| 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. | 2014 | 25078908 |
| 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. | 2016 | 27287539 |
| 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 ... | 0 | 25148391 |
| 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. | 2014 | 24387674 |
| 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 ... | 2013 | 23875178 |
| contributions to rickettsioses research in colombia (1917-1943), luis b. patiño camargo. | colombian physician luis benigno patiño camargo was one of the pioneers in the study of rickettsioses in south america, demonstrating for the first time in colombia the presence of rickettsia rickettsii as the etiological agent of a highly deadly exanthematic febrile syndrome in the 1930s. however, patiño-camargo performed other investigations from 1917-1943, which represent the first descriptions and scientific evidence of the presence of r. prowazekii and r. typhi in colombia. almost 60 years ... | 2016 | 27074327 |
| rickettsia rickettsii isolation from naturally infected amblyomma parvum ticks by centrifugation in a 24-well culture plate technique. | rocky mountain spotted fever is an acute illness caused by rickettsia rickettsii (r. rickettsii) and is transmitted by the bite of ticks of the genera dermacentor, amblyomma and rhipicephalus. the illness results in a high mortality rate and may be easily confused with other febrile syndromes. in yucatan state, mexico, childhood cases with a high mortality have been reported. in this work we report the isolation of a mexican r. rickettsii strain from a tick egg mass using an alternative method f ... | 2013 | 26623321 |
| comparative growth of spotted fever group rickettsia spp. strains in vero cells. | in brazil, the spotted fever group (sfg) rickettsia rickettsii and rickettsia parkeri related species are the etiological agents of spotted fever rickettsiosis. however, the sfg, rickettsia rhipicephali, that infects humans, has never been reported. the study of growth dynamics can be useful for understanding the infective and invasive capacity of these pathogens. here, the growth rates of the brazilian isolates r. rickettsii str. taiaçu, r. parkeri str. at#24, and r. rhipicephali hj#5, were eva ... | 0 | 27508322 |
| brazilian spotted fever: the importance of dermatological signs for early diagnosis. | brazilian spotted fever is an acute febrile infectious disease caused by rickettsia rickettsii, transmitted by tick bite. as this disease is rare and has high mortality rates in brazil, the clinical aspects and epidemiological data may help the diagnosis. we report a case of brazilian spotted fever in a 19-year-old patient who presented maculopapular exanthema in the palmar region and upper limbs, lymphadenopathy, fever, chills, headache, conjunctival hyperemia, nausea, vomiting, dyspnea, myalgi ... | 0 | 25830998 |
| rickettsia rickettsii in amblyomma patinoi ticks, colombia. | | 0 | 25695155 |
| comparative genome sequencing of rickettsia rickettsii strains that differ in virulence. | rickettsia rickettsii is an obligate intracellular pathogen that is the causative agent of rocky mountain spotted fever. strains of r. rickettsii differ dramatically in virulence. in a guinea pig model of infection, the severity of disease as assessed by fever response varies from the most virulent, sheila smith, to iowa, which causes no fever. to identify potential determinants of virulence in r. rickettsii, the genomes of two additional strains were sequenced for comparison to known sequences ... | 2015 | 25644009 |
| expanding range of amblyomma americanum and simultaneous changes in the epidemiology of spotted fever group rickettsiosis in the united states. | spotted fever group (sfg) rickettsia species are etiologic agents of a wide range of human infections from asymptomatic or mild infections to severe, life-threatening disease. in the united states, recent passive surveillance for sfg rickettsiosis shows an increased incidence and decreased severity of reported cases. the reasons for this are not well understood; however, we hypothesize that less pathogenic rickettsiae are causing more human infections, while the incidence of disease caused by mo ... | 2015 | 26503270 |
| seroepidemiologic study of human infections with spotted fever group rickettsiae in north carolina. | increasing entomologic and epidemiologic evidence suggests that spotted fever group rickettsiae (sfgr) other than rickettsia rickettsii are responsible for spotted fever rickettsioses in the united states. a retrospective seroepidemiologic study was conducted on stored acute- and convalescent-phase sera that had been submitted for rocky mountain spotted fever testing to the north carolina state laboratory of public health. we evaluated the serologic reactivity of the paired sera to r. rickettsii ... | 2014 | 25187639 |
| rickettsia vini n. sp. (rickettsiaceae) infecting the tick ixodes arboricola (acari: ixodidae). | recently, a new rickettsia named 'candidatus rickettsia vini' belonging to the spotted fever group has been molecularly detected in ixodes arboricola ticks in spain, the czech republic, slovakia and turkey, with prevalence reaching up to 100 %. the aim of this study was to isolate this rickettsia in pure culture, and to describe it as a new rickettsia species. | 2016 | 27565956 |
| the characterization and manipulation of the bacterial microbiome of the rocky mountain wood tick, dermacentor andersoni. | in north america, ticks are the most economically impactful vectors of human and animal pathogens. the rocky mountain wood tick, dermacentor andersoni (acari: ixodidae), transmits rickettsia rickettsii and anaplasma marginale to humans and cattle, respectively. in recent years, studies have shown that symbiotic organisms are involved in a number of biochemical and physiological functions. characterizing the bacterial microbiome of d. andersoni is a pivotal step towards understanding symbiont-hos ... | 2015 | 26653035 |
| targeted knockout of the rickettsia rickettsii ompa surface antigen does not diminish virulence in a mammalian model system. | strains of rickettsia rickettsii, the causative agent of rocky mountain spotted fever (rmsf), differ dramatically in virulence despite >99% genetic homology. spotted fever group (sfg) rickettsiae produce two immunodominant outer membrane proteins, rickettsial ompa (rompa) and rompb, which are conserved throughout the sfg and thought to be fundamental to pathogenesis. rompa is present in all virulent strains of r. rickettsii but is not produced in the only documented avirulent strain, iowa, due t ... | 2015 | 25827414 |
