TitleAbstractYear(sorted ascending)
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
feeding period required by amblyomma aureolatum ticks for transmission of rickettsia rickettsii to vertebrate hosts.rocky mountain spotted fever is endemic to the são paulo metropolitan area, brazil, where the etiologic agent, rickettsia rickettsii, is transmitted to humans by adult amblyomma aureolatum ticks. we determined the minimal feeding period required by a. aureolatum nymphs and adults to transmit r. rickettsii to guinea pigs. unfed nymphs and unfed adult ticks had to be attached to the host for >10 hours to transmit r. rickettsii. in contrast, fed ticks needed a minimum of 10 minutes of attachment to ...025148391
rickettsia and vector biodiversity of spotted fever focus, atlantic rain forest biome, brazil. 024565262
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
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 ...200111113545
biology of amblyomma aureolatum (pallas, 1772) (acari: ixodidae) on some laboratory hosts in brazil.the ixodid amblyomma aureolatum is suspected to play a role in the epidemiology of wild life-cycle hemoparasites, which frequently infect dogs in rural and hunting areas in brazil. little is known about its bionomics. the objective of the present study was to evaluate some bionomic aspects of a. aureolatum ticks in brazil. one engorged female, collected from a dog (canis familiaris) in são sebastião das aguas claras, state of minas gerais, was used to establish a colony in the laboratory. subseq ...200212386709
amblyomma aureolatum (pallas, 1772) and amblyomma ovale koch, 1844 (acari: ixodidae): hosts, distribution and 16s rdna sequences.dna sequences of amblyomma aureolatum (pallas, 1772) and amblyomma ovale koch, 1844 were obtained to determine genetic differences between these tick species. collections of these species are discussed in relation to distribution and hosts. seven ticks collections (four from brazil, one from argentina, one from uruguay and one from usa) house a total of 1272 a. aureolatum (224 males, 251 females, 223 nymphs and 574 larvae) and 1164 a. ovale (535 males, 556 females, 66 nymphs and 7 larvae). the l ...200312719142
amblyomma aureolatum and ixodes auritulus (acari: ixodidae) on birds in southern brazil, with notes on their ecology.between january 1999 and december 2000, 876 bird specimens were captured in three different ecological environments from the reinhard maack park, curitiba, state of paraná, southern brazil. a total of 142 birds (16.2%) were infested with amblyomma aureolatum (pallas 1772) (n=699) and/or ixodes auritulus neumann, 1904 (n=18) ticks. questing a. aureolatum nymphs (n=2) and adults (n=5) were also collected from the soil and the vegetation. none of the i. auritulus were collected off-host. we collect ...200314974693
study of the seasonal dynamics, life cycle, and host specificity of amblyomma aureolatum (acari: ixodidae).in the first part of this study, monthly infestation by ticks was evaluated on dogs from december 2000 to november 2002 in the rural area of taiaçupeba, são paulo. adults of amblyomma aureolatum (pallas) were found on dogs in all months, with a mean prevalence per month of 46.9 +/- 15.7% (range, 25-80%). the mean tick relative abundance per month was 2.4 +/- 2.7 ticks (range, 0.5-14 ticks), and the mean tick mean intensity per month was 4.7 +/- 4.2 ticks (range, 1.5-23.3 ticks). no a. aureolatum ...200415185932
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 ...200414715737
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
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 ...200516081219
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 ...200516082932
a collection of ticks (ixodidae) from wild birds in uruguay.thirty nine wild birds from seven families (alcedinidae, emberizidae, furnariidae, parulidae, trochilidae, turdidae and tyrannidae) were caught from 4 to 7 of february, 2004 at rincón da vassoura (31 degrees 15' s 56 degrees 03' w) department of tacuarembó, uruguay. ninety one nymphs and forty one larvae of ixodidae were recovered from them. the majority of ticks were conventionally identified but 16s mitochondrial rdna sequences were obtained for larvae and nymphs of amblyomma with uncertain sp ...200516132744
