states.lyme disease is the most commonly reported vector-borne disease in the united states and is transmitted by borrelia burgdorferi-infected ixodes species. the disease is typically characterized by an erythema migrans (em) rash at the site of tick feeding. em rashes have also been associated with feeding by amblyomma americanum ticks despite evidence suggesting that they are incompetent vectors for lyme disease. in 1996, a borrelia organism only recently cultivated in the laboratory was described i ...200516417434
detection of rickettsia rickettsii in the tick amblyomma cajennense in a new brazilian spotted fever-endemic area in the state of minas gerais.the present study evaluated rickettsial infection in amblyomma spp. ticks collected in a farm in coronel pacheco, a brazilian spotted fever (bsf) endemic area. a total of 78 a. cajennense and 78 a. dubitatum free-living adult ticks were collected and tested by polymerase chain reaction (pcr) targeting a fragment of the rickettsial gene glta. only one pool of three a. cajennense ticks showed the expected product by pcr. this pool was further tested by pcr using sets of primers targeting the ricke ...200616444414
theileriosis in a white-tailed deer (odocoileus virginianus) fawn.a white-tailed deer (odocoileus virginianus) fawn was collected in missouri (usa) and submitted for diagnostic evaluation. necropsy and histologic examination revealed severe amblyomma americanum infestation, pronounced icterus, and marked hemosiderin deposition in the liver and spleen. whole blood evaluation revealed a normocytic normochromic anemia and a piroplasm parasitemia of approximately 70%. the piroplasm was identified as theileria cervi by polymerase chain reaction and sequencing of th ...200516456174
white-tailed deer (odocoileus virginianus) develop spirochetemia following experimental infection with borrelia lonestari.borrelia lonestari is considered a putative agent of southern tick-associated rash illness (stari) and is known to occur naturally only in lone star ticks (amblyomma americanum) and white-tailed deer (odocoileus virginianus). we used a low passage isolate of b. lonestari (ls-1) to inoculate white-tailed deer, c3h mice, holstein cattle, and beagles. animals were monitored via examination of giemsa and acridine orange stained blood smears, polymerase chain reaction (pcr), indirect fluorescent anti ...200616459029
ectoparasites of free-ranging pumas and jaguars in the paraguayan chaco.ectoparasites were collected from seven puma (puma concolor) and seven jaguar (panthera onca) live-captures (each representing six different animals) in the paraguayan chaco from 2002 to 2004. the same five species of ectoparasites were recovered from both host species: the flea, pulex simulans (total on both hosts combined=30 male, 49 female), and the ticks, amblyomma cajennense (1 male, 4 female, 46 nymphs, 241 larvae), amblyomma parvum (42 male, 25 female), amblyomma tigrinum (1 male, 7 femal ...200616464533
first report of the male of amblyomma rotundatum (acari: ixodidae) from a field-collected host.an adult male of the tick amblyomma rotundatum koch was collected on a naturally infested lizard, tropidurus sp. (squamata: tropiduridae), at monte negro, state of rondonia, brazil. the tick's identity was confirmed morphologically and by analysis of the second internal transcribed spacer of the ribosomal dna. this is the third known male specimen of a. rotundatum, a species that has been shown to reproduce exclusively by parthenogenesis. the two previously reported male specimens seemed to be p ...200516465732
rickettsia parkeri as a paradigm for multiple causes of tick-borne spotted fever in the western hemisphere.among the many contributions made to rickettsiology by entomologist and rickettsiologist ralph r. parker was his discovery in 1937 of a novel rickettsia isolated from the gulf coast tick, amblyomma maculatum. this bacterium was subsequently characterized as a unique rickettsial species in 1965 and named rickettsia parkeri in honor of its discoverer. during the next several decades r. parkeri was generally considered as one of several "nonpathogenic" spotted fever group (sfg) rickettsiae that res ...200516481534
detection of a typhus group rickettsia in amblyomma ticks in the state of nuevo leon, mexico.the state of nuevo leon, mexico has had outbreaks of typhus group rickettsiosis, most recently recognized in 1997. evaluation of the sera of 345 patients with a dengue-like illness revealed that 25.5% had antibodies reactive with typhus group rickettsiae and 16% had antibodies to rickettsia parkeri. rickettsiae were detected by pcr and shell-vial isolations in the field-collected amblyomma ticks. molecular characterization by dna sequence analysis of the glta, ompb, and 17-kda gene identified th ...200516481535
phylogenetic analysis of a novel molecular isolate of spotted fever group rickettsiae from northern peru: candidatus rickettsia andeanae.phylogenetic analysis of five rickettsial genes (17-kda gene, glta, ompb, ompa, and sca4) from two molecular isolates of candidatus rickettsia andeanae from two ticks (amblyomma maculatum and ixodes boliviensis) collected from two domestic horses living in two separate locations in northern peru (coletas and naranjo) was conducted to more clearly characterize this recently reported novel spotted fever group (sfg) rickettsia. following nested polymerase chain reaction (pcr) amplification of the 1 ...200516481537
novel spotted fever group rickettsiae (sfgr) infecting amblyomma americanum ticks in ohio, usa. 200516481541
overcoming barriers to the transformation of the genus ehrlichia.while bacterial transformation has evolved since the early 20th century to allow for the genetic manipulation of a variety of microbial agents, rickettsial organisms have proved resistant to such advances until only recently. the ehrlichia are small, gram-negative, obligately intracellular bacterial parasites, which belong to the family anaplasmataceae and cause a variety of infections in human and animal hosts. e. chaffeensis is the causative agent of human monocytotropic ehrlichiosis and is tr ...200516481548
rickettsia africae in the west indies.rickettsia africae is the agent of african tick-bite fever, a mild but common disease of local persons and tourists in africa. the major vector of this spotted fever group rickettsia is most likely amblyomma variegatum, the tropical bont tick, which has become widely distributed through the west indies in the last 30 years. this report reviews all available information on r. africae in the west indies.200616494746