| inadequacy of igm antibody tests for diagnosis of rocky mountain spotted fever. | among 13 suspected rocky mountain spotted fever (rmsf) cases identified through an enhanced surveillance program in tennessee, antibodies to rickettsia rickettsii were detected in 10 (77%) patients using a standard indirect immunofluorescent antibody (ifa) assay. immunoglobulin m (igm) antibodies were observed for 6 of 13 patients (46%) without a corresponding development of igg, and for 3 of 10 patients (30%) at least 1 year post-onset. however, recent infection with a spotted fever group ricke ... | 2014 | 25092818 |
| phylogeography of rickettsia rickettsii genotypes associated with fatal rocky mountain spotted fever. | rocky mountain spotted fever (rmsf), a tick-borne zoonosis caused by rickettsia rickettsii, is among the deadliest of all infectious diseases. to identify the distribution of various genotypes of r. rickettsii associated with fatal rmsf, we applied molecular typing methods to samples of dna extracted from formalin-fixed, paraffin-embedded tissue specimens obtained at autopsy from 103 case-patients from seven countries who died of rmsf. complete sequences of one or more intergenic regions were am ... | 2014 | 24957541 |
| hitch-hiker taken for a ride: an unusual cause of myocarditis, septic shock and adult respiratory distress syndrome. | rocky mountain spotted fever (rmsf) is a serious tick-borne illness caused by rickettsia rickettsii that is endemic in southeastern usa. although rmsf has been described as causing the classic clinical triad of fever, headache and a characteristic rash, serious and potentially life-threatening manifestations can occur. cardiopulmonary involvement, although infrequent, may occur with severe cases of rmsf. rickettsial myocarditis is an uncommon occurrence. we present a case of a previously healthy ... | 2013 | 23314875 |
| rhipicephalus sanguineus (acari: ixodidae) biting a human being in portoalegre city, rio grande do sul, brazil. | we report the finding of a female brown dog tick, rhipicephalus sanguineus (acari: ixodidae) on the scalp of a male patient inporto alegre, rio grande do sul, brazil. human parasitism by this tick is rare and has seldomly been reported in the literature, despite its recognized importance since it can act as a vector of rickettsia rickettsii, the agent of spotted fever. | 2016 | 27074329 |
| multispacer typing (mst) of spotted fever group rickettsiae isolated from humans and rats in chengmai county, hainan province, china. | spotted fever caused by spotted fever group rickettsiae (sfgr) is found throughout china. during 2007-2008, 28 human sfgr isolates and 34 rat sfgr isolates including 15 isolates from rattus fulvescens, 5 isolates from r. edwardsi, 7 isolates from callosciurus erythraeus roberti and 7 isolates from dremomys rufigenis) were obtained from l929 cell culture. previous research indicated that the 62 strains of sfgr mentioned above shared not only the same serophenotype but also 100% of identity sequen ... | 2014 | 25324688 |
| serosurvey for selected pathogens in free-ranging american black bears (ursus americanus) in maryland, usa. | american black bears (ursus americanus) in maryland, usa, live in forested areas in close proximity to humans and their domestic pets. from 1999 to 2011, we collected 84 serum samples from 63 black bears (18 males; 45 females) in five maryland counties and tested them for exposure to infectious, including zoonotic, pathogens. a large portion of the bears had antibody to canine distemper virus and toxoplasma gondii, many at high titers. prevalences of antibodies to zoonotic agents such as rabies ... | 2014 | 25075540 |
| prevalence of antibodies to spotted fever group rickettsia spp. and ehrlichia spp. in coyotes (canis latrans) in oklahoma and texas, usa. | coyotes (canis latrans) are commonly infested with ticks, including amblyomma americanum, the predominant vector of ehrlichia chaffeensis and ehrlichia ewingii; dermacentor variabilis, an important vector of rickettsia rickettsii; and amblyomma maculatum, a major vector of rickettsia parkeri, a spotted fever group (sfg) rickettsia. to determine the degree to which coyotes are infected with or exposed to tick-borne bacterial disease agents, serum samples collected from coyotes in oklahoma and tex ... | 2013 | 23778619 |
| seroprevalence of tick-borne infections in military working dogs in the republic of korea. | in this study we endeavored to determine the seroprevalence of tick-borne infections in the military working dog (mwd) population in the republic of korea (rok). our sample population consisted of 182 serum samples from mwds for 3 different years (1996, 2002, and 2007). in addition, 63 whole blood samples from 2007 were available for polymerase chain reaction (pcr). serum samples were evaluated by a commercially available enzyme-linked immunosorbent assay (elisa) and immunofluorescence assay (if ... | 2012 | 23167501 |
| chemical characterization and acaricide potential of essential oil from aerial parts of tagetes patula l. (asteraceae) against engorged adult females of rhipicephalus sanguineus (latreille, 1806). | rhipicephalus sanguineus, commonly known as the brown dog tick, is one of the most widely distributed species of tick. in dogs, it can cause anemia and provide the transmission of pathogenic microorganisms such as babesia canis, ehrlichia canis, hepatozoon canis, anaplasma platys, and mycoplasma haemocanis. to man, it can transmit the intracellular parasites rickettsia rickettsii and rickettsia conorii, the causative agents of the rocky mountain spotted fever in the americas and mediterranean an ... | 2013 | 23508761 |
| highly sensitive loop-mediated isothermal amplification for the detection of leptospira. | leptospirosis is a worldwide zoonosis caused by an infection with the pathogenic species of leptospira. we have developed a loop-mediated isothermal amplification (lamp) assay to detect the dna of leptospira spp. six sets of primers targeting the gene of the subsurface protein, lipl32, were evaluated for their detection sensitivity. the best primer set detected less than 25 copies of lipl32 per reaction of both plasmid dna template and purified leptospiral genomic dna. by combining primers targe ... | 2015 | 26904743 |
| perinuclear antineutrophil cytoplasmic autoantibodies in dogs infected with various vector-borne pathogens and in dogs with immune-mediated hemolytic anemia. | to determine the prevalence of perinuclear antineutrophil cytoplasmic autoantibodies (panca) in dogs with confirmed or suspected immune-mediated hemolytic anemia (imha) or dogs infected with various vector-borne pathogens, including rickettsia rickettsii, bartonella henselae, bartonella vinsonii subsp berkhoffii, ehrlichia canis, borrelia burgdorferi, and leishmania infantum. | 2012 | 22924722 |
