| 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 |
| rickettsiosis caused by rickettsia conorii in uruguay. | the first three human cases of rickettsiosis caused by rickettsia conorii in montevideo, uruguay were described in 1990. all of them showed an initial papulosquamous lesion on the scalp from a canine tick bite (amblyomma triste). at the same time, fever and regional adenopathies were observed. serological diagnosis was made by the indirect igm immunofluorescent technique on glass smears of r. conorii (biomerieux laboratories, france). all patients had a benign disease course after been treated w ... | 2003 | 12860638 |
| ticks (ixodida: ixodidae) parasitising humans in uruguay. | during routine collections between november 1999 and november 2002, three species of tick (amblyomma tigrinum, amblyomma triste and rhipicephalus sanguineus) were found on humans in southern uruguay. the finding of r. sanguineus and a. triste on humans is of particular concern because these tick species may be involved in the transmission of the pathogens causing human rickettsioses, a type of disease already known to occur in uruguay. | 2003 | 14613636 |
| life cycle and host specificity of amblyomma triste (acari: ixodidae) under laboratory conditions. | we report biological data of two generations of amblyomma triste in laboratory and compared the suitability of different host species. infestations by larval and nymphal stages were performed on guinea pigs (cavia porcellus), chickens (gallus gallus), rats (rattus norvegicus), rabbits (oryctolagus cuniculus), wild mice (calomys callosus), dogs (canis familiaris) and capybaras (hydrochaeris hydrochaeris). infestations by adult ticks were performed on dogs, capybaras and rabbits. tick developmenta ... | 2003 | 14756395 |
| rickettsia parkeri in amblyomma triste from uruguay. | our goal was to detect whether spotted fever group rickettsia are found in the suspected vector of rickettsioses, amblyomma triste, in uruguay. rickettsia parkeri was detected in a. triste, which suggests that this species could be considered a pathogenic agent responsible for human rickettsioses in uruguay. | 2004 | 15496258 |
| 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 |
| 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 |
| rickettsia parkeri as a paradigm for multiple causes of tick-borne spotted fever in the western hemisphere. | among the many contributions made to rickettsiology by entomologist and rickettsiologist ralph r. parker was his discovery in 1937 of a novel rickettsia isolated from the gulf coast tick, amblyomma maculatum. this bacterium was subsequently characterized as a unique rickettsial species in 1965 and named rickettsia parkeri in honor of its discoverer. during the next several decades r. parkeri was generally considered as one of several "nonpathogenic" spotted fever group (sfg) rickettsiae that res ... | 2005 | 16481534 |
| amblyomma triste (koch, 1844) (acari: ixodidae): morphological description of the ovary and of vitellogenesis. | the present study presents the morphology, histology, and the dynamics of vitellogenesis in females of the tick amblyomma triste. the ovary in this species is of the panoistic type, therefore it lacks nurse cells. it is composed of a layer of epithelial cells that outwardly form the wall of the ovary, but also originate the pedicel, the structure that attaches the oocytes to its external margin, as well the oocytes themselves. in amblyomma triste, the oocytes develop in four synchronic stages, w ... | 2006 | 16540108 |
| 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 |
| vitellogenesis in the tick amblyomma triste (koch, 1844) (acari: ixodidae) role for pedicel cells. | this study presents new information on the vitellogenesis of the tick amblyomma triste. in this species, the ovary consists of a layer of epithelial cells, which form the ovarian wall, oogonia and developing oocytes; and the pedicel, a cellular structure that synthesizes and provides yolk precursors for developing oocytes. the pedicel also attaches oocytes to the external surface of the epithelial wall. in this study, evidence is provided in support of pedicel cells in providing compounds for oo ... | 2007 | 16978785 |
| 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 |
| rickettsia parkeri in uruguay. | | 2006 | 17283648 |
| amblyomma triste (koch, 1844) (acari: ixodidae) ovaries: an ultrastructural analysis. | this study presents an ultrastructural analysis of the ovary of the tick, amblyomma triste. the ovary of this species is of the panoistic type that is, without nursing and follicular cells. it is composed of a layer of epithelial cells forming a wall and of germinative cells that generate the oocytes which remain attached to the external margin of this wall by a multicellular pedicel. the different developmental stages in the oocytes had been described by oliveira et al. [oliveira, p.r., bechara ... | 2007 | 17433302 |
