| the pathogenesis of the vascular lesions in experimental rickettsial disease of the guinea pig (rocky mountain spotted fever group). a light, immunofluorescent and electron microscopic study. | | 1973 | 4119475 |
| a new pathogenic spotted fever group rickettsia from africa. | a spotted fever group (sfg) rickettsia was isolated in zimbabwe from a patient with tick-bite, fever, headache and regional lymphadenopathy. a further six isolates were obtained from amblyomma hebraeum ticks collected in zimbabwe. these human and tick isolates were indistinguishable from each other, and from an ethiopian sfg rickettsia, by microimmunofluorescence (mif), sodium dodecyl sulphate-polyacrylamide gel electrophoresis (sds-page), western blotting and polymerase chain reaction followed ... | 1994 | 7911846 |
| astrakhan fever rickettsiae: antigenic and genotypic analysis of isolates obtained from human and rhipicephalus pumilio ticks. | two spotted fever group rickettsia strains, a-108 and a-167, were isolated from the hemolymph of rhipicephalus pumilio ticks collected in the astrakhan region of russia, which is area endemic for astrakhan fever. these tick isolates were compared with a strain isolated from a patient suffering from astrakhan fever and with reference spotted fever group rickettsiae strains. new tick isolates and the human strain were identical in their serologic, antigenic, and genetic characteristics by several ... | 1994 | 7985764 |
| first cases of spotted fever group rickettsiosis in thailand. | the first three cases of spotted fever group rickettsiosis from thailand are reported. the patients presented with fever, headache, lymphadenopathy, and petechial maculopapular rash. one patient also had an eschar and overt evidence of confusion. an indirect fluorescent antibody test, an indirect immunoperoxidase test, and an enzyme-linked immunosorbent assay demonstrated a broad, strong reactions of the sera of the patients with spotted fever group rickettsia antigens of many species, but not w ... | 1994 | 8024059 |
| evaluation of the pathogenic potential of rickettsia canada and rickettsia prowazekii organisms in dogs. | an unusual pattern of seroreactivity to antigens of rickettsial organisms (rickettsia rickettsii, r rhipicephali, r montana, and r bellii), particularly to r bellii antigen, was detected in 3 dogs during a 2-month period. thus, studies were initiated to clarify the pathogenic potential of the more distantly related rickettsial organisms (r canada and r prowazekii) in dogs. because r bellii are nonpathogenic rickettsiae that share numerous common properties with spotted fever-group and typhus-gro ... | 1995 | 7601694 |
| genotypic characterization of rickettsiae by dna probes generated from rickettsia prowazekii dna. | southern blot analysis of hindiii-cleaved rickettsial dna was used for genotypic characterization of the typhus group (tg) species (r. prowazekii, r. typhi, r. canada) and a few species of the spotted fever group (sfg) rickettsiae (r. sibirica, r. conorii, r. akari). four different dna probes were employed. pbh11 and pbh13 probes were morphospecific hindiii fragments of r. prowazekii dna. mw218 probe contained the gene for 51 k antigen and mw264 probe contained the citrate synthase gene of r. pr ... | 1994 | 7976865 |
| dna typing of rickettsiae in naturally infected ticks using a polymerase chain reaction/restriction fragment length polymorphism system. | we used the polymerase chain reaction/restriction fragment length polymorphism (pcr/rflp) rickettsial typing system of regnery and others to rapidly identify rickettsiae in naturally infected ticks. unlike previously described methods, our pcr assays type rickettsiae directly from tick tissues without first isolating the organisms. we collected 226 adult dermacentor andersoni ticks in the bitterroot mountains of western montana and analyzed them for possible rickettsial infection by hemolymph te ... | 1994 | 7906924 |
| detection of dna of causative agent of spotted fever group rickettsiosis in japan from the patient's blood sample by polymerase chain reaction. | the polymerase chain reaction (pcr) was applied for the etiological diagnosis of spotted fever group (sfg) rickettsiosis in japan. nucleotide primers derived from the 17-kda antigen gene of rickettsia rickettsii primed a rickettsia-specific 246-base-pair product for all of the katayama, abe, misaka and kojima strains, which we had isolated previously. moreover, we were able to detect the same product by pcr amplification from the peripheral blood of a patient in the acute stage of the illness. t ... | 1994 | 7799840 |
| identification of spotted fever group rickettsiae isolated from dermacentor marginatus and ixodes ricinus ticks collected in switzerland. | when 155 ticks collected in different regions of switzerland were tested by the hemolymph test, 10.3% were found to contain spotted fever group rickettsiae. six rickettsial isolates were made from dermacentor marginatus ticks and three were made from ixodes ricinus ticks. the polymerase chain reaction followed by restriction fragment length polymorphism analysis showed that the dermacentor ticks were infected with rickettsia length polymorphism analysis showed that the dermacentor ticks were inf ... | 1994 | 7915498 |