| health survey of free-ranging raccoons (procyon lotor) in central park, new york, new york, usa: implications for human and domestic animal health. | we conducted health assessments on 113 free-ranging raccoons ( procyon lotor ) in central park, new york city, us, in february 2010, september 2010, and november 2011 in conjunction with a trap-vaccinate-release program to control a raccoon rabies epizootic. five individuals were sampled at two time points for 118 raccoon examinations in total. we tested 13 of 13 and 8 of 13 euthanized raccoons for rabies and canine distemper virus (cdv), respectively, by antigen testing on brain tissue; all wer ... | 2017 | 28135131 |
| serological evidence of exposure to tick-borne agents in opossums (didelphis spp.) in the state of são paulo, brazil. | this work involved a serological investigation of tick-borne pathogens in opossums in eight municipalities of the state of são paulo, brazil. serum samples from 109 opossums (91 didelphis aurita and 18 didelphis albiventris) were tested to detect antibodies to rickettsia rickettsii (taiaçu strain, 1:64 cut-off) and ehrlichia canis (são paulo strain, 1:40 cut-off), by indirect immunofluorescence assay (ifa); and against borrelia burgdorferi (strain g39/40) by enzyme-linked immunosorbent assay (el ... | 2016 | 27276663 |
| incident tick-borne infections in a cohort of north carolina outdoor workers. | tick-borne diseases cause substantial morbidity throughout the united states, and north carolina has a high incidence of spotted fever rickettsioses and ehrlichiosis, with sporadic cases of lyme disease. the occupational risk of tick-borne infections among outdoor workers is high, particularly those working on publicly managed lands. this study identified incident tick-borne infections and examined seroconversion risk factors among a cohort of north carolina outdoor workers. workers from the nor ... | 2016 | 27008102 |
| multiple-host pathogens in domestic hunting dogs in nicaragua's bosawás biosphere reserve. | nicaragua's bosawás biosphere reserve is a vast forested area inhabited largely by indigenous mayangna and miskitu people. most bosawás residents rely on subsistence hunting and swidden agriculture, and hunting dogs are important for finding and securing wild game. we investigated the health of hunting dogs in three communities differing in location, size, and economy. dogs in all communities were nutritionally compromised and experienced a heavy burden of disease. seroprevalence of canine diste ... | 2017 | 28012903 |
| physiological characterization of the hematophagy of ornithodoros rostratus (acari: argasidae) on live hosts. | ornithodoros rostratus is an argasid tick and its importance is based on its hematophagy and the resulting transmission of pathogens such as rickettsia rickettsii and coxiella burnetii to its vertebrate hosts. in the face of a lack of physiological studies related to hematophagy in argasid ticks, this paper aims to identify and characterize the events that occur throughout the feeding by o. rostratus on live hosts. electrical signals and alterations on the feeding site were monitored using intra ... | 2016 | 27625415 |
| prevalence of rickettsia species in dermacentor variabilis ticks from ontario, canada. | relatively little is known about the prevalence of rickettsial species in dermacentor ticks in eastern canada. in this study, dermacentor ticks from the province of ontario, canada, were tested for the presence of spotted fever group rickettsial (sfgr) species, coxiella burnetii and francisella tularensis. rickettsia rickettsii was not detected in any ticks tested, but r. montanensis was detected at a prevalence of 2.2% in d. variabilis (17/778). two other sfgr species, r. parkeri and candidatus ... | 2016 | 27318438 |
| serological characterization of surface-exposed proteins of coxiella burnetii. | the obligate intracellular gram-negative bacterium coxiella burnetii causes q fever, a worldwide zoonosis. here we labelled cox. burnetii with biotin and used biotin-streptavidin affinity chromatography to isolate surface-exposed proteins (seps). using two-dimensional electrophoresis combined with mass spectrometry, we identified 37 proteins through bioinformatics analysis. thirty seps expressed in escherichia coli (recombinant seps, rseps) were used to generate microarrays, which were probed wi ... | 2014 | 25298245 |
| antibodies for rickettsia spp. in patients with negative serology for dengue virus, leptospirosis, and meningococcal disease in municipalities of são paulo state, brazil. | brazilian spotted fever is an infectious disease with a high mortality rate if not treated early. differential diagnosis is difficult, as the first clinical signs are non-specific and can be confused with other diseases. the aim of the study was to investigate evidence of infection with rickettsia rickettsii and rickettsia parkeri in negative sera samples, collected in 2014, from patients with suspected leptospirosis, dengue fever, and meningococcal disease in atibaia and bragança paulista munic ... | 2016 | 27812650 |
| vector-borne infections in tornado-displaced and owner-relinquished dogs in oklahoma, usa. | to determine the prevalence of infection with vector-borne agents in a cross-section of dogs from oklahoma, where canine vector-borne diseases are common, blood samples were evaluated through serology and molecular analysis. antibodies reactive to ehrlichia spp., rickettsia rickettsii, r. montanensis, and "r. amblyommii" were detected in 10.5% (11/105), 74.3% (78/105), 58.1% (61/105), and 55.2% (58/105) of dogs, respectively. presence of spotted fever group rickettsia spp. dna was identified in ... | 2016 | 27119261 |
| the prevalence of rickettsial and ehrlichial organisms in amblyomma americanum ticks collected from ohio and surrounding areas between 2000 and 2010. | the lone star tick, amblyomma americanum, feeds upon a variety of hosts and is a known vector of several human pathogens. in ohio, populations of a. americanum have been expanding their range and increasing in abundance and distribution, thereby elevating the public health concerns regarding bites from this species. we used a set of pcr assays to detect the presence of ehrlichial and rickettsial species in a. americanum ticks submitted to the ohio department of health zoonotic disease program ov ... | 2014 | 25108789 |