| ultrastructural detection of proteins, lipids and carbohydrates in oocytes of amblyomma triste (koch, 1844) (acari; ixodidae) during the vitellogenesis process. | the ovary of the tick amblyomma triste is classified as panoistic, which is characterized by the presence of oogonia without nurse and follicular cells. the present study has demonstrated that the oocytes in all developmental stages (i-iv) are attached to the ovary through a pedicel, a cellular structure that synthesizes and provides carbohydrate, lipids and proteins supplies for the oocytes during the vitellogenesis process. the lipids are deposited during all oocyte stages; they are freely dis ... | 2007 | 17544471 |
| [parasitism by amblyomma triste in domestic cat]. | amblyomma triste is an ixodidae, ectoparasite of several mammals' species, with occurrence reported in argentina, brazil, colombia, ecuador, peru, uruguay and venezuela. the aim of this work was to register the parasitism by a. triste in domestic cat (felis catus) in rio grande do sul state, brazil. | 2007 | 17706014 |
| detection of alpha and gamma-proteobacteria in amblyomma triste (acari: ixodidae) from uruguay. | amblyomma triste is the most prevalent tick species reported in human tick bites in uruguay and has been found to be infected with rickettsia parkeri, but no other microorganisms have been reported from this tick. a sample of 254 adults of a. triste was collected by flagging on vegetation in suburban areas in southern uruguay. pools of five ticks were assembled and a screening for the dna from the resulting 51 pools was realized by pcr assays using primers for amplifying a fragment of 16s rrna g ... | 2008 | 18071910 |
| rickettsia parkeri in brazil. | we report finding rickettsia parkeri in brazil in 9.7% of amblyomma triste ticks examined. an r. parkeri isolate was successfully established in vero cell culture. molecular characterization of the agent was performed by dna sequencing of portions of the rickettsial genes glta, htra, ompa, and ompb. | 2007 | 18214195 |
| amblyomma triste koch, 1844 (acari: ixodidae): hosts and seasonality of the vector of rickettsia parkeri in uruguay. | amblyomma triste koch, 1844, the tick species most frequently involved in human bites in uruguay, has been implicated as a vector of human rickettsiosis. seasonal abundance of adult a. triste was examined by standard flagging at three sites where human tick bites and cases of the disease have been reported. adult tick activity occurred from august to february (end of winter to mid summer in the southern hemisphere) with a peak in spring. activity declined in step with decreasing temperatures and ... | 2008 | 18565680 |
| rickettsia parkeri in argentina. | clinical reports of an eschar-associated rickettsiosis in the paraná river delta of argentina prompted an evaluation of amblyomma triste ticks in this region. when evaluated by pcr, 17 (7.6%) of 223 questing adult a. triste ticks, collected from 2 sites in the lower paraná river delta, contained dna of rickettsia parkeri. | 2008 | 19046514 |
| guinea pigs develop cutaneous basophilia after repeated infestations by nymphs of the tick amblyomma triste. | this study investigated the development of resistance in guinea pigs to nymphs of amblyomma triste ticks after repeated infestations. guinea pigs were infested thrice, at 30-day intervals, with 30 nymphs of a. triste per animal per infestation. acquisition of resistance was evaluated by determining: nymph yielding rate, engorgement period, and weight. skin biopsies of tick bite sites were collected at 24, 48, and 96 h after tick attachment for inflammatory cell counts. engorged nymphs weighed 5. ... | 2008 | 19120217 |
| 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 ... | 2010 | 20097813 |
| detection of "candidatus rickettsia sp. strain argentina"and rickettsia bellii in amblyomma ticks (acari: ixodidae) from northern argentina. | ixodid ticks were collected from vegetation and from humans, wild and domestic mammals in a rural area in the semi-arid argentine chaco in late spring 2006 to evaluate their potential role as vectors of spotted fever group (sfg) rickettsiae. a total of 233 adult ticks, identified as amblyomma parvum, amblyomma tigrinum and amblyomma pseudoconcolor, was examined for rickettsia spp. we identified an sfg rickettsia of unknown pathogenicity, "candidatus rickettsia sp. strain argentina", in a. parvum ... | 2010 | 20186466 |