| genotypic and antigenic identification of two new strains of spotted fever group rickettsiae isolated from china. | four isolates of spotted fever group rickettsiae isolated from ticks in china were compared with all known species and strains of spotted fever group rickettsiae by immunofluorescence assay, dna polymerase chain reaction followed by restriction endonuclease fragment length polymorphism analysis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and western immunoblot. the chinese isolates belonged to three types, including a novel serotype which has not been described before. one isolat ... | 1993 | 8093253 |
| the isolation of strains of rickettsiae of the spotted fever group in israel and their differentiation from other members of the group by immunofluorescence methods. | | 1974 | 4208205 |
| plaque assay of rickettsiae in a mammalian cell line. | clear-cut and repeatable plaque assays were obtained for three rickettsiae of the spotted fever group (rickettsia rickettsi, r. conori, and r. montana) in vero cells used in a manner similar to that for arboviruses. in addition, three typhus group agents (r. typhi, r. canada, r. prowazeki) induced plaques in these cells. in preliminary tests coxiella burneti (nine mile strain) failed to produce plaques. comparable results were obtained in plastic flasks and plastic culture trays incubated in amb ... | 1974 | 4208640 |
| species-specific balb/c mouse antibodies to rickettsiae studied by western blotting. | balb/c mice were inoculated intraperitoneally either once only, or up to four times at weekly intervals, with viable rickettsia rickettsii, rickettsia conorii or the israeli spotted fever group rickettsia. sera collected one week after the last inoculation were tested for the presence of antibodies reactive with the above organisms by indirect fluorescent antibody testing and western blot. with repeated inoculations there was a general progressive rise in homologous and heterologous immunofluore ... | 1994 | 8050715 |
| identification of a novel rickettsial infection in a patient diagnosed with murine typhus. | identification of elb agent-infected fleas and rodents within several foci of murine typhus in the united states has prompted a retrospective investigation for this agent among human murine typhus patients. this agent is a recently described rickettsia which is indistinguishable from rickettsia typhi with currently available serologic reagents. molecular analysis of the 17-kda antigen gene and the citrate synthase gene has discriminated this bacterium from other typhus group and spotted fever gr ... | 1994 | 8027348 |
| use of immunogold assay for a rapid evaluation of antigens of spotted fever group rickettsiae. | rabbit-antihuman igg, yolk immunoglobulins (igy) and monoclonal antibodies against rickettsia conorii were adsorbed to colloidal gold. thus obtained conjugates were found to be active and responded specifically to the agent of the mediterranean spotted fever. the suitability of the immunogold assay as a alternative to other known immunoenzymatic or immunofluorescent methods for assessing the presence and/or activity of rickettsial antigens is discussed. | 1993 | 8105664 |
| ancestral divergence of rickettsia bellii from the spotted fever and typhus groups of rickettsia and antiquity of the genus rickettsia. | the eubacterial genus rickettsia belongs to the alpha subgroup of the phylum proteobacteria. this genus is usually divided into three biotypes on the basis of vector host and antigenic cross-reactivity characteristics. however, the species rickettsia bellii does not fit into this classification scheme; this organism has characteristics common to both the spotted fever group and the typhus group biotypes and also exhibits some unique features. sequences of the 16s rrna and 23s rrna genes from ric ... | 1994 | 7981106 |
| tick-borne rickettsiae of the spotted fever group in west pakistan. ii. serological classification of isolates from west pakistan and thailand: evidence for two new species. | | 1973 | 4734280 |
| first isolation of a rickettsia closely related to japanese spotted fever pathogen from a tick in japan. | in may 1993, we collected unfed ticks in anan, tokushima prefecture, shikoku district, japan, a highly endemic area of japanese spotted fever (jsf). we isolated jsf rickettsiae from these ticks by inoculating tick-emulsions into l-929 cells. of the four genera and seven species of ticks examined, only one larva of dermacentor taiwanensis sugimoto yielded a rickettsial isolate. the isolate (dt-1 strain) was found to belong to the serotype common to the causative agent of jsf. this was based on it ... | 1994 | 8189407 |
| tick-borne rickttsiae of the spotted fever group in west pakistan. i. isolation of strains from ticks in different habitats. | | 1970 | 5536972 |
| rickettsia massiliae sp. nov., a new spotted fever group rickettsia. | we propose the name rickettsia massiliae sp. nov. (type strain, mtu1 in the collection of the world health organization collaborative center for rickettsial reference, marseille, france) for a spotted fever group rickettsia determined to be distinct from previously recognized species by the serotyping method (l. beati, j.-p. finidori, b. gilot, and d. raoult, j. clin. microbiol. 30:1922-1930, 1992). this rickettsia has biological characteristics similar to those of the other spotted fever group ... | 1993 | 8240964 |
| antigen-capture enzyme immunoassay: a comparison with other methods for the detection of spotted fever group rickettsiae in ticks. | to evaluate the prevalence of spotted fever group rickettsiae along the adriatic coast of croatia, 832 ticks were examined by hemolymph test, direct immunofluorescence, antigen-capture enzyme immunoassay, and polymerase chain reaction. very good agreement was observed among direct immunofluorescence, polymerase chain reaction, and antigen-capture enzyme immunoassay. twelve ticks that were positive by hemolymph test and negative by both direct immunofluorescence and polymerase chain reaction pres ... | 1994 | 8147495 |
