| relative susceptibility of jamaican strains of boophilus microplus, amblyomma cajennense, and anocentor nitens to various acaricides. | | 1977 | 604370 |
| some aspects of the ecology and lifecycle of amblyomma cajennense (fabricius 1787) in trinidad and their influence on tick control measures. | the distribution in trinidad of the tick amblyomma cajennense is defined, and the methods used to determine the boundaries of the infested areas are outlined. the relationships between climate, vegetation and husbandry methods and the distribution of the tick are described. monthly tick collections from specific animals to determine exact seasonal variations were not possible but a study was made of the normal life cycle under laboratory conditions, the results being used to assist in interpreti ... | 1975 | 1124964 |
| comparative infections of epizootic and enzootic strains of venezuelan equine encephalomyelitis virus in amblyomma cajennense (acari: ixodidae). | to compare the potential for an enzootic or an epizootic strain of venezuelan equine encephalomyelitis (vee) virus to infect amblyomma cajennense (f.), larval ticks were fed on guinea pigs (strain 13) inoculated with an enzootic viral strain of variant i-e (68u201) or on guinea pigs inoculated with an epizootic strain of variant i-a (trinidad donkey). peak viremias were 10(5.2) plaque-forming units (pfu)/ml and 10(7.3) pfu/ml in guinea pigs infected with enzootic and epizootic viral strains, res ... | 1992 | 1404262 |
| feeding efficiency of larval hyalomma truncatum (acari: ixodidae) on hosts previously exposed to ticks. | the effect of guinea pig response to feeding larval hyalomma truncatum koch ticks was studied by measuring the percentage of ticks engorging and molting, their engorged weight, and hemoglobin content. four guinea pigs were infested with 100, 200, 400, and 1,000 larvae, respectively, on three occasions at 21-d intervals, followed by a fourth infestation with 500 larvae. during the second, third, and fourth infestations, significantly fewer ticks engorged on each guinea pig than during the first i ... | 1992 | 1495048 |
| a contribution to the anatomy and histology of the female reproductive system of amblyomma cajennense (acarina: ixodidae). | the genital system of the tick amblyomma cajennense is composed of several parts: a single tubular ovary where a great number of ova develop except for a longitudinal groove on its dorsal surface, with feeding the ova develop multiplying the size and weight of the ovary, as they reach maturity they are ovulated into the lumen. two oviducts are connected to the ovary on each side, these thicken at a certain region forming the knee shaped ampulla. this significant region is where great numbers of ... | 1992 | 1500779 |
| 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 ... | 1991 | 1875367 |
| ecological aspects of four species of ticks found on cattle in salta, northwest argentina. | the seasonal activity of amblyomma cajennense, amblyomma neumanni, amblyomma parvum and boophilus microplus on cattle was studied in a ranch located in the northern part of the phytogeographical district of the chaco serrano where the habitat had suffered minimal human disturbance. the female ticks on one side of 10-25 cows were counted at intervals of 20-50 days from 29 october 1985 to 5 november 1986. the percentage of cattle parasitized with larvae and nymphs of amblyomma was recorded, along ... | 1990 | 2343535 |
| comparison of the isozyme phenotypes of the morphologically similar ticks amblyomma cajennense and a. imitator (acari: ixodidae) from south texas. | a survey of amblyomma koch tick populations in southern texas revealed that a. imitator kohls was restricted to the two most southern counties, but that a. cajennense (fabricius) ranged at least as far north as kingsville, tex. females of the two species could be distinguished by the presence of chitinous tubercles on the festoons of a. cajennense and the presence of projections over both sides of the apron of the genital aperture in a. imitator. males were distinguished by size, ornamentation, ... | 1989 | 2926774 |
| danger of introducing heartwater onto the american mainland: potential role of indigenous and exotic amblyomma ticks. | the existence of heartwater on 3 islands of the central lesser antilles and the presence of an efficient vector originating from africa, amblyomma variegatum, on most of the islands of this region constitute a serious threat for livestock on the american mainland. the disease can be introduced there either by infected animals or infected ticks. the most likely way is probably the transportation of domestic animals which are heavily infested by ticks. due to the low rate of infection of ticks in ... | 1987 | 3329328 |
| the ecology of amblyomma cajennense a parasite of man and animals in trinidad. | | 1973 | 4777424 |
| pheromone-induced aggregation of ixodid ticks before host contact. | the presence of a pre-feeding aggregation pheromone was demonstrated in the species dermacentor variabilis, dermacentor andersoni, dermacentor parumapertus, amblyomma americanum and haemaphysalis leporispalustris by assay within a petri dish. however, amblyomma maculatum and amblyomma cajennense did not aggregate in the sector containing discs of presumed pheromone within the hour period. d. andersoni and a. americanum recognized each other's pheromone and a. americanum recognized that of h. lep ... | 1983 | 6683667 |
| [seasonal dynamics in the development of boophilus microplus and amblyomma cajennense in camagüey, cuba]. | studies were carried out on the occurrence of the ixodic ticks in farm animals in the province of camagüey, cuba. most spread proved to be the boophilus microplus and amblyomma cajennense species. as many as three waves of parasitic activity were seen with b. microplus: at the end of the winter season, in the months of may and june, and in the autumn (october and november). only one wave was there with the activity of a. cajennense, covering the period of march-september. | 1984 | 6740935 |
