relative susceptibility of jamaican strains of boophilus microplus, amblyomma cajennense, and anocentor nitens to various acaricides. 1977604370
effects of temperature and humidity on ovipositional biology and egg development of the tropical horse tick, dermacentor (anocentor) nitens.the ovipositional biology and egg development of the tropical horse tick, dermacentor (anocentor) nitens (neumann), was observed at four temperatures (20, 25, 30, and 35 degrees c) and relative humidities (40, 61, 75, and 91% rh). relative humidity had little effect on length of preoviposition and oviposition periods. with increased rearing temperatures, there was a decrease in both preoviposition and oviposition periods. oviposition rate increased with temperature and was not affected by relati ...19921495053
venezuelan equine encephalomyelitis virus infection in and transmission by the tick amblyomma cajennense (arachnida: ixodidae).to assess a possible role of ticks as the maintenance host for epizootic strains of venezuelan equine encephalomyelitis (vee) virus, laboratory experiments were conducted to determine if ticks could become infected, maintain, and transmit the virus. larval and nymphal amblyomma cajennense (f.) and larval dermacentor nitens neumann ticks were exposed to epizootic vee virus (trinidad donkey strain) by allowing them to feed on viremic guinea pigs (strain 13). in a. cajennense, transstadial transmis ...19911875367
parasitic phase of anocentor nitens (acarina: ixodidae) in cattle.the parasitic phase of anocentor nitens (neumann) in cattle was studied. larval stage was present up to 15 days post-infestation (p.i.), concomitant with nymphae from day 8 p.i. nymphae were observed up to day 23 p.i., adults being seen from day 15 p.i. onwards. male ticks disclosed active movements from day 17 p.i. and detachment of engorged females began 22 to 24 days p.i. massive detachment occurred from day 28 p.i. preferential sites of parasitic stages were ear and neck (lateral side).19892626578
formulation of medium for tick cell culture.we examined the effectiveness of bovine cholesterol concentrate in reducing the high level (10-20%) of fetal bovine serum (fbs) necessary to promote tick cell growth in vitro. tick cell lines isolated from embryos of anocentor nitens (ane 58), boophilus microplus (bme 26), and rhipicephalus appendiculatus (rae 25) were used. they were incubated in l-15 (bme 26) or l-15b (ane 58 and rae 25) supplemented with 10% tryptose phosphate broth (tpb), 5% (ane 58 and bme 26) or 3% fbs, 10-90 microns/ml ch ...19892766897
effect of age on cholinesterase activity and protein of unfed larval ticks.the cholinesterase (ache) activity and total protein in homogenates of unfed larvae of amblyomma americanum (l.), a. cajennense (fabricius), a. maculatum koch, anocentor nitens neumann, and boophilus microplus (canestrini) were determined weekly in ticks 1-6 wk of age. there was a considerable variation in total protein, ache, and the ratio of ache to protein as the ticks aged. however, ache activities were constant or increased with age and total protein levels were constant or decreased. no di ...19892918444
prevalence of piroplasmosis in equines in the colombian province of cordoba.eighty-two equine sera from 13 farms in northern colombia were examined for antibodies to babesia caballi and b. equi using the complement fixation (cf) and the indirect fluorescent antibody (ifa) test. seroreactors to both piroplasms were present on all farms. the ifa test indicated a prevalence of 90% for b. caballi and 94% for b. equi. the cf test detected antibodies to b. caballi in 41% and to b. equi in 65% of the animals. the prevalence of seroreactors in different age groups revealed a si ...19883041656
chromosomes of the tropical horse tick, dermacentor nitens (acari: ixodidae), with notes on the life cycle. 19873437366
ticks on livestock in st. lucia.cattle, sheep, goats and horses were examined for ticks. over 95% of holstein cross-breeds, 28% of sheep (local mixed breeds) and 18% of goats (local mixed breeds) examined from 18 august to 4 september 1983 were infested with the southern cattle tick, boophilus microplus canestrini. about 90 and 17% of the horses examined were infested with the tropical horse tick, anocentor nitens neumann, and the tropical bont tick, amblyomma variegatum fabricius, respectively. the tropical bont tick was foun ...19854090245
observations on the development of babesia caballi (nuttall) in the tropical horse tick dermacentor nitens neumann. 19684973786
some effects of parasitism by babesia caballi on the tropical horse tick, dermacentro (=anocentor) nitens. 19704986167
the effects of 20-hydroxyecdysone and juvenile hormone iii on tick cells.two cell lines isolated from rhipicephalus appendiculatus ( rae 25) and anocentor (= dermacentor) nitens (ane 58) responded to the invertebrate hormones 20-hydroxyecdysone (20-he) and juvenile hormone iii (jh iii) in vitro. in the presence of 0.2 or 2 nmolar 20-he, the cells of the continuous line rae 25 attached to the culture substrate at a rate of 9% per hr for the first 8 hr, as did cells in growth medium. twenty or 200 nmolar of 20-he reduced the rate of cell attachment to 6% per hr, and in ...19836674457
anopheles stephensi and toxorhynchites amboinensis: aseptic rearing of mosquito larvae on cultured cells.aseptic larvae of anopheles stephensi and toxorhynchites amboinensis were reared on a continuous cell line (ru tae 12 v) from the mosquito, t. amboinensis, that grew in suspension as multicellular vesicles. surface-sterilized eggs were hatched in a 24-well plate containing 0.2 ml of leibovitz's l-15 medium per well and incubated in a humidified atmosphere. toxorhynchites amboinensis eggs of 36 hr or older were placed singly to assure hatching and avoid cannibalism. hatching rates were over 80%. ...19826129294
epidemiological aspects of the brazilian spotted fever: seasonal activity of ticks collected in an endemic area in são paulo, brazil.ticks were collected from vegetation and animals at monthly intervals during one year (1993-1994) in an endemic area of brazilian spotted fever in the country of pedreira, state of são paulo. six species of ticks were identified amblyomma cajennense, amblyomma cooperi, amblyomma triste, anocentor nitens, rhipicephalus sanguineus and boophilus microplus. only the first species was sufficiently numerous to permit a quantitative study with seasonal activity, although the distribution and source of ...19979197151