| health evaluation and survey of zoonotic pathogens in free-ranging capybaras (hydrochoerus hydrochaeris). | capybaras (hydrochoerus hydrochaeris) are the world's largest rodents and play an epidemiologic role in the transmission of zoonotic pathogens, including the causative agents of brazilian spotted fever, leptospirosis, and others. we surveyed the health of 31 free-ranging capybaras at the alberto löfgren state park, são paulo, brazil using a variety of diagnostic methods. hematology and serum chemistry were consistent with mild malnutrition and parasitism but did not indicate severe physiologic i ... | 2014 | 24779462 |
| detection of rickettsiae in fleas and ticks from areas of costa rica with history of spotted fever group rickettsioses. | outbreaks of spotted fevers have been reported in costa rica since the 1950s, although vectors responsible for transmission to humans have not been directly identified. in this study, species of rickettsia were detected in ectoparasites from costa rica, mostly from five study sites where cases of spotted fevers have been reported. ticks and fleas were collected using drag cloths or directly from domestic and wild animals and pooled according to species, host, and location. pools were analyzed in ... | 2016 | 27592065 |
| seroprevalence of rickettsia spp. in equids and molecular detection of 'candidatus rickettsia amblyommii' in amblyomma cajennense sensu lato ticks from the pantanal region of mato grosso, brazil. | the aim of the study was to evaluate exposure of equids to rickettsial agents (rickettsia rickettsii, rickettsia parkeri, 'candidatus rickettsia amblyommii', rickettsia rhipicephali, and rickettsia bellii) and rickettsial infection in ticks of a pantanal region of brazil. sera of 547 equids (500 horses and 47 donkeys) were evaluated by indirect immunofluorescence assay. in total, 665 adults and 106 nymphal pools of amblyomma cajennense f. sensu lato, 10 dermacentor nitens neumann ticks, and 88 l ... | 2014 | 26309313 |
| experimental infection with rickettsia rickettsii in an amblyomma dubitatum tick colony, naturally infected by rickettsia bellii. | amblyomma dubitatum engorged females, naturally infected by rickettsia bellii, were used to establish a laboratory colony. larvae, nymphs, and adults were exposed to two strains of rickettsia rickettsii by feeding on needle-inoculated guinea pigs, and thereafter reared on uninfected guinea pigs. after acquisition feeding, engorged larvae and nymphs molted to nymphs and adults, respectively, which were shown to be infected (confirming transstadial perpetuation), and were able to transmit both str ... | 2014 | 25108783 |
| environmental infestation and rickettsial infection in ticks in an area endemic for brazilian spotted fever. | brazilian spotted fever (bsf), caused by rickettsia rickettsii, is endemic in the municipality of americana, southeastern brazil, where the disease is transmitted by the tick amblyomma cajennense. this study evaluated the tick fauna and rickettsial infection in free-living ticks that were captured monthly using dry ice traps in areas endemic for bsf in americana, from july 2009 to june 2010. two tick species were captured: a. cajennense (6,122 larvae; 4,265 nymphs; 2,355 adults) and amblyomma du ... | 2013 | 24142167 |
| exposure of dogs to spotted fever group rickettsiae in urban sites associated with human rickettsioses in costa rica. | the zoonotic transmission cycles of rickettsia rickettsii and other spotted fever group (sfg) rickettsiae in latin america have usually been associated with rural or sylvatic environments, although domestic dogs can be implicated in more populated settings. in this study, exposure of dogs to sfg rickettsiae in the greater metropolitan area of costa rica was investigated. dogs from sites associated with human cases and from dog shelters were evaluated by indirect immunofluorescence assay (ifa) us ... | 2016 | 26995323 |
| rickettsia rickettsii and rickettsia felis infection in rhipicephalus sanguineus ticks and ctenocephalides felis fleas co-existing in a small city in yucatan, mexico. | | 2015 | 26611982 |
| human spotted fever group rickettsioses are underappreciated in southern taiwan, particularly for the species closely-related to rickettsia felis. | despite increased identification of spotted fever group rickettsioses (sfgr) in animals and arthropods, human sfgr are poorly characterized in taiwan. | 2014 | 24755560 |
| rickettsia felis infection in cat fleas ctenocephalides felis felis. | the present study evaluated the rickettsial infection in a laboratory colony of cat fleas, ctenocephalides felis felis (bouche) in brazil. all flea samples (30 eggs, 30 larvae, 30 cocoons, 30 males, and 30 females) tested by polymerase chain reaction (pcr) were shown to contain rickettsial dna. pcr products, corresponding to the rickettsial glta, htra, ompa and ompb gene partial sequences were sequenced and showed to correspond to rickettsia felis, indicating that the flea colony was 100% infect ... | 2010 | 24031560 |
| human infections by multiple spotted fever group rickettsiae in tennessee. | rocky mountain spotted fever is the most common tick-borne disease in tennessee. however, rickettsia rickettsii has rarely been isolated from endemic ticks, suggesting rickettsioses may be caused by other species. a total of 56 human serum samples that were serologically positive for exposure to rickettsia were obtained from commercial laboratories in 2010 and 2011. in addition, 20 paired sera from patients with encephalitis and positive rickettsia serology were obtained from the tennessee unexp ... | 2016 | 27022147 |
| molecular detection of rickettsia species within ticks (acari: ixodidae) collected from arkansas united states. | rocky mountain spotted fever (rmsf), caused by the etiological agent rickettsia rickettsii, is the most severe and frequently reported rickettsial illness in the united states, and is commonly diagnosed throughout the southeast. with the discoveries of rickettsia parkeri and other spotted fever group rickettsiae (sfgr) in ticks, it remains inconclusive if the cases reported as rmsf are truly caused by r. rickettsii or other sfgr. arkansas reports one of the highest incidence rates of rmsf in the ... | 2015 | 26334827 |
| infection of amblyomma ovale with rickettsia species atlantic rainforest in serra do mar, são paulo state, brazil. | rickettsia rickettsii and rickettsia sp. strain atlantic rainforest, that is considered to represent a genetic variant of rickettsia parkeri, are confirmed as being capable of infecting humans in brazil. this study reports the detection and characterization, by pcr and nucleotide sequencing, of rickettsia sp. strain atlantic rain forest in amblyomma ovale parasitizing a human, in ticks infesting dogs and in free-living ticks collected from the environment where the human infestation was recorded ... | 2016 | 27430967 |