| mammalian wildlife diseases as hazards to man and livestock in an area of the llanos orientales of colombia. | development of the llanos orientales of colombia, and access to underdeveloped areas in the llanos, may create disease hazards to man and domestic animals or introduce exotic pathogens, creating reservoirs of infection for domestic animals and acting as limiting factors on the native wild species. a survey of wild animals common to the llanos revealed a number of parasites indigenous to the area. a total total of 59 mammalian species, representing eight orders were examined. haematozoa were repr ... | 1981 | 6788961 |
| tick paralysis in brazil. | from july to december 1977 and from june to november 1978 the toxic effects of amblyomma cajennense were studied in cattle sheep and goats. locomotor disturbances commencing as hind-limb paralysis ascended to the upper nervous centres causing paralysis. this was observed in natural infections and confirmed experimentally. tick paralysis is reported for the first time in brazil, manifesting itself in a different form to that usually attributed clinically to the disease. also for the first time re ... | 1983 | 6868132 |
| amblyomma ticks found on cattle in the northwest of argentina. preliminary report. | the phytogeographical and seasonal distributions of three species of amblyomma ticks found on cattle are presented. the material studied was collected during a four-year survey in the northwest of argentina. amblyomma neumanni shows predilection for the chaqueno serrano district although it was also found in ecotones (phytogeographical transition zones) of the adjacent western chaqueno district and the province of las yungas. amblyomma cajennense was found in the western chaqueno and chaqueno se ... | 1982 | 7081892 |
| epidemiological investigation for arboviruses in jamaica, west indies. | arbovirus investigation in jamaica was undertaken between 1960 and 1975. serological studies showed that antibodies to dengue type virus and st. louis encephalitis virus (sle) were prevalent throughout the island for several years. in urban communities, the incidence of dengue antibody was higher than for sle; however, in children under 10 years of age antibody to both viruses was rarely present. in rural areas, sle was prevalent in adults and children. this virus was isolated fom culex nigripal ... | 1980 | 7406115 |
| seasonal incidence and hemoparasite infection rates of ixodid ticks (acari: ixodidae) detached from cattle in costa rica. | to determine the tick species hindering the cattle industry in costa rica and to assess infection rates of ticks with three important hemoparasite species, cattle were monitored during a period of six months (october 1992-march 1993). four farms were located in the dry pacific region of the canton of tilarán and a fifth farm on the slopes of the poás volcano in a cool tropical cloud-forest ecosystem. on each farm 3 to 5 animals of 6 to 24 months of age were selected at random. all ticks were rem ... | 1994 | 7501871 |
| vector situation of tick-borne diseases in the caribbean islands. | the most important ticks transmitting diseases to ruminants in the caribbean islands are: amblyomma variegatum, vector of cowdriosis and associated with acute dermatophilosis; amblyomma cajennense, potential vector of cowdriosis; boophilus microplus, vector of babesiosis and anaplasmosis. at the present time, amblyomma variegatum is widespread in the lesser antilles from barbados to puerto rico. the intensity of the tick control program varies in the different islands and the tick infestation in ... | 1995 | 7597781 |
| 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, ... | 1995 | 7676590 |
| seasonal variation of ticks (ixodidae) in bos taurus x bos indicus cattle under rotational grazing in forested and deforested habitats in northwestern argentina. | the seasonal occurrence of ticks infesting cattle was monitored in a bos taurus x bos indicus commercial herd fed on a combination of native grasses and annual pastures in northwestern argentina. the number of female ticks (boophilus and amblyomma) and the proportion of cattle infested with larvae and nymphs of amblyomma ticks were recorded from a sample of 15 cows in 24 visits at intervals of 21-50 days from 5 december 1986 to 24 november 1988. the cattle were maintained on native grasses in fo ... | 1994 | 7839563 |
| using cuticular hydrocarbon composition to elucidate phylogenies in tick populations (acari: ixodidae). | cuticular hydrocarbon composition is used to explain hypothetical phylogenies among sympatric and allopatric populations of amblyomma cajennense, a. variegatum and ixodes ricinus tick species. the method proposed here uses a parsimony analysis of endemicity by disjunct biochemical data (paedb) based in the pattern of cuticular hydrocarbons. the advantage of our approach is that information contained in fragments that are not conserved in all the individuals of a populations need not be discarded ... | 1994 | 7863854 |
| cytosystematics of five north american amblyomma (acarina: ixodidae) species. | the karyotypes of 5 species of amblyomma ticks found in north america were examined for the presence and location of constitutive heterochromatin (c-bands). all specimens examined had 20 autosomes and an xx:xo sex-determining system, with the x being the largest element in the karyotype. except as noted in text, the autosomes of all species were acrocentric and heterochromatin was restricted to the centromeric region. the third largest autosome in 4 of the 5 species displayed a consistent band o ... | 1995 | 7876973 |
| patterns of cuticular hydrocarbon variation and genetic similarity between natural populations of amblyomma cajennense (acari: ixodidae). | gas chromatography has been used to analyze the variation in cuticular hydrocarbon patterns between several populations of amblyomma cajennense. 88 compounds were detected and these could be divided into 17 groups of hydrocarbons. heterozygosis in the populations ranges from 0% to 25.84%. isomers for pentacosane, heptacosane and nonatriacontane are the most variable, with 13, 10 and 11 variants, respectively. nei's genetic identity and genetic distance show that populations may be considered as ... | 1993 | 7903139 |