hemorrhagic disease in dogs infected with an unclassified intraendothelial piroplasm in southern brazil.a hemorrhagic disease affecting dogs in brazil, referred to popularly as "nambiuvú" (bloody ears) and believed to be transmitted by ticks, has been observed in animals infected with an organism described originally in 1910 as a piroplasm, and known locally as rangelia vitalii. in this series of 10 cases, the disease was characterized by anaemia, jaundice, fever, spleno- and lymphadenomegaly, hemorrhage in the gastrointestinal tract, and persistent bleeding from the nose, oral cavity and tips, ma ...200516153781
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 ...200516223955
ticks (ixodidae) on humans in south america.twenty eight species of ixodidae have been found on man in south america (21 amblyomma, 1 boophilus, 2 dermacentor, 2 haemaphysalis, 1 ixodes and 1 rhipicephalus species). most of them are rarely found on man. however, three species frequently parasitize humans in restricted areas of argentina (a. neumanni reported from 46 localities), uruguay (a. triste from 21 sites) and argentina-brazil (a. parvum from 27 localities). the most widespread ticks are a. cajennense (134 localities in argentina, b ...200617103085
isolation of rickettsia rickettsii and rickettsia bellii in cell culture from the tick amblyomma aureolatum in brazil.brazilian spotted fever (bsf) is a highly lethal disease caused by rickettsia rickettsii. in the present study, rickettsial infection was evaluated in 669 amblyomma aureolatum adult ticks collected from naturally infested dogs in taiaçupeba, a bsf-endemic area in the state of são paulo. ten (1.49%) ticks were infected with rickettsia bellii, and 6 (0.89%) ticks were infected with r. rickettsii. both rickettsia species were isolated and established in vero cell cultures. the rickettsia isolates w ...200617114770
first record of amblyomma aureolatum (pallas, 1772) (acari: ixodidae) parasitizing alouatta guariba (humboldt) (primata: atelidae) in southern brazil.a female of amblyomma aureolatum was found on the howler monkey alouatta guariba, in cachoeira do sul, rio grande do sul, southern brazil. this is the first record of this tick species parasitizing this primate species in brazil.200617196126
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
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 ...200717553977
rickettsia infection in five areas of the state of são paulo, brazil.this study investigated rickettsial infection in animals, humans, ticks, and fleas collected in five areas of the state of são paulo. eight flea species (adoratopsylla antiquorum antiquorum, ctenocephalides felis felis, polygenis atopus, polygenis rimatus, polygenis roberti roberti, polygenis tripus, rhopalopsyllus lugubris, and rhopalopsyllus lutzi lutzi), and five tick species (amblyomma aureolatum, amblyomma cajennense, amblyomma dubitatum, ixodes loricatus, and rhipicephalus sanguineus) were ...200718094887
isolation of rickettsia rhipicephali and rickettsia bellii from haemaphysalis juxtakochi ticks in the state of são paulo, 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 ...200717142361
serosurvey of rickettsia spp. in dogs and humans from an endemic area for brazilian spotted fever in the state of são paulo, brazil.the present study provides a rickettsial serosurvey in 25 dogs and 35 humans in an endemic area for brazilian spotted fever in the state of são paulo, where the tick amblyomma aureolatum is the main vector. testing canine and human sera by indirect immunofluorescence against four rickettsia antigens (r. rickettsii, r. parkeri, r. felis and r. bellii) showed that 16 (64%) of canine sera and 1 (2.8%) of human sera reacted to at least one of these rickettsial antigens with titers >0r= 64. seven can ...200818278271
canine vector-borne diseases in brazil.abstract: canine vector-borne diseases (cvbds) are highly prevalent in brazil and represent a challenge to veterinarians and public health workers, since some diseases are of great zoonotic potential. dogs are affected by many protozoa (e.g., babesia vogeli, leishmania infantum, and trypanosoma cruzi), bacteria (e.g., anaplasma platys and ehrlichia canis), and helminths (e.g., dirofilaria immitis and dipylidium caninum) that are transmitted by a diverse range of arthropod vectors, including tick ...200818691408