| comparative value of blood and skin samples for diagnosis of spotted fever group rickettsial infection in model animals. | the definitive diagnosis of spotted fever group (sfg) rickettsioses in humans is challenging due to the retrospective nature and cross reactivity of the serological methods and the absence of reliable and consistent samples for molecular diagnostics. existing data indicate the transient character of bacteremia in experimentally infected animals. the ability of arthropod vectors to acquire rickettsial infection from the laboratory animals in the absence of systemic infection and known tropism of ... | 2016 | 27282078 |
| national surveillance of spotted fever group rickettsioses in the united states, 2008-2012. | spotted fever group (sfg) rickettsioses are notifiable conditions in the united states caused by the highly pathogenic rickettsia rickettsii and less pathogenic rickettsial species such as rickettsia parkeri and rickettsia sp. 364d. surveillance data from 2008 to 2012 for sfg rickettsioses are summarized. incidence increased from 1.7 cases per million person-years (py) in 2000 to 14.3 cases per million py in 2012. during 2008-2012, cases of sfg rickettsiosis were more frequently reported among m ... | 2016 | 26324732 |
| first report of mild brazilian spotted fever associated to arthritis. | we describe the first brazilian case of mild rickettsiosis, complicated by knee monoarthritis, in young adult bitten by a tick on his left leg in camburi zone, located in são sebastião municipality, southern coastal region of the state of são paulo, in the atlantic rainforest region, brazil. the patient developed inoculation eschar at the tick bite site associated with enlarged lymph nodes in the left groin, fever, polyarthralgia, headache and macular rash. twenty days after tick bite episode, h ... | 2017 | 25054603 |
| rickettsial infections in the tropics and in the traveler. | the purpose of this review is to describe recent advances in our understanding of the pathogenesis, epidemiology, and clinical features of rickettsial diseases with emphasis placed on those relating to travel and tropical medicine. | 2013 | 23842049 |
| evaluation of an association of alpha-cypermethrin and flufenoxuron for tick control in an area at risk of brazilian spotted fever. | brazilian spotted fever (bsf) is an endemic anthropozoonosis caused by gram-negative bacteria (rickettsia rickettsii) that is associated with the risk of human infection by ticks. in the city of americana, são paulo (sp), brazil, there were 12 cases (67% lethal) between 2004 and 2015. this study evaluated the effectiveness of control over tick infestations in an area at risk of bsf, in a field trial on an association of alpha-cypermethrin (3%) and flufenoxuron (3%) (tenopa(®)) conducted in ameri ... | 2017 | 28377149 |
| rocky mountain spotted fever in mexico: past, present, and future. | rocky mountain spotted fever, a tick-borne zoonosis caused by rickettsia rickettsii, is among the most lethal of all infectious diseases in the americas. in mexico, the disease was first described during the early 1940s by scientists who carefully documented specific environmental determinants responsible for devastating outbreaks in several communities in the states of sinaloa, sonora, durango, and coahuila. these investigators also described the pivotal roles of domesticated dogs and rhipiceph ... | 2017 | 28365226 |
| predictive factors for fatal tick-borne spotted fever in brazil. | in brazil, two pathogenic rickettsia species have been identified causing tick-borne spotted fever (sf). the aetiological agent rickettsia rickettsii causes serious illness, particularly in the south-eastern region of the country. moreover, the rickettsia sp. strain atlantic rainforest cause milder clinical manifestations in south-eastern, south and north-east regions. this study has sought to analyse predictive factors for fatal sf. a case-control study was performed using disease notification ... | 2017 | 28169507 |
| [fatal case of rickettsiosis in a toddler from southeastern mexico]. | rocky mountain spotted fever is a disease caused by rickettsia rickettsii, a bacteria transmitted by infected ticks. it is characterized by fever, exanthema, arthralgias and myalgias; but sometimes its clinical presentation is non specific. due to its similarities with other exanthematic diseases like dengue or chikungunya, rocky mountain spotted fever is not a first line diagnosis, even though countries like mexico show the ecologic and socioeconomic characteristics that favor its transmission, ... | 2017 | 28097845 |
| proteolytic cleavage of the immunodominant outer membrane protein rompa in rickettsia rickettsii. | rickettsia rickettsii, the causative agent of rocky mountain spotted fever, contains two immunodominant proteins, rompa and rompb, in the outer membrane. both rompa and rompb are conserved throughout spotted fever group rickettsiae as members of a family of autotransporter proteins. previously, it was demonstrated that rompb is proteolytically processed, with the cleavage site residing near the autotransporter domain at the carboxy-terminal end of the protein, cleaving the 168-kda precursor into ... | 2017 | 28031280 |
| probability of occurrence of the brazilian spotted fever in northeast of paraná state, brazil. | brazilian spotted fever (bsf) is a fatal zoonosis because of the difficulties in its early diagnosis and treatment. occurrences of bsf in the northeast of the state of paraná prompted investigation of areas at risk of this rickettsiosis in the municipalities of japira, jaboti, pinhalão and tomazina. to determine the areas at risk, 592 serum samples from dogs and 230 from equids were analyzed by means of the indirect immunofluorescence assay (ifa) for rickettsia rickettsii and r. parkeri . in add ... | 2016 | 27925056 |
| 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 ... | 2017 | 27880877 |
| notes from the field: community-based prevention of rocky mountain spotted fever - sonora, mexico, 2016. | rocky mountain spotted fever (rmsf), a life-threatening tickborne zoonosis caused by rickettsia rickettsii, is a reemerging disease in mexico (1,2). r. rickettsii is an intracellular bacterium that infects vascular endothelium and can cause multisystem organ failure and death in the absence of timely administration of a tetracycline-class antibiotic, typically doxycycline. epidemic rmsf, as described in parts of arizona and mexico, is associated with massive local infestations of the brown dog t ... | 2016 | 27880753 |