| isolation of rickettsia parkeri and identification of a novel spotted fever group rickettsia sp. from gulf coast ticks (amblyomma maculatum) in the united states. | until recently, amblyomma maculatum (the gulf coast tick) had garnered little attention compared to other species of human-biting ticks in the united states. a. maculatum is now recognized as the principal vector of rickettsia parkeri, a pathogenic spotted fever group rickettsia (sfgr) that causes an eschar-associated illness in humans that resembles rocky mountain spotted fever. a novel sfgr, distinct from other recognized rickettsia spp., has also been detected recently in a. maculatum specime ... | 2010 | 20208020 |
| seasonal dynamics and hosts of amblyomma triste (acari: ixodidae) in argentina. | the seasonal dynamics and host usage of amblyomma triste in argentina were analyzed. adults of a. triste were present from early winter to mid-summer, with the peak of abundance from late winter to mid-spring (august to october). larvae and nymphs were found from december to june, with the peak of abundance in summer. there were no differences among the biological parameters (pre-moult period of larvae and nymphs, pre-oviposition period of females, and minimum incubation period of eggs) of engor ... | 2011 | 21536384 |
| tick-borne bacteria in free-living jaguars (panthera onca) in pantanal, brazil. | abstract tick-borne bacteria were investigated in 10 free-living jaguars and their ticks in the pantanal biome, brazil. jaguar sera were tested by indirect fluorescent antibody assays using rickettsia rickettsii, rickettsia parkeri, rickettsia amblyommii, rickettsia rhipicephali, rickettsia felis, rickettsia bellii, ehrlichia canis, and coxiella burnetii as crude antigens. all 10 jaguar sera reacted (titer ≥64) to at least one rickettsia species; 4 and 3 sera reacted with e. canis and c. burneti ... | 2011 | 21612532 |
| rickettsia parkeri rickettsiosis, argentina. | rickettsia parkeri, a recently identified cause of spotted fever rickettsiosis in the united states, has been found in amblyomma triste ticks in several countries of south america, including argentina, where it is believed to cause disease in humans. we describe the clinical and epidemiologic characteristics of 2 patients in argentina with confirmed r. parkeri infection and 7 additional patients with suspected r. parkeri rickettsiosis identified at 1 hospital during 2004-2009. the frequency and ... | 2011 | 21762568 |
| avian migrants facilitate invasions of neotropical ticks and tick-borne pathogens into the united states. | migratory birds have the potential to transport exotic vectors and pathogens of human and animal health importance across vast distances. we systematically examined birds that recently migrated to the united states from the neotropics for ticks. we screened both ticks and birds for tick-borne pathogens, including rickettsia species and borrelia burgdorferi. over two spring seasons (2013 and 2014), 3.56% of birds (n = 3,844) representing 42.35% of the species examined (n = 85) were infested by ti ... | 2015 | 26431964 |
| conserved amblyomma americanum tick serpin19, an inhibitor of blood clotting factors xa and xia, trypsin and plasmin, has anti-haemostatic functions. | tick saliva serine protease inhibitors (serpins) facilitate tick blood meal feeding through inhibition of protease mediators of host defense pathways. we previously identified a highly conserved amblyomma americanum serpin 19 that is characterised by its reactive center loop being 100% conserved in ixodid ticks. in this study, biochemical characterisation reveals that the ubiquitously transcribed a. americanum serpin 19 is an anti-coagulant protein, inhibiting the activity of five of the eight s ... | 2015 | 25957161 |
| 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 ... | 2015 | 25881916 |
| 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 ... | 0 | 24092850 |
| 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 ... | 2014 | 24423244 |
| 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 ... | 2013 | 23936795 |
| importation of exotic ticks and tick-borne spotted fever group rickettsiae into the united states by migrating songbirds. | birds are capable of carrying ticks and, consequently, tick-transmitted microorganisms over long distances and across geographical barriers such as oceans and deserts. ticks are hosts for several species of spotted fever group rickettsiae (sfgr), which can be transmitted to vertebrates during blood meals. in this study, the prevalence of this group of rickettsiae was examined in ticks infesting migratory songbirds by using polymerase chain reaction (pcr). during the 2009 and 2010 spring migratio ... | 2013 | 24252263 |
| tick-borne rickettsial pathogens in questing ticks, removed from humans and animals in mexico. | tick-borne rickettsial diseases (tbrd) are commonly encountered in medical and veterinary clinical settings. the control of these diseases is difficult, requiring disruption of a complex transmission chain involving a vertebrate host and ticks. the geographical distribution of the diseases is related to distribution of the vector, which is an indicator of risk for the population. a total of 1107 were collected by tick drag from forests, ecotourism parks and hosts at 101 sites in 22 of the 32 sta ... | 0 | 26726019 |