new epidemiological data on brazilian spotted fever in an endemic area of the state of são paulo, brazil.the present work evaluated rickettsial infection in dogs and their ticks in an area endemic for brazilian spotted fever (bsf) in the metropolitan area of são paulo, brazil, where the tick amblyomma aureolatum was presumed to be the vector of the disease. ticks were collected on dogs from 185 houses, encompassing single infestations by rhipicephalus sanguineus, amblyomma aureolatum, amblyomma longirostre, or amblyomma sp. in dogs from 60 (32.4%), 77 (41.6%), 2 (1.1%), and 25 (13.5%) houses, respe ...200818847319
comparative susceptibility of larval stages of amblyomma aureolatum, amblyomma cajennense, and rhipicephalus sanguineus to infection by rickettsia rickettsii.the current study compared the susceptibility of larval stages of amblyomma cajennense (f.), amblyomma aureolatum (pallas), and rhipicephalus sanguineus (latreille) to infection by a brazilian strain of rickettsia rickettsii. guinea pigs experimentally infected by r. rickettsii were simultaneously infested by larvae of the three tick species. recovered engorged larvae were allowed to molt to nymphs and held in an incubator at 23 degrees c and 85-90% rh. subsequent flat nymphs were tested for ric ...200819058642
ecological aspects of the free-living ticks (acari: ixodidae) on animal trails within atlantic rainforest in south-eastern a recent ecological study of the ticks on animal trails within an area of atlantic rainforest in south-eastern brazil, amblyomma aureolatum, a. brasiliense, a. incisum, a. ovale and haemaphysalis juxtakochi were found questing on the vegetation. most of the ticks recorded by a small, man-made dam on the forest border were a. dubitatum but a few a. brasiliense and a. cajennense, one a. incisum and one h. juxtakochi were also found. the seasonal activity of the ticks indicated that a. incisum a ...200919173777
ecology of rickettsia in south america.until the year 2000, only three rickettsia species were known in south america: (i) rickettsia rickettsii, transmitted by the ticks amblyomma cajennense, and amblyomma aureolatum, reported in colombia, argentina, and brazil, where it is the etiological agent of rocky mountain spotted fever; (ii) rickettsia prowazekii, transmitted by body lice and causing epidemic typhus in highland areas, mainly in peru; (iii) rickettsia typhi, transmitted by fleas and causing endemic typhus in many countries. d ...200919538276
wide dispersal and possible multiple origins of low-copy-number plasmids in rickettsia species associated with blood-feeding arthropods.plasmids are mobile genetic elements of bacteria that can impart important adaptive traits, such as increased virulence or antibiotic resistance. we report the existence of plasmids in rickettsia (rickettsiales; rickettsiaceae) species, including rickettsia akari, "candidatus rickettsia amblyommii," r. bellii, r. rhipicephali, and reis, the rickettsial endosymbiont of ixodes scapularis. all of the rickettsiae were isolated from humans or north and south american ticks. r. parkeri isolates from b ...201020097813
survey of ticks (acari: ixodidae) and their rickettsia in an atlantic rain forest reserve in the state of são paulo, brazil.the current study investigated the occurrence of ticks and their rickettsiae in the serra do mar state park, which encompasses one of the largest atlantic rain forest reserves of brazil. from july 2008 to june 2009, a total of 2439 ticks (2,196 free living and 243 collected on hosts) was collected, encompassing the following 13 species: amblyomma aureolatum (pallas), amblyomma brasiliense aragao, amblyomma dubitatum neumann, amblyomma fuscum neumann, amblyomma incisum neumann, amblyomma longiros ...201020939390
amblyomma aureolatum (acari: ixodidae) parasitizing margay (leopardus wiedii) in rio grande do sul.we report the finding of amblyomma aureolatum (acari: ixodidae) parasitizing margay (leopardus wiedii) in the locality of gravataí (29° 47' 12.9" s and 50° 53' 44.1" w; 241 m alt.), state of rio grande do sul, southern brazil. this is the first report of this species of ixodidae on margay in southern brazil. this finding indicates an increased number of hosts for this tick species.201020943026
