| effect of antipyretic therapy on the duration of illness in experimental influenza a, shigella sonnei, and rickettsia rickettsii infections. | to determine whether antipyretic therapy prolongs the course of experimental influenza a, shigella sonnei, and rickettsia rickettsii infections. | 2000 | 11130213 |
| canine rocky mountain spotted fever: a retrospective study of 30 cases. | rocky mountain spotted fever (rmsf) was diagnosed in 30 dogs examined at north carolina state university, veterinary teaching hospital between 1984 and 1997. historical, physical examination, and laboratory abnormalities were reviewed. diagnostic criteria included a four-fold rise in antibody titer to rickettsia rickettsii (r. rickettsii) (n=15) or a single r. rickettsii antibody titer of 1:1,024 or greater (n=15; when this initial titer was determined one week or more after the onset of clinica ... | 2001 | 11204476 |
| rodent ectoparasites from two locations in northwestern florida. | from feb.-apr. 1999, 19 species of ectoparasitic arthropods (2 sucking lice, 4 fleas, 4 ticks, 2 mesostigmatid mites, 5 chiggers, 2 fur mites) were recovered from 106 rodents belonging to 5 species (cotton mouse, peromyscus gossypinus, n = 64; cotton rat, sigmodon hispidus, n = 23; eastern woodrat, neotoma floridana, n = 9; golden mouse, ochrotomys nuttalli, n = 9; eastern gray squirrel, sciurus carolinensis, n = 1) at tall timbers research station, leon county, florida. during the same period, ... | 2000 | 11217221 |
| a serological survey of rural dogs and cats on the southwestern canadian prairie for zoonotic pathogens. | a survey for antibodies against agents of plague, tularemia, and rocky mountain spotted fever (rmsf), and against sin nombre hantavirus (snv), bartonella henselae and b. clarridgeiae was conducted in the summer of 1995 using serum from rural dogs and cats living in the vicinity of four public parks in southeastern alberta and southwestern saskatchewan. antibodies to all pathogens were detected in all survey areas. overall prevalence rates were 0.075 for yersinia pestis, 0.089 for francisella tul ... | 2001 | 11257996 |
| molecular cloning, sequence and characterization of cjst, a putative protease from rickettsia rickettsii. | the cloning and sequencing of a gene from rickettsia rickettsii which confers haemolytic activity on escherichia coli strain tb1 is described. the open reading frame of the haemolysis-promoting gene, cjst, is 1041 bp and encodes a putative protein with a molecular mass of 33 825 da. cjst has high sequence similarity to several bacterial proteases, particularly type iv signal peptidases. cell lysates from an e. coli clone containing cjst in puc19 (pjon1) exhibited greater protease activity in fun ... | 2001 | 11312615 |
| assessing the association between the geographic distribution of deer ticks and seropositivity rates to various tick-transmitted disease organisms in dogs. | to determine whether the geographic distribution of deer ticks (ixodes scapularis) was associated with the distribution of dogs seropositive for various tick-transmitted disease organisms (ie, borrelia burgdorferi, rickettsia rickettsii, the human granulocytic ehrlichiosis [hge] agent, ehrlichia canis, and bartonella vinsonii subsp berkhoffii). | 2001 | 11318358 |
| [ehrlichiosis infection prevalence in spain or cross reactions]. | | 2001 | 11333754 |
| quantitative analyses of variations in the injury of endothelial cells elicited by 11 isolates of rickettsia rickettsii. | eleven isolates of spotted fever group rickettsiae from the blood of patients or ixodid ticks from north and south america were characterized. all isolates were identified as rickettsia rickettsii using restriction fragment length polymorphism analysis of a 532-bp rompa gene fragment obtained by pcr. the ability of the r. rickettsii isolates to elicit cytopathic effects and parameters of oxidative injury were examined in cultured human ea.hy 926 endothelial cells. cytopathic effects were determi ... | 2001 | 11427428 |
| serological evidence for the continued presence of human rickettsioses in southern india. | rickettsiosis is generally believed to have disappeared from many parts of india. however, the serological testing of 37 residents of southern india who presented with fever of unknown aetiology in 1996-1998 confirmed that spotted fever, epidemic/endemic typhus and scrub typhus continue to occur in southern india. the epidemiology and magnitude of the problem need to be evaluated. | 2001 | 11454249 |
| serologic and molecular evidence of coinfection with multiple vector-borne pathogens in dogs from thailand. | forty-nine dogs from thailand were evaluated for serologic evidence of exposure or polymerase chain reaction (pcr) evidence of infection with vectorborne pathogens, including ehrlichia sp. (ehrlichia canis, ehrlichia chaffeensis, ehrlichia equi, and ehrlichia risticii), bartonella vinsonii subsp. berkhoffi (bvb), spotted fever group (sfg) rickettsiae (rickettsia rickettsii), typhus group (tg) rickettsiae (rickettsia canada, rickettsia prowazekii, and rickettsia typhi), and babesia sp. (babesia c ... | 2001 | 11596732 |
| spotted fever in brazil: a seroepidemiological study and description of clinical cases in an endemic area in the state of são paulo. | during 1985-1995, illnesses clinically and epidemiologically compatible with brazilian spotted fever were identified in 17 patients in the county of pedreira, in the state of são paulo, brazil. spotted-fever group rickettsial infection was confirmed by serology and/or immunostaining of tissues in 10 of these patients. immunostaining confirmed infection in a 37-year-old pregnant patient, although rickettsial antigens were not demonstrable in the tissues of the fetus. a serosurvey was conducted in ... | 2001 | 11693878 |