rickettsiae-infected ticks in an endemic area of spotted fever in the state of minas gerais, brazil.a study on tick-borne rickettsiosis was developed in the county of santa cruz do escalvado, state of minas gerais, brazil, where a clinical case of the disease, confirmed by necropsy, had been reported. of the 1,254 ticks collected, 1,061 belonged to the amblyomma genus, 57 to the rhipicephalus sanguineus species, 81 to boophilus microplus, and 46 to anocentor nitens. the hemolymph test associated with giménez staining showed that 18 of the 221 a. cajennense specimens, 1 of the 16 r. sanguineus, ...19979361740
recognition of the tick genus anocentor schulze, 1937 (acari: ixodidae) by numerical taxonomy.we report on an evaluation of the systematic position of the tick anocentor nitens (neumann), examining particularly whether anocentor should be regarded as a subgenus of dermacentor or as a separate genus. twelve species of ixodidae were analyzed phenetically by using 24 characters of adult ticks. a phenogram indicated 3 clusters, with anocentor more closely related to rhipicephalus than to dermacentor. the results of this study endorse the validity of the monotypic genus anocentor.19989775625
encephalitozoon-like microsporidia in the ticks amblyomma cajennense and anocentor nitens (acari: ixodidae).a encephalitozoon-like microsporidia was found in epithelial cells of the midgut and the salivary glands of amblyomma cajennense (f.) and anocentor nitens (neumann) that had fed on rabbits. ultrastructural studies demonstrated that all stages of the life cycle of the parasite occur in parasitophorous vacuoles and contain only 1 nucleus. the sporonts detach from the limiting membrane of the vacuole and divide by binary fission to produce the sporoblasts, each presenting a thickened electron-dense ...19989835698
presence of sex pheromones in anocentor nitens (acari: ixodidae).the aim of this study was to investigate whether there are sex pheromones in the tropical horse tick, anocentor nitens (neumann). when virgin males and females, fed on rabbits for 3-7 d, were tested reciprocally, there was a direct correlation between attractiveness and the period of feeding; attraction was greater (and with the fastest responses) in males and females fed for at least 6 d (sexually active males and confirmed attractive females). the capacity of sexually active males to orient to ...199910071492
seroepidemiologic studies on babesia equi and babesia caballi infections in brazil.horses from six stud farms representing the most frequent types of horse breeding in brazil were tested for babesia antibodies by the ifa test. the farms are located at the tropic of capricorn at an altitude of 472-715 m where temperatures below 0 degrees c may occur. horses of conventional stud farms were infested with dermacentor nitens, amblyomma cajennense, and boophilus microplus. infestation with bo. microplus was associated with direct or indirect contact of horses with cattle, and was no ...199910447188
seasonal dynamics of the free-living phase of anocentor nitens at pedro leopoldo, minas gerais, understanding of seasonal dynamics in the free-living phase of the tropical horse tick, anocentor nitens, is vital for effective control measures. this study examines seasonal changes in the oviposition and incubation periods, eclosion rates, reproductive success, and larval survival in the free-living phase during the period june 1995-july 1997. ten engorged female ticks, placed individually in wire-gauze tubes, were exposed in a field of brachiaria decumbens fortnightly each month, and moni ...199910628702
laboratory study of anocentor nitens (neumann) (acarina: ixodidae), the tropical horse tick. 19695807854
report on ticks collected in the southeast and mid-west regions of brazil: analyzing the potential transmission of tick-borne pathogens to man.specimens of ticks were collected in 1993, 1996, 1997, and 1998, mostly from wild and domestic animals in the southeast and mid-west regions of brazil. nine species of amblyommidae were identified: anocentor nitens, amblyomma cajennense, amblyomma ovale, amblyomma fulvum, amblyomma striatum, amblyomma rotundatum, boophilus microplus, boophilus annulatus, and rhipicephalus sanguineus. the potential of these tick species as transmitters of pathogens to man was analyzed. a flaviviridade flavivirus ...199910881097
a review of the ticks (acari, ixodida) of brazil, their hosts and geographic distribution - 1. the state of rio grande do sul, southern brazil.a review of the ticks (acari, ixodida) of the state of rio grande do sul, southern brazil, was completed as a step towards a definitive list (currently indicated as 12) of such species, their hosts and distribution. the ticks: argas miniatus (poultry), ixodes loricatus (opossums), amblyomma aureolatum (dogs), a. calcaratum (anteaters), a. cooperi (capybaras), a. nodosum (anteaters), a. tigrinum (dogs) (neotropical) and rhipicephalus sanguineus (dogs) (introduced, cosmopolitan, afrotropical) were ...200010904399
thermal constant estimation in tropical horse tick, anocentor nitens (acari:ixodidae).experience has demonstrated that the exclusive use of acaricides as a control method against cattle ticks causes several problems, and is not totally effective. other methods need to be added in order to achieve better and more profitable control of these parasites. groups of 12 to 15 engorged ticks, bred on bovines, were individually incubated at six temperatures (t = 24, 26, 28, 30, 32, and 34 degrees c) and four relatives humidities (rh = 100, 80, 75.5, and 70%), creating 24 variants. the ons ...200011193636
larval survival of anocentor nitens under simulated natural conditions.basic knowledge about the survival of free living stages of ticks is of great importance as a practical tool to improve control methods. for anocentor nitens there is little information on this subject. eighty-four engorged females were incubated at 30 degrees c and 100% relative humidity. after 17 days, groups of 5,500 eggs each were collected and isolated in vials. age zero was defined as 10 days after eclosion had begun. at this time vials with larvae were attached to 40 sorghum halepense pla ...200011193638
risk factors to tick infestations and their occurrence on horses in the state of são paulo, brazil.from december 1998 to march 1999, 40 stud farms were studied in the state of são paulo, brazil. during visits to farms, horses reared under grazing conditions were examined for the presence of ticks. on each farm visit, horse pastures were closely inspected and a questionnaire was given to the farm supervisor with the purpose of gaining information about ecological and management variables (independent variables) that could be associated with the presence and infestation levels of ticks on the f ...200111337122