| sequence analysis of the 190-kda antigen-encoding gene of rickettsia conorii (malish 7 strain). | the complete nucleotide (nt) sequence of the gene (rompa) encoding the 190-kda immunodominant surface antigen (rompa) of rickettsia conorii (malish 7 strain) was determined. sequence analysis revealed an orf of 6063 nt encoding a deduced protein of 203,247 da. ten consecutive highly conserved repeat units, located at the 5' end of rompa, spanned 2.2 kb. two types of repeats could be identified: type i of 225 bp, and type ii of 216 bp. the order and number of repeats differed from those reported ... | 1994 | 8125327 |
| brazilian spotted fever in espirito santo, brazil: description of a focus of infection in a new endemic region. | although brazilian spotted fever is known to occur in several adjacent states, infection with spotted fever group (sfg) rickettsiae has not previously been documented in the brazilian state of espirito santo. we report a cluster of two proven and four suspected cases of brazilian spotted fever in a small valley near colatina, espirito santo. four patients died without confirmatory serologic or pathologic studies. the two surviving patients had serologic and/or pathologic evidence of infection wi ... | 1993 | 8357085 |
| glomerular response in human and experimental rickettsial disease (rocky mountain spotted fever group). a light and electron microscopy study. | | 1968 | 5684481 |
| first isolation of rickettsia slovaca from dermacentor marginatus in france. | three rickettsial strains isolated from dermacentor marginatus ticks in southern france in 1991 were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, western blotting with polyclonal mouse antisera, microimmunofluorescence serologic typing, and the polymerase chain reaction followed by analysis of restriction fragment length polymorphisms. by these methods, the isolates appear to be identical to the spotted fever group rickettsia, rickettsia slovaca, which has so far b ... | 1993 | 8095380 |
| spotted fever group rickettsial infection in south-eastern australia: isolation of rickettsiae. | flinders island spotted fever (fisf), a spotted fever group (sfg) rickettsial disease first described in 1991, occurs in south-eastern australia. the isolation of the aetiological agent is described for the first time having been obtained from the blood of two patients. an additional 22 cases are also reported. of these patients four had positive initial serology, and 20 showed seroconversion (using rickettsia australis as antigen). acute phase blood specimens taken from seven patients caused ne ... | 1993 | 8403837 |
| fatal israeli spotted fever in children. | we describe three israeli children with fatal spotted fever. clinical disease was characterized by irreversible shock, encephalopathy, renal failure, bleeding tendency, and death within 24 hours of admission. none of the patients had a history of tick bite, and no tache noire was noted. one child presented without rash, and the other two did not have antibodies to spotted-fever-group rickettsiae. the disease was confirmed by isolation of rickettsia conorii from the patients' blood and tissues in ... | 1993 | 8286624 |
| [analysis of fatty acid composition of spotted fever group rickettsiae isolated in china by gas chromatography]. | in present paper, fatty acid composition of seven chinese isolates of sfg rickettsiae and six prototype strains of sfg rickettsiae were analyzed by gc-ms. tested prototype strains of sfg rickettsiae were r. sibirica (strains 232 and 246), r. conorii (simko), r. rickettsi (r), r. akari (kaplan), r. australis (w58); chinese isolates were an-84, se-85, w-88 (human strain), mt-84, ft-84 (d. nuttalli strain), to-85 (ova of nuttalli) and chinese reference strain -jh-74 (d. nuttalli). they were propaga ... | 1993 | 8256442 |
| genotypic identification and phylogenetic analysis of the spotted fever group rickettsiae by pulsed-field gel electrophoresis. | using pulsed-field gel electrophoresis, we studied the chromosomes of spotted fever group rickettsiae. we digested the dna of 16 species currently known to belong to this group with smai, eagi, and bsshii. the genome size of 13 rickettsiae was between 1,200 and 1,300 kb. "rickettsia massiliae" and "r. helvetica" genome sizes were 1,370 and 1,397 kb, respectively, and that of r. bellii was 1,660 kb. it was possible to obtain distinctive patterns for each species, but in r. conorii, 10 isolates ex ... | 1993 | 8393009 |
| chemical properties of lipopolysaccharides from spotted fever group rickettsiae and their common antigenicity with lipopolysaccharides from proteus species. | the lipopolysaccharides (lps) isolated from spotted fever group (sfg) rickettsia strains thai tick typhus tt-118 and katayama were characterized by chemical analyses, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, enzyme-linked immunosorbent assay (elisa), and immunoblotting. these lps did not contain heptose, but they contained 3-deoxy-d-manno-octulosonic acid (kdo), glucosamine, quinovosamine, phosphate, ribose, an unknown neutral sugar, and palmitic acid. resolution of the apparen ... | 1993 | 8406824 |