| risk of lyme disease: perceptions of residents of a lone star tick-infested community. | lone star ticks (amblyomma americanum) have been suggested as a vector of the agent of lyme disease (borrelia burgdorferi sensu lato) in the usa, based on associations with an infection manifesting mainly as erythema migrans. in laboratory experiments, however, they failed to transmit b. burgdorferi sensu stricto. | 2001 | 11693973 |
| immunization with a portion of rickettsial outer membrane protein a stimulates protective immunity against spotted fever rickettsiosis. | two approaches for presentation of a part of the rickettsial outer membrane protein a (ompa) of rickettsia rickettsii, namely (1) recombinant mycobacterium vaccae (rmv) or (2) recombinant dna vaccine, stimulated protective immunity against a lethal challenge with the closely related bacterium, r. conorii, in mice. after primary immunization with rmv and booster immunization with homologous recombinant protein, 67 and 55% of mice were protected against challenge in two experiments. dna vaccinatio ... | 2001 | 11738766 |
| evidence of rodent-associated bartonella and rickettsia infections among intravenous drug users from central and east harlem, new york city. | we tested serum samples collected in 1997 and 1998 from a cohort of 204 injection drug users (idus) recruited from central and east harlem, new york city, new york, for antibodies reactive with seven rickettsial or bartonella spp. antigens. rodent-associated bartonella elizabethae and rickettsia akari were the primary etiologic agents of interest. the testing panel also included bartonella henselae, bartonella quintana, rickettsia prowazekii, rickettsia rickettsii, and rickettsia typhi. the high ... | 2001 | 11791987 |
| rocky mountain spotted fever: a review for the pediatrician. | | 2002 | 11905289 |
| atypical fulminant rickettsia rickettsii infection (brazilian spotted fever) presenting as septic shock and adult respiratory distress syndrome. | brazilian spotted fever, caused by rickettsia rickettsii, has been increasingly reported in brazil especially in the southeastern states. the severe and fulminant forms of the disease are not unusual but most of the reported fatal cases have shown some typical clinical clue, which leads the attending physician to a correct diagnosis. we report a probable case of atypical fulminant brazilian spotted fever that presented full-blown septic shock associated with adult respiratory distress syndrome ( ... | 2002 | 11980610 |
| rocky mountain spotted fever. | rocky mountain spotted fever (rmsf) is a fulminant tick-borne infection by rickettsia rickettsii. the classical diagnostic triad is fever, headache and rash in a patient with a recent tick bite. with prompt, appropriate antimicrobial therapy, patient outcomes are excellent. however, rmsf is often misdiagnosed, particularly during the initial stages of illness, and as a result, patient outcomes are sometimes suboptimal. | 2002 | 11982306 |
| endothelial cell apoptosis in sepsis. | to discuss a potential role for endothelial cell apoptosis in the pathogenesis of sepsis. | 2002 | 12004240 |
| rickettsia rickettsii infection of cultured human endothelial cells induces heme oxygenase 1 expression. | existing evidence suggests that oxidative insults and antioxidant defense mechanisms play a critical role in the host cell response during infection of endothelial cells by rickettsia rickettsii, the causative agent of rocky mountain spotted fever. heme oxygenase (ho), a rate-limiting enzyme in the pathway for heme catabolism, protects against oxidant damage in a variety of stress situations. here, we report on the expression of the inducible and constitutive ho isozymes, ho-1 and ho-2, during r ... | 2002 | 12117910 |
| short report: concurrent rocky mountain spotted fever in a dog and its owner. | a sequential occurrence of rocky mountain spotted fever (rmsf) in a dog and its owner is described. diagnosis of rmsf in the animal guided subsequent testing for and diagnosis of the same disease in the human patient. previous reports of concurrent rmsf in dogs and their owners are reviewed, and the epidemiologic significance of this occurrence is discussed. | 2002 | 12135293 |
| rickettsia rickettsii: as virulent as ever. | | 2002 | 12201574 |
| fever and rash in a 3-year-old girl: rocky mountain spotted fever. | initial symptoms of rocky mountain spotted fever (rmsf), a tick-borne illness caused by rickettsia rickettsii, are nonspecific and include headache, gastrointestinal disturbances, malaise, and myalgias, followed by fever and rash. the classic triad of fever, rash, and history of tick exposure is uncommon at presentation. clinical manifestations of rmsf range from virtually asymptomatic to severe. because of the potentially fatal outcome of rmsf, presumptive clinical diagnosis and empiric antimic ... | 2002 | 12353892 |
| rickettsial, ehrlichial and bartonella infections of the myocardium and pericardium. | myocarditis and pericarditis are uncommon complications of human rickettsial, ehrlichial and bartonella infections. myocardial inflammation usually occurs in the setting of acute disseminated infection. organisms associated with myocarditis include: rickettsia rickettsii, r. conorii, orientia tsutsugamushi, coxiella burnetii, anaplasma phagocytophila (the causative agent of human granulocytic ehrlichiosis) and bartonella henselae. pericarditis has been described in the setting of r. conorii and ... | 2003 | 12456377 |