seasonal analysis of the number of aeropiles in anocentor nitens (neumann, 1897) (acari: ixodidae) from the state of rio de janeiro, brazil.variation between aeropile numbers of the right and left peritrematic plate in male and female anocentor nitens (neumann, 1897) is reported from a site in brazil. from january to december 1998, 146 males and 247 females of a. nitens were recovered from equus caballus l. in silva jardim district, state of rio de janeiro. asymmetry of numbers of aeropiles between right and left plates occurred in 83.6% of the males and 82.2% of the females. differences in the number of aeropiles between the sexes ...200111500781
horse resistance to natural infestations of anocentor nitens and amblyomma cajennense (acari: ixodidae).the objective of this study was to investigate some aspects of horse resistance to natural infestations of anocentor nitens and amblyomma cajennense over a 2-year period. free-living stages of a. nitens were used to evaluate the influence of season of the year on horse resistance. every 2 weeks, 10 selected engorged females, weighing 150-329 mg, were removed from naturally infested horses and were individually placed into glass tubes closed with a cotton stopper, and maintained in an incubator. ...200211812624
seasonal dynamics of ticks (acari: ixodidae) on horses in the state of são paulo, brazil.natural tick infestations were assessed every 14 days on horses over a 2-year period. amblyomma cajennense adult ticks were counted individually, without detachment from the horses. larvae and nymphs of a. cajennense were collected using a rubber scraper that scratched engorged immature ticks from the host. adult females of anocentor nitens larger than 4mm length were counted on the horses. blood samples were also obtained from the horses every 14 days and macroclimatic data were obtained for th ...200211879967
the role of 2,6-dichlorophenol as sex pheromone of the tropical horse tick anocentor nitens (acari: ixodidae).the objective of this study was to evaluate the role of 2,6-dichlorophenol (2,6-dcp) as sex pheromone of anocentor nitens. sex pheromones were extracted by submerging 150 female fed for 6 days in hexane (3 ml) for two hours and sonicating them for 15 min. the extract was analyzed by gc-ms employing the single ion monitoring (sim) method. identification of 2,6-dcp was based on the comparison of mass spectra with a computer search using the nist library and by matching the mass spectrum of the pea ...200212593587
ticks (acari: ixodidae) on wild marsh-deer (blastocerus dichotomus) from southeast brazil: infestations before and after habitat loss.the lake from porto-primavera hydroelectric power station inundated an area of 2,200 km2 at the border of são paulo and mato-grosso do sul states, brazil. infestations by ticks were evaluated on 135 marsh deer, blastocerus dichotomus (illiger), captured before and after inundation. ticks were collected for identification, and infestation level of animals was assessed by scoring. deer were divided into four groups according to capture location and temporal relation to the inundation. groups 1, 2, ...200312943103
effect of photoperiod on patterns of oviposition of anocentor nitens neumann (acarina: ixodidae). 19695387544
the hereditary transmission of babesia caballi in the tropical horse tick, dermacentor nitens neumann. 196414125923
phylogenetic analysis of the francisella-like endosymbionts of dermacentor ticks.bacterial endosymbionts with significant homology to francisella tularensis (gamma-proteobacteria) have been described from at least five species of ticks in three different genera, including two north american dermacentor species [d. andersoni stiles and d. variabilis (say)]. the evolutionary relationships among the francisella-like endosymbionts (fle) from different hosts and between fle and the arthropod-borne pathogen f. tularensis are not known. a 1,169-base fragment of the 16s rdna and a 7 ...200415185926
rickettsial infection in animals and brazilian spotted fever endemicity.we compared the rickettsial infection status of amblyomma cajennense ticks, humans, dogs, and horses in both brazilian spotted fever (bsf)-endemic and -nonendemic areas in the state of sao paulo, brazil. most of the horses and few dogs from bsf-endemic areas had serologic titers against rickettsia rickettsii antigens. in contrast, no dogs or horses from bsf-nonendemic areas had serologic titers against r. rickettsii antigens, although they were continually exposed to a. cajennense ticks. all hum ...200515752445
epidemiological aspects of equine babesioses in a herd of horses in brazil.epidemiological studies of babesia equi and b. caballi were undertaken in a herd of 120 pastured horses in rio de janeiro, brazil. the area where the horses were held was shown to be highly endemic for both babesia spp., i.e. the prevalence of b. equi antibodies in horses aged 6 months or older ranged from 90.6% to 100% as determined by the immunofluorescence antibody (ifa) test, and the prevalence of b. caballi antibodies as determined by western blot ranged from 59.4% to 65.5%. from the herd, ...19957676590
seasonal dynamics of anocentor nitens on horses in brazil.anocentor nitens is a widespread ectoparasite of horses in brazil. a study of the seasonal dynamics of the parasitic phase of this tick was made by regular census of engorging females (>/=4mm) on free-ranging horses, fortnightly from july 1995 to july 1997, at pedro leopoldo, minas gerais. twenty horses were divided into four groups of five animals per group, each having a similar mix of resistant and less resistant animals, based on initial infestation. every 2 weeks, one of the groups, in sequ ...200010760407
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
natural co-infection of babesia caballi and encephalitozoon-like microsporidia in the tick anocentor nitens (acari: ixodidae).the present paper reports the occurrence of natural co-infection of babesia caballi and encephalitozoon-like microsporidia in the tick anocentor nitens. engorged females of ticks, collected from a naturally b. caballi-infected horse, were incubated at 27 degrees c and relative humidity over 83%. after a 6-day incubation period, giemsa-stained smears prepared from hemolymph were examined microscopically under oil immersion. b. caballi infected ticks were dissected and samples of midgut tissue wer ...200616973173
transmission of equine piroplasmosis by dermacentor nitens neumann. 196313974501
the ticks (acari: ixodida: argasidae, ixodidae) of paraguay.the ticks reported in paraguay, which are here reviewed, can be categorized as 'endemic or established' (argas persicus or a sibling species, ornithodoros hasei, o. rostratus, o. rudis, o. talaje/o. puertoricensis, amblyomma aureolatum, am. auricularium, am. brasiliense, am. cajennense, am. calcaratum, am. coelebs, am. dissimile, am. dubitatum, am. incisum, am. longirostre, am. nodosum, am. ovale, am. pacae, am. parvum, am. pseudoconcolor, am. rotundatum, am. scutatum, am. tigrinum, am. triste, ...200717362600