| effects of temperature on fecundity and viral replication in amblyomma cajennense (arachnida: ixodidae) infected with venezuelan equine encephalomyelitis virus. | to assess how temperature affects fecundity and venezuelan equine encephalomyelitis (vee) viral replication in vee-infected amblyomma cajennense (f.), adult ticks were inoculated intracoelomically with either vee virus (i-a variant) or diluent. ticks were held at 19, 26, or 33 degrees c and tested for vee virus over 20 d. up to 10 pairs of ticks (1 female:1 male) from each temperature group were allowed to feed on guinea pigs on day 8 after inoculation. maximum titers did not differ significantl ... | 1993 | 8433340 |
| survival and water-balance characteristics of unfed adult amblyomma cajennense (acari: ixodidae). | off-host survival, water balance, and cold tolerance of unfed adult, cayenne ticks, amblyomma cajennense (f.), were examined to evaluate species characteristics important to zoogeography and off-host ecology. survivorship decreased when males and females were subjected to progressively drier constant environmental conditions. average maximum survival was 641.2 and 682.5 d at 85% rh and 23 degrees c (2.98 mm hg) for males and females, respectively. mean survival in both sexes was progressively le ... | 1996 | 8906907 |
| evidence for attachment pheromones in the cayenne tick (acari:ixodidae). | evidence is presented for the existence of male-produced attachment pheromones in the tick amblyomma cajennense (f). unfed males and females attached significantly faster to shaved sides on bovine hosts where preattached males were present than did adult ticks released in control areas. attached ticks did not form clusters around the preattached males as described for other species of amblyomma. they attached in areas under bags where they had been released, but were not necessarily close to the ... | 1997 | 9103768 |
| enema infusion technique inappropriate for evaluating viral competence of ticks. | to determine whether anal infusion of virus simulates the natural route of infection rather than intracoelomic injection, we compared the course of venezuelan equine encephalitis (vee) virus infection in amblyomma cajennense (f.) ticks that had been exposed to virus by enema infusion with that in ticks fed on a viremic host or exposed by intracoelomic inoculation. although virus was detected in virtually all ticks 14 d after exposure, orally exposed ticks contained significantly less virus (10(1 ... | 1997 | 9151493 |
| 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 ... | 1997 | 9197151 |
| artificial feeding of amblyomma cajennense (fabricius, 1787) (acari:ixodidae) through silicone membrane. | an artificial feeding system was used where citrated bovine blood was offered to male and female amblyomma cajennense. vestiges of blood, sweat, hair and exfoliated skin were used as phago-stimulants placed on the surface of the silicone membrane. the ticks were collected, as engorged nymphs, from naturally infested equines, with the ecdysis occurring in the laboratory. four hundred ticks were used, 50% being female, at three to four weeks post-ecdysis. vestiges of blood on the silicone membrane ... | 1997 | 9361751 |
| host specificity of amblyomma cajennense (fabricius, 1787) (acari: ixodidae) with comments on the drop-off rhythm. | the parasitic specificity of larval, nymph and adult amblyomma cajennense on six different host species: oryctolagus cuniculus, rattus norvegicus, gallus gallus domesticus, anas platyrhynchus, coturnix coturnix and streptopelia decorata is described. in terms of the numbers of larvae and nymphs recovered, o. cuniculus was the best host species. the modal day for drop-off of larvae and nymphs was day three for the mammal hosts, but variable in the birds. we conclude that adult a. cajennense have ... | 1998 | 9698869 |
| detection of a spotted fever group rickettsia in amblyomma cajennense (acari: ixodidae) in south texas. | thai tick typhus rickettsia (strain tt-118), a spotted fever group rickettsia of indeterminant pathogenicity, was isolated from a mixed pool of larval ixodes and rhipicephalus ticks collected from thailand in 1962. here we report the surprising finding of a spotted fever group rickettsia with closest sequence homology to the thai tick typhus rickettsia in amblyomma cajennense (f.) ticks from south texas. sequence analysis was performed on segments of 3 genes that differentiate rickettsial specie ... | 1998 | 9701930 |
| population dynamics of immature amblyomma maculatum (acari: ixodidae) and other ectoparasites on meadowlarks and northern bobwhite quail resident to the coastal prairie of texas. | a survey of ectoparasites from 219 meadowlarks conducted during 2 consecutive fall-winter periods in a coastal prairie found immature amblyomma maculatum koch to be the most abundant parasite. peak larval infestations occurred in december with 80-100% of collected birds infested and with a monthly mean of up to 34 larvae per bird. peak nymphal infestations occurred in february or march with 95-100% of birds infested and with a monthly mean of up to 11 nymphs per bird. seasonal dynamics of these ... | 1998 | 9701932 |
| 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 ... | 1998 | 9835698 |
| wild birds as hosts of amblyomma cajennense (fabricius, 1787) (acari: ixodidae). | we evaluated the prevalence, mean intensity and relative density of ticks in 467 wild birds of 67 species (12 families) from forest and cerrado habitats at two protected areas of minas gerais, between march and september 1997. ticks collected (n=177) were identified as larvae and nymphs of amblyomma cajennense and four other species of amblyomma. we report for the first time 28 bird species as hosts of the immature stages of a. cajennense, demonstrating the lack of host specificity of the larvae ... | 1999 | 10419381 |
| 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 ... | 1999 | 10447188 |