amblyomma cajennense (acari: ixodidae): salivary gland cells of partially engorged females ticks and the production of lipid by their mitochondria.morphologically, the salivary glands of ticks are paired structures consisting of a secretory and an excretory portion, lacking a reservoir for the storage of the secretion. the secretory portion is composed in females by cells that form acini classified into the types i, ii, and iii. the excretory possess a major duct, from which arise several intermediate ducts that then subdivide to form the canaliculi or acinal tubules, which end at the acini from where they collect the secretion. the presen ...200616500644
[rickettsiae detection in amblyomma ticks (acari: ixodidae) collected in the urban area of campinas city, sp].the city of campinas is located in an endemic area for brazilian spotted fever in são paulo state, where several cases have recently occurred. capybaras have been associated with the cycle of this disease, for they present positive serology and serve as host for ticks of the genus amblyomma, the main vectors of brazilian spotted fever. ticks were collected both from capybaras and from the vegetation in the city park lago do café, located in the urban area of campinas city, sp, a site associated ...200616501770
kinetics of borrelia burgdorferi infection in larvae of refractory and competent tick vectors.the acquisition of borrelia burgdorferi by the larvae of competent and refractory ixodid ticks was assessed by quantitative polymerase chain reaction (pcr). larvae were fed on infected mice, and the spirochete loads were determined during feeding and up to 93 d postfeeding. amblyomma americanum (l.) was refractory to b. burgdorferi infection, with almost no detection of spirochete dna during or postfeeding. in contrast, ixodes scapularis say supported high loads of spirochetes (10(3)-10(4) per l ...200616506448
parasites of the collared peccary from texas.results of a survey of the parasites of the collared peccary (dicotyles tajacu angulatus) in texas are presented. three ectoparasites, amblyomma cajennense, dermacentor variabilis, and pulex porcinus were very common on peccaries from south texas, but less common or absent in arid west texas. sucking lice, pecaroecus javalii, were common on peccaries from west texas, but were not found in south texas. the known range of this louse in texas is extended into the big bend area. two ticks, amnblyomm ...197016509125
amblyomma triste (koch, 1844) (acari: ixodidae): morphological description of the ovary and of vitellogenesis.the present study presents the morphology, histology, and the dynamics of vitellogenesis in females of the tick amblyomma triste. the ovary in this species is of the panoistic type, therefore it lacks nurse cells. it is composed of a layer of epithelial cells that outwardly form the wall of the ovary, but also originate the pedicel, the structure that attaches the oocytes to its external margin, as well the oocytes themselves. in amblyomma triste, the oocytes develop in four synchronic stages, w ...200616540108
interactions between climate, host refuge use, and tick population dynamics.the relationship between australian sleepy lizard (tiliqua rugosa) microhabitat use and tick (amblyomma limbatum) population dynamics was investigated. over 3 years (2002-2004) between 23 and 50 lizards were radio-tracked up to four times a week to record microhabitat use and each fortnight to determine tick loads. daily maximum temperature was highly predictive of lizard microhabitat use. in hotter fortnights lizards used larger bushes and burrows for refuge. peak background tick infestation le ...200616541265
importation of exotic ticks into the united kingdom via the international trade in reptiles.due to the increased trade in exotic reptiles, many of which are infested with ticks of various genera, there is an increased risk of exotic ticks and pathogens being introduced and potentially becoming established in new geographical areas. despite the number and variety of tick species collected from reptiles, their role in the maintenance of pathogens and transmission to humans has not been fully investigated for all species. the potential public health risks to the united kingdom have been e ...200616550335
cross-sectional survey of ixodid tick species on grazing cattle in japan.ixodid tick species were collected from cattle in 60 grazing fields throughout japan. haemaphysalis longicornis was mainly recovered in the western and southern regions, while ixodes species were collected mainly in the central to northern regions. other tick species such as amblyomma testudinarium, boophilus microplus, h. flava and h. kitaokai were identified from a few fields in the central and southern regions. haemaphysalis longicornis were recovered in the fields with higher temperatures an ...200616550336
acaricide efficiency of amitraz/cypermethrin and abamectin pour-on preparations in game.the efficacy of an amitraz/cypermethrin pour-on preparation (1% w/v each) was tested against natural tick infestations of buffaloes, eland and blesbok in three separate trials. the eland were also treated with a 0.02% abamectin (w/v) acaricidal pour-on preparation. the amitraz/cypermethrin pour-on was effective against amblyomma hebraeum, rhipicephalus evertsi evertsi, rhipicephalus appendiculatus and hyalomma marginatum rufipes on the buffaloes. both acaricides were effective against r. appendi ...200516562734
ticks on crested francolins, francolinus sephaena, and on the vegetation on a farm in limpopo province, south africa.ticks were collected at approximately bi-monthly intervals between june 1996 and june 1997 from crested francolins, francolinus sephaena, and from the vegetation on a mixed cattle and wildlife farm in limpopo province, south africa. the birds were infested with the immature stages of 13 tick species, of which amblyomma hebraeum, amblyomma marmoreum and hyalomma marginatum rufipes were the most numerous and prevalent. ten ixodid tick species were collected from the vegetation, of which the immatu ...200516562738