| phylogenetic analysis of the erythrocytic anaplasma species based on 16s rdna and groel (hsp60) sequences of a. marginale, a. centrale, and a. ovis and the specific detection of a. centrale vaccine strain. | phenotypic criteria for the identification of erythrocytic ruminant anaplasma species has relied on subjective identification methods such as host pathogenicity (virulence for cattle or sheep) and/or the location of anaplasma inclusion bodies within the host's red cells. sequence comparisons of new and available genbank accessions were investigated to elucidate the relationships among these closely related anaplasma species. twenty-one 16s rdna and groel (hsp60) sequences from 13 anaplasma margi ... | 2003 | 12488078 |
| comparison of pcr assays for detection of the agent of human granulocytic ehrlichiosis, anaplasma phagocytophilum. | human granulocytic ehrlichiosis is an emerging infectious disease in the united states and europe, and pcr methods have been shown to be effective for the diagnosis of acute infections. numerous pcr assays and primer sets have been reported in the literature. the analytical sensitivities (limits of detection) of 13 published pcr primer sets were compared using dna extracted from serial dilutions of anaplasma phagocytophilum-infected hl-60 cells. the specificity of the assays that were able to de ... | 2003 | 12574272 |
| effects of ectopically expressed neuronal wiskott-aldrich syndrome protein domains on rickettsia rickettsii actin-based motility. | neuronal wiskott-aldrich syndrome protein (n-wasp) and the actin-related protein 2/3 (arp2/3) complex have emerged as critical host proteins that regulate pathogen actin-based motility. actin tail formation and motility in listeria monocytogenes require the arp2/3 complex but bypasses n-wasp signaling. motility of shigella flexneri and vaccinia virus requires both n-wasp and the arp2/3 complex. functional roles for these cytoskeletal regulatory proteins in actin-based motility of rickettsia rick ... | 2003 | 12595475 |
| brazilian spotted fever: description of a fatal clinical case in the state of rio de janeiro. | we describe a case of brazilian spotted fever in a previously healthy young woman who died with petechial rash associated to acute renal and respiratory insufficiency 12 days following fever, headache, myalgia, and diarrhea. serologic test in a serum sample, using an immunofluorescence assay, revealed reactive igm/igg. | 2002 | 12621675 |
| urban zoonoses caused by bartonella, coxiella, ehrlichia, and rickettsia species. | the last half of the 20th century witnessed an increase in the occurrence and recognition of urban zoonoses caused by members of the genera bartonella, coxiella, ehrlichia, and rickettsia, all traditionally considered to be members of the family rickettsiaceae. in recent years, new human pathogens (bartonella elizabethae, bartonella henselae, and rickettsia felis) have been recognized in urban environments. other newly recognized pathogens (ehrlichia chaffeensis and ehrlichia phagocytophila in t ... | 2001 | 12653141 |
| characterization of the ftsz gene from ehrlichia chaffeensis, anaplasma phagocytophilum, and rickettsia rickettsii, and use as a differential pcr target. | degenerate primers corresponding to highly conserved regions of previously characterized ftsz genes were used to pcr amplify a portion of the ftsz gene from the genomic dna of ehrlichia chaffeensis (ftsz(ech)), anaplasma phagocytophilum (ftsz(ap)), and rickettsia rickettsii (ftsz(rr)). genome walking was then used to amplify the 5' and 3' termini of the genes. the dna sequences of the resulting amplification products yielded open reading frames coding for proteins with molecular masses of 42.0, ... | 2003 | 12804116 |
| nuclear factor kappa b protects against host cell apoptosis during rickettsia rickettsii infection by inhibiting activation of apical and effector caspases and maintaining mitochondrial integrity. | apoptotic host cell death is a critical determinant in the progression of microbial infections and outcome of resultant diseases. the potentially fatal human infection caused by rickettsia rickettsii, the etiologic agent of rocky mountain spotted fever, involves the vascular endothelium of various organ systems of the host. earlier studies have shown that survival of endothelial cells (ec) during this infection depends on their ability to activate the transcription factor nuclear factor kappa b ... | 2003 | 12819104 |
| rickettsialpox in new york city: a persistent urban zoonosis. | rickettsialpox, a spotted fever rickettsiosis, was first identified in new york city (nyc) in 1946. during the next five years, approximately 540 additional cases were identified in nyc. however, during the subsequent five decades, rickettsialpox received relatively little attention from clinicians and public health professionals, and reporting of the disease diminished markedly. during february 2001 through august 2002, 34 cases of rickettsialpox in nyc were confirmed at cdc from cutaneous biop ... | 2003 | 12860597 |
| physician knowledge of the diagnosis and management of rocky mountain spotted fever: mississippi, 2002. | rocky mountain spotted fever (rmsf), a tick-borne illness that has its highest incidence in the south central and southeastern united states, is often a diagnostic challenge, as patients frequently present with nonspecific symptoms during the early stages of illness. rmsf has a high case fatality rate among untreated individuals, and the median time from onset of symptoms to death is only eight days, making early recognition and treatment of rmsf crucial. in two mississippi public health distric ... | 2003 | 12860642 |