experimental infection of amblyomma aureolatum ticks with rickettsia rickettsii.we experimentally infected amblyomma aureolatum ticks with the bacterium rickettsia rickettsii, the etiologic agent of rocky mountain spotted fever (rmsf). these ticks are a vector for rmsf in brazil. r. rickettsii was efficiently conserved by both transstadial maintenance and vertical (transovarial) transmission to 100% of the ticks through 4 laboratory generations. however, lower reproductive performance and survival of infected females was attributed to r. rickettsii infection. therefore, bec ...201121529391
spotted fever group rickettsia infecting ticks (acari: ixodidae) in the state of santa catarina, brazil.during 2006-2008, a total of 260 adult ticks were collected from domestic and wild animals in different regions of the state of santa catarina (sc), brazil, including areas where human cases of brazilian spotted fever have been reported. collected ticks belonging to nine species (amblyomma aureolatum, amblyomma cajennense, amblyomma dubitatum, amblyomma longirostre, amblyomma ovale, amblyomma tigrinum, dermacentor nitens, rhipicephalus microplus and rhipicephalus sanguineus) were tested by polym ...201122241112
rickettsial infection in ticks collected from road-killed wild animals in rio de janeiro, brazil.during 2008-2010, ticks were collected from road-killed wild animals within the serra dos orgãos national park area in the state of rio de janeiro, brazil. in total, 193 tick specimens were collected, including amblyomma dubitatum neumann and amblyomma cajennense (f.) from four hydrochoerus hydrochaeris (l.), amblyomma calcaratum neumann and a. cajennense from four tamandua tetradactyla (l.), amblyomma aureolatum (pallas) and a. cajennense from five cerdocyon thous l., amblyomma longirostre (koc ...201223270184
rickettsia bellii infecting amblyomma sabanerae ticks in el salvador.four amblyomma sabanerae ticks collected from a turtle (kinosternon sp.) in san miguel, el salvador, were found by molecular analysis to be infected by rickettsia bellii. we provide the first report of rickettsia bellii in central america, and the first report of a rickettsia species in el salvador.201223265378
association between sepsis and rocky mountain spotted fever.rocky mountain spotted fever (rmsf) is a disease caused by the gram-negative coccobacillus rickettsia ricketsii which has been on the rise since the last decade in the usa. the symptoms are common to the many viral diseases, and the classic triad of fever, rash and headache is not always present when rmsf is diagnosed. it may progress to severe cases such as renal failure, disseminated intravascular coagulation and septicaemia. this report aims to present a fulminant case of rmsf associated with ...201223220832
rickettsial infection in ticks (acari: ixodidae) collected on birds in southern brazil.the aim of the study was to evaluate rickettsial infection in ticks from wild birds of the semidecidual and atlantic rainforest remnants of three municipalities of the state of paraná, southern brazil. overall, 53 larvae and nymphs collected from birds were checked for the presence of rickettsia dna by molecular tests. five tick species were tested: amblyomma aureolatum (pallas), amblyomma calcaratum neumann, amblyomma longirostre (koch), amblyomma ovale koch, and amblyomma parkeri fonseca and a ...201222679880
epidemiology of brazilian spotted fever in the atlantic forest, state of são paulo, brazil.the tick-borne bacterium rickettsia rickettsii is the aetiological agent of brazilian spotted fever (bsf). the present study evaluated tick infestations on wild and domestic animals, and the rickettsial infection in these animals and their ticks in 7 forest areas adjacent to human communities in the são paulo metropolitan area (spma). the results were compared to ecological traits of each sampled area. two main tick species, amblyomma aureolatum and rhipicephalus sanguineus, were collected from ...201222716923
host blood meal-dependent growth ensures transovarial transmission and transstadial passage of rickettsia sp. phylotype g021 in the western black-legged tick (ixodes pacificus).in this study, we explored the growth dynamics of rickettsia sp. phylotype g021 during transovarial transmission and transstadial passage by ixodes pacificus using real-time quantitative pcr. four parental engorged i. pacificus females were allowed to complete their developmental stages until the f2-generation eggs yielded unfed larvae. all eggs, larvae, nymphs, and adults tested through 2 generations were found to be infected with phylotype g021. hence, we conclude that the efficiency of transo ...201323876278