[characterization of rickettsia spp. circulating in a silent peri-urban focus for brazilian spotted fever in caratinga, minas gerais, brazil].the present study was intended to characterize rickettsia spp. circulating in arthropod vectors in caratinga, minas gerais, brazil, by pcr and to investigate the presence of antibodies against the spotted fever rickettsiae group (sfrg) in dogs and horses. 2,610 arthropods were collected and taxonomically identified. dna samples obtained from these vectors were submitted to pcr and cycle-sequenced. ctenocephalides and amblyomma cajennense showed sequences presenting 100.0% homology with r. felis. ...200616583093
performance of a prototype baited-trap in attracting and infecting the tick amblyomma variegatum (acari: ixodidae) in field experiments.investigations were commenced to study the potential use of the fungi, beauveria bassiana, metarhizium anisopliae, and the attraction-aggregation-attachment pheromone (aaap) for the control of ambloyomma variegatum as an environmentally friendly technology. the objective of the study was to develop and test a device, which could be used for pheromone and carbon dioxide delivery and infection of ticks with the fungi in an attempt to control the tick populations in the vegetation. using a pheromon ...200616596354
tick infestations of the eastern cottontail rabbit (sylvilagus floridanus) and small rodentia in northwest alabama and implications for disease transmission.studies were conducted over a four-county area of northwest alabama to determine the association of eastern cottontail rabbits with dermacentor variabilis, the eastern united states vector of rocky mountain spotted fever. a secondary objective was to compare infestations of this tick on rabbits with infestations on commonly encountered rodent species as a means of determining the relative importance of each in the disease transmission cycle. these epidemiologic surveys were conducted in response ...200516599149
multiple pruritic papules from lone star tick larvae bites.ticks are the second most common vectors of human infectious diseases in the world. in addition to their role as vectors, ticks and their larvae can also produce primary skin manifestations. infestation by the larvae of ticks is not commonly recognized, with only 3 cases reported in the literature. the presence of multiple lesions and partially burrowed 6-legged tick larvae can present a diagnostic challenge for clinicians.200616618870
human infestation by larval amblyomma ticks. 200616618871
the impact of 2 dipping systems on endemic stability to bovine babesiosis and anaplasmosis in cattle in 4 communally grazed areas in limpopo province, south africa.a 12-month study was conducted in 4 communal grazing areas in the bushbuckridge region, limpopo province, south africa. the main objective was to investigate the impact of reduced acaricide application on endemic stability to bovine babesiosis (babesia bigemina and babesia bovis) and anaplasmosis (anaplasma marginale) in the local cattle population. to this end 60 cattle in each communal grazing area were bled at the beginning and the conclusion of the experimental period and their sera were ass ...200516642719
[the effect of immersion in distilled water on the engorged larvae and nymphs of amblyomma dubitatum neumann, 1899 (acari: ixodidae)].to evaluate the effect of the immersion of engorged larvae and nymphs of amblyomma dubitatum experimentally fed on rabbits, the ticks were collected and formed control groups, without immersion, and groups witch were immersed by 24, 48, 72, 96 hours and, for engorged larvaes, by eight weeks, in test tubes containing distilled water. during all experiment ticks were kept at 27 +/- 1 degrees c, 80 +/- 10% ru and scotophase the parameters evaluated were: pre-ecdysis, ecdysis and moulting periods; a ...200616646997
the natural hosts of larvae and nymphs of amblyomma tigrinum koch, 1844 (acari: ixodidae).the hosts of larvae and nymphs of amblyomma tigrinum, a tick whose adults feed on wild and domestic canidae in south america, are uncertain. a 17 months survey was carried out trapping wild vertebrates in north-western córdoba, argentina, to evaluate their parasitism with a. tigrinum subadults. larvae and nymphs of this tick species were identified conventionally and by comparison of 16s rdna sequences with genbank deposited sequences. a total of 207 small and medium-sized rodents and 182 birds ...200616682121
[human ehrlichiosis].human ehrlichiosis is a newly recognized disease. it is a tick-borne disease caused by several bacterial species of the genhus erlichia. these are small gram-negative pleomorphic cocci, that are obligatory intracellular bacteria. tick ixodes is the principle vector in europe, and amblyomma amenicanum in the united states. bacterial organisms replicate in a tick, and are transmited from infected cells in a vector to the blood cells of animals or humans. human ehrlichiosis is a name for a group of ...200616683411
mating success of two geographically distinct populations of gulf coast ticks, amblyomma maculatum koch.gulf coast ticks collected from refugio co., tx and osage co., ks are reproductively compatible despite differences in genetic haplotypes, geographic separation and seasonal phenologies. two heifers per mating combination (tx males x tx females, ks males x ks females, tx males x ks females, ks males x tx females) were each infested with 360 pairs of gulf coast ticks. only mean pre-oviposition and mean egg conversion efficiency index for the texas male-kansas female mating were significantly diff ...200616713094
hosts, seasonality and geographic distribution of the south african tortoise tick, amblyomma marmoreum.the tortoise tick amblyomma marmoreum was collected from large numbers of reptiles and other animals during the course of numerous surveys conducted in south africa. a total of 1229 ticks, of which 550 were adults, were recovered from 309 reptiles belonging to 13 species, with leopard tortoises, geochelone pardalis being the most heavily infested. the 269 birds sampled harboured 4901 larvae, 217 nymphs and no adult ticks, and the prevalence of infestation was greatest on helmeted guineafowls, nu ...200616715875
successful and currently ongoing parasite eradication programs.the eradication of parasitic diseases is not a new concept. the most successful programs of parasite eradication have occurred with species of veterinary importance. the first such program, the eradication of texas cattle fever from the united states, is one of the great success stories of disease eradication. the american screwworm eradication program is ongoing and is serving as a guiding impetus for many of the ongoing or proposed vector eradication schemes around the world. the success of th ...200616730411