| high prevalence of "candidatus rickettsia andeanae" and apparent exclusion of rickettsia parkeri in adult amblyomma maculatum (acari: ixodidae) from kansas and oklahoma. | amblyomma maculatum (the gulf coast tick), an aggressive, human-biting, nearctic and neotropical tick, is the principal vector of rickettsia parkeri in the united states. this pathogenic spotted fever group rickettsia species has been identified in 8-52% of questing adult gulf coast ticks in the southeastern united states. to our knowledge, r. parkeri has not been reported previously from adult specimens of a. maculatum collected in kansas or oklahoma. a total of 216 adult a. maculatum ticks wer ... | 2015 | 25773931 |
| tick-induced allergies: mammalian meat allergy, tick anaphylaxis and their significance. | serious tick-induced allergies comprise mammalian meat allergy following tick bites and tick anaphylaxis. mammalian meat allergy is an emergent allergy, increasingly prevalent in tick-endemic areas of australia and the united states, occurring worldwide where ticks are endemic. sensitisation to galactose-α-1,3-galactose (α-gal) has been shown to be the mechanism of allergic reaction in mammalian meat allergy following tick bite. whilst other carbohydrate allergens have been identified, this alle ... | 2015 | 25653915 |
| the sialotranscriptome of amblyomma triste, amblyomma parvum and amblyomma cajennense ticks, uncovered by 454-based rna-seq. | tick salivary constituents antagonize inflammatory, immune and hemostatic host responses, favoring tick blood feeding and the establishment of tick-borne pathogens in hosts during hematophagy. amblyomma triste, a. cajennense and a. parvum ticks are very important in veterinary and human health because they are vectors of the etiological agents for several diseases. insights into the tick salivary components involved in blood feeding are essential to understanding vector-pathogen-host interaction ... | 2014 | 25201527 |
| candidatus rickettsia andeanae, a spotted fever group agent infecting amblyomma parvum ticks in two brazilian biomes. | adult ticks of the species amblyomma parvum were collected from the vegetation in the pantanal biome (state of mato grosso do sul) and from horses in the cerrado biome (state of piauí) in brazil. the ticks were individually tested for rickettsial infection via polymerase chain reaction (pcr) targeting three rickettsial genes, glta, ompa and ompb. overall, 63.5% (40/63) and 66.7% (2/3) of a. parvum ticks from pantanal and cerrado, respectively, contained rickettsial dna, which were all confirmed ... | 0 | 24714968 |
| rickettsia parkeri rickettsiosis in different ecological regions of argentina and its association with amblyomma tigrinum as a potential vector. | rickettsia parkeri, a newly recognized tick-borne pathogen of humans in the americas, is a confirmed cause of spotted fever group rickettsiosis in argentina. until recently, almost all cases of r. parkeri rickettsiosis in argentina have originated from the paraná river delta, where entomological surveys have identified populations of r. parkeri-infected amblyomma triste ticks. in this report, we describe confirmed cases of r. parkeri rickettsiosis from córdoba and la rioja provinces, which are l ... | 2014 | 25349376 |
| rickettsia parkeri rickettsiosis, arizona, usa. | in the united states, all previously reported cases of rickettsia parkeri rickettsiosis have been linked to transmission by the gulf coast tick (amblyomma maculatum). here we describe 1 confirmed and 1 probable case of r. parkeri rickettsiosis acquired in a mountainous region of southern arizona, well beyond the recognized geographic range of a. maculatum ticks. the likely vector for these 2 infections was identified as the amblyomma triste tick, a neotropical species only recently recognized in ... | 0 | 27089251 |
| the evolution of the dystroglycan complex, a major mediator of muscle integrity. | basement membrane (bm) extracellular matrices are crucial for the coordination of different tissue layers. a matrix adhesion receptor that is important for bm function and stability in many mammalian tissues is the dystroglycan (dg) complex. this comprises the non-covalently-associated extracellular α-dg, that interacts with laminin in the bm, and the transmembrane β-dg, that interacts principally with dystrophin to connect to the actin cytoskeleton. mutations in dystrophin, dg, or several enzym ... | 2015 | 26319583 |