ecology, biology and distribution of spotted-fever tick vectors in brazil.spotted-fever-caused rickettsia rickettsii infection is in brazil the major tick-borne zoonotic disease. recently, a second and milder human rickettsiosis caused by an agent genetically related to r. parkeri was discovered in the country (atlantic rainforest strain). both diseases clearly have an ecological background linked to a few tick species and their environment. capybaras (hydrochoerus hydrochaeris) and amblyomma cajennense ticks in urban and rural areas close to water sources are the mai ...201323875178
comparative evaluation of infected and noninfected amblyomma triste ticks with rickettsia parkeri, the agent of an emerging rickettsiosis in the new world.the distribution of rickettsia parkeri in south america has been associated with amblyomma triste ticks. the present study evaluated under laboratory conditions two colonies of a. triste: one started from engorged females that were naturally infected by r. parkeri (designated as infected group); the other started from noninfected females (designated as control group). both colonies were reared in parallel for five consecutive generations. tick-naïve domestic rabbits were used for feeding of each ...201323936795
natural blood feeding and temperature shift modulate the global transcriptional profile of rickettsia rickettsii infecting its tick vector.rickettsia rickettsii is an obligate intracellular tick-borne bacterium that causes rocky mountain spotted fever (rmsf), the most lethal spotted fever rickettsiosis. when an infected starving tick begins blood feeding from a vertebrate host, r. rickettsii is exposed to a temperature elevation and to components in the blood meal. these two environmental stimuli have been previously associated with the reactivation of rickettsial virulence in ticks, but the factors responsible for this phenotype c ...201324155949
molecular epidemiology of the emerging zoonosis agent anaplasma phagocytophilum (foggie, 1949) in dogs and ixodid ticks in brazil.anaplasma phagocytophilum is an emerging pathogen of humans, dogs and other animals, and it is transmitted by ixodid ticks. the objective of the current study was a) detect a. phagocytophilum in dogs and ixodid ticks using real-time polymerase chain reaction (qpcr); and b) determine important variables associated to host, environment and potential tick vectors that are related to the presence of a. phagocytophilum in dogs domiciled in rio de janeiro, brazil.201324330631
lyme borreliosis: a review of data on transmission time after tick attachment.lyme borreliosis is increasing rapidly in many parts of the world and is the most commonly occurring vector-borne disease in europe and the usa. the disease is transmitted by ticks of the genus ixodes. they require a blood meal at each stage of their life cycle and feed on a wide variety of wild and domestic animals as well as birds and reptiles. transmission to humans is incidental and can occur during visits to a vector habitat, when host mammals and their associated ticks migrate into the urb ...201425565881
epidemiology of rickettsia sp. strain atlantic rainforest in a spotted fever-endemic area of southern brazil.the present study was performed in vila itoupava, an area of the state of santa catarina, southern brazil, in which a tick-borne spotted fever illness has been endemic since 2003. notably, both the etiological agent and the vector of these spotted fever cases remain unknown. during january 2011, humans, domestic dogs, and their ticks were sampled in households that are typically surrounded by highly preserved atlantic rainforest fragments. ticks collected from dogs were amblyomma ovale (34% prev ...201425108786
dogs, cats, parasites, and humans in brazil: opening the black box.dogs and cats in brazil serve as primary hosts for a considerable number of parasites, which may affect their health and wellbeing. these may include endoparasites (e.g., protozoa, cestodes, trematodes, and nematodes) and ectoparasites (i.e., fleas, lice, mites, and ticks). while some dog and cat parasites are highly host-specific (e.g., aelurostrongylus abstrusus and felicola subrostratus for cats, and angiostrongylus vasorum and trichodectes canis for dogs), others may easily switch to other h ...201424423244