| rickettsia rickettsii infection in the pine vole, microtus pinetorum: kinetics of infection and quantitation of antioxidant enzyme gene expression by rt-pcr. | the pine vole, microtus pinetorum, was evaluated as a laboratory animal model for infection with rickettsia rickettsii. voles demonstrated signs of acute disease, and 45% of infected animals died following intraperitoneal infection with 3 x 10(6) plaque forming units of r. rickettsii. spleen, liver, kidney, lung, brain, testes and blood were analyzed for rickettsial burden by a quantitative pcr assay. the distribution of rickettsiae in tissues during the course of infection was determined by imm ... | 2003 | 12860675 |
| rickettsial actin-based motility: behavior and involvement of cytoskeletal regulators. | actin-based motility (abm) is employed by spotted fever group (sfg) rickettsiae, such as rickettsia rickettsii, to promote cell-to-cell spread. time-lapse video microscopy revealed that abm is not strictly confined to sfg rickettsiae as typhus group r. typhi moved at approximately the same rate as r. rickettsii (approximately 4 micro m/min), but in a highly erratic fashion. a number of common behaviors were observed between abm of r. typhi and r. rickettsii, such as entrance into plasma membrane ... | 2003 | 12860687 |
| molecular and functional analysis of the lepb gene, encoding a type i signal peptidase from rickettsia rickettsii and rickettsia typhi. | the type i signal peptidase lepb genes from rickettsia rickettsii and rickettsia typhi, the etiologic agents of rocky mountain spotted fever and murine typhus, respectively, were cloned and characterized. sequence analysis of the cloned lepb genes from r. rickettsii and r. typhi shows open reading frames of 801 and 795 nucleotides, respectively. alignment analysis of the deduced amino acid sequences reveals the presence of highly conserved motifs that are important for the catalytic activity of ... | 2003 | 12867468 |
| the immunologic response of dogs to bartonella vinsonii subspecies berkhoffii antigens: as assessed by western immunoblot analysis. | bartonella vinsonii subspecies berkhoffii is a recently recognized zoonotic pathogen that causes endocarditis, granulomatous rhinitis, and granulomatous lymphadenitis in dogs. isolation of b. vinsonii (berkhoffii) from blood or tissue samples is frequently unsuccessful; therefore, diagnosis is primarily dependent on serologic or molecular testing modalities. because previous canine serologic studies have used an indirect immunofluorescence assay (ifa), without western immunoblot (wi) confirmatio ... | 2003 | 12918816 |
| interference phenomenon in animal infections with rickettsiae of rocky mountain spotted fever. | | 1953 | 13037839 |
| natural infection of the tick, amblyomma cajennense, with rickettsia rickettsii in panama. | | 1953 | 13065638 |
| a quantitative analysis of the factors involved in the variations in virulence of rickettsiae. | | 1953 | 13076181 |
| the epidemiology of rocky mountain spotted fever. i. the characterization of strain virulence of rickettsia rickettsii. | | 1953 | 13080263 |
| recovery of a rickettsia of the spotted fever group from microtus pennsylvanicus from virginia. | | 1954 | 13167137 |
| the epidemiology of rocky mountain spotted fever. ii. studies on the biological survival mechanism of rickettsia rickettsii. | | 1954 | 13207101 |
| persistence of rickettsia rickettsii in a patient recovered from rocky mountain spotted fever. | | 1954 | 13212060 |
| the effect of red blood cells on experimental infection of white rats with the r strain of rickettsia rickettsii. | | 1958 | 13508659 |
| identification of rickettsia rickettsii in the wood tick, dermacentor andersoni, by means of fluorescent antibody. | | 1960 | 13688983 |
| the transmission of low virulent strains of rickettsia rickettsii. | | 1961 | 13737980 |
| spotted fever vaccine; potency assay by direct challenge of vaccinated mice with toxin of rickettsia rickettsii. | | 1961 | 13866804 |
| cell-wall constituents of rickettsiae and psittacosis-lymphogranuloma organisms. | | 1963 | 13942448 |
| [experiments on the problem of the transovarian transmission of rickettsia]. | | 1962 | 14000181 |
| ecology of rocky mountain spotted fever in western montana. i. isolation of rickettsia rickettsii from wild mammals. | | 1962 | 14041199 |
| [pullulation of rickettsia ricketsii in rats infected by intraperitoneal injections of blood]. | | 1963 | 14101730 |
| studies on infectious diseases in wild animals in utah. v. experimental rocky mountain spotted fever in the coyote, canis latrans lestes merriam. | | 1963 | 14170550 |
| [sensitivity of the bat artibus lituratus palmarum to rickettsia rickettsii]. | | 1963 | 14190216 |
| results of a five-year survey for certain enzootic diseases in the fauna of western utah. | | 1965 | 14248984 |
| [experimental transmission of rickettsiae to arthropods]. | | 1964 | 14249721 |
| the rocky mountain spotted fever group of rickettsias. | | 1965 | 14318051 |
| [study on spotted fever group rickettsiae in guangdong province]. | to explore the existence of spotted fever group rickettsiae (sfgr) in guangdong province. | 2003 | 14521792 |