rhythm of engorgement and detachment of anocentor nitens females feeding on horses.the present study evaluated the engorgement and drop-off rhythms of anocentor nitens females feeding on horses. drop-off rhythm was evaluated at 6h-intervals (06:00, 12:00, 18:00, and 00:00 h) on horses held in stalls or in a pasture. a new method of marking feeding female ticks (the bowknot technique) was developed to evaluate ticks on horses in pasture that attached to different parts of the horse's body. this technique was highly successful, indicating no significant interference on tick engo ...200616481114
ticks and tick-borne disease in guatemalan cattle and horses.blood samples and ticks were collected from 48 cattle and 74 horses from seven sites in the peten region of guatemala. data on body condition, mucous membrane capillary refill time and tick infestation levels were recorded for each animal in the study. horses had significantly higher levels of tick infestation than cattle, as well as poorer body condition scores. seroprevalence of babesia spp. was 95.8% for b. bovis in cattle, 89.6% for b. bigemina in cattle, and 92.7% for b. equi in horses. ser ...200515936147
rocky mountain spotted fever, colombia.we investigated 2 fatal cases of rocky mountain spotted fever that occurred in 2003 and 2004 near the same locality in colombia where the disease was first reported in the 1930s. a retrospective serosurvey of febrile patients showed that > 21% of the serum samples had antibodies aaainst spotted fever group rickettsiae.200718214179
tick fauna from two locations in the brazilian savannah.the cerrado is brazil's tropical savannah, which is arguably under greater threat than the amazon rainforest. the cerrado biome of tropical south america covers about 2 million km(2) and is considered a biodiversity hot spot which means that it is especially rich in endemic species and particularly threatened by human activities. the cerrado is increasingly exposed to agricultural activities which enhance the likelihood of mixing parasites from rural, urban and wildlife areas. information about ...200717828441
molecular identification of rickettsia felis in ticks and fleas from an endemic area for brazilian spotted fever.rickettsioses are arthropod-borne diseases caused by parasites from the order rickettsiales. the most prevalent rickettsial disease in brazil is brazilian spotted fever (bsf). this work intends the molecular detection of those agents in ectoparasites from an endemic area of bsf in the state of espírito santo. a total of 502 ectoparasites, among them amblyomma cajennense, amblyomma dubitatum (a. cooperi), riphicephalus sanguineus, anocentor nitens and ctenocephalides felis, was collected from dom ...200818425272
[parasites of the central american tapir tapirus bairdii (perissodactyla: tapiridae) in chiapas, mexico].we analyzed 19 samples of baird's tapir feces from la sepultura biosphere reserve, collected between march and july 1999. we also took samples directly from a male tapir captured at the montes azules biosphere reserve. both reserves are in chiapas, mexico. we used five techniques: flotation, macmaster, micrometric, ritchie's sedimentation and ferreira's quantitative. in addition, we collected ectoparasites from animals captured in both reserves and from a captive couple from tuxtla gutierrez, ch ...200618494314
[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
transmission of babesia caballi by dermacentor nitens (acari: ixodidae) is restricted to one generation in the absence of alimentary reinfection on a susceptible equine host.the tropical horse tick, dermacentor nitens, is a natural vector of babesia caballi in the americas. b. caballi, one of the etiologic agents of equine piroplasmosis, occurs widely throughout the world, but the united states and a few other countries are considered to be free of infection. b. caballi is transovarially transmitted by the one-host tick d. nitens; we tested the hypothesis that b. caballi can persist in multiple generations of d. nitens in the absence of opportunity to reacquire infe ...200819058641
evaluation of the efficacy of strains of steinernema carpocapsae santa rosa and all (steinernematidae: rhabditida) to control engorged female anocentor nitens (acari: ixodidae).in view of the need to combat the generalized spread of resistance in ticks to commercial acaricides, the objective of this study was to evaluate the action of entomopathogenic nematodes (steinernema carpocapsae, strains santa rosa and all) on engorged female anocentor nitens. five ticks per petri dish were exposed to concentrations of 500, 5,000, or 25,000 infective juveniles of s. carpocapsae for 72 h. after transferring the ticks to clean plates, biological parameters were analyzed. related t ...200919123009
francisella-like endosymbiont dna and francisella tularensis virulence-related genes in brazilian ticks (acari: ixodidae).ticks are vectors of a variety of pathogens, including francisella tularensis. bacteria in the genus francisella have been identified mostly in the northern hemisphere and include tick endosymbionts. francisella has never been described in brazil, where amblyomma spp. ticks are known as the vector of many bacterial zoonotic pathogens. in the present work, we have identified bacterial dna sequences with identity to francisella genes in amblyomma dubitatum neumann dermacentor nitens (neumann), and ...200919351090
structural study of the salivary glands of anocentor nitens (acari: ixodidae) during the feeding cycle.the salivary glands of anocentor nitens (neumann,1897) occur in pairs and are located in the anterolateral region of the general cavity, with milky white color and approximately equal sizes. they consist of a secretory portion and an excretion duct. in some glandular acini, all the cells had a basophilic appearance they were stained by hematoxylin, whereas others presented cells with different staining affinities. in this work, we describe the variations observed in these glands during the feedi ...201019544533
[occurrence of ticks (acari: ixodidae) in the municipality of goiatins, tocantins].due to a suspected human case of brazilian lyme-like disease in the city of goiatins, tocantins state, an epidemiological survey was carried out in eight counties in this region during september 2007 and february 2008, where 1,890 ticks were collected from domestic animals and from the environment. a total of eight tick species were identified: rhipicephalus sanguineus, rhipicephalus (boophilus) microplus, dermacentor nitens, amblyomma cajennense, amblyomma oblongoguttatum, amblyomma ovale, ambl ...200919602318