an in vivo rodent model for identifying and characterizing acaricides.evaluation of candidate acaricides in livestock or companion animals is expensive, time-consuming, and usually requires large quantities of test material. to identify promising substances at the earliest possible stage of the development process, robust and predictive surrogate animal models, capable of rapidly characterizing potency with minimal compound requirements, are necessary. the objective of this study was to generate an in vivo surrogate animal bioassay capable of rapidly and accuratel ...200616739411
pharmacological characterization of the ergot alkaloid receptor in the salivary gland of the ixodid tick amblyomma hebraeum.female ticks of the family ixodidae osmoregulate by secreting the excess fluid of the blood meal back into the host's circulation via the salivary glands. at least three receptors control salivary fluid secretion in the tick amblyomma hebraeum: (1) dopamine (da) stimulates fluid secretion via a da receptor, (2) ergot alkaloids (eras) stimulate fluid secretion via an era-sensitive receptor (the natural ligand of which has not been identified), and (3) a gaba receptor potentiates the action of da ...200616788036
a novel real-time pcr assay for the speciation of medically important ticks.the identification of ticks using morphological characters is a well-established practice, however specimens that are small or damaged are often difficult to speciate. a novel, rapid real-time pcr assay, which targets the second internal transcribed spacer (its2) region in the nuclear ribosomal dna gene, was developed for identification of four tick species of utmost medical importance in the united states: ixodes scapularis, i. pacificus, dermacentor variabilis, and amblyomma americanum. comput ...200616796512
relative abundance and survival of the tick amblyomma americanum collected from sunlit and shaded habitats.the population density of host-searching nymphal and adult lone star ticks, amblyomma americanum (l.) (acari: ixodidae), was determined at the robinson tract of the kansas ecological reserves and a private farm 5 km north-west of the robinson tract using standard drag cloth methods. nymphs, males and females were counted and collected weekly from shaded habitats and adjacent sunlit habitats from mid-may through late july, 2003. of the 1598 nymphs and 549 males collected by drag sampling, 74.0% a ...200616796613
rickettsia tamurae sp. nov., isolated from amblyomma testudinarium ticks.rickettsia sp. strain at-1(t) was isolated from amblyomma testudinarium ticks in japan in 1993. comparative analysis of sequences obtained from 16s rrna, glta, ompa, ompb and sca4 gene fragments demonstrated those from at-1(t) to be markedly different from those of other members of the spotted fever group. using mouse serotyping, it was also observed that rickettsia sp. strain at-1(t) was different from other rickettsia species with validly published names. such genotypic and phenotypic characte ...200616825648
tickborne arbovirus surveillance in market livestock, nairobi, kenya.to identify tickborne viruses circulating in kenya and the surrounding region, we conducted surveillance at abattoirs in nairobi, kenya. species of ticks collected included rhipicephalus pulchellus (56%), amblyomma gemma (14%), r. appendiculatus (8%), a. variegatum (6%), and others. a total of 56 virus isolates were obtained, 26 from a. gemma, 17 from r. pulchellus, 6 from a. variegatum, and 7 from other species. virus isolates included dugbe virus (dugv), an unknown virus related to dugv, thogo ...200616836823
inferring the population structure and demographic history of the tick, amblyomma americanum linnaeus.a hierarchial population genetic study was conducted on 703 individual amblyomma americanum from nine populations in georgia, u.s.a. populations were sampled from the coastal plain, midland piedmont region, and the upper piedmont region. twenty-nine distinct haplotypes were found. a minimum spanning tree was constructed that indicated these haplotypes comprised two lineages, the root of which was distinctly star-like. the majority of the variation found was among ticks within each population, in ...200616859107
efficacy of imidacloprid (8.8% w/w) plus permethrin (44% w/w) spot-on topical solution against amblyomma americanum infesting dogs using a natural tick exposure model.this study evaluated the efficacy of an imidacloprid 8.8% w/w + permethrin 44% w/w spot-on topical solution (k9 advantix, bayer animal health) against amblyomma americanum using a natural field exposure model. sixteen beagles were divided into two groups of eight dogs each. one group of dogs was treated with k9 advantix and the other group served as untreated controls. on day -1 and at 3, 7, 14, 21 and 28 days after treatment, the dogs were walked for 80 minutes in an a. americanum-infested habi ...200616871491
ticks (acari: ixodida: argasidae, ixodidae) infesting humans in northwestern cordoba province, argentina.ticks infesting humans were collected from september 2004 to august 2005 in northwestern córdoba in an area with a southern limit in the locality of dean funes (30 degrees 25's 64 degrees 20'w) and san josé de las salinas (30 degrees 00's 64 degrees 37'w) in the north. the collections consisted in ticks found attached on man obtained from three sources: 1) specimens fixed on two workers during two successive days per month of field work in the northern part of the area which belongs to western c ...200616871909
antimicrobial activity in the egg wax of the african cattle tick amblyomma hebraeum (acari: ixodidae).eggs of the tick amblyomma hebraeum koch (acari: ixodidae) inhibited the growth of escherichia coli and serratia marcescens (gram-negative bacteria) in solid culture, but not the growth of staphylococcus epidermidis, and only marginally the growth of bacillus subtilis (gram-positive bacteria). when egg wax was extracted with chloroform/methanol (2:1), the extract contained antibacterial activity, but the denuded eggs did not. when assayed against bacteria in liquid culture, the aqueous phase inh ...200616874555