| enzyme-linked immunosorbent assay for detection of human immunoglobulin g to lipopolysaccharide of spotted fever group rickettsiae. | an enzyme-linked immunosorbent assay for detecting human immunoglobulin g to spotted fever group rickettsiae was developed and tested. the assay uses proteinase k-resistant material, characteristic of the rickettsial lipopolysaccharides shown to be group specific by immunoblots, as the antigen. the results indicate that the assay provides a sensitive, yet specific, alternative method for diagnosing rickettsial diseases. | 1993 | 8417018 |
| comparison of latex agglutination, indirect immunofluorescent antibody, and enzyme immunoassay methods for serodiagnosis of rocky mountain spotted fever in dogs. | indirect immunofluorescent antibody (ifa), latex agglutination (la), and enzyme immunoassay (eia) methods were compared for evaluation of the serum antibody responses of dogs experimentally and naturally exposed to spotted fever-group rickettsiae. selected sera (obtained on days 1, 42, 53, 124, 145, 236, 255, 264, and 292) were examined from three 8-month-old female beagles inoculated with rickettsia rickettsii on days 34 and 250 of the study. a second group of dogs comprised three 8-month-old f ... | 1993 | 8427468 |
| development and characterization of high-titered, group-specific fluorescent-antibody reagents for direct identification of rickettsiae in clinical specimens. | rabbits were inoculated with purified antigen preparations of coxiella burnetii and representative species of the spotted fever and typhus groups of rickettsiae. their antibody responses were monitored by complement fixation tests; high-titered antisera were fractionated with ammonium sulfate and then labeled with fluorescein isothiocyanate by the dialysis method. the conjugates had homologous 3+ staining titers of 1:256 to 1:2,048 and did not exhibit nonspecific staining. the rickettsia rickett ... | 1980 | 6769955 |
| rickettsial antibody prevalence in southern israel: igg antibodies to coxiella burnetii, rickettsia typhi, and spotted fever group rickettsiae among urban- and rural-dwelling and bedouin women. | a retrospective serological survey was carried out using sera obtained from women at childbirth in the southern desert region of israel to determine exposure experience to three rickettsial agents: coxiella burnetii, rickettsia typhi, and spotted fever group rickettsiae. using the indirect fluorescent antibody method for determining igg antibodies, it was found that about 40% of all sera examined demonstrated antibodies to one or more rickettsiae. bedouin women appeared to be at greater risk of ... | 1983 | 6418016 |
| the occurrence of the brown dog tick, rhipicephalus sanguineus (latr. 1806), a possible vector of the spotted fever group rickettsiae, on sheep in the negev region in israel. | | 1984 | 6546817 |
| mediterranean spotted fever in marseille, france: correlation between prevalence of hospitalized patients, seroepidemiology, and prevalence of infected ticks in three different areas. | we report the results of a comparison of several epidemiologic and ecologic parameters affecting the incidence and seroprevalence of mediterranean spotted fever (msf) in northern, central, and southeastern marseille, an area endemic for this disease. in northern marseille, the incidence of hospitalized patients with msf was 24.2/100,000 persons compared with 9.8/100,000 and 8.8/100,000 for the central and southeastern regions, respectively. the seroprevalence in sera from blood donors, determine ... | 1993 | 8447529 |
| cloning, sequencing, and expression of the gene coding for an antigenic 120-kilodalton protein of rickettsia conorii. | several high-molecular-mass (above 100 kda) antigens are recognized by sera from humans infected with spotted fever group rickettsiae and may be important stimulators of the host immune response. molecular cloning techniques were used to make genomic rickettsia conorii (malish 7 strain) libraries in expression vector lambda gt11. the 120-kda r. conorii antigen was identified by monospecific antibodies to the recombinant protein expressed on construct lambda 4-7. the entire gene dna sequence was ... | 1994 | 8112862 |
| phylogenetic analysis of the genus rickettsia by 16s rdna sequencing. | rickettsiae are gram-negative bacteria which multiply only inside host cells and need arthropods either as reservoirs or as vectors. using the polymerase chain reaction and an automated laser fluorescent dna sequencer, we amplified and sequenced the 16s rrna (rdna) of all available bacteria of the genus rickettsia. r. tsutsugamushi remained close to the other bacteria of the genus rickettsia using this technique, contrary to previous conclusions based on the study of the sta-58 protein antigen. ... | 1995 | 8525055 |
| directional actin polymerization associated with spotted fever group rickettsia infection of vero cells. | members of the spotted fever group (sfg) of rickettsiae spread rapidly from cell to cell by an unknown mechanism(s). staining of rickettsia rickettsii-infected vero cells with rhodamine phalloidin demonstrated unique actin filaments associated with one pole of intracellular rickettsiae. f-actin tails greater than 70 microns in length were seen extending from rickettsiae. treatment of infected cells with chloramphenicol eliminated rickettsia-associated f-actin tails, suggesting that de novo prote ... | 1993 | 8478082 |
| transfiguration of rickettsial diseases: tsutsugamushi disease and spotted fever group rickettsiosis in japan. | | 1993 | 8204977 |