imidocarb dipropionate clears persistent babesia caballi infection with elimination of transmission potential.antimicrobial treatment of persistent infection to eliminate transmission risk represents a specific challenge requiring compelling evidence of complete pathogen clearance. the limited repertoire of antimicrobial agents targeted at protozoal parasites magnifies this challenge. using babesia caballi as both a model and a specific apicomplexan pathogen for which evidence of the elimination of transmission risk is required for international animal movement, we tested whether a high-dose regimen of ...200919620328
detection and identification of rickettsial agents in ticks from domestic mammals in eastern panama.several outbreaks of rocky mountain spotted fever have occurred in recent years in colombian communities close to the border with panama. however, little is known about rickettsiae and rickettsial diseases in eastern panamanian provinces, the darien province and the kuna yala, located north of the endemic area in colombia. in 2007, 289 ticks were collected in several towns from dogs, horses, mules, cows, and pigs. dna was extracted from 124 dermacentor nitens, 64 rhipicephalus sanguineus, 43 amb ...200919645289
ticks (acari: ixodidae) within various phytophysiognomies of a cerrado reserve in uberlândia, minas gerais, brazil.cerrado biome, the south american savannah, covers about 2 million km(2) and is very rich in endemic species but threatened by agriculture. in this report free-living tick species are presented, and their seasonal and relative distribution within the various phytophysiognomies in a small cerrado reserve in minas gerais state, brazil. overall 2,694 free-living ticks were found during a 2 years sampling period with co(2) traps and cloth dragging. of these, 73.5% were amblyomma cajennense and 0.6% ...201019693680
ticks on domestic animals in pernambuco, northeastern brazil.the objective of this article was to discuss some aspects of ticks associated with domestic animals in the state of pernambuco, northeastern brazil, based on a literature review and present new data obtained from recent tick collections carried out in this northeastern brazilian state. from august 2007 to june 2008, 1,405 ticks were collected and five species were identified: amblyomma cajennense (fabricius, 1787), amblyomma ovale koch, 1844, dermacentor nitens neumann, 1897, rhipicephalus (boop ...200919772771
surveys for ectoparasites on wildlife associated with amblyomma variegatum (acari: ixodidae)-infested livestock in st. croix, u.s. virgin islands.surveys in 2001, 2005, and 2006 attempted to determine the role of wildlife in maintenance and dissemination of the tropical bont tick, amblyomma variegatum (f.) (acari: ixodidae), in st. croix, u.s. virgin islands. small mammals; birds; white-tailed deer, odocoileus virginianus (zimmermann); and feral cattle, bos taurus l., were examined at nine premises, in mountainous rain forest, and in surrounding areas in western st. croix, an area including and central to all known bont tick-infested prem ...200919960701
prevalence of equine piroplasmosis and its association with tick infestation in the state of são paulo, brazil.serum samples were collected from 582 horses from 40 stud farms in the state of são paulo and tick (acari: ixodidae) infestations were evaluated on them. serum samples were subjected to the complement fixation test (cft) and a competitive inhibition elisa (celisa) for babesia caballi and theileria equi. logistic regression analyses were performed to construct multivariate models that could explain the dependent variable (horses positive for b. caballi or t. equi) as a function of the independent ...200920040201
[artificial feeding through capillaries tubes of engorged partially females of the tick dermacentor (anocentor) nitens].artificial feeding is an important toll for studying ticks feeding mechanism and transmission of pathogenic agents in the absence of vertebrate host. the objective was to feed artificially of engorged partially females of dermacentor (anocentor) nitens, proceeding of infested naturally equines and evaluate the influence of this technique on biological parameters of species. engorged partially females were collected, weighted and separate by weight in two range of 40 to 60 milligrams and 61 to 10 ...200820059812
[control of anocentor nitens (neumann, 1897) (acari: ixodidae) on equines].this trial evaluated control practices of anocentor nitens on equines, using spraying devices and application of acaricide paste formulation in the auricular pavilion and nasal diverticulum. the study was carried out from october 2003 to march of 2008 and the evaluations had been divided in the following stages: phase 1--out/03 mar/04 and phases 2, 3, 4 and 5, respectively, correspondents to the month's periods until março/08. it was used score of 0 to 3 to classify infestation levels. from abr/ ...200820059817
acaricidal activity of the essential oils from eucalyptus citriodora and cymbopogon nardus on larvae of amblyomma cajennense (acari: ixodidae) and anocentor nitens (acari: ixodidae).the present study evaluated the acaricidal activity of essential oils from eucalyptus citriodora and cymbopogon nardus on non-engorged larvae of amblyomma cajennense and anocentor nitens. in order to carry out the study, six groups were formed, each concentration being a treatment (6.25%, 12.5%, 25%, and 50%, respectively) and also with the creation of a control group (distilled water) and a positive control (deltametrine). for each treatment, approximately 100 larvae of these ticks were placed ...201020640444
occurrence of ticks (acari: ixodidae) on human hosts, in three municipalities in the state of pará, brazil.assuming the existence of tick parasitism in humans in the state of pará, an aggregate observational study was developed along a transversal line in three cities of the state, during two years. interviews and examinations of 2,160 townspeople and tourists were carried out, without discrimination of ethnic, sex, age, or social status, and classified for effects analyzed for four bands of age, six types of activities in the society, and two sexes. larvae, nymphs, and adults of ticks had been ident ...201020943016
rickettsia in synanthropic and domestic animals and their hosts from two areas of low endemicity for brazilian spotted fever in the eastern region of minas gerais, brazil.the aim of this study was to understand the current epidemiology of rickettsial diseases in two rickettsial-endemic regions in brazil. in the municipalities of pingo d'agua and santa cruz do escalvado, among serum samples obtained from horses and dogs, reactivity by immunofluorescent assay against spotted fever group rickettsiae was verified. in some serum samples from opossums (didelphis aurita) captured in santa cruz do escalvado, serologic response against rickettsiae was also verified. polym ...201021118939