ticks (acari: ixodidae) parasitizing humans in an atlantic rainforest reserve of southeastern brazil with notes on host suitability.while conducting projects on ticks from deer and on tick ecology in animal trails in an atlantic rainforest reserve in southeastern brazil, researchers of our group were bitten by ticks several times. some of these episodes were recorded. three species of adult ticks attached to humans: amblyomma brasiliense aragão, amblyomma incisum neumann, and amblyomma ovale koch. eight nymphal attachments with engorgement on humans were recorded. from these, six molted to adults of a. incisum, one to an adu ...200616900313
unique macrophage and tick cell-specific protein expression from the p28/p30-outer membrane protein multigene locus in ehrlichia chaffeensis and ehrlichia canis.ehrlichia chaffeensis and ehrlichia canis are tick-transmitted rickettsial pathogens that cause human and canine monocytic ehrlichiosis respectively. we tested the hypothesis that these pathogens express unique proteins in response to their growth in vertebrate and tick host cells and that this differential expression is similar in closely related ehrlichia species. evaluation of nine e. chaffeensis isolates and one e. canis isolate demonstrated that protein expression was host cell-dependent. t ...200616922866
birds as hosts of immature ixodid ticks in free state province, south africa.the objective of this study was to determine the species spectrum of ixodid ticks infesting birds in free state province, south africa. to this end a large number of birds belonging to several species were examined for ticks and a total of 180 birds belonging to 39 species at 17 localities were infested, and ticks belonging to eight species were recovered. the immature stages of only two, namely amblyomma marmoreum and hyalomma marginatum rufipes, were sufficiently prevalent and numerous to safe ...200616958263
species diversity and seasonality of free-living ticks (acari: ixodidae) in the natural habitat of wild marsh deer (blastocerus dichotomus) in southeastern brazil.this study evaluated the presence and seasonal activity of free-living ticks in remaining marsh areas by the paraná river, in brazil. eight field trips (once per season) for collection of ticks were performed during 2 years. using co2 traps, dragging, and visual inspection of vegetation, five free-living tick species were collected, in the following order of abundance: amblyomma cajennense, amblyomma dubitatum, amblyomma triste, amblyomma coelebs, and amblyomma nodosum. the seasonal pattern of a ...200716962241
a preliminary investigation of ehrlichia species in ticks, humans, dogs, and capybaras from brazil.a molecular epidemiologic investigation in two brazilian states (rondônia and são paulo) was undertaken to determine if ehrlichia species responsible for human and animal ehrlichioses in north america could be found in brazilian vectors, potential natural mammalian reservoirs and febrile human patients with a tick bite history. samples, including 376 ticks comprising 9 amblyomma species, 29 capybara (hydrochaeris hydrochaeris) spleens, 5 canine blood, and 75 human blood samples from febrile pati ...200716962245
[study of foveae dorsales of nymphs and adults of four species of ticks (acari: ixodidae) by scanning electron microscopy].the foveae dorsalis, the external opening of the sex pheromone 2,6-dichlorophenol producer gland, of amblyomma cajennense, dermacentor nitens, rhipicephalus (boophilus) microplus and rhipicephalus sanguineus was studied with scanning electron microscopy. at least three specimens from each stage: unfed larvae, nymphs, females and males, and females fed for 4 to 6 days were examined. the foveae dorsales were not observed in larvae and r. (b.) microplus males. the foveae dorsales were observed as p ...200616978471
vitellogenesis in the tick amblyomma triste (koch, 1844) (acari: ixodidae) role for pedicel cells.this study presents new information on the vitellogenesis of the tick amblyomma triste. in this species, the ovary consists of a layer of epithelial cells, which form the ovarian wall, oogonia and developing oocytes; and the pedicel, a cellular structure that synthesizes and provides yolk precursors for developing oocytes. the pedicel also attaches oocytes to the external surface of the epithelial wall. in this study, evidence is provided in support of pedicel cells in providing compounds for oo ...200716978785
haemaphysalis longicornis: molecular characterization of a homologue of the macrophage migration inhibitory factor from the partially fed ticks.the macrophage migration inhibitory factor (mif) has been identified from some vertebrates and invertebrates. mif is related to inflammation, tumor growth, and angiogenesis in vertebrates. here, we report the molecular characterization of a homologue of mif from partially fed haemaphysalis longicornis. the sequence analysis of the h. longicornis mif (hlmif) indicated that its deduced amino acid sequence has an identity of 77% with the mif of the tick amblyomma americanum. western blot analysis u ...200716987517
the natural hosts for larvae and nymphs of amblyomma neumanni and amblyomma parvum (acari: ixodidae).based on the hypothesis that birds and rodents are important hosts for subadults of the neotropical amblyomma neumanni and amblyomma parvum ticks, a survey of these type of hosts was carried out from july 2004 to march 2006, in quilino (a. parvum) and dean funes (a. neumanni), córdoba province, argentina. additionally, monthly tick counts were performed on cattle and goats with occasional tick search in other domestic hosts. records of questing height of subadult ticks on vegetation were also ca ...200617006739
ticks (acari: ixodidae) associated with wildlife and vegetation of haller park along the kenyan coastline.this artcile describes the results obtained from a tick survey conducted in haller park along the kenyan coastline. the survey aimed at evaluating tick-host associations, assessing tick population density, and providing baseline information for planning future tick control and management in the park. ticks (2,968) were collected by handpicking from eight species of wildlife and by dragging in 14 selected sites within the park. a considerable proportion of ticks were also collected from leaves, s ...200617017210
a spotted fever group rickettsia from an exotic tick species, amblyomma exornatum (acari: ixodidae), in a reptile breeding facility in the united states.adults and nymphs of amblyomma exornatum koch (acari: ixodidae), an exotic african tick of monitor lizards, were collected from a gray's monitor lizard, varanus olivaceus hallowell, that died in a reptile facility in alabama. nine adult ticks were tested by polymerase chain reaction for rickettsial agents. dna from a novel spotted fever group rickettsia was amplified and sequenced from one of the nine ticks. the novel rickettsia was most similar to "rickettsia anan," which is associated with amb ...200617017252