rickettsial infection in amblyomma cajennense ticks and capybaras (hydrochoerus hydrochaeris) in a brazilian spotted fever-endemic area.brazilian spotted fever (bsf), caused by the bacterium rickettsia rickettsii, is the deadliest spotted fever of the world. in most of the bsf-endemic areas, capybaras (hydrochoerus hydrochaeris) are the principal host for the tick amblyomma cajennense, which is the main vector of bsf.201424387674
genetic identification of rickettsial isolates from fatal cases of brazilian spotted fever and comparison with rickettsia rickettsii isolates from the american continents.fifteen bacterial isolates from spotted fever group rickettsiosis in brazil were genetically identified as rickettsia rickettsii. in a phylogenetic analysis with other r. rickettsii isolates from genbank, the central/south american isolates showed low polymorphism and formed a clade distinct from two north american clades, with the north american clades having greater in-branch polymorphism.201425078908
isolation and characterization of microsatellite loci from the tick amblyomma aureolatum (acari: ixodidae).amblyomma aureolatum (pallas) is the main vector of the bacterium rickettsia rickettsii, the etiological agent of brazilian spotted fever. this disease is the most lethal human spotted fever rickettsiosis in the world. microsatellite loci were isolated from a dinucleotide-enriched library produced from a. aureolatum sampled in southeastern brazil. eight polymorphic microsatellites were further characterized among 38 individuals sampled from são paulo metropolitan region. the number of observed a ...201425501172
canine rangeliosis due to rangelia vitalii: from first report in brazil in 1910 to current day - a review.canine rangeliosis (popular names: "nambi-uvú", i.e. ``bleeding ears''; "peste de sangue", i.e. ``bleeding plague''; and "febre amarela dos cães", i.e. ``yellow fever of dogs'') is a tick-borne haemolytic and haemorrhagic disease caused by the protozoan parasite rangelia vitalii which infects erythrocytes, leukocytes, and endothelial cells of blood capillaries. rangelia vitalii was first reported as a novel piroplasm of dogs in 1910 in brazil, a discovery that was met with skepticism at that tim ...201424950853
dynamics of cell and tissue genesis in the male reproductive system of ticks (acari: ixodidae) amblyomma cajennense [corrected] (fabricius, 1787) and amblyomma aureolatum (pallas, 1772): a comparative analysis.ticks are classified into three families: argasidae, ixodidae, and nutalliellidae. the taxonomy and phylogeny within ixodidae are still discussed by the specialists, thus requiring further studies. amblyomma cajennese and amblyomma aureolatum (brazil) belong to two species complexes known as "cajennese" and "ovale", respectively, and are directly related to the transmission of the brazilian spotted fever. this confirms the medical and veterinary significance of these species, as well as the need ...201424553976
rickettsial infections in ticks from wild birds in paraguay.ticks were collected from wild birds at 3 locations in paraguay during the south american winter in august and september 2012. in total, 480 birds belonging to 106 species were examined. overall, 31 (6.5%) birds representing 21 species were found parasitized by ticks which were identified as amblyomma calcaratum neumann (2 larvae, 20 nymphs), amblyomma longirostre (koch) (17 larvae, 3 nymphs), amblyomma parvum aragão (7 nymphs), amblyomma aureolatum (pallas) (1 nymph), amblyomma ovale koch (1 ny ...201424231270
altitudinal assessment of amblyomma aureolatum and amblyomma ovale (acari: ixodidae), vectors of spotted fever group rickettsiosis in the state of são paulo, brazil.amblyomma aureolatum (pallas) and amblyomma ovale koch are common ectoparasites of domestic dogs in são paulo state, southeastern brazil, where they are vectors of distinct spotted fever group rickettsioses, one caused by rickettsia rickettsii (transmitted by a. aureolatum), and the other caused by rickettsia sp. strain atlantic rainforest (transmitted by a. ovale). for the present study, we performed an altitudinal assessment of all 1992-2012 records of a. aureolatum and a. ovale retrieved from ...201526336213