efficacy of 2,6-dichlorophenol lure to control dermacentor nitens.this study was carried out with the objective of evaluating the efficacy of a 2,6-dichlorophenol (2,6-dcp) lure to control dermacentor nitens (acari: ixodidae). slow-release formulations of the pheromone formulated with and without cypermethrin were prepared. olfactometer bioassays were used to define the best dose of the pheromone and to evaluate the effect of cypermethrin with 2,6-dcp attractiveness. sexually active males were released 15 cm from 2 cmx1 cm pieces of polypropylene treated with ...200717459588
detection of theileria and babesia in brown brocket deer (mazama gouazoubira) and marsh deer (blastocerus dichotomus) in the state of minas gerais, brazil.intraerythrocytic protozoan species of the genera theileria and babesia are known to infect both wild and domestic animals, and both are transmitted by hard-ticks of the family ixodidae. the prevalences of hemoprotozoa and ectoparasites in 15 free-living mazama gouazoubira, two captive m. gouazoubira and four captive blastocerus dichotomus from the state of minas gerais, brazil, have been determined through the examination of blood smears and the use of nested polymerase chain reaction (npcr). t ...201021354704
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
association of different genetic types of francisella-like organisms with the rocky mountain wood tick (dermacentor andersoni) and the american dog tick (dermacentor variabilis) from localities near their northern distributional limits.dermacentor andersoni and dermacentor variabilis from allopatric and sympatric populations near their northern distributional limits were examined for the presence of francisella species using molecular techniques that targeted 373 bp of the 16s ribosomal rna gene. although there was no evidence for the presence of francisella tularensis in any tick, francisella-like endosymbionts (fles) were common in d. andersoni and d. variabilis adults and immatures. a significantly greater proportion of fem ...201122179251
tick cell lines for study of crimean-congo hemorrhagic fever virus and other arboviruses.abstract continuous cell lines derived from many of the vectors of tick-borne arboviruses of medical and veterinary importance are now available. their role as tools in arbovirus research to date is reviewed and their potential application in studies of tick cell responses to virus infection is explored, by comparison with recent progress in understanding mosquito immunity to arbovirus infection. a preliminary study of propagation of the human pathogen crimean-congo hemorrhagic fever virus (cc ...201121955214
acaricidal activity of hydroethanolic formulations of thymol against rhipicephalus sanguineus (acari: ixodidae) and dermacentor nitens (acari: ixodidae) larvae.the aim of this study was to assess the acaricidal activity of hydroethanolic formulations of thymol at varying concentrations on rhipicephalus sanguineus and dermacentor nitens larvae. the larval packet test was used and the thymol concentrations tested were 2.5, 5.0, 10.0, 15.0 and 20.0mg/ml. the control group was exposed only to water and ethanol (50/50%) and there were 10 repetitions for each treatment. the mortality was evaluated after 24h. for the r. sanguineus larvae, the mortality rates ...201122137349
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
molecular detection of bartonella species in ticks from peru.a total of 103 ticks, collected from canines, horses, donkeys, and snakes from peru, were screened for the presence of bartonella dna by polymerase chain reaction analysis. bartonella dna was detected in two ticks using bartonella 16s-23s intergenic spacer region primers and in an additional two ticks using bartonella nadh dehydrogenase gamma subunit gene (nuog) primers. bartonella rochalimae eremeeva et al., b. quintana schmincke, and b. elizabethae daly et al. dna was detected in a rhipicephal ...201122238888
quantification of sex pheromone from anocentor nitens by gas chromatography-mass spectrometry-selected ion monitoring.two highly sensitive and selective methods based on gas chromatography coupled to mass spectrometry (gc-ms) in the selected ion monitoring (sim) mode have been developed for the quantification of 2,6-dichlorophenol (2,6-dcp), a sex pheromone of the tick females of anocentor nitens. standard addition method and calibration curve techniques using 5-bromine-4-hydroxy-3-methoxybenzaldehyde (5-brv) as internal standard (is) afforded detection limit of 0.1ngml(-1). the calibration curve was linear ove ...200418969341
first record of borrelia burgdorferi b31 strain in dermacentor nitens ticks in the northern region of parana (brazil).the aim of this study was to investigate the presence of dna of borrelia burgdorferi sensu lato (s.l.) in ticks that feed on horses used for animal traction in rural jataizinho, parana, brazil. between february and june 2008, a total of 224 ticks was collected of which 75% were identified as dermacentor nitens and 25% as amblyomma cajenense. to amplify b. burgdorferi s.l. dna, the intergenic space region (isr) between the 5s (rrf) 23s (rrl) rrna genes was used as targets for nested-pcr. two tick ...201424516456
borrelia burgdorferi sensu lato in humans in a rural area of paraná state, brazil.this study describes the detection of borrelia garinii and borrelia burgdorferi sensu stricto (s.s.) in brazilian individuals using pcr and dna sequencing. our results suggest that these species are emerging pathogens in this country, and additional studies are necessary to determine the epidemiological characteristics of this disease in brazil.201526273276
tick-borne infections in human and animal population worldwide.the abundance and activity of ectoparasites and its hosts are affected by various abiotic factors, such as climate and other organisms (predators, pathogens and competitors) presenting thus multiples forms of association (obligate to facultative, permanent to intermittent and superficial to subcutaneous) developed during long co-evolving processes. ticks are ectoparasites widespread globally and its eco epidemiology are closely related to the environmental conditions. they are obligatory hematop ...201527047089
potentially novel ehrlichia species in horses, nicaragua.ehrlichia sp. dna was amplified from 4 ehrlichia-seroreactive horses from mérida, nicaragua. sequencing of 16s rdna, sodb, and groel genes indicated that the bacterium is most likely a novel ehrlichia species. the tick vector and the potential for canine and human infection remain unknown.201525625228