| evidence of rickettsial spotted fever and ehrlichial infections in a subtropical territory of jujuy, argentina. | between november 1993 and march 1994, a cluster 6 pediatric patients with acute febrile illnesses associated with rashes was identified in jujuy province, argentina. immunohistochemical staining of tissues confirmed spotted fever group rickettsial infection in a patient with fatal disease, and testing of serum of a patient convalescing from the illness by using an indirect immunofluorescence assay (ifa) demonstrated antibodies reactive with spotted fever group rickettsiae. a serosurvey was condu ... | 1999 | 10463693 |
| serologic study of the prevalence of rickettsiosis in yucatán: evidence for a prevalent spotted fever group rickettsiosis. | because of the discovery of a spotted fever group rickettsiosis with signs and symptoms similar to dengue fever in yucatan, mexico, immunofluorescence assay (ifa) serology was performed on sera from 390 persons selected from a representative geographic distribution of rural yucatan to detect antibodies reactive with rickettsia rickettsii, r. akari, a thai strain (tt-118) that is most closely related to a rickettsia identified in amblyomma cajennense ticks in southern texas, and r. typhi. the ifa ... | 1999 | 10497980 |
| comparison of efficacy of american and african amblyomma ticks as vectors of heartwater (cowdria ruminantium) infection by molecular analyses and transmission trials. | the ability of amblyomma americanum, amblyomma cajennense, amblyomma maculatum, and amblyomma variegatum to acquire and transmit cowdria ruminantium infection was investigated. uninfected nymphs were fed on clinically reacting c. ruminantium-infected sheep and then analyzed for infection by specific dna detection assays and by tick transmission trials. by polymerase chain reaction (pcr), the mean infection prevalence of a. maculatum ticks (50.7%) was similar to that of a. variegatum, elevage str ... | 2000 | 10701562 |
| 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 ... | 1999 | 10881097 |
| population dynamics of the free-living stages of amblyomma cajennense (fabricius, 1787) (acari: ixodidae) on pastures of pedro leopoldo, minas gerais state, brazil. | a study on the population behavior of amblyomma cajennense larvae, nymphs and adult free-living stages was carried out in pedro leopoldo county, minas gerais state, brazil, from july 1995 to july 1997. larvae were collected from pasture from april to october using the technique of drag sampling with flannelette. the maximal larval population was observed during autumn (may) representing, respectively, 48 and 82% of the total numbers recovered during the first and the second years of the experime ... | 2000 | 10996741 |
| ticks (acari: ixodidae) associated with rural dogs in uruará, eastern amazon, brazil. | a survey of 124 dogs for ticks was conducted from august to november 1998 in 68 small farms of uruará municipality in eastern amazon-brazil. we collected 55 ticks from 18 dogs (14.5%). amblyomma oblongoguttatum koch, amblyomma ovale koch, and amblyomma cajennense (f.) were found on nine, six, and one dog, respectively. fourteen small farms (20.5%) had at least one dog with ticks. | 2000 | 11004794 |
| diversity of ectoparasites in sheep flocks in são paulo, brazil. | the occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. sheep production used to be a predominantly family activity in the state of são paulo (brazil), but it began to become a commercial activity in the past decade. thus, information about the ectoparasites existing in sheep flocks has become necessary. the present data were obtained by means of questionnaires sent to all sheep breeders belonging to the 'associação paulista de criadores de ovinos' (aspaco; ... | 2000 | 11020945 |
| hepatozoon canis infection associated with dog ticks of rural areas of rio de janeiro state, brazil. | hepatozoon canis is a tick-borne protozoan that infects dogs and has been reported throughout the world. manifestation of h. canis infection varies from being sub-clinical in apparently healthy dogs to severe illness. the main vector of the infection is the dog tick, rhipicephalus sanguineus although other species may also transmit this agent. h. canis has been reported previously in brazil, but mostly as an occasional finding during laboratory exams and always associated with other diseases. th ... | 2001 | 11113545 |
| ticks (acari: ixodidae) associated with wild animals in the pantanal region of brazil. | this paper describes the identification of ticks from wild animals of the pantanal region in brazil as part of a comprehensive study about established and emerging tick-host relationships and related pathological aspects. eighty-one animals were captured (representing 13 species, six orders), and ticks were found on 63 (78%). tick species identified included boophilus microplus (canestrini), amblyomma cajennense (f.), amblyomma parvum aragão, amblyomma pseudoconcolor aragão, amblyomma scalpturat ... | 2000 | 11126563 |
| parasitism by ixodes didelphidis and i. loricatus (acari: ixodidae) on small wild mammals from an atlatic forest in the state of sao paulo, brazil. | from january 1995 to june 1996, ticks were studied in a fragment of atlantic forest in a residential area in the city of itapevi, state of sao paulo, brazil. cases of human lyme disease-like illness were registered in this area during the spring of 1992. the monthly relative density of ticks was determined and the influence of seasonal climatic conditions was evaluated as well as the relationship between ticks and hosts. ticks (n = 88) were collected from small mammals captured (n = 134) in mont ... | 2000 | 11185614 |
| ticks associated with wild animals in the nhecolândia pantanal, brazil. | a study of ticks associated with wild animals was carried out from september 1996 to april 1998 at the fazenda alegria (21,000 ha), in the nhecolândia pantanal, state of mato grosso do sul, brazil, a sunken plain bordering the upper paraguay river, located 19 x 08's; 56 x 46'w. a total of 81 wild animals (13 species, 6 orders) were captured with the aid of nets, and ticks were found on 63 (78%). tick species identified included boophilus microplus (canestrini), amblyomma cajennense (f.), a. parv ... | 2000 | 11193635 |