| histoarchitecture of the ovary of rhipicephalus (boophilus) annulatus during pre- and postengorgement period. | the present communication describes the detailed day wise study of histological changes of the ovary of rhipicephalus (boophilus) annulatus in the postengorgement period together with the systematic classification of their oocytes. the ovary of r. (b.) annulatus is panoistic type with an asynchronous development of oocytes. all the stages (ii, iii, iv, and v) of oocytes except stage i were similar to r. (b.) microplus. the stage i oocytes showed basophilia, which was not reported earlier in othe ... | 2015 | 25664337 |
| molecular identification of rickettsia parkeri infecting amblyomma triste ticks in an area of argentina where cases of rickettsiosis were diagnosed. | specimens of the hard tick amblyomma triste were found infected with rickettsia parkeri in an area of argentina (general lavalle, buenos aires province) where cases of human illness attributed to this microorganism have been reported. molecular detection of r. parkeri was based on polymerase chain reactions that amplify a ca. 400-bp fragment of the 23s-5s intergenic spacer and a ca. 500-bp fragment of the gene encoding a 190-kda outer membrane protein. three (6.97%) of 43 a. triste ticks were de ... | 0 | 23440128 |
| novel babesia and hepatozoon agents infecting non-volant small mammals in the brazilian pantanal, with the first record of the tick ornithodoros guaporensis in brazil. | taking into account the diversity of small terrestrial mammals of the pantanal, the present study aimed to verify the occurrence of infection by ehrlichia spp., anaplasma spp., rickettsia spp., hepatozoon spp., babesia spp. and parasitism by ticks in non-volant small mammals collected in the brazilian pantanal. samples of blood, liver and spleen were collected from 64 captured animals, 22 marsupials and 42 rodents. pathogen detection was performed by the use of genus-specific polymerase chain re ... | 2016 | 26782931 |
| bacteria of the genera ehrlichia and rickettsia in ticks of the family ixodidae with medical importance in argentina. | the aim of this study was to get an overview about the occurrence of bacteria from the genus ehrlichia and rickettsia in ixodid ticks with medical importance in argentina. therefore, in 2013 and 2014, free-living ticks were collected in different provinces of northern argentina. these ticks were determined as amblyomma sculptum, amblyomma neumanni, amblyomma parvum, amblyomma triste, amblyomma ovale, amblyomma tonelliae and haemaphysalis juxtakochi. all samples were tested to determine the infec ... | 2017 | 27812828 |
| dynamics of exposure to rickettsia parkeri in cattle in the paraná river delta, argentina. | several cases of human rickettsiosis caused by rickettsia parkeri were recently documented in the paraná river delta of argentina, where the tick vector is amblyomma triste koch. as cattle suffer recurrent a. triste infestations, they are at risk of becoming infected with r. parkeri herein we investigated the dynamics of r. parkeri and its a. triste vector in a herd of beef cattle. cattle were followed for 18 mo and samples were analyzed for the presence of antibodies against four rickettsia spe ... | 2016 | 26794232 |
| rickettsia parkeri: a rickettsial pathogen transmitted by ticks in endemic areas for spotted fever rickettsiosis in southern uruguay. | at first rickettsia conorii was implicated as the causative agent of spotted fever in uruguay diagnosed by serological assays. later rickettsia parkeri was detected in human-biting amblyomma triste ticks using molecular tests. the natural vector of r. conorii, rhipicephalus sanguineus, has not been studied for the presence of rickettsial organisms in uruguay. to address this question, 180 r. sanguineus from dogs and 245 a. triste from vegetation (flagging) collected in three endemic localities w ... | 2012 | 22634883 |
| [amblyomma triste and amblyomma tigrinum (acari: ixodidae) in sympatry in santa fe province, argentina]. | the aim of this communication is to report, for the first time, the occurrence of amblyomma triste in santa fe province, argentina, and to add a new isolation place for amblyomma tigrinum. both species of ticks are vectors of rickettsia parkeri, a spotted fever group rickettsia. ticks were recovered from tourists in august 2014 and december 2015 at the federico wildermuth foundation (31° 59's, 61° 24'o), san martin department, santa fe province. five adult ticks were morphologically identified a ... | 2016 | 27723618 |
| rickettsial infection in ticks from wild birds from cerrado and the pantanal region of mato grosso, midwestern brazil. | the involvement of different species of ticks and wild animals, such as birds, play an important role in the epidemiology of tick-borne diseases. birds may serve as reservoirs for some tick-borne diseases, and may carry and spread hematophagous ectoparasites mechanically. this study aimed to show the diversity of ticks on birds and molecular detection of rickettsial infection in ticks from pantanal and cerrado, two similar brazilian biomes characterized by hydrological seasons. during two years, ... | 2015 | 26232933 |