brazilian borreliosis with special emphasis on humans and horses.borreliosis caused by borrelia burgdorferi sensu lato is a cosmopolitan zoonosis studied worldwide; it is called lyme disease in many countries of the northern hemisphere and lyme-like or baggio-yoshinari syndrome in brazil. however, despite the increasing number of suspect cases, this disease is still neglected in brazil by the medical and veterinary communities. brazilian lyme-like borreliosis likely involves capybaras as reservoirs and amblyomma and rhipicephalus ticks as vectors. thus, domes ...201627769883
bacteria associated with amblyomma cajennense tick eggs.ticks represent a large group of pathogen vectors that blood feed on a diversity of hosts. in the americas, the ixodidae ticks amblyomma cajennense are responsible for severe impact on livestock and public health. in the present work, we present the isolation and molecular identification of a group of culturable bacteria associated with a. cajennense eggs from females sampled in distinct geographical sites in southeastern brazil. additional comparative analysis of the culturable bacteria from an ...201526537602
nhumirim virus, a novel flavivirus isolated from mosquitoes from the pantanal, brazil.we describe the isolation of a novel flavivirus, isolated from a pool of mosquitoes identified as culex (culex) chidesteri collected in 2010 in the pantanal region of west-central brazil. the virus is herein designated nhumirim virus (nhuv) after the name of the ranch from which the mosquito pool was collected. flavivirus rna was detected by real-time rt-pcr of homogenized mosquitoes and from the corresponding c6/36 culture supernatant. based on full-genome sequencing, the virus isolate was gene ...201425252815
update on tick-borne rickettsioses around the world: a geographic approach.tick-borne rickettsioses are caused by obligate intracellular bacteria belonging to the spotted fever group of the genus rickettsia. these zoonoses are among the oldest known vector-borne diseases. however, in the past 25 years, the scope and importance of the recognized tick-associated rickettsial pathogens have increased dramatically, making this complex of diseases an ideal paradigm for the understanding of emerging and reemerging infections. several species of tick-borne rickettsiae that wer ...024092850
effect of attractant sex pheromone on immature larval stages of ixodid tick species.attractant sex pheromone (asp) 2,6-dichloro phenol was used in the current study to evaluate the percentage attraction and the behavioural responses of the five ixodid tick species namely rhipicephalus sanguineus, rhipicephalus microplus (boophilus microplus), haemaphysalis bispinosa, rhipicephalus haemaphysaloides and hyalomma marginatum using petridish bioassay. two concentrations of 2,6-dcp (0.1 m and 0.05 m) was used for the larval stages of all five ixodid tick species of which 0.1 m concen ...201224082519
synanthropic mammals as potential hosts of tick-borne pathogens in panama.synanthropic wild mammals can be important hosts for many vector-borne zoonotic pathogens. the aim of this study was determine the exposure of synanthropic mammals to two types of tick-borne pathogens in panama, spotted fever group rickettsia (sfgr) and borrelia relapsing fever (rf) spirochetes. one hundred and thirty-one wild mammals were evaluated, including two gray foxes, two crab-eating foxes (from zoos), four coyotes, 62 opossum and 63 spiny rats captured close to rural towns. to evaluate ...201728060928
host specificity in a diverse neotropical tick community: an assessment using quantitative network analysis and host specificity is a fundamental determinant of tick population and pathogen transmission dynamics, and therefore has important implications for human health. tick host specificity is expected to be particularly high in the tropics, where communities of ticks, hosts and pathogens are most diverse. yet the degree to which tropical tick species are host-specific remains poorly understood. combining new field data with published records, we assessed the specificity of tick-host associations in pan ...201627357506
ticks and rickettsiae from wildlife in belize, central america.the agents of spotted fevers in latin america are rickettsia rickettsii, r. parkeri, rickettsia sp. strain atlantic rainforest, and r. massiliae. in continental central america, r. rickettsii remains the only known pathogenic tick-borne rickettsia. in the present study, ticks were collected from wild mammals in natural areas of belize. besides providing new data of ticks from belize, we investigated rickettsial infection in some of these ticks. our results provide ticks harboring rickettsial age ...201626831147
growth of ehrlichia canis, the causative agent of canine monocytic ehrlichiosis, in vector and non-vector ixodid tick cell lines.canine monocytic ehrlichiosis is caused by ehrlichia canis, a small gram-negative coccoid bacterium that infects circulating monocytes. the disease is transmitted by the brown dog tick rhipicephalus sanguineus s.l. and is acknowledged as an important infectious disease of dogs and other members of the family canidae worldwide. e. canis is routinely cultured in vitro in the canine monocyte-macrophage cell line dh82 and in non-vector ixodes scapularis tick cell lines, but not in cells derived from ...201626837859
propagation of the israeli vaccine strain of anaplasma centrale in tick cell lines.anaplasma centrale has been used in cattle as a live blood vaccine against the more pathogenic anaplasma marginale for over 100 years. while a. marginale can be propagated in vitro in tick cell lines, facilitating studies on antigen production, immunisation and vector-pathogen interaction, to date there has been no in vitro culture system for a. centrale. in the present study, 25 cell lines derived from 13 ixodid tick species were inoculated with the israeli vaccine strain of a. centrale and mon ...201526210950
importance of ticks and their chemical and immunological control in livestock.the medical and economic importance of ticks has long been recognized due to their ability to transmit diseases to humans and animals. ticks cause great economic losses to livestock, and adversely affect livestock hosts in several ways. loss of blood is a direct effect of ticks acting as potential vector for haemo-protozoa and helminth parasites. blood sucking by large numbers of ticks causes reduction in live weight and anemia among domestic animals, while their bites also reduce the quality of ...017048307
rickettsia and vector biodiversity of spotted fever focus, atlantic rain forest biome, brazil. 024565262