| 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 ... | 2001 | 11337122 |
| quantitative analyses of variations in the injury of endothelial cells elicited by 11 isolates of rickettsia rickettsii. | eleven isolates of spotted fever group rickettsiae from the blood of patients or ixodid ticks from north and south america were characterized. all isolates were identified as rickettsia rickettsii using restriction fragment length polymorphism analysis of a 532-bp rompa gene fragment obtained by pcr. the ability of the r. rickettsii isolates to elicit cytopathic effects and parameters of oxidative injury were examined in cultured human ea.hy 926 endothelial cells. cytopathic effects were determi ... | 2001 | 11427428 |
| ixodes rubicundus nymphs are short-day diapause-induced ticks with thermolabile sensitivity and desiccation resistance. | the karoo paralysis tick, ixodes rubicundus neumann (acari: ixodidae), is a semi-voltine ixodid that survives stressful environmental conditions using morphogenetic diapause (eggs and engorged nymphs) and desiccation resistance. both photoperiod and temperature influence diapause induction in the engorged nymph. ixodes rubicundus nymphs are typical long-day photoperiodic organisms. the critical photoperiod is approximately 13.5 h light, 10.5 h dark, and they display a thermolabile response. the ... | 2001 | 11583453 |
| 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. ... | 2002 | 11812624 |
| 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 ... | 2002 | 11879967 |
| the sex ratio of amblyomma cajennense (acari: ixodidae) with notes on the male feeding period in the laboratory. | to evaluate the sex ratio of field collected nymphal amblyomma cajennense ticks, we collected 5326 engorged nymphs from naturally infested horses in pirassununga county and allowed them to molt to adults in the laboratory. they yielded a sex ratio of 1:1.83 (m:f). three and two engorged females were collected from horses pastured at pirassununga county and from tapirs pastured in sorocaba county, respectively. these females were allowed to oviposit and their progeny were reared until the adult s ... | 2002 | 11879968 |
| rickettsia felis in ctenocephalides spp. fleas, brazil. | in june 2000, suspected cases of brazilian spotted fever (bsf) occurred in coronel fabriciano municipality, minas gerais state, brazil. pooled fleas collected near two fatal cases contained rickettsial dna. the nucleotide sequence alignment of the 391-bp segment of the 17-kda protein gene showed that the products were identical to each other and to the r. felis 17-kda gene, confirming circulation of r. felis in brazil. | 2002 | 11927031 |
| analysis of serum and whole blood values in relation to helminth and ectoparasite infections of feral pigs in texas. | in the summers of 1996 and 1997, 60 wild pigs (sus scrofa) were necropsied from three sites in south texas (usa) to test the hypothesis that serum and whole blood parameters vary significantly (p < or = 0.05) with the prevalence and intensity of parasites infecting wild pigs. we found ten parasite species: five nematodes (metastrongylus salmi, metastrongylus pudentotectus, stephanurus dentatus, oesophagostomum dentatum, and physocephalus sexalatus); four ixodid ticks (amblyomma cajennense, ambly ... | 2002 | 12038138 |
| evidence of spotted fever group rickettsiae in state of rio de janeiro, brazil. | ticks were obtained from dogs from february to september of 1999 at weekly intervals, in the county of piraí, state of rio de janeiro. four hundred seventy four ixodids were taxonomically identified, 103 amblyomma cajennense, seven amblyomma ovale, 209 rhipicephalus sanguineus, and 155 amblyomma sp. an hemolymph test associated with giemsa's stain revealed two specimens in 163 ticks tested (r. sanguineus and amblyomma sp), containing rickettsia-like organisms. direct immunofluorescence verified ... | 2002 | 12163909 |
| gynandromorphism in amblyomma cajennense and rhipicephalus sanguineus (acari: ixodidae). | during a survey of ticks on horses in november 2000, at the university of são paulo farm in pirassununga county, são paulo, brazil, 1 gynandromorph of amblyomma cajennense was collected from a naturally infested horse. in another survey on dogs in march 2001, in the urban area of monte negro, rondônia, brazil, a gynandromorph of rhipicephalus sanguineus was collected from a naturally infested dog. both specimens are described and classified as perfect bipartite protogynanders. | 2002 | 12197141 |
| development of resistance to nymphs of amblyomma cajennense ticks (acari:ixodidae) in dogs. | ticks have long been regarded as constraints to humans and domestic animals, but hosts often develop resistance to ticks after repeated infestations. the purpose of this investigation was to study the possible acquisition of immunity in domestic dogs to nymphs of a. cajennense by determining the tick alimentary performance after successive controlled infestations. mean engorged weight of nymphs was not significantly different among the three infestations; molting rate from nymph to adult ticks, ... | 2002 | 12381587 |
| hypersensitivity induced in dogs by nymphal extract of amblyomma cajennense ticks (acari:ixodidae). | in general, hosts develop resistance to ticks after repeated infestations; nevertheless, several studies on naturally occurring host-tick interactions were unable to detect resistance of hosts to ticks even after repeated infestations. the purpose of this investigation was to study the type of cutaneous hypersensitivity to unfed nymphal extract of a. cajennense in dogs, which, unlike guinea pigs, do not develop resistance. a first, but no second, peak in skin reaction was observed, suggesting th ... | 2002 | 12381588 |