| prevalence of rickettsia-like organisms and spotted fever group rickettsiae in ticks (acari: ixodidae) from zimbabwe. | the prevalence of rickettsia-like organisms in ticks from zimbabwe was determined using the hemolymph test. amblyomma hebraeum had the highest prevalence of rickettsia-like organisms. other species with rickettsia-like organisms included amblyomma sparsum, amblyomma variegatum, hyalomma marginatum rufipes, ripicephalus simus, haemaphysalis leachi, amblyomma rhinocerotis, and hyalomma truncatum. ticks with no demonstrable rickettsia-like organisms infection were boophilus decoloratus, haemaphysal ... | 1995 | 8551500 |
| [seroprevalence of rickettsial infections of the boutonneuse fever group or its apparent group in bangui (central african republic)]. | 115 sera from african individuals, including 66 hiv-1-infected individuals and 49 hiv-seronegative age-matched healthy controls, living in bangui, central african republic, were screened for rickettsia conorii antibody by indirect immunofluorescent assay; 53 (46%) sera had significant igg to r. conorii titer, and 5 (4.3%) had significant igm to r. conorii titer, without significant difference between hiv-positive and negative individuals. these findings indicate a great exposure to spotted fever ... | 1995 | 8555768 |
| hemocytic rickettsia-like organisms in ticks: serologic reactivity with antisera to ehrlichiae and detection of dna of agent of human granulocytic ehrlichiosis by pcr. | ixodid ticks were collected from connecticut, massachusetts, missouri, pennsylvania, rhode island, and british columbia (canada) during 1991 to 1994 to determine the prevalence of infection with hemocytic (blood cell), rickettsia-like organisms. hemolymph obtained from these ticks was analyzed by direct and indirect fluorescent antibody (fa) staining methods with dog, horse, or human sera containing antibodies to ehrlichia canis, ehrlichia equi, or rickettsia rickettsii. of the 693 nymphal and a ... | 1995 | 8567911 |
| spotted fever group rickettsiae in dermacentor variabilis from cape cod, massachusetts. | spotted fever group (sfg) rickettsiae were identified by indirect immunofluorescent antibody tests in 1.1% of 6,956 specimens of dermacentor variabilis collected on cape cod, massachusetts. forty-one of 45 rickettsial isolates were serotyped as rickettsia montana, one as rickettsia rickettsii, and three were unidentified. studies of canines and humans with clinical evidence of spotted fever, and of healthy dogs with antibody to sfg rickettsiae, indicated that exposure of the canine population to ... | 1980 | 6773430 |
| rickettsiosis in japan. | the rickettsial diseases of man in japan include tsutsugamushi disease (scrub typhus), murine typhus, which occurs sporadically, and one of spotted fever group diseases, recognized as a new entity since 1984. starting from 1976, there has been a remarkable resurgence in the number of reported cases of tsutsugamushi disease in japan after several years of virtual absence, and endemics are still continuing after reaching a prominent outbreak in 1984. its yearly incidences from 1982 to 1986 were 53 ... | 1988 | 3210342 |
| identification of spotted fever group rickettsiae from human and tick sources in the people's republic of china. | | 1987 | 3305723 |
| confirmation that rickettsia helvetica sp. nov. is a distinct species of the spotted fever group of rickettsiae. | we propose the name rickettsia helvetica sp. nov. for a rickettsial serotype of unknown pathogenicity isolated in 1979 in switzerland from ixodes ricinus ticks and designated the swiss agent. the growth characteristics and the results of microimmunofluorescence serologic typing, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, western blotting (immunoblotting) with specific mice sera, and a polymerase chain reaction followed by restriction fragment length polymorphism analysis confirme ... | 1993 | 8102245 |
| detection of spotted fever group rickettsiae in ticks and rodents by polymerase chain reaction technique in people's republic of china. | the polymerase chain reaction (pcr) technique for amplification of genomic fragments of spotted fever group (sfg) rickettsiae directly from field samples of ticks, tick ova, tick larvae, tick faeces and organs of wild mice was employed for the first time in p.r. of china. ticks and rodents were collected in beijing and heilongjiang, hainan and hebei provinces. the pcr primers were designed from the dna sequence encoding the 190 k protein of r. rickettsii for a 532 bp long product. seven of ten t ... | 1995 | 8722295 |
| serologic response to rickettsial antigens in patients with astrakhan fever. | astrakhan fever is a new spotted fever group (sfg) rickettsiosis. sera of patients with astrakhan fever have been examined by microimmunofluorescence and western immunoblotting to determine the serologic responses to the astrakhan strain and to r. conorii m-1 strain and the israelian isolate of sfg rickettsiae. the serologic response to specific rickettsial agent and to israelian isolate has been found to be similar, but was different of that to r. conorii. immunoglobulin g (igg) and igm antibod ... | 1995 | 8549703 |
| serological evidence of infection by spotted fever group rickettsiae in karnataka state. | | 1980 | 6780455 |
| antibodies to spotted fever group rickettsiae in dogs in croatia. | the prevalence of igg antibodies to spotted fever group rickettsiae was studied by the indirect immunofluorescent antibody assay in a sample of 194 canine sera from different parts of croatia. dogs (n = 141) from urban and suburban-semirural environs from the middle part of the eastern coast of adriatic sea, and dogs (n = 53) from zagreb, the capital of croatia located in the northern continental part of croatia, were tested. the total of 88 (62.4%) dogs from southern coastal croatia had antibod ... | 1995 | 8549704 |