| mycobacterium marinum escapes from phagosomes and is propelled by actin-based motility. | mycobacteria are responsible for a number of human and animal diseases and are classical intracellular pathogens, living inside macrophages rather than as free-living organisms during infection. numerous intracellular pathogens, including listeria monocytogenes, shigella flexneri, and rickettsia rickettsii, exploit the host cytoskeleton by using actin-based motility for cell to cell spread during infection. here we show that mycobacterium marinum, a natural pathogen of fish and frogs and an occa ... | 2003 | 14597736 |
| isolation of bartonella washoensis from a dog with mitral valve endocarditis. | we report the first documented case of bartonella washoensis bacteremia in a dog with mitral valve endocarditis. b. washoensis was isolated in 1995 from a human patient with cardiac disease. the main reservoir species appears to be ground squirrels (spermophilus beecheyi) in the western united states. based on echocardiographic findings, a diagnosis of infective vegetative valvular mitral endocarditis was made in a spayed 12-year-old female doberman pinscher. a year prior to presentation, the re ... | 2003 | 14605197 |
| rocky mountain spotted fever as a cause of macular star figure. | an 86-year-old woman with a history of tick bites in the previous months developed subnormal visual acuity in both eyes, keratic precipitates, anterior chamber and vitreous cells, optic disc edema, retinal hemorrhages, and retinal arteriolar sheathing. she had no fever or skin rash. three weeks later, binocular macular star figures appeared. brain imaging was negative; cerebrospinal fluid disclosed a lymphocytic pleocytosis and elevated protein. the serum rickettsia rickettsii antibody test was ... | 2003 | 14663310 |
| rickettsia species infecting amblyomma cooperi ticks from an area in the state of são paulo, brazil, where brazilian spotted fever is endemic. | owing to the potential role of the tick amblyomma cooperi in the enzootic cycle of rickettsia rickettsii, the etiologic agent of brazilian spotted fever (bsf), this study evaluated infection by rickettsia species in a. cooperi ticks collected from an area in brazil where bsf is endemic. among a total of 40 a. cooperi adult ticks collected in an area of bsf endemicity in the state of são paulo, pcr analysis detected dna of rickettsia bellii in 16 ticks (40%), and 3 other ticks (7.5%) were positiv ... | 2004 | 14715737 |
| antinuclear antibodies can be detected in dog sera reactive to bartonella vinsonii subsp. berkhoffii, ehrlichia canis, or leishmania infantum antigens. | the presence of antinuclear antibodies (anas) is used to support a clinical diagnosis of systemic lupus erythematosus (sle) in dogs. however, clinicians must interpret the detection of anas with caution, particularly in light of increasing evidence that dogs with known bacterial and protozoal infections can have high ana titers. retrospectively, medical records were reviewed for all dogs that were concurrently tested for antinuclear antigens and bartonella vinsonii (berkhoffii), ehrlichia canis, ... | 2004 | 14765731 |
| rickettsia parkeri: a newly recognized cause of spotted fever rickettsiosis in the united states. | ticks, including many that bite humans, are hosts to several obligate intracellular bacteria in the spotted fever group (sfg) of the genus rickettsia. only rickettsia rickettsii, the agent of rocky mountain spotted fever, has been definitively associated with disease in humans in the united states. herein we describe disease in a human caused by rickettsia parkeri, an sfg rickettsia first identified >60 years ago in gulf coast ticks (amblyomma maculatum) collected from the southern united states ... | 2004 | 14999622 |
| phylogeny of rickettsia spp. inferred by comparing sequences of 'gene d', which encodes an intracytoplasmic protein. | 'gene d' is the ps120-protein-encoding gene, first described in rickettsia conorii and rickettsia japonica. sequence analysis of a 3030 bp fragment of 'gene d' in 24 representatives of the genus rickettsia was carried out to complete phylogenetic analyses previously inferred by comparison of gene sequences encoding citrate synthase, 17 kda antigen and rompa and rompb. the phylogenetic relationships between rickettsiae were inferred from the comparison of both the gene and the derived protein seq ... | 2001 | 11491333 |
| rocky mountain spotted fever. | | 2002 | 12458609 |
| [emerging and reemerging rickettsiosis in an endemic area of minas gerais state, brazil]. | this article describes a serological survey for rickettsiosis in the county of novo cruzeiro, minas gerais state, brazil, in 1998, testing schoolchildren and dogs. sera included 331 samples from schoolchildren from an endemic area and 142 samples from schoolchildren from a non-endemic area in the county. all children examined were healthy and had not reported clinical symptoms of brazilian spotted fever prior to the serological survey. some 35 children in the endemic area were reactive to ricket ... | 2002 | 12488886 |
| deep origin of plastid/parasite atp/adp translocases. | membrane proteins that transport atp and adp have been identified in mitochondria, plastids, and obligate intracellular parasites. the mitochondrial atp/adp transporters are derived from a broad-specificity transport family of eukaryotic origin, whereas the origin of the plastid/parasite atp/adp translocase is more elusive. here we present the sequences of five genes coding for atp/adp translocases from four species of rickettsia. the results are consistent with an early duplication and divergen ... | 2003 | 12574860 |