| ticks associated with armadillo (euphractus sexcinctus) and anteater (myrmecophaga tridactyla) of emas national park, state of goias, brazil. | this study was conducted in october 1998 and november 1999 in the emas national park (131,868 ha), a savanna-type cerrado region situated in the far south of goias state, brazil, near the geographic center of south america (15 degrees -23 degrees s; 45 degrees -55 degrees w). animals were captured with the aid of nets and anesthetized (15 mg/kg ketamine + 1 mg/kg xylasine) in order to collect ticks for identification and to establish laboratory colonies. they included giant anteaters (myrmecopha ... | 2002 | 12381607 |
| lack of parthenogenesis by amblyomma cajennense (acari: ixodidae). | some reproductive parameters of adult stages of amblyomma cajennense ticks were studied. the capacity of virgin females to reproduce by parthenogenesis was evaluated, during an experimental infestation, in absence of males, on a horse (equus cabalus). ticks were spread either completely free or in limited sites on the body of the animal. the engorged virgin females showed longer feeding periods and lighter body weights than those that had been fertilized. some of these unmated females produced s ... | 2002 | 12386707 |
| identification of ctenocephalides felis fleas as a host of rickettsia felis, the agent of a spotted fever rickettsiosis in yucatań, mexico. | in search for the vector of the recently recognized spotted fever rickettsiosis of the yucatán, ticks, fleas, and lice were collected from vegetation and dogs in localities where seropositive persons had been found. the arthropods were examined by polymerase chain reaction (pcr) using primers for the genus-specific 17-kda protein gene followed by restriction fragment length polymorphism (rflp) and dna sequencing. eleven (20%) of 54 pools of ctenocephalides felis fleas contained dna of rickettsia ... | 2002 | 12653300 |
| larval behavioral diapause regulates life cycle of amblyomma cajennense (acari: ixodidae) in southeast brazil. | previous studies have determined that amblyomma cajennense (f.) produces one generation per year in southeastern brazil. larvae predominate from april to july, nymphs from july to october, and adults from october to march. in the current study, we observed engorged females, their eggs, and respective larvae in the field. engorged females were released in grass plots under natural conditions, at monthly intervals, from october 2000 to march 2001. preoviposition periods lasted 1-2 wk, and mean egg ... | 2003 | 12693845 |
| rickettsia honei: a spotted fever group rickettsia on three continents. | rickettsia honei (also known as strain tt-118) has been detected on three continents. originally isolated in thailand in 1962 (and confirmed in 2001), it has also been detected on flinders island (australia) in 1993 and in texas (usa) in 1998. on each continent it has been associated with a different species of tick. the original isolate (thai tick typhus strain tt-118) was from a pool of larval ixodes and rhipicephalus ticks. later it was detected in i. granulatus from rattus rattus. its pathog ... | 2003 | 12860601 |
| 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, ... | 2003 | 12943103 |
| natural infection of the tick, amblyomma cajennense, with rickettsia rickettsii in panama. | | 1953 | 13065638 |
| [studies on the transmission of toxoplasma gondii. ii. note on the experimental transmission by the tick amblyomma cajennense]. | | 1958 | 13848246 |
| acquired resistance of horses to amblyomma cajennense (fabricius, 1787) ticks. | acquired immunity of horses to larvae, nymphs and adults of the amblyomma cajennense tick was evaluated through three consecutive experimental infestations of tick-bite naïve hosts. data from these infestations were compared to those from field-sensitized horses and donkeys. it was observed that tick-bite naïve horses developed a low level of resistance after two infestations as shown by a significant decrease in larval yield and a tendency for lower engorged weight of nymphs during third infest ... | 2003 | 14637029 |
| seasonal dynamics of the cayenne tick, amblyomma cajennense on horses in brazil. | the population dynamics of all stages of the cayenne tick, amblyomma cajennense (fabricius) (acari: ixodidae) on horses was evaluated over a period of 2 years in the district of pedro leopoldo, state of minas gerais, brazil. every 14 days, the left side of 20 horses was brushed for collection of immature stages; counts of adults were also undertaken. infestation by larvae was detected from april to august, whereas nymphs were observed from june to october. infestation by adults was detected thro ... | 2003 | 14651655 |
| rickettsia species infecting amblyomma cooperi ticks from an area in the state of são paulo, brazil, where brazilian spotted fever is endemic. | owing to the potential role of the tick amblyomma cooperi in the enzootic cycle of rickettsia rickettsii, the etiologic agent of brazilian spotted fever (bsf), this study evaluated infection by rickettsia species in a. cooperi ticks collected from an area in brazil where bsf is endemic. among a total of 40 a. cooperi adult ticks collected in an area of bsf endemicity in the state of são paulo, pcr analysis detected dna of rickettsia bellii in 16 ticks (40%), and 3 other ticks (7.5%) were positiv ... | 2004 | 14715737 |
| fatal spotted fever rickettsiosis, minas gerais, brazil. | the emergence and reemergence of a serious infectious disease are often associated with a high case-fatality rate because of misdiagnosis and inappropriate or delayed treatment. the current reemergence of spotted fever rickettsiosis caused by rickettsia rickettsii in brazil has resulted in a high proportion of fatal cases. we describe two familial clusters of brazilian spotted fever in the state of minas gerais, involving six children 9 months to 15 years of age; five died. immunohistochemical i ... | 2003 | 14718082 |