natural infection of wild canids (cerdocyon thous and lycalopex gymnocercus) with the intraendothelial piroplasm rangelia vitalii in southern brazil.rangelia vitalii is a piroplasm that infects canines, causing lesions typical of a hemolytic disorder. two wild canids, a crab-eating fox (cerdocyon thous) and a pampas fox (lycalopex gymnocercus), were presented for necropsy in setor de patologia veterinária at the universidade federal do rio grande do sul, porto alegre, brazil. on gross examination, both animals had pale mucosae and moderate tick infestation (amblyomma aureolatum). there was severe splenomegaly, and the liver had a diffusely o ...201526251988
satellite hyperspectral imagery to support tick-borne infectious diseases surveillance.this study proposed the use of satellite hyperspectral imagery to support tick-borne infectious diseases surveillance based on monitoring the variation in amplifier hosts food sources. to verify this strategy, we used the data of the human rickettsiosis occurrences in southeastern brazil, region in which the emergence of this disease is associated with the rising capybara population. spatio-temporal analysis based on monte carlo simulations was used to identify risk areas of human rickettsiosis ...201526599337
vector potential and population dynamics for amblyomma inornatum.we studied the natural life cycle of amblyomma inornatum and its vector potential in south texas. this tick is distributed throughout south texas and most of central america. a. inornatum represented 1.91% of the ticks collected by carbon dioxide traps during a study of free-living ticks in the tamaulipan biotic province in south texas. the life cycle of a. inornatum in south texas showed a clear seasonal pattern consistent with one generation per year. nymphs emerged in the spring with a peak i ...201525881916
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
epidemiological surveillance of capybaras and ticks on warning area for brazilian spotted fever.the vulnerability of tropical developing countries to the emerging disease constitutes a critical phenomenon in which the invasion of wild niches by human hosts, contributes to expansion of zoonotic diseases, such as the brazilian spotted fever (bsf). this study performed a diagnosis of species occurrence of their hosts (hydrochoerus hydrochaeris) and vectors (amblyomma sculptum and amblyomma dubitatum) on the warning area for this reemerging disease in brazil.201527047211
brazilian spotted fever with an approach in veterinary medicine and one health perspective.there is increasing interaction between man and pathogens transmitted by arthropods, especially by ticks. it is on this background that a holistic approach stands out, for the sake of public health. brazilian spotted fever is an endemic disease at the country's southeast, with amblyomma sculptum as its major contributor, followed by a. aureolatum and potentially rhipicephalus sanguineus. dogs have been considered sentinels, and in some areas the disease in dogs can precede human disease. conside ...201626881183
geographical distribution of amblyomma cajennense (sensu lato) ticks (parasitiformes: ixodidae) in brazil, with description of the nymph of a. cajennense (sensu stricto).until recently, amblyomma cajennense (fabricius, 1787) was considered to represent a single tick species in the new world. recent studies have split this taxon into six species. while the a. cajennense species complex or a. cajennense (sensu lato) (s.l.) is currently represented by two species in brazil, a. cajennense (sensu stricto) (s.s.) and amblyomma sculptum berlese, 1888, their geographical distribution is poorly known.201627036324
characterization of genetic variability and population structure of the tick amblyomma aureolatum (acari: ixodidae).the hard tick amblyomma aureolatum (pallas) is a vector of the bacterium rickettsia rickettsii, the etiologic agent of brazilian spotted fever (bsf) in parts of brazil. despite its wide distribution in southeastern south america and its public health importance, there is no information about genetic variation of this species that might help to understand the epidemiology of bsf. using data from eight microsatellite markers and ticks from six localities, we used a population genetics approach to ...201627230435