| a fatal case of brazilian spotted fever in a non-endemic area in brazil: the importance of having health professionals who understand the disease and its areas of transmission. | brazilian spotted fever (bsf) is caused by the bacterium rickettsia rickettsii. because of its high case-fatality rate and apparent increase in areas of transmission, it is considered to be the rickettsial illness of primary public health interest. cases of this disease have historically occurred in southeastern brazil. this article reports the first fatal case of bsf in southern brazil. this case high lights the importance of bsf to be considered as a differential diagnosis for acute hemorrhagi ... | 2016 | 27812666 |
| vectorial competence of amblyomma tonelliae to transmit rickettsia rickettsii. | the aim of this work was to test the vectorial competence of amblyomma tonelliae (ixodida: ixodidae) to transmit rickettsia rickettsii (rickettsiales: rickettsiaceae), the agent of rocky mountain spotted fever (rmsf). all parasitic stages of a. tonelliae were exposed to r. rickettsii by allowing each stage to feed on hosts inoculated with this pathogen. thereafter, ticks were fed on uninfected hosts. all stages of a. tonelliae were able to acquire the r. rickettsii infection and maintain it by t ... | 2016 | 27677425 |
| [severe spotted fever by rickettsia rickettsii, in tourist in the argentine northwest]. | on the fifth day after leaving the parque nacional el rey, province of salta, argentina, where she made rural tourism, a woman of italian origin, aged 47, developed an acute fever followed by a petechial and purpuric rash that progressed rapidly to multiorgan failure. she died on the sixth day after hospitalization. there were references to tick bites and a skin lesion similar to tache noire was found. the autopsy showed generalized vasculitis, ascites, pulmonary edema, acute tubular necrosis an ... | 2016 | 27723622 |
| high prevalence of "candidatus rickettsia amblyommii" in amblyomma ticks from a spotted fever endemic region in north argentina. | ticks from an endemic spotted fever region in argentina were analysed by pcr for spotted fever group rickettsiae. dna of "candidatus rickettsia amblyommii" was found in 21.3% of amblyomma hadanii and in 44.0% of a. neumanni. amblyomma sculptum (formerly a. cajennense) and haemaphysalis juxtakochi were negative for rickettsial dna. dna of rickettsia rickettsii, the etiological agent of the clinical cases reported within the studied region was not detected in the analysed sample. | 2016 | 27260814 |
| 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 ... | 2016 | 27230435 |
| distribution of spotted fever group rickettsiae in hard ticks (ixodida: ixodidae) from panamanian urban and rural environments (2007-2013). | tick-borne rickettsiosis is an important emerging disease in panama; to date, there have been 12 confirmed cases, including eight fatalities. to evaluate the distribution of rickettsiae in panamanian ticks, we collected questing and on-host ticks in urban and rural towns in elevations varying between 0 and 2300 m. a total of 63 sites (13 urban and 50 rural towns) were used to develop models of spatial distributions. we found the following tick species: rhipicephalus sanguineus s.l. (present in 5 ... | 2016 | 27068930 |
| amblyomma mixtum koch, 1844 (acari: ixodidae): first record confirmation in colombia using morphological and molecular analyses. | up to some years ago, the taxon amblyomma cajennense represented a single tick species in the new world, from southern united states to northern argentina. recent studies, based on genetic, reproductive and morphological data reorganized this taxon into a complex of the following 6 valid species: a. cajennense sensu stricto, amblyomma mixtum, amblyomma sculptum, amblyomma interandinum, amblyomma tonelliae, and amblyomma patinoi. according to this classification, the a. cajennense complex is curr ... | 2016 | 27062448 |
| first report of rickettsia identical to r. slovaca in colony-originated d. variabilis in the united states: detection, laboratory animal model, and vector competence of ticks. | ticks of the genus dermacentor are known vectors of rickettsial pathogens in both the old world and new world. in north america, dermacentor variabilis and d. andersoni are vectors of rickettsia rickettsii, while in europe, d. marginatus and d. reticulatus transmit r. slovaca and r. raoultii, respectively. neither the presence of r. slovaca in the americas nor the ability of american tick species to maintain this pathogen have been reported. here we describe detection of rickettsia genetically i ... | 2016 | 26808054 |
| estimation of rickettsia rickettsii copy number in the blood of patients with rocky mountain spotted fever suggests cyclic diurnal trends in bacteraemia. | | 2016 | 26724989 |
| effect of rickettsia rickettsii (rickettsiales: rickettsiaceae) infection on the biological parameters and survival of its tick vector-dermacentor variabilis (acari: ixodidae). | rocky mountain spotted fever, caused by rickettsia rickettsii, is a potentially fatal tick-borne disease spread from north america to argentina. the major vectors of r. rickettsii in the united states are dermacentor andersoni stiles and dermacentor variabilis (say). it is generally believed that vector ticks serve as major reservoirs of r. rickettsii in nature; however, the ability of ticks to support the indefinite perpetuation of r. rickettsii has been challenged by reports of deleterious eff ... | 2016 | 26494822 |
| rickettsia infection could be the missing piece of the buerger's disease puzzle. | rickettsia was suggested as a possible etiology of buerger's disease (bd) in the 1980s but this suggestion was never ruled out or proven. recently, we found evidence of rickettsia by polymerase chain reaction in 3 out of 25 biopsy samples from the amputated limb of a young man diagnosed with bd. | 2015 | 26344511 |
| 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 ... | 2015 | 26336213 |
| pathogenic potential of a costa rican strain of 'candidatus rickettsia amblyommii' in guinea pigs (cavia porcellus) and protective immunity against rickettsia rickettsii. | 'candidatus rickettsia amblyommii' is a spotted fever group rickettsia that is not considered pathogenic, although there is serologic evidence of possible infection in animals and humans. the aim of this study was to evaluate the pathogenic potential of a costa rican strain of 'candidatus r. amblyommii' in guinea pigs and determine its capacity to generate protective immunity against a subsequent infection with a local strain of rickettsia rickettsii isolated from a human case. six guinea pigs w ... | 2015 | 26210090 |