evaluation of an imidacloprid (8.8% w/w)--permethrin (44.0% w/w) topical spot-on and a fipronil (9.8% w/w)--(s)-methoprene (8.8% w/w) topical spot-on to repel, prevent attachment, and kill adult ixodes scapularis and amblyomma americanum ticks on dogs.this study evaluated the effectiveness of two topical spot-on formulations -- imidacloprid(8.8% w/w)-permethrin (44.0% w/w) and fipronil (9.8% w/w)-(s)-methoprene (8.8% w/w)--to repel, prevent the attachment of, and kill adult ixodes scapularis and amblyomma americanum on dogs. twelve purpose-bred beagles were distributed into three groups of four dogs each; one group served as untreated controls, and each of the other two groups received one of the test products. dogs were exposed to 25 adult t ...200617039440
african tick bite fever: a not-so-uncommon illness in international travelers.african tick bite fever is a rickettsial illness that has recently emerged as a significant disease among international travelers. the vector is the amblyomma tick, which is endemic to sub-saharan africa and parts of the eastern caribbean.200617043186
attachment kinetics of the adult tick amblyomma variegatum to cattle.at the beginning of the 1999 rainy season, three traditional cattle herds were monitored for 48 days while grazing in the bushy savannah of southwestern burkina faso. cattle in each herd were caught on several occasions each day and the attached ticks were counted. this confirmed that amblyomma variegatum fabricius (acari: ixodidae) adults picked up in the pastures mainly attach to the interdigital areas (87% of the 791 ticks captured), and reach the predilection sites later (chest and udder/ing ...200617044883
molecular characterisation of camp-dependent protein kinase (pk-a) catalytic subunit isoforms in the male tick, amblyomma hebraeum.the camp-dependent protein kinase (protein kinase a, pk-a) plays a central role in the regulation of diverse aspects of cellular activity. specifically, pk-a appears to play a key controlling role in the maturation of spermatids. using a pcr-based approach, with degenerate primers from the highly conserved regions of the pk-a catalytic (c) subunit in combination with 5' and 3' race, we have cloned three cdnas for the pk-a c-subunit of the male tick, amblyomma hebraeum. the three cdnas have open ...200617049629
parasites of domestic and wild animals in south africa. xlvii. ticks of tortoises and other reptiles.a total of 586 reptiles, belonging to 35 species and five subspecies, were examined in surveys aimed at determining the species spectrum and geographic distribution of ticks that infest them. of these reptiles 509 were tortoises, 28 monitor or other lizards, and 49 snakes. nine ixodid tick species, of which seven belonged to the genus amblyomma, and one argasid tick, ornithodoros compactus were recovered. seven of the ten tick species are parasites of reptiles. amongst these seven species amblyo ...200617058444
highly prevalent coxiella sp. bacterium in the tick vector amblyomma americanum.laboratory-reared and field-collected amblyomma americanum ticks were hosts of a coxiella sp. and a rickettsia sp. while the coxiella sp. was detected in 50 of 50 field-collected ticks, the rickettsia sp. was absent from 32% of ticks. the coxiella sp. showed evidence of a reduced genome and may be an obligate endosymbiont.200717085709
migratory songbirds disperse ticks across canada, and first isolation of the lyme disease spirochete, borrelia burgdorferi, from the avian tick, ixodes auritulus.during a 3-yr comprehensive study, 196 ixodid ticks (9 species) were collected from 89 passerine birds (32 species) from 25 localities across canada to determine the distribution of avian-associated tick species and endogenous lyme disease spirochetes, borrelia burgdorferi johnson, schmid, hyde, steigerwalt, and brenner. we report the following first records of tick parasitism on avian hosts: the rabbit-associated tick, ixodes dentatus marx, from manitoba and ontario; the mouse tick, ixodes muri ...200517089744
fecal nirs: detection of tick infestations in cattle and horses.anti-tick treatments are often applied concurrent to routine livestock management practices with little regard to actual infestation levels. prescription treatments against ticks on grazing cattle would be facilitated by non-invasive detection methods. one such method is fecal near infrared spectroscopy (nirs). four studies utilizing cattle (bos spp.) and one with horses (equus caballus) fed varying diets and infested with either amblyomma americanum, a. maculatum, a. cajennense or dermacentor a ...200717097809
new member of the protein disulfide isomerase (pdi) family identified in amblyomma variegatum tick.ticks belonging to arthropoda are blood feeding, geographically widespread ectoparasites of mammals, reptiles and birds. their saliva contains active substances that protect them from host immune attack and allow for transmission of various pathogens during the feeding process. characterization of tick saliva components can therefore contribute to the development of effective methods for the control of tick-borne diseases. here we describe the identification and basic characterization of a gene ...200617098169
ticks (ixodidae) on humans in south america.twenty eight species of ixodidae have been found on man in south america (21 amblyomma, 1 boophilus, 2 dermacentor, 2 haemaphysalis, 1 ixodes and 1 rhipicephalus species). most of them are rarely found on man. however, three species frequently parasitize humans in restricted areas of argentina (a. neumanni reported from 46 localities), uruguay (a. triste from 21 sites) and argentina-brazil (a. parvum from 27 localities). the most widespread ticks are a. cajennense (134 localities in argentina, b ...200617103085
brazilian spotted fever: a case series from an endemic area in southeastern brazil: epidemiological aspects.brazilian spotted fever (bsf) is the most important tick-borne disease in brazil and is caused by rickettsia rickettsii and transmitted by the ixodid tick amblyomma cajennense, its main vector. we present epidemiologic aspects of a case series of patients admitted to the hospital das clínicas da unicamp from 1985 to 2003 with a confirmed diagnosis of bsf either by a fourfold rise in indirect immunofluorescence (ifa) titers of igg antibodies reactive with r. rickettsii or isolation of r. ricketts ...200617114702