| rickettsia australis infection: a murine model of a highly invasive vasculopathic rickettsiosis. | a mouse model of spotted fever group rickettsiosis, in which disease results from disseminated rickettsial infection of endothelial cells and vascular damage, was developed by intravenous inoculation of 6- to 8-week-old, male, balb/c mice with rickettsia australis. animals developed progressively severe vasculitis, interstitial pneumonia, and multifocal hepatic necrosis. these lesions correlated with early disseminated infection of endothelial cells followed by growth and invasion of rickettsiae ... | 1993 | 8494048 |
| isolation of spotted fever group rickettsiae from humans in japan. | | 1988 | 3411156 |
| a new spotted-fever-group rickettsiosis. | | 1996 | 8709763 |
| rocky mountain spotted fever in an endemic area in minas gerais, brazil. | only one species of spotted fever-group rickettsiae that is pathogenic for humans has been isolated in brazil, where few physicians are familiar with this disease. in order to obtain information on tick-borne rickettsiosis, a study was performed in the county of santa cruz do escalvado, state of minas gerais, brazil, where a fatal clinical case confirmed by specific immunofluorescence had been reported. serum samples obtained from 679 humans and 96 dogs were tested by indirect immunofluorescence ... | 1994 | 8524052 |
| rocky mountain spotted fever in dogs. | infection with rickettsiae of the spotted fever group was clinically and serologically diagnosed in four dogs from two households on long island. in two dogs, clinical signs included high fever (to 40.5 c), abdominal pain, lethargy, depression, anorexia, and nystagmus. one of these dogs had conjunctivitis and petechial hemorrhages in the oral mucous membranes. the third dog initially had high fever, evidence of abdominal pain, anorexia, and depression. the fourth dog appeared clinically normal. ... | 1980 | 7380721 |
| genetic variation in australian spotted fever group rickettsiae. | rickettsiae were isolated by cell culture of buffy coat blood from six patients with spotted fever from southeastern australia and flinders island in bass strait. the isolates were genetically compared with two previous rickettsia australis patient isolates. the genus-specific 17-kda genes from the isolates were compared after dna amplification and restriction fragment analysis of the amplified dna. this comparison revealed that mainland rickettsial isolates from southeastern australia were iden ... | 1996 | 8735110 |
| differentiation of spotted fever group rickettsiae by sequencing and analysis of restriction fragment length polymorphism of pcr-amplified dna of the gene encoding the protein rompa. | currently, the genotypic identification of the spotted fever group (sfg) rickettsiae is based on restriction fragment length polymorphism analysis of pcr-amplified genes coding for the enzyme citrate synthase and the surface proteins rompa and rompb. a set of useful restriction endonucleases was found following comparison of rickettsia rickettsii and r. prowazekii sequences. however, by using three pcr amplifications and four enzyme digestions with this set, it was impossible to differentiate be ... | 1996 | 8862558 |
| demonstration of a heat-stable 120-kilodalton protein of rickettsia japonica as a spotted fever group-common antigen. | genomic libraries of rickettsia japonica were cloned into an expression vector lambda gt11. a clone expressing a protein reactive with antiserum against 120-kilodalton (kda) proteins, a mixture of heat-modifiable and heat-stable polypeptides, was selected and designated as lambda rj120-1. the expressed protein has a molecular mass of 180 kda. western immunoblotting demonstrated that the expressed protein was a fusion protein with beta-galactosidase. the antiserum against 120-kda proteins was abs ... | 1996 | 8867609 |
| evidence for a high prevalence of spotted fever group rickettsial infections in diverse ecologic zones of inner mongolia. | a 3-year study of spotted fever group rickettsial ecology in inner mongolia revealed that nearly half of the human population tested had antibodies to rickettsia sibirica detected by complement fixation test. infected persons, ticks and a high proportion of seropositive livestock and wild rodents were found in all five vegetation zones (desert, steppe, forest, forest-grassland and grassland). | 1995 | 7641832 |
| isolation of rickettsia akari from a patient in a region where mediterranean spotted fever is endemic. | rickettsia akari was isolated from blood collected from a patient in croatia in 1991. we believe this is the first human isolate of r. akari to be reported in more than 40 years and the first ever from southern europe. the croatian isolate was antigenically and genetically indistinguishable from the prototype american strain and a ukrainian strain. in all probability, rickettsialpox would be diagnosed more frequently and over a wider geographic area if physicians gave greater consideration to th ... | 1996 | 8838175 |
| rickettsia africae sp. nov., the etiological agent of african tick bite fever. | we propose the name rickettsia africae sp. nov. (with type strain z9-hu) for a distinct species of spotted fever group (sfg) rickettsiae that is the etiological agent of african tick bite fever in humans. this rickettsia has a distinct natural cycle and can be phenotypically distinguished from the other sfg rickettsiae by microimmunofluorescence serotyping, by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and by western blotting (immunoblotting). genotypic differences between r. afr ... | 1996 | 8934912 |