| risk factors associated with the transmission of brazilian spotted fever in the piracicaba river basin, state of são paulo, brazil. | brazilian spotted fever (bsf) is a disease transmitted by ticks for which the etiological agent is rickettsia rickettsii. the present essay evaluates the risk factors associated with the transmission of cases of bsf in the time period between 2003 and 2013 in the piracicaba river basin, state of são paulo. | 2015 | 25860458 |
| [seroprevalence of risk factors associated with rickettsiosis (rickettsia rickettsii) in humans in baja california, mexico]. | rickettsiosis caused by rickettsia rickettsii is capable of infecting vertebrates, including humans. the symptoms are high fever, headache, myalgia, nausea, vomiting, abdominal pain, and cough. mortality can be up to 30% in untreated patients. | 2015 | 25739483 |
| rickettsia rickettsii outer membrane protein ybgf induces protective immunity in c3h/hen mice. | rickettsia rickettsii is the etiological agent of rocky mountain spotted fever (rmsf). ybgf and tolc are outer membrane-associated proteins of r. rickettsii that play important roles in its interaction with host cells. we investigated the immunogenicity of ybgf and tolc for protection against rmsf. we immunized c3h/hen mice with recombinant r. rickettsii ybgf (rybgf) or tolc (rtolc). rickettsial burden and impairment in the lungs, spleens, and livers of rybgf-immunized mice were significantly lo ... | 2015 | 25714655 |
| enhanced protection against rickettsia rickettsii infection in c3h/hen mice by immunization with a combination of a recombinant adhesin radr2 and a protein fragment rompb-4 derived from outer membrane protein b. | two surface proteins of rickettsia rickettsii, outer membrane protein b (ompb) and adhesion 2 (adr2), have been recognized as protective antigens. herein, the immunization with both ompb and adr2 was performed in mice so as to explore whether their combination could induce an enhanced immunoprotection against r. rickettsii infection. | 2015 | 25597943 |
| 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 ... | 2014 | 25501172 |
| a cluster of rickettsia rickettsii infection at an animal shelter in an urban area of brazil. | rickettsia rickettsii infection is being increasingly recognized as an important cause of fatal acute illness in brazil, where this tick-borne disease is designated brazilian spotted fever (bsf). in this study we report five fatal cases of bsf in employees of an animal shelter in an urban area in the municipality of rio de janeiro in southeast brazil after a natural disaster on 11 january 2011. four of the cases occurred from 27 january to 11 april 2011, while the fifth fatal case was identified ... | 2015 | 25483025 |
| case report: co-infection of rickettsia rickettsii and streptococcus pyogenes: is fatal rocky mountain spotted fever underdiagnosed? | rocky mountain spotted fever, a tick-borne disease caused by rickettsia rickettsii, is challenging to diagnose and rapidly fatal if not treated. we describe a decedent who was co-infected with group a β-hemolytic streptococcus and r. rickettsii. fatal cases of rocky mountain spotted fever may be underreported because they present as difficult to diagnose co-infections. | 2014 | 25331804 |
| "rickettsia amblyommii" induces cross protection against lethal rocky mountain spotted fever in a guinea pig model. | rocky mountain spotted fever (rmsf) is a severe illness caused by rickettsia rickettsii for which there is no available vaccine. we hypothesize that exposure to the highly prevalent, relatively nonpathogenic "rickettsia amblyommii" protects against r. rickettsii challenge. to test this hypothesis, guinea pigs were inoculated with "r. amblyommii." after inoculation, the animals showed no signs of illness. when later challenged with lethal doses of r. rickettsii, those previously exposed to "r. am ... | 2014 | 25072985 |
| [latinamerican guidelines of riicer for diagnosis of tick-borne rickettsioses]. | tick-borne rickettsioses are worldwide infectious diseases that are considered emerging and re-emerging. until recently the only tick-borne rickettsiosis present in latin america was rickettsia rickettsii infection, but to date, with the incorporation of new tools as pcr and sequencing and the quick cellular close tube cultures (shell-vial), new species has been involved as human pathogens. in these guidelines, we offer an update of the microbiological assays for diagnosing rickettsioses. beside ... | 2014 | 24740776 |
| serologic evidence of human rickettsia infection found in three locations in panamá. | since the middle of last century, cases of rickettsiosis have been found in panamá when outbreaks of murine typhus and spotted fever were reported. since then, little information exists about its prevalence in this country, since it is most often is misdiagnosed as another disease. | 2013 | 24652247 |
| surface protein adr2 of rickettsia rickettsii induced protective immunity against rocky mountain spotted fever in c3h/hen mice. | rickettsia rickettsii is the pathogen of rocky mountain spotted fever (rmsf), a life-threatening tick-transmitted infection. adr2 was a surface-exposed adhesion protein of r. rickettsii and its immunoprotection against rmsf was investigated in mice. | 2014 | 24582636 |
| "rickettsia amblyommii" and r. montanensis infection in dogs following natural exposure to ticks. | to determine the risk of canine infection with spotted fever group (sfg) rickettsia spp. following natural tick exposure, 10 dogs determined to be free of evidence of exposure to or infection with tick-borne disease agents were exposed to ticks via weekly walks in a wooded area in north-central oklahoma. after each walk, dogs were examined and the number and species of ticks present were recorded. the dogs were then returned to outdoor kennels to allow the infestations and subsequent transmissio ... | 2014 | 24359419 |
| crystal structure of the n-terminal domains of the surface cell antigen 4 of rickettsia. | the obligate intracellular, gram-negative bacterium rickettsia is the causative agent of spotted fevers and typhus in humans. surface cell antigen (sca) proteins surround these bacteria. we recently reported the co-localization of one of these proteins, sca4, with vinculin in cells at sites of focal adhesions and demonstrated that two vinculin binding sites directed the sca4/vinculin interaction. here we report the 2.2 å crystal structure of the conserved n-terminal 38 kda domain of sca4 from ri ... | 2013 | 23904352 |