| factors affecting patterns of amblyomma triste (acari: ixodidae) parasitism in a rodent host. | here we offer a multivariable analysis that explores associations of different factors (i.e., environmental, host parameters, presence of other ectoparasites) with the interaction of amblyomma triste immature stages and one of its main hosts in argentina, the rodent akodon azarae. monthly and for two years, we captured and sampled rodents at 16 points located at 4 different sites in the parana river delta region. the analyses were conducted with generalized linear mixed models with a negative bi ... | 2015 | 26104965 |
| seroepidemiological survey of rickettsia spp. in dogs from the endemic area of rickettsia parkeri rickettsiosis in uruguay. | rickettsia parkeri rickettsiosis is a vector-borne zoonosis that occurs in some countries of the american continent. following the first description and determination of the pathogenicity to humans in 2004 in usa, this bacterium has been reported in several south american countries. human cases have been diagnosed in both uruguay and argentina in the past years. this study consisted in a serosurvey of 1000 domestic dogs living in the endemic area of rickettsiosis in uruguay, where amblyomma tris ... | 2015 | 25735816 |
| rickettsia parkeri infecting free-living amblyomma triste ticks in the brazilian pantanal. | the present study evaluated the infection of rickettsiae in 151 rhipicephalus sanguineus, 59 amblyomma ovale, 166 amblyomma triste, one amblyomma dissimile and four amblyomma dubitatum ticks collected in the municipality of poconé, state of mato grosso, within the pantanal biome of brazil. ticks were individually processed by the hemolymph test with gimenez staining, isolation of rickettsia in vero cell culture by the shell vial technique, and polymerase chain reaction (pcr) targeting the citrat ... | 2015 | 25650348 |
| rickettsial infection in animals, humans and ticks in paulicéia, brazil. | a previous study in paulicéia municipality, south-eastern brazil, reported 9.7% of the amblyomma triste ticks to be infected by rickettsia parkeri, a bacterial pathogen that causes spotted fever in humans. these a. triste ticks were shown to be associated with marsh areas, where the marsh deer blastocerus dichotomus is a primary host for this tick species. during 2008-2009, blood serum samples were collected from 140 horses, 41 dogs, 5 opossums (didelphis albiventris) and 26 humans in farms from ... | 2015 | 25643912 |
| in vitro isolation and infection intensity of rickettsia parkeri in amblyomma triste ticks from the paraná river delta region, argentina. | in the present study, we report the first in vitro isolation and infection intensity of rickettsia parkeri in amblyomma triste ticks from argentina. no genetic differences in the molecular targets evaluated were found between r. parkeri isolates from argentina and those r. parkeri isolates reported in uruguay and brazil, both obtained from a. triste. only a minor difference was observed when compared to r. parkeri isolated from amblyomma maculatum from united states. moreover, the prevalence of ... | 2014 | 25113981 |
| first molecular detection of rickettsia parkeri in amblyomma tigrinum and amblyomma dubitatum ticks from uruguay. | rickettsia parkei is the etiological agent of spotted fever in uruguay, where is transmitted to humans by the tick amblyomma triste. in the present study, ticks were collected from capybaras (hydrochoerus hydrochaeris) and domestic dogs during 2011-2012 in different parts of uruguay. three out of 11 (27.3%) amblyomma dubitatum ticks collected from capybaras, and 4 out of 6 (66.7%) amblyomma tigrinum ticks collected from dogs were shown by molecular analyses to be infected by rickettsia parkeri s ... | 2014 | 25108780 |
| amblyomma triste (acari: ixodidae): new north american collection records, including the first from the united states. | new distribution records for the neotropical tick, amblyomma triste koch, are identified from 27 specimens in 18 separate collections. these collections originated from six now recognized geographical foci in two states in the united states (cochise and santa cruz counties, arizona, and brewster and jeff davis counties, texas) and from import cattle, bos taurus l., presented for entry at the united states border and originating in three mexican states (coahuila, durango, and sonora). for at leas ... | 2010 | 20695268 |