comparative efficacy of oral administrated afoxolaner (nexgard™) and fluralaner (bravecto™) with topically applied permethrin/imidacloprid (advantix(®)) against transmission of ehrlichia canis by infected rhipicephalus sanguineus ticks to dogs.the ability of the topical spot-on advantix(®) (50 % permethrin/10 % imidacloprid) to prevent transmission of ehrlichia canis by infected rhipicephalus sanguineus ticks to dogs has previously been reported. the recent market introduction of chewable tablets containing the novel compounds, afoxolaner (nexgard™) and fluralaner (bravecto™) enabled us to conduct a comparative efficacy study with respect to the ability of these three products to block transmission of e. canis by ticks to dogs. the sp ...201627317101
virulence genes of rickettsia rickettsii are differentially modulated by either temperature upshift or blood-feeding in tick midgut and salivary glands.rickettsia rickettsii, the etiological agent of rocky mountain spotted fever, is transmitted to humans by ticks. during tick feeding, r. rickettsii is exposed to both temperature elevation and components of the blood meal, which have previously been associated with the reactivation of its virulence. these environmental stimuli were also reported to modulate virulence genes of r. rickettsii infecting a set of organs of adult females of its natural vector, amblyomma aureolatum.201627287539
risk factors for bartonella species infection in blood donors from southeast brazil.bacteria from the genus bartonella are emerging blood-borne bacteria, capable of causing long-lasting infection in marine and terrestrial mammals, including humans. bartonella are generally well adapted to their main host, causing persistent infection without clinical manifestation. however, these organisms may cause severe disease in natural or accidental hosts. in humans, bartonella species have been detected from sick patients presented with diverse disease manifestations, including cat scrat ...201626999057
association of the occurrence of brazilian spotted fever and atlantic rain forest fragmentation in the são paulo metropolitan region, brazil.brazilian spotted fever (bsf) is a zoonotic disease caused by the bacterium rickettsia rickettsii. in the são paulo metropolitan region (spmr) it is transmitted by amblyomma aureolatum ticks. in this region, annual lethality of the disease can reach 80% and spatial occurrence depends on environmental factors and more particularly on the presence and interaction of domestic and wild carnivores as well as the presence and characteristics of the remnant atlantic rain forest patches. this study anal ...201727880877
the distinct transcriptional response of the midgut of amblyomma sculptum and amblyomma aureolatum ticks to rickettsia rickettsii correlates to their differences in susceptibility to infection.rickettsia rickettsii is a tick-borne obligate intracellular bacterium that causes rocky mountain spotted fever (rmsf). in brazil, two species of ticks in the genus amblyomma, a. sculptum and a. aureolatum, are incriminated as vectors of this bacterium. importantly, these two species present remarkable differences in susceptibility to r. rickettsii infection, where a. aureolatum is more susceptible than a. sculptum. in the current study, a. aureolatum and a. sculptum ticks were fed on suitable h ...201728503490
ticks infesting captive and free-roaming wild animal species at the são paulo zoo, são paulo, brazil.ticks are ectoparasites of worldwide distribution that affect vertebrates and can transmit pathogens to animals and humans. the zoological park foundation of são paulo (fpzsp) is located in a conservation unit in one of the most important remaining fragments of the atlantic rainforest biome in the suburbs of são paulo, brazil. the fpzsp houses more than 3,000 wild animals on exhibit, in breeding programs and in environmental education programs, and also attracts migratory birds and free-roaming ...201728700000
ixodidae fauna of domestic dogs in parana, southern brazil.the present study aimed to contribute towards identification and registration of tick species that parasitize dogs in rural and urban areas of three mesoregions of paraná, southern brazil, and to estimate the rate of occurrence of each species. fifty-six dogs with ticks living in three mesoregions: metropolitana de curitiba (mc), centro oriental (cop) and centro sul paranaense (csp), were used in the study. from these 56 dogs, 253 ticks were collected and were identified and morphologically char ...201728678895
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