| eia with species-specific monoclonal antibodies: a novel seroepidemiologic tool for determination of the etiologic agent of spotted fever rickettsiosis. | all currently available assays for antibodies to the etiologic agents of spotted fever group rickettsioses detect reactivity with antigens of lipopolysaccharides and the major cell wall proteins, which contain epitopes that are shared among many spotted fever group rickettsiae. the hypothesis of this study was that a monoclonal antibody to a species-specific epitope of rickettsia rickettsii would be blocked from binding to the rickettsial surface if the rickettsiae were incubated previously with ... | 1993 | 7693827 |
| characterization of and application of monoclonal antibodies against rickettsia africae, a newly recognized species of spotted fever group rickettsia. | rickettsia africae is a newly described species which causes african tick bite fever. mediterranean spotted fever caused by r. conorii is endemic in the same regions of africa as tick bite fever, and differentiation of the two syndromes by characterization of their etiological agents is important for epidemiological studies. r. africae and r. conorii are, however, difficult to distinguish, and therefore, our aim was to produce monoclonal antibodies to address this problem. monoclonal antibodies ... | 1997 | 8968882 |
| the biology of rickettsiae. | rickettsiae are bacterial obligate intracellular parasites ranging from harmless endosymbionts to the etiologic agents of some of the most devastating diseases known to mankind. rickettsiae are primarily associated with arthropod vectors in which they may exist commensally and, in most cases, only accidentally infect humans. these fascinating microbes are the prototypical obligate intracellular parasites. other than being extremely fastidious in their growth requirements, however, rickettsiae ar ... | 1996 | 8805076 |
| epidemiological survey of small rodents for spotted fever rickettsial antibody in hokkaido, japan. | the prevalence of antibody against spotted fever group rickettsia (sfgr) was investigated with rickettsia japonica antigen in small rodents captured in an area in hokkaido, where no human cases of sfgr infection had been reported. antibody against sfgr was found in apodemus speciosus and clethrionomys rufocanus but not in apodemus argenteus. none of these rodents had antibody against r. typhi. this is the first report of the antibody against sfgr in rodents in hokkaido. | 1996 | 8806039 |
| african tick-bite fever. an imported spotless rickettsiosis. | to characterize the clinical presentation and course of african tick-bite fever, a recently rediscovered rickettsiosis caused by rickettsia africae (a new species within the spotted fever group of rickettsiae), to establish its relationship with amblyomma tick species, and to discuss its role in the etiology of fever in patients who are returning from the tropics. | 1997 | 8996049 |
| serological survey of spotted fever group rickettsia in wild rats in thailand in the 1970s. | in thailand, the first human cases of spotted fever group rickettsiosis were reported in 1994, but no serosurveys on wild rats have yet been conducted. we investigated the seroepidemiology in wild rats collected in the 1970s from two regions in thailand, and found a 62.2% positive rate of antibodies for spotted fever group rickettsia (sfgr) by the indirect immunofluorescence antibody test. of the antibody-positive rats, 82.2% had higher titers of antibodies against tt-118 than those against rick ... | 1996 | 9013486 |
| characterization of a spotted fever group rickettsia from ixodes ricinus ticks in sweden. | a spotted fever group rickettsia isolated from the common tick, ixodes ricinus, was genetically characterized by pcr and genomic sequencing. this study was performed with nymphal and adult ticks collected in southern and central sweden. i. ricinus is the only north european tick species of medical importance which is regularly collected from humans. no species of the genus rickettsia has previously been found in scandinavian ticks, nor has any case of domestic rickettsial infection in humans or ... | 1997 | 8968916 |
| protein characterization of australian spotted fever group rickettsiae and monoclonal antibody typing of rickettsia honei. | rickettsial proteins romp a and romp b exist in both rickettsia australis and rickettsia honei but differ in molecular weight and antigenicity; in addition, they produce distinct immunogenic responses and appear to be to conformationally dependent antigens. species-specific monoclonal antibodies for other spotted fever group rickettsial species did not react with r. honei. a pcr product of the repeat region of the romp a gene from r. honei was amplified and calculated to contain 11 repeat units. | 1997 | 8968920 |
| [spotted fever group rickettsiosis and vectors in kanagawa prefecture]. | primer pairs for pcr were designed from the gene encoding the 17,000-molecular-weight genus-common antigen of rickettsia japonica, rickettsia rickettsii, rickettsia conorii, rickettsia typhi and rickettsia prowazekii. primers r1, r2 were designed for amplifying the genomic dna from spotted fever group (sfg) rickettsiae and epidemic typhus rickettsiae. primers rj5, rj10 were designed for amplifying the genomic dna from only r. japonica. using the primers r1, r2, about a 540-bp fragment was observ ... | 1996 | 8741704 |