| localization of antigenic sites in unfed nymphs of amblyomma triste koch 1844 (acari: ixodidae) ticks by immunohistochemistry. | the reactivity of sera collected from guinea pigs after three infestations with amblyomma triste nymphs on histological sections of the same tick species was investigated through immunohistochemistry to identify potential target cells and tissues. six guinea pigs were infested thrice, at 30 day intervals, with 30 nymphs of a. triste per animal per infestation. blood samples were collected from the guinea pigs 15 days after each infestation for serum separation; normal serum was obtained before t ... | 2010 | 20537113 |
| 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 |
| ecology of the interaction between ixodes loricatus (acari: ixodidae) and akodon azarae (rodentia: criceridae). | the present study explores associations of different factors (i.e. host parameters, presence of other ectoparasites and [mainly biotic] environmental factors) with burdens of ixodes loricatus immature stages in one of its main hosts in argentina, the rodent akodon azarae. for 2 years, rodents were trapped and sampled monthly at 16 points located in four different sites in the parana river delta region. data were analysed with generalized linear mixed models with a negative binomial response (cou ... | 2015 | 26122994 |
| multiplex qpcr assay for identification and differentiation of amblyomma americanum, amblyomma cajennense, and amblyomma maculatum (ixodida: ixodidae) tick species in the eastern united states. | many ticks of the genus amblyomma are vectors of human pathogens, and the correct species identification is medically and epidemiologically important. morphological identification is time-consuming and requires a high level of expertise. identification of engorged, immature, or damaged ticks and the differentiation of closely related species remain problematic. here, we report the development of a real-time taqman assay for the genomic identification and differentiation of amblyomma americanum ( ... | 2014 | 25118411 |
| ticks (acari: ixodidae) on wild birds in north-central argentina. | ixodid ticks were collected from wild birds in five ecoregions in north-central argentina, namely: selva de las yungas, esteros del iberá, delta e islas del paraná, selva paranaense and chaco seco. a total of 2199 birds belonging to 139 species, 106 genera, 31 families and 11 orders were captured, but ticks were collected only from 121 birds (prevalence=5.5%) belonging to 39 species (28.1%) and three orders: tinamiformes (tinamidae) and falconiformes (falconidae) in selva de las yungas and passe ... | 2014 | 25108788 |
| a third amblyomma species and the first tick-borne rickettsia in chile. | during november 2010, three ticks were collected from three dogs living in the rural area of arica, northern chile. morphological analyses of the ticks in the laboratory revealed that they were most similar to amblyomma maculatum koch and amblyomma triste koch. however, because of unique metatarsal spurs, neither of the chilean specimens could be assigned with certainty to a. maculatum or a. triste, based on external morphology. the mitochondrial 16s rrna gene partial sequences obtained from two ... | 2012 | 22308792 |
| [detection of rickettsia andeanae in two regions of chile]. | candidatus 'rickettsia andeanae' is recently recognized specie, with no attributed pathogenic role so far. it has been reported in amblyomma ticks from peru, usa and argentina, and recently in chile, in one specimen of amblyomma triste from a rural locality in arica. | 2013 | 24248107 |
| distribution and genetic variation of amblyomma triste (acari: ixodidae) in argentina. | a study was conducted to investigate the distribution of amblyomma triste in argentina under the hypothesis that this tick prevails in riparian localities along the paraná river and adjacent humid environments from 34° 30' s to 25° 20' s, approximately. ticks were collected from mammals and vegetation in those environments from november 2008 to october 2012. additionally, genetic variation was tested from argentinean, brazilian, chilean, and uruguayan populations of a. triste by comparing sequen ... | 2013 | 23647652 |
| rickettsia parkeri (rickettsiales: rickettsiaceae) detected in ticks of the amblyomma maculatum (acari: ixodidae) group collected from multiple locations in southern arizona. | rickettsia parkeri is an emerging human pathogen transmitted by amblyomma ticks in predominately tropical and subtropical regions of the western hemisphere. in 2014 and 2015, one confirmed case and one probable case of r. parkeri rickettsiosis were reported from the pajarita wilderness area, a semi-arid mountainous region in southern arizona. to examine more closely the potential public health risk of r. parkeri in this region, a study was initiated to investigate the pervasiveness of amblyomma ... | 2017 | 28981813 |