isolation of rickettsia rickettsii and rickettsia bellii in cell culture from the tick amblyomma aureolatum in brazil.brazilian spotted fever (bsf) is a highly lethal disease caused by rickettsia rickettsii. in the present study, rickettsial infection was evaluated in 669 amblyomma aureolatum adult ticks collected from naturally infested dogs in taiaçupeba, a bsf-endemic area in the state of são paulo. ten (1.49%) ticks were infected with rickettsia bellii, and 6 (0.89%) ticks were infected with r. rickettsii. both rickettsia species were isolated and established in vero cell cultures. the rickettsia isolates w ...200617114770
the use of a pour-on and spray dip containing amitraz to control ticks (acari: ixodidae) on cattle.knockdown and persistence efficacies of a pour-on containing amitraz 1% and cypermethrin 1% and a spray dip containing 12.5% amitraz were compared. knock-down and persistence efficacies of the amitraz spray dip against rhipicephalus (boophilus) decoloratus and amblyomma hebraeum were significantly higher for the duration of the trial than those of the pour-on. in the case of rhipicephalus appediculatus and rhipicephalus evertsi evertsi, efficacy was significantly higher on days 2 and 5. resistan ...200617120621
infection of ixodes scapularis ticks with rickettsia monacensis expressing green fluorescent protein: a model system.ticks (acari: ixodidae) are ubiquitous hosts of rickettsiae (rickettsiaceae: rickettsia), obligate intracellular bacteria that occur as a continuum from nonpathogenic arthropod endosymbionts to virulent pathogens of both arthropod vectors and vertebrates. visualization of rickettsiae in hosts has traditionally been limited to techniques utilizing fixed tissues. we report epifluorescence microscopy observations of unfixed tick tissues infected with a spotted fever group endosymbiont, rickettsia m ...200717125789
emerging tick-borne disease in african vipers caused by a cowdria-like organism.heartwater is a tick-borne infectious disease caused by the rickettsial organism cowdria ruminantium, currently ehrlichia ruminantium. it poses an imminent threat to the western hemisphere, where it could cause mortality in cattle and other ruminant livestock in excess of 70%. it has been reported in the caribbean; and its vector, amblyomma sparsum, has been found on imported african spurred tortoises (geochelone sulcata) and leopard tortoises (geochelone pardalis) in southern florida in the uni ...200617135546
a survey of free-living ixodid ticks on a commercial game farm in the thabazimbi district, limpopo province, south africa.free-living stages of ticks on a commercial game farm in the thabazimbi district, limpopo province, south africa, were collected by drag-sampling with flannel strips during the period september 2003 to august 2004. a total of 5 tick species was collected from 4 sites. boophilus decoloratus was the most abundant species, followed by amblyomma hebraeum. seasonal abundance of the ticks was quantified and an optimum time to implement control measures against the ticks is proposed.200617137055
prevalence of ehrlichia, borrelia, and rickettsial agents in amblyomma americanum (acari: ixodidae) collected from nine states.ambyomma americanum (l.) (acari: ixodidae) is an aggressive tick that feeds on humans during all postembryonic life stages. in many regions of the united states, it is the tick most commonly found attached to humans. public health interest has grown recently, due to the recognition of new human pathogens transmitted by a. americanum and the expanding distribution of the tick. a. americanum is a vector of several bacteria pathogenic to humans. ehrlichia chaffeensis and ehrlichia ewingii cause mod ...200617162962
relative abundance and prevalence of selected borrelia infections in ixodes scapularis and amblyomma americanum (acari: ixodidae) from publicly owned lands in monmouth county, new jersey.to evaluate their potential importance in the transmission of ixodid tick-borne borrelioses in monmouth county, nj, we collected host-seeking ixodes scapularis say and amblyomma americanum (l.) (acari: ixodidae) adults and nymphs to determine relative encounter frequencies and the infection prevalence of selected borrelia spp. in their respective tick vectors. we also reviewed records of all ticks submitted for identification by the public in monmouth county during 2001-2005. relative abundance ...200617162963
first record of amblyomma aureolatum (pallas, 1772) (acari: ixodidae) parasitizing alouatta guariba (humboldt) (primata: atelidae) in southern brazil.a female of amblyomma aureolatum was found on the howler monkey alouatta guariba, in cachoeira do sul, rio grande do sul, southern brazil. this is the first record of this tick species parasitizing this primate species in brazil.200617196126
footbath acaricide treatment to control cattle infestation by the tick amblyomma variegatum.previous studies have shown that about 90% of adult amblyomma variegatum fabricius (acari: ixodidae) picked up daily by grazing cattle are still attached to the interdigital areas in the evening, when the animals return from pasture. it was therefore postulated that a targeted treatment, designed to kill the ticks attached to the feet, would limit infestation of the predilection sites. footbaths filled with various pyrethroid formulations were used over 3 years, at the beginning of the rainy sea ...200617199752
sero-prevalence and risk indicators for canine ehrlichiosis in three rural areas of brazil.ehrlichia canis has a worldwide geographic distribution, occurring particularly in tropical and subtropical areas. in brazil, the main vector in urban areas is believed to be the brown dog tick rhipicephalus sanguineus, but little is known about the occurrence, transmission and other epidemiological aspects of canine ehrlichiosis in rural areas, where amblyomma ticks are found more frequently than r. sanguineus. a sero-prevalence study of canine ehrlichiosis was carried out in three distinct rur ...200717204439
association of the bovine leukocyte antigen major histocompatibility complex class ii drb3*4401 allele with host resistance to the lone star tick, amblyomma americanum.the mhc of cattle, known as the bovine leukocyte antigen (bola) complex, plays an integral role in disease and parasite susceptibility, and immune responsiveness of the host. while susceptibility to tick infestation in cattle is believed to be heritable, genes that may be responsible for the manifestation of this phenotype remain elusive. in an effort to analyze the role that genes within the bola complex may play in host resistance to ticks, we have evaluated components of this system within a ...200717208379