molecular ecological insights into neotropical bird-tick the tropics, ticks parasitize many classes of vertebrate hosts. however, because many tropical tick species are only identifiable in the adult stage, and these adults usually parasitize mammals, most attention on the ecology of tick-host interactions has focused on mammalian hosts. in contrast, immature neotropical ticks are often found on wild birds, yet difficulties in identifying immatures hinder studies of birds' role in tropical tick ecology and tick-borne disease transmission. in panama ...201627203693
candidatus rickettsia andeanae, a spotted fever group agent infecting amblyomma parvum ticks in two brazilian ticks of the species amblyomma parvum were collected from the vegetation in the pantanal biome (state of mato grosso do sul) and from horses in the cerrado biome (state of piauí) in brazil. the ticks were individually tested for rickettsial infection via polymerase chain reaction (pcr) targeting three rickettsial genes, glta, ompa and ompb. overall, 63.5% (40/63) and 66.7% (2/3) of a. parvum ticks from pantanal and cerrado, respectively, contained rickettsial dna, which were all confirmed ...024714968
native strains of beauveria bassiana for the control of rhipicephalus sanguineus sensu lato.rhipicephalus sanguineus sensu lato ticks are widespread worldwide due to their adaptability to survive under different environmental conditions. they may act as vectors of a wide range of pathogens to humans and animals and their control is based on the use of chemical products on dogs and in the environment. alternative control strategies, such as the use of entomopathogenic fungi as bio-control agents have also been investigated. the ability of native strains of beauveria bassiana sensu lato ...201525651851
detection of rickettsia parkeri from within piura, peru, and the first reported presence of candidatus rickettsia andeanae in the tick rhipicephalus sanguineus.domestic farm animals (n=145) were sampled for the presence of ectoparasites in northwestern peru during march, 2008. ninety domestic animals (62%) were positive for the presence of an ectoparasite(s) and produced a total collection of the following: 728 ticks [amblyomma maculatum, anocentor nitens, rhipicephalus (boophilus) microplus, rhipicephalus sanguineus, and otobius megnini], 12 lice (haematopinus suis), and 3 fleas (ctenocephalides felis). a rickettsia genus-specific qpcr assay was perfo ...201323488453
molecular detection of theileria spp. in livestock on five caribbean islands.theileria spp. are tick-transmitted, intracellular apicomplexan protozoan parasites infecting a wide range of animals. as there is very limited information on the prevalence of theileria spp. in the caribbean we used the recently described genus-specific pan-theileria fret-qpcr to identify infected animals in the region and a standard 18s rrna gene pcr and sequencing to determine the species involved. we found theileria spp. in 9% of the convenience samples of animals (n = 752) studied from five ...201526783522
chemical composition and insecticidal activity of plant essential oils from benin against anopheles gambiae (giles).insecticide resistance in sub-saharan africa and especially in benin is a major public health issue hindering the control of the malaria vectors. each anopheles species has developed a resistance to one or several classes of the insecticides currently in use in the field. therefore, it is urgent to find alternative compounds to conquer the vector. in this study, the efficacies of essential oils of nine plant species, which are traditionally used to avoid mosquito bites in benin, were investigate ...201324298981
molecular epidemiology of theileria equi in horses and their association with possible tick vectors in the state of rio de janeiro, brazil.the aim of this study was to detect theileria equi (laveran 1901) dna in horses and ticks using real-time pcr and to list the factors associated with infection in animals located in the seropedica and petropolis municipalities of the state of rio de janeiro. we tested blood samples from 314 horses and samples from 300 ticks, including 191 amblyomma cajennense, 104 dermacentor nitens, and 5 ixodida larvae. factors inherent to the horse, the ownership, and animal management were obtained from an e ...201323474658
comparative genomic analysis and phylogenetic position of theileria equi.transmission of arthropod-borne apicomplexan parasites that cause disease and result in death or persistent infection represents a major challenge to global human and animal health. first described in 1901 as piroplasma equi, this re-emergent apicomplexan parasite was renamed babesia equi and subsequently theileria equi, reflecting an uncertain taxonomy. understanding mechanisms by which apicomplexan parasites evade immune or chemotherapeutic elimination is required for development of effective ...201223137308
an insight into the microbiome of the amblyomma maculatum (acari: ixodidae).the aim of this study was to survey the bacterial diversity of amblyomma maculatum koch, 1844, and characterize its infection with rickettsia parkeri. pyrosequencing of the bacterial 16s rrna was used to determine the total bacterial population in a. maculatum. pyrosequencing analysis identified rickettsia in a. maculatum midguts, salivary glands, and saliva, which indicates successful trafficking in the arthropod vector. the identity of rickettsia spp. was determined based on sequencing the ric ...024605461
serum antibodies from a subset of horses positive for babesia caballi by competitive enzyme-linked immunosorbent assay demonstrate a protein recognition pattern that is not consistent with infection.tick-borne pathogens that cause persistent infection are of major concern to the livestock industry because of transmission risk from persistently infected animals and the potential economic losses they pose. the recent reemergence of theileria equi in the united states prompted a widespread national survey resulting in identification of limited distribution of equine piroplasmosis (ep) in the u.s. horse population. this program identified babesia caballi-seropositive horses using rhoptry-associ ...201324049108
molecular characterization of anaplasma marginale in ticks naturally feeding on buffaloes.anaplasma marginale is the most prevalent pathogen transmitted by ticks in cattle in tropical and subtropical regions of the world. however, the tick species involved in the transmission of a. marginale in buffaloes in brazil have not been identified. the objective of the present study was to determine the presence of a. marginale in ticks parasitizing water buffaloes. a total of 200 samples of rhipicephalus microplus, dermacentor nitens, amblyomma cajennense, and amblyomma maculatum were collec ...201526209411
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