| fort chaffee revisited: the epidemiology of tick-borne rickettsial and ehrlichial diseases at a natural focus. | a retrospective cohort study was conducted among troops training at fort chaffee, arkansas, from may through june 1997, to identify infections caused by tick-borne pathogens. serum samples were tested by ifas for antibodies to selected rickettsia and ehrlichia species and by an investigational eia for spotted fever group rickettsia lipopolysaccharide antigens. of 1,067 guardsmen tested, 162 (15.2%) had antibodies to one or more pathogens. of 93 guardsmen with paired serum samples, 33 seroconvert ... | 2001 | 12653142 |
| platelet aggregation in dogs experimentally infected with rickettsia rickettsii. | platelet aggregation studies were performed on nine beagle dogs experimentally infected with rickettsia rickettsia. platelets from dogs with rocky mountain spotted fever tended to be more aggregable than controls. | 1990 | 12684943 |
| antibodies reactive to rickettsia rickettsii among children living in the southeast and south central regions of the united states. | the reported annual incidence of rocky mountain spotted fever in the united states is 2.2 per million, but studies have suggested that human infection with rickettsia rickettsii may be more common. this study estimated the prevalence of antibodies reactive to r rickettsii among children living in the southeastern and south central united states. | 2003 | 12742879 |
| ecology and epidemiology of spotted fever group rickettsiae and new data from their study in russia and kazakhstan. | rickettsiae represent a wide range of pathogenicity from classic and new pathogens to endosymbionts of eukaryotic cells. recent studies of rickettsiae have widened the number of representatives of genus rickettsia, especially in the spotted fever group (sfg). rickettsiae of sfg are tick-borne microorganisms with effective transovarial and transstadial transmission. the main hosts are ticks (dermacentor, rhipicephalus, haemophysalis, ixodes, and amlyomma). strategy of maintenance of tick microorg ... | 2003 | 12860595 |
| interactions of rickettsia rickettsii with endothelial nuclear factor-kappab in a "cell-free" system. | | 2003 | 12860701 |
| genetic analysis of isolates of rickettsia rickettsii that differ in virulence. | we examined the degree of intraspecies genetic polymorphisms present among 13 r. rickettsii strains isolated from the blood of patients and ixodid ticks from north and south america. preliminary confirmation of these isolates as r. rickettsii was done by evaluating rsai and psti restriction fragment length polymorphic (rflp) sites in a 631 bp fragment of the rompa gene amplified with primers encompassing the rr190.70-701 nt region. all isolates had the same profile, which was identical to that p ... | 2003 | 12860712 |
| serologic evidence of infection with ehrlichiae and spotted fever group rickettsiae among residents of gag island, indonesia. | the causative agents of scrub and murine typhus are considered endemic to indonesia. however, the presence of spotted fever group rickettsiae and ehrlichiae have not been previously described in this country. during an investigation of arthropod-borne diseases on gag island, located northwest of the island of new guinea in eastern indonesia, the prevalence of antibody to the etiologic agents of monocytic ehrlichiosis, spotted fever rickettsiosis, and scrub and murine typhus were determined. anal ... | 2003 | 12875301 |
| cross-protection between distantly related spotted fever group rickettsiae. | two excellent c3h/hen mouse models of spotted fever rickettsioses caused by the distantly related organisms, rickettsia conorii and rickettsia australis, were utilized to evaluate the possibility of the stimulation of broad cross-protective immunity. sublethal infection stimulated complete immunity, that is absence of disease, after challenge with a dose of the heterologous rickettsia that uniformly killed naïve mice. in contrast, heterologous immune sera did not protect mice against a lethal do ... | 2003 | 12922124 |
| spotted fever rickettsiosis in coronel fabriciano, minas gerais state. | we report cases of spotted fever rickettsiosis in coronel fabriciano municipality of minas gerais state, brazil. the cases occurred in may and june of 2000. during this period there were two deaths among children from an area named pedreira in a periurban area of this municipality. in a boy who died with clinical manifestations of brazilian spotted fever, a necropsy revealed the presence of a spotted fever group rickettsia. the serological results confirm the difficulty in the differential diagn ... | 2003 | 12937725 |
| [artificial transmission of rickettsia rickettsii (rocky mountain spotted fever) on insects, especially on body lice]. | | 1952 | 13015971 |
| factors affecting the growth of rickettsias of the spotted fever group in fertile hens' eggs. | | 1962 | 13917322 |
| effect of dichlorotetrafluoroethane on the infectivity of viruses and rickettsiae sensitive to trichlorotrifluoroethane. | | 1963 | 14131240 |
| serologically detected "new" tick-borne zoonoses in eastern croatia. | to establish serologically a contact with causative agents of human monocytic and granulocytic ehrlichiosis, human babesiosis, recently detected rickettsioses, and lyme disease in individuals with a history of tick bite from three counties in eastern croatia. | 2003 | 14515426 |
| implications of presumptive fatal rocky mountain spotted fever in two dogs and their owner. | a dog was examined because of petechiation, an inability to stand, pale mucous membranes, a possible seizure, and thrombocytopenia. tick-borne illness was suspected, but despite treatment, the dog died. eight days later, a second dog owned by the same individual also died. the dog was not examined by a veterinarian, but rocky mountain spotted fever (rmsf) was suspected on the basis of clinical signs. two weeks after the second dog died, the owner was examined because of severe headache, fever, n ... | 2003 | 14627095 |