| the distribution and ecological 'preferences' of the tick amblyomma cajennense (acari: ixodidae), an ectoparasite of humans and other mammals in the americas. | the distribution and ecological 'preferences', in the nearctic and neotropical regions, of the prominent, pathogen-carrying tick amblyomma cajennense (fabricius) were reviewed, on the basis of the published literature, satellite imagery, and the examination of several tick collections. the tick has been collected from the southern u.s.a. (texas and florida) to northern argentina, but is probably absent from uruguay and southern brazil (the few records of the species in these areas probably repre ... | 2004 | 15119974 |
| cutaneous hypersensitivity induced in rabbits by extracts of the tick amblyomma cajennense (acari: ixodidae). | the cutaneous hypersensitivity test was used to correlate host resistance to ticks and type of reactions elicited by aomblyomma cajennense (fabricius, 1787) tick extract in rabbits. rabbits were divided into 3 groups of 2 animals each: naive, pre-infested and control. cutaneous hypersensitivity was induced by intradermal inoculation of 25 microg extract in 0.03 ml of phosphate buffered saline (pbs) in rabbit ears. control rabbits were inoculated with pbs only. the ear thickness was measured with ... | 2004 | 15214693 |
| cross-reactivity between antigens from amblyomma cajennense and a. hebraeum (acari: ixodidae). | laboratory animals exposed to feeding ticks develop resistance which is reflected by a decline in tick engorgement weight, egg-laying by adults and reduced egg viability. serum antibodies from these hosts and their reaction with tick antigens have been detected by different methods, including precipitation techniques, immunofluorescent techniques, elisa and western blots. however, little is known about the effects of antibodies on ticks that engorge on resistant hosts, or which tissues of the ti ... | 2004 | 15214694 |
| amblyomma cajennense ticks induce immediate hypersensitivity in horses and donkeys. | since host immune reaction to ticks interferes with tick-borne pathogen transmission, it is important to recognize naturally occurring tick-host immune relationships to better understand the epidemiology of such infectious diseases. amblyomma cajennense is an important tick-borne disease vector in the neotropical region and horses maintain it in domestic environments. in the present work intradermal testing of a. cajennense tick exposed horses and donkeys using crude tick antigens was used to ev ... | 2004 | 15285143 |
| morphological characterization of the ovary and vitellogenesis dynamics in the tick amblyomma cajennense (acari: ixodidae). | in this work we describe the internal morphology of the female reproductive system of the cayenne tick amblyomma cajennense. this system is represented by a panoistic ovary, which lacks nurse cells in the germarium. this ovary consists of a single tube, in which a large number of oocytes develop asynchronously, thus accompanying the processes of yolk deposition in the oocytes. the oocytes were classified into stages that varied from i to v, according to: cytoplasm appearance, presence of the ger ... | 2004 | 15482894 |
| characterization of spotted fever group rickettsiae in flea and tick specimens from northern peru. | evidence of spotted fever group (sfg) rickettsiae was obtained from flea pools and individual ticks collected at three sites in northwestern peru within the focus of an outbreak of febrile disease in humans attributed, in part, to sfg rickettsia infections. molecular identification of the etiologic agents from these samples was determined after partial sequencing of the 17-kda common antigen gene (htra) as well as pairwise nucleotide sequence homology with one or more of the following genes: glt ... | 2004 | 15528680 |
| rickettsia bellii and rickettsia amblyommii in amblyomma ticks from the state of rondônia, western amazon, brazil. | this study evaluates the rickettsial presence in amblyomma ticks from eight areas of the amazon forest in rondônia, brazil. the following tick species (number in parentheses) were examined: amblyomma ovale koch (121), amblyomma cajennense (f.) (41), amblyomma naponense (packard) (36), amblyomma scalpturatum neumann (35), amblyomma oblongoguttatum koch (30), amblyomma incisum neumann (27), amblyomma rotundatum koch (16), amblyomma coelebs neumann (10), and amblyomma humerale koch (6). ticks were ... | 2004 | 15605647 |
| 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 ... | 2005 | 15752445 |
| 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 ... | 2005 | 15936147 |
| diagnosis of hepatozoon spp. in amblyomma ovale and its experimental transmission in domestic dogs in brazil. | transmission of hepatozoon spp. to dogs was investigated using four species of ixodid ticks: rhipicephalus sanguineus, amblyomma aureolatum, amblyomma ovale and amblyomma cajennense. we collected completely or partially engorged adult ticks of these species from dogs that were naturally infested and positive for hepatozoon spp. we selected some of these ixodids and inoculated them orally in four negative dogs. the other ticks were dissected and examined for oocysts. of all dogs inoculated orally ... | 2005 | 16081219 |
| ticks (acari: ixodida) on wild carnivores in brazil. | the present study reports field data of ticks infesting wild carnivores captured from july 1998 to september 2004 in brazil. additional data were obtained from one tick collection and from previous published data of ticks on carnivores in brazil. during field work, a total of 3437 ticks were collected from 89 cerdocyon thous (crab-eating fox), 58 chrysocyon brachyurus (maned wolf), 30 puma concolor (puma), 26 panthera onca (jaguar), 12 procyon cancrivorus (crab-eating raccoon), 4 speothos venati ... | 2005 | 16082932 |
| [the effect of immersion in distilled water on the engorged larvae and nymphs of amblyomma cajennense (fabricius,1787)(acari: ixodidae)]. | to evaluate the effect of the immersion of engorged larvae and nymphs of amblyomma cajennense, these stages were immersed by 24, 48, 72 and 96 hours in test tubes containing distilled water. the period of premolt of the nymphs increased proportionally to the time of immersion (p<0.05). the ecdisis period, the longevity and the mortality (days) were similar in all of treatments (p>0.05). the percentage of ecdisis in nymphs was reduced after 72 hours of immersion of the larvae (p<0.05). none of th ... | 2005 | 16153347 |