an investigation into the distribution, host-preference and population density of ixodid ticks affecting domestic animals in bangladesh.to study the distribution, host-preference and population density of ixodid ticks in bangladesh, an attempt was made to collect adult ticks from various host animals in three distinct topographic zones, viz. flood plains, hills and steppe 'barind'. five species of ixodid ticks were recorded, namely, boophilus microplus (56.3%), haemaphysalis bispinosa (11.3%), rhipicephalus sanguineus (14.7%), hyalomma anatolicum anatolicum (15.0%) and amblyomma testudinarium (2.8%). the data showed that b. micr ...200617243476
infection of a goat with a tick-transmitted ehrlichia from georgia, u.s.a., that is closely related to ehrlichia ruminantium.we detected a novel tick-transmitted ehrlichia in a goat following exposure to lone star ticks (amblyomma americanum) from a park in the metropolitan area of atlanta, ga, u.s.a. nineteen days after infestation with field-collected adult ticks, the goat developed a fever of two days duration, which coincided with mild clinical pathologic changes and the presence of dna from a novel ehrlichia in peripheral blood. the goat transmitted ehrlichiae to uninfected nymphal a. americanum that fed upon the ...200617249337
infection by rickettsia bellii and candidatus "rickettsia amblyommii" in amblyomma neumanni ticks from argentina.the tick species, amblyomma neumanni (acari: ixodidae) is the most frequent tick parasitizing humans in northwestern argentina. the present study evaluated the rickettsial infection among 55 a. neumanni adult free-living ticks collected in dean funes, córdoba province. ticks were individually processed by the hemolymph test with gimenez staining, isolation of rickettsia in vero cell culture by the shell vial technique, and polymerase chain reaction (pcr) targeting the citrate synthase rickettsia ...200717264991
ixodid ticks on dogs in the eastern region of the eastern cape province, south africa.the objective of this study was to determine the species composition and geographic distribution of ixodid ticks infesting domestic dogs in the eastern region of the eastern cape province. seventy-two communal cattle dip-tanks within this region were randomly selected as survey localities and their geographic coordinates recorded. in addition to ticks that were collected from five cattle and five goats at each of the dip-tanks, ticks were also collected from five dogs whenever possible. no dogs ...200617283731
[insects know no border.].one of the major consequences of the joined action of demographic pressure and evolution of human activities lies in enormous increase of transportation, both in frequence and speed; taking advantage of these facilities, some arthropods could increase their geographical distribution and create new health threats. several demonstrative examples are exposed in order to illustrate this anthropic dissemination of the vectors : the introduction of anopheles gambiae s.l. in mauritius island between 18 ...199617292311
tick paralysis of a snake caused by amblyomma rotundatum (acari: ixodidae).a lethargic southern black racer, coluber constrictor priapus dunn and wood, wild-caught in the florida keys, monroe county, fl, was found to be paralyzed by the bite of a female ixodid tick, amblyomma rotundatum koch (acari: ixodidae). removal of the tick restored the snake to normalcy within 18 h. other, earlier reported cases of tick toxicosis in reptiles are reviewed and clarified. evidently, the present incident is the only reported case of tick paralysis in a poikilotherm found in a natura ...200717294934
parasites of free-ranging small canids and felids in the bolivian chaco.parasite surveys of free-ranging wildlife provide important information for monitoring population health. between march 2001 and march 2003, we sampled 10 ocelots (leopardus pardalis), eight geoffroy's cats (oncifelis geoffroyi), a jaguarundi (herpailurus yaguarondi), five pampas foxes (pseudalopex gymnocercus), and three crab-eating foxes (cerdocyon thous) at three sites in the bolivian chaco. the objective of the study was to survey the parasite fauna of these carnivores and compare prevalence ...200617312790
differential transcription of the major antigenic protein 1 multigene family of ehrlichia ruminantium in amblyomma variegatum ticks.the rickettsial pathogen ehrlichia ruminantium causes heartwater in ruminants and is transmitted by ticks of the genus amblyomma. the map1 gene, encoding the major surface protein map1, is a member of a multigene family containing 16 paralogs. in order to investigate differential transcription of genes of the map1 multigene family in vivo in unfed and feeding ticks, rna was extracted from midguts and salivary glands of e. ruminantium-infected adult female amblyomma variegatum ticks and analysed ...200717321077
health evaluation of a radiocollared population of free-ranging baird's tapirs (tapirus bairdii) in costa rica.the health of a population of free-ranging tapirs (tapirus bairdii) inhabiting corcovado national park, costa rica, was assessed as part of an ongoing ecologic study. nineteen tapirs were immobilized between march 1997 and february 2000, and samples of blood, skin biopsies, and ectoparasites were collected. ticks were identified as amblyomma oblongoguttatum or a. coelebs. hematology and serum biochemistry results suggest statistically significant differences between free-ranging and captive popu ...200517323556
using invaded range data to model the climate suitability for amblyomma variegatum (acari: ixodidae) in the new world.climate matching models are in increasing use to predict distributions of living organisms, using records of the known distribution of a species to map its expected range of habitat suitability. here, we modelled the known distribution of the tick amblyomma variegatum in africa as a preliminary step to delineate the most probable range of climatically suitable habitat for the tick in the new world. we used two presence-only methods (one based in the gower distance, the other based on the maximum ...200717347921
Displaying items 1201 - 1300 of 1744