| [mortality from rickettsia rickettsii spotted fever in patients at a pediatric hospital in the state of sonora, 2004-2012]. | | 2013 | 23546404 |
| a 6-year-old girl with fever, rash, and increased intracranial pressure. | rocky mountain spotted fever (rmsf) is a well-described, potentially lethal, tick-borne zoonotic infection and has very effective therapy. however, the diagnosis might not be made early enough, often leading to worse outcomes. | 2013 | 23485263 |
| modelling spatial concordance between rocky mountain spotted fever disease incidence and habitat probability of its vector dermacentor variabilis (american dog tick). | the spatial distribution of dermacentor variabilis, the most commonly identified vector of the bacterium rickettsia rickettsii which causes rocky mountain spotted fever (rmsf) in humans, and the spatial distribution of rmsf, have not been previously studied in the south central united states of america, particularly in texas. from an epidemiological perspective, one would tend to hypothesise that there would be a high degree of spatial concordance between the habitat suitability for the tick and ... | 2012 | 23242684 |
| ixodid fauna and zoonotic agents in ticks from dogs: first report of rickettsia rickettsii in rhipicephalus sanguineus in the state of mato grosso do sul, mid-western brazil. | ticks from 148 dogs from the urban area of the municipality of campo grande, state of mato grosso do sul, brazil, were collected, classified and analyzed using polymerase chain reaction (pcr) for the identification of rickettsia spp., trypanosoma cruzi and leishmania spp. a total of 2015 ticks were collected. the species rhipicephalus sanguineus (98.9 %) and amblyomma cajennense (1.1 %) were identified. molecular analysis revealed that no tick samples were infected by t. cruzi. regarding leishma ... | 2013 | 23229491 |
| features of brazilian spotted fever in two different endemic areas in brazil. | brazilian spotted fever (bsf) caused by rickettsia rickettsii is the most important rickettsiosis and the only reportable tick-borne disease in brazil. in brazil, the hard tick amblyomma cajennense is the most important bsf vector; however, in são paulo state, a. aureolatum was also recognized as a vector species in remaining atlantic forest areas near the metropolitan area of são paulo city. we analyzed clinical and epidemiological features of bsf cases from two distinct areas where a. cajennen ... | 2012 | 23168052 |
| solution structure of the cold-shock-like protein from rickettsia rickettsii. | rocky mountain spotted fever is caused by rickettsia rickettsii infection. r. rickettsii can be transmitted to mammals, including humans, through the bite of an infected hard-bodied tick of the family ixodidae. since the r. rickettsii genome contains only one cold-shock-like protein and given the essential nature of cold-shock proteins in other bacteria, the structure of the cold-shock-like protein from r. rickettsii was investigated. with the exception of a short α-helix found between β-strands ... | 2012 | 23143233 |
| 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 ... | 2012 | 22716923 |
| rickettsial retinitis: acute unilateral vision loss with cystoid macular edema and stellate maculopathy. | to report on the presentation and treatment of a patient with infectious posterior segment uveitis because of infection with rickettsia rickettsii. | 2011 | 25390168 |
| microscopic and molecular identification of hemotropic mycoplasmas in south american coatis (nasua nasua). | hemoplasmas were detected in two apparently healthy captive south american coatis (nasua nasua) from southern brazil during an investigation for vector-borne pathogens. blood was subjected to packed cell volume (pcv) determination, a commercial real-time pcr panel for the detection of anaplasma spp., babesia spp., bartonella spp., hepatozoon spp., leishmania spp., mycoplasma haemofelis, 'candidatus mycoplasma turicensis', 'candidatus mycoplasma haemominutum', neorickettsia risticii, rickettsia r ... | 2017 | 28750863 |
| epidemiology of spotted fever group rickettsioses and acute undifferentiated febrile illness in villeta, colombia. | etiology of acute undifferentiated febrile syndrome (aufs) is often unknown, leading to inaccurate diagnosis and treatment. villeta town has been identified as an endemic area for spotted fever group (sfg) rickettsioses but little is known about possible amplifier hosts and other rickettsia species different from rickettsia rickettsii. besides, few studies have approached other aufs etiologies in the region. we investigated the role of dengue, leptospirosis, rickettsioses, human anaplasmosis, an ... | 2017 | 28722568 |
| comparative vertical transmission of rickettsia by dermacentor variabilis and amblyomma maculatum. | the geographical overlap of multiple rickettsia and tick species coincides with the molecular detection of a variety of rickettsial agents in what may be novel tick hosts. however, little is known concerning transmissibility of rickettsial species by various tick hosts. to examine the vertical transmission potential between select tick and rickettsial species, two sympatric species of ticks, dermacentor variabilis and amblyomma maculatum, were exposed to five different rickettsial species, inclu ... | 2017 | 28433729 |
| first report of a rickettsia asembonensis related infecting fleas in brazil. | the present study was performed in a non-endemic area for spotted fever (sf) in imperatriz microregion, state of maranhão, brazil. blood samples and ectoparasites were collected from 300 dogs of the imperatriz microregion. canine serum samples were tested individually by indirect immunofluorescence assay (ifa), using five rickettsia isolates from brazil. antibodies reactive to at least one of the five species of rickettsia were detected in 1.6% of the dogs (5/300). these sera were considered rea ... | 2017 | 28427962 |
| anaplasma, ehrlichia and rickettsia species infections in cats: european guidelines from the abcd on prevention and management | anaplasma species, ehrlichia species and rickettsia species are vector-borne pathogens infecting a wide variety of mammals, but causing disease in very few of them. infection in cats: anaplasma phagocytophilum is the most important feline pathogen among these rickettsial organisms, and coinfections are possible. little information is available on the pathogenesis of these agents in cats. clinical signs are usually reported soon after tick infestation. they are mostly non-specific, consisting of ... | 2017 | 28438088 |