| tick-borne rickettsioses around the world: emerging diseases challenging old concepts. | during most of the 20th century, the epidemiology of tick-borne rickettsioses could be summarized as the occurrence of a single pathogenic rickettsia on each continent. an element of this paradigm suggested that the many other characterized and noncharacterized rickettsiae isolated from ticks were not pathogenic to humans. in this context, it was considered that relatively few tick-borne rickettsiae caused human disease. this concept was modified extensively from 1984 through 2005 by the identif ... | 2005 | 16223955 |
| 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 ... | 2005 | 16323054 |
| 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 ... | 2006 | 16444414 |
| 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 ... | 2006 | 16464533 |
| 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 ... | 2006 | 16500644 |
| [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 ... | 2006 | 16501770 |
| 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 ... | 1970 | 16509125 |
| [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. ... | 2006 | 16583093 |
| isolation and identification of rickettsia massiliae from rhipicephalus sanguineus ticks collected in arizona. | twenty rhipicephalus sanguineus ticks collected in eastern arizona were tested by pcr assay to establish their infection rate with spotted fever group rickettsiae. with a nested pcr assay which detects a fragment of the rickettsia genus-specific 17-kda antigen gene (htra), five ticks (25%) were found to contain rickettsial dna. one rickettsial isolate was obtained from these ticks by inoculating a suspension of a triturated tick into monolayers of vero e6 monkey kidney cells and xtc-2 clawed toa ... | 2006 | 16885311 |
| 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 ... | 2007 | 16962241 |
| [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 ... | 2006 | 16978471 |
| 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 ... | 2006 | 17114702 |
| isolation of rickettsia rhipicephali and rickettsia bellii from haemaphysalis juxtakochi ticks in the state of são paulo, brazil. | in the present study, attempts to isolate rickettsia in cell culture were performed individually in seven specimens of haemaphysalis juxtakochi ticks collected in the state of são paulo (southeastern brazil). rickettsia was successfully isolated by the shell vial technique and established in vero cell culture from six ticks (six isolates). dna extracted from infected cells of these isolates was tested by pcr and dna sequencing, using genus-specific rickettsia primers targeting the genes glta, ht ... | 2007 | 17142361 |
| gene silencing of the tick protective antigens, bm86, bm91 and subolesin, in the one-host tick boophilus microplus by rna interference. | the use of rna interference (rnai) to assess gene function has been demonstrated in several three-host tick species but adaptation of rnai to the one-host tick, boophilus microplus, has not been reported. we evaluated the application of rnai in b. microplus and the effect of gene silencing on three tick-protective antigens: bm86, bm91 and subolesin. gene-specific double-stranded (dsrna) was injected into two tick stages, freshly molted unfed and engorged females, and specific gene silencing was ... | 2007 | 17196597 |
| flinders island spotted fever rickettsioses caused by "marmionii" strain of rickettsia honei, eastern australia. | australia has 4 rickettsial diseases: murine typhus, queensland tick typhus, flinders island spotted fever, and scrub typhus. we describe 7 cases of a rickettsiosis with an acute onset and symptoms of fever (100%), headache (71%), arthralgia (43%), myalgia (43%), cough (43%), maculopapular/petechial rash (43%), nausea (29%), pharyngitis (29%), lymphadenopathy (29%), and eschar (29%). cases were most prevalent in autumn and from eastern australia, including queensland, tasmania, and south austral ... | 2007 | 17553271 |
| molecular typing of isolates of rickettsia rickettsii by use of dna sequencing of variable intergenic regions. | rickettsia rickettsii, the causative agent of rocky mountain spotted fever, is found throughout the americas, where it is associated with different animal reservoirs and tick vectors. no molecular typing system currently exists to allow for the robust differentiation of isolates of r. rickettsii. analysis of eight completed genome sequences of rickettsial species revealed a high degree of sequence conservation within the coding regions of chromosomes in the genus. intergenic regions between codi ... | 2007 | 17553977 |
| [efficiency of beauveria bassiana and metarhizium anisopliae formulations on amblyomma cajennense (fabricius, 1787) nymphae]. | amblyomma cajennense is a vector of several infectious diseases on mammals and became a serious problem in some localities in brazil. entomopathogenic fungi are very important biocontrol agents and could be a viable alternative for the control of this tick in permanent preserved areas. the aim of this study was to evaluated the mortality of tick nymphae treated with beauveria bassiana and metarhizium anisopliae formulations in laboratory conditions. non fed nymphae were inoculated with 2x10(7) a ... | 2007 | 17588319 |
| repellent efficacy of formic acid and the abdominal secretion of carpenter ants (hymenoptera: formicidae) against amblyomma ticks (acari: ixodidae). | formic acid is a substance produced by some ants for defense, trail marking, and recruitment. some animals are known to rub ants or other arthropods on parts of their plumage or fur to anoint themselves with released substances. a recent study with a semifree-ranging group of capuchin monkeys, cebus apella l., in the tietê ecological park, sao paulo, brazil, an area of occurrence of the tick species amblyomma cajennense (f.), revealed that "anting" with carpenter ants, camponotus rufipes f. (hym ... | 2007 | 17695031 |