| evaluation of a pcr assay for quantitation of rickettsia rickettsii and closely related spotted fever group rickettsiae. | a spotted fever rickettsia quantitative pcr assay (sq-pcr) was developed for the detection and enumeration of rickettsia rickettsii and other closely related spotted fever group rickettsiae. the assay is based on fluorescence detection of sybr green dye intercalation in a 154-bp fragment of the rompa gene during amplification by pcr. as few as 5 copies of the rompa gene of r. rickettsii can be detected. sq-pcr is suitable for quantitation of r. rickettsii and 10 other genotypes of spotted fever ... | 2003 | 14662926 |
| spotted-fever-group rickettsioses in north asia. | | 2003 | 14667766 |
| fatal spotted fever rickettsiosis, minas gerais, brazil. | the emergence and reemergence of a serious infectious disease are often associated with a high case-fatality rate because of misdiagnosis and inappropriate or delayed treatment. the current reemergence of spotted fever rickettsiosis caused by rickettsia rickettsii in brazil has resulted in a high proportion of fatal cases. we describe two familial clusters of brazilian spotted fever in the state of minas gerais, involving six children 9 months to 15 years of age; five died. immunohistochemical i ... | 2003 | 14718082 |
| nf-kappab activation suppresses host cell apoptosis during rickettsia rickettsii infection via regulatory effects on intracellular localization or levels of apoptogenic and anti-apoptotic proteins. | rickettsia rickettsii, a gram-negative and obligate intracellular bacterium, is the causative agent of rocky mountain spotted fever. in human infections, the primary target of r. rickettsii infection is vascular endothelium. our laboratory has shown that activation of nuclear transcription factor-kappa b (nf-kappab) during r. rickettsii infection of cultured human endothelial cells protects against apoptosis by preventing the activation of apical caspases-8 and -9, and the effector caspase-3. to ... | 2004 | 15135541 |
| fatal cases of rocky mountain spotted fever in family clusters--three states, 2003. | rocky mountain spotted fever (rmsf), a tickborne infection caused by rickettsia rickettsii and characterized by a rash, has a case-fatality rate as high as 30% in certain untreated patients. even with treatment, hospitalization rates of 72% and case-fatality rates of 4% have been reported. this report summarizes the clinical course of three fatal cases of rmsf in children and related illness in family members during the summer of 2003. these cases underscore the importance of 1) prompt diagnosis ... | 2004 | 15152183 |
| rocky mountain spotted fever at koair children's hospital, 1990-2002. | the reported average annual incidence of rocky mountain spotted fever (rmsf) in kentucky is less than 5 per million population, although seroprevalence studies suggest that exposure to rickettsia riskettsii, the causative agent, is relatively common among children. the experience with rmsf at kosair children's hospital over a 12-year period was reviewed. fifteen cases were identified (5 boys and 10 girls). illness onset ranged from april to october, and 4 patients resided in jefferson county. th ... | 2004 | 15152446 |
| a rickettsia wasp-like protein activates the arp2/3 complex and mediates actin-based motility. | spotted fever group rickettsia are obligate intracellular pathogens that exploit the host cell actin cytoskeleton to promote motility and cell-to-cell spread. although other pathogens such as listeria monocytogenes use an arp2/3 complex-dependent nucleation mechanism to generate comet tails consisting of y-branched filament arrays, rickettsia polymerize tails consisting of unbranched filaments by a previously unknown mechanism. we identified genes in several rickettsia species encoding proteins ... | 2004 | 15236643 |
| prevalence of antibodies to spotted fever group rickettsiae in humans and domestic animals in a brazilian spotted fever-endemic area in the state of são paulo, brazil: serologic evidence for infection by rickettsia rickettsii and another spotted fever group rickettsia. | in serum samples obtained from all the healthy humans, horses, dogs, and donkeys present on three farms in the pedreira municipality, an endemic area for brazilian spotted fever, an indirect immunofluorescence assay (ifa) detected antibodies against rickettsia rickettsii in 17 (77.3%) horses, 5 (31.3%) dogs (titers ranging from 64 to 4,048), and none of 4 donkeys or 50 humans. five canine and eight equine sera with high antibody titers to r. rickettsii were also tested by ifa against r. bellii, ... | 2004 | 15238696 |
| bartonella henselae igg antibodies are prevalent in dogs from southeastern usa. | in contrast to the large body of literature regarding bartonella henselae in humans and cats, there is little information about b. henselae as an infectious agent in dogs. due to the paucity of information regarding the b. henselae serology in dogs, we performed a cross-sectional serosurvey using b. henselae antigen in order to compare the seroprevalence between sick and healthy dogs from the south-eastern usa. ninety-nine sera were collected from clinically healthy dogs. three hundred and one s ... | 2004 | 15369661 |