| [the application of pcr to epidemiological study on spotted fever group rickettsiae]. | it was the first time that a primer pairs derived from the 190kda protein antigen gene of r. rickettsii were used to amplify sfgr dna in ticks, tick ova, larva, tick faeces and rodent organs which were collected in hebei, heilongjiang, hainan and beijing. a 532bp fragment was respectively amplified from above samples. the results were partially in concordance with data obtained through rickettsiae isolation. it was suggested that pcr is a rapid, specific, sensitive and practical method for detec ... | 1995 | 7767922 |
| citrate synthase gene comparison, a new tool for phylogenetic analysis, and its application for the rickettsiae. | using pcr and an automated laser fluorescent dna sequencer, we amplified and sequenced a 1,234-bp fragment of the citrate synthase-encoding gene (glta) of 28 bacteria belonging to the genus rickettsia. comparative sequence analysis showed that most of the spotted fever group (sfg) rickettsiae belonged to one of two subgroups. the first subgroup included rickettsia massiliae, strain bar 29, rickettsia rhipicephali, "rickettsia aeschlimanni," and rickettsia montana, which have been isolated only f ... | 1997 | 9103608 |
| epidemiology and ecology of rickettsial diseases in the people's republic of china. | since 1949, information on rickettsial diseases in the people's republic of china has been virtually nonexistent in the west. this is the first comprehensive review of the ecology and epidemiology of chinese rickettsial diseases to be published outside the people's republic. at least five rickettsioses exist in china: scrub typhus, murine typhus, epidemic typhus, q fever, and one or more spotted fever-group (sfg) rickettsioses. although epidemic typhus has been controlled and scrub typhus has ab ... | 1987 | 3326129 |
| rickettsia aeschlimannii sp. nov., a new spotted fever group rickettsia associated with hyalomma marginatum ticks. | we formally propose the name rickettsia aeschlimannii sp. nov. for a new spotted fever group (sfg) rickettsia, strain mc16t, isolated from hyalomma marginatum marginatum ticks collected in morocco. this organism shows a typical rickettsial morphology when analyzed by electron microscopy. after characterization by serotyping, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, western immunoblotting, pcr-restriction fragment length polymorphism (rflp), pulsed-field gel electrophoresis, and ... | 1997 | 9103647 |
| biological and genetic characterization of rickettsia sibirica strains isolated in the endemic area of the north asian tick typhus. | restriction fragment length polymorphism (rflp) analysis of polymerase chain reaction-amplified gene fragments was used to characterize 24 isolates of spotted fever group rickettsiae previously identified as rickettsia sibirica from their serologic properties. these strains were obtained in russia between 1946 and 1991 from humans and different species of ixodid ticks. the rflp analysis was performed using amplified dna products obtained with a genus-specific primer pair derived from the r. prow ... | 1996 | 9025699 |
| serological studies of the antigenic similarity between typhus group rickettsiae and weil-felix test antigens. | the sera from two patients with murine typhus reacted with whole cells of rickettsia prowazekii, r. typhi, and proteus vulgaris ox19, and with lipopolysaccharides (lps) from the spotted fever group rickettsia strain tt-118 and p. vulgaris ox19 in the enzyme-linked immunosorbent assay. sera from these patients reacted with ladder-like bands of lps from r. prowazekii and r. typhi in the immunoblot, whereas the reactivity of these sera with lps from p. vulgaris ox19 differed from each other. these ... | 1995 | 7783679 |
| production of monoclonal antibodies against rickettsia massiliae and their use in antigenic and epidemiological studies. | rickettsiae are gram-negative, obligate intracellular bacteria which have historically been divided into three groups: the typhus group, the scrub typhus group, and the spotted fever group (sfg). recently, several new sfg rickettsiae have been characterized, and most of these species are associated with ticks and have, as yet, no known pathogenicity toward humans. rickettsia massiliae, which is widely distributed in europe and africa, is one such rickettsia. in order to investigate the antigenic ... | 1997 | 9196180 |
| unrecognized spotted fever group rickettsiosis masquerading as dengue fever in mexico. | although rocky mountain spotted fever was documented in northern mexico during the 1940s, spotted fever group (sfg) rickettsioses have subsequently received little attention in mexico. in this study, sera collected in 1993 from 50 patients from the mexican states of yucatan and jalisco, who were suspected clinically to have dengue fever but had no antibodies to dengue virus, were examined by indirect immunofluorescence for igm antibodies reactive with rickettsia rickettsii, r. akari, and r. typh ... | 1996 | 8780453 |
| mediterranean spotted fever: a preliminary tick field study. | we studied the prevalence of rickettsialike organisms infection in different tick species (3154 adults) collected in several areas of the ebro valley (spain). the gimenez stain showed a prevalence of rickettsia-like organisms in 38.6% of the studied ticks. using the immunofluorescence assay, only two species, rhipicephalus sanguineus (16.4%) and r. pusillus (19.9%) have shown organisms compatible with spotted fever group rickettsiae. | 1996 | 8905308 |
| genotypic evaluation of rickettsial