| rickettsial vaccines: the old and the new. | in the past century vaccine development for prevention of rickettsial diseases has been prolific. however, in the past 20 years no new rickettsial vaccine has been manufactured and there are currently no new or old rickettsial vaccines licensed. early rickettsial vaccines were difficult, expensive and very hazardous to produce. molecular biology techniques of today are currently being used to develop new rickettsial vaccines that are standardized, inexpensive, nonhazardous and efficacious. | 2004 | 15485334 |
| transfusion-transmitted tick-borne infections: a cornucopia of threats. | over the past several decades, the frequency of contact between humans and ticks has increased dramatically. concomitantly, several newly recognized tick-borne pathogens have emerged joining those already known to be transmitted by ticks. together these factors have led to an enhanced public health awareness of ticks, tick-borne agents, and their associated diseases. reports that several of these agents are transmitted by blood transfusion have raised concerns about blood safety. the primary age ... | 2004 | 15497129 |
| sequence and expression analysis of the ompa gene of rickettsia peacockii, an endosymbiont of the rocky mountain wood tick, dermacentor andersoni. | the transmission dynamics of rocky mountain spotted fever in montana appears to be regulated by rickettsia peacockii, a tick symbiotic rickettsia that interferes with transmission of virulent rickettsia rickettsii. to elucidate the molecular relationships between the two rickettsiae and glean information on how to possibly exploit this interference phenomenon, we studied a major rickettsial outer membrane protein gene, ompa, presumed to be involved in infection and pathogenesis of spotted fever ... | 2004 | 15528527 |
| nf-kappab activation during rickettsia rickettsii infection of endothelial cells involves the activation of catalytic ikappab kinases ikkalpha and ikkbeta and phosphorylation-proteolysis of the inhibitor protein ikappabalpha. | rocky mountain spotted fever, a systemic tick-borne illness caused by the obligate intracellular bacterium rickettsia rickettsii, is associated with widespread infection of the vascular endothelium. r. rickettsii infection induces a biphasic pattern of the nuclear factor-kappab (nf-kappab) activation in cultured human endothelial cells (ecs), characterized by an early transient phase at 3 h and a late sustained phase evident at 18 to 24 h. to elucidate the underlying mechanisms, we investigated ... | 2005 | 15618150 |
| functional analysis of seca homologues from rickettsiae. | the molecular basis of protein secretion that underlines rickettsial pathogenesis remains unknown. this paper reports the molecular and functional analysis of the putative seca gene, an essential component of the sec-dependent protein secretion pathway, from rickettsia rickettsii and rickettsia typhi, the aetiological agents of rocky mountain spotted fever and murine typhus, respectively. the sequence analysis of the cloned seca genes from r. rickettsii and r. typhi show orfs of 2721 and 2718 nt ... | 2005 | 15699207 |
| rickettsial infection in animals and brazilian spotted fever endemicity. | we compared the rickettsial infection status of amblyomma cajennense ticks, humans, dogs, and horses in both brazilian spotted fever (bsf)-endemic and -nonendemic areas in the state of sao paulo, brazil. most of the horses and few dogs from bsf-endemic areas had serologic titers against rickettsia rickettsii antigens. in contrast, no dogs or horses from bsf-nonendemic areas had serologic titers against r. rickettsii antigens, although they were continually exposed to a. cajennense ticks. all hum ... | 2005 | 15752445 |
| changes in the adherens junctions of human endothelial cells infected with spotted fever group rickettsiae. | rickettsiae of the spotted fever group are obligately intracellular bacteria that primarily infect the vascular endothelium, invade adjacent cells propelled by actin polymerization, and cause severe systemic diseases. endothelial dysfunction and vascular leakage develop as a consequence; this effect is the pathophysiological mechanism that explains most clinical manifestations. here we report that rickettsial infection of cultured primary human endothelial cells is associated with the formation ... | 2005 | 15778845 |
| [rocky mountain spotted fever in an american tourist]. | in a 28-year-old male american tourist who presented in the hospital with fever, cold shivers, headache, nausea, myalgia and arthralgia, rocky mountain spotted fever was suspected, partly because he came from an endemic region (the state of georgia). the patient was treated with doxycycline, 100 mg b.i.d.; 9 days after the first appearance of the symptoms, the diagnosis was confirmed by the report of a positive antibody titre against rickettsia rickettsii. the patient did not have exanthema. he ... | 2005 | 15835630 |
| central nervous system dysfunction associated with rocky mountain spotted fever infection in five dogs. | five dogs from the northeastern united states were presented with clinical signs of neurological disease associated with rocky mountain spotted fever (rmsf) infection. four of the five dogs had vestibular system dysfunction. other neurological signs included paresis, tremors, and changes in mentation. all of the dogs had an elevated indirect fluorescent antibody titer or a positive semiquantitative enzyme screening immunoassay titer for rickettsia rickettsii at the time of presentation. although ... | 2005 | 15995164 |
| rocky mountain spotted fever--changing ecology and persisting virulence. | | 2005 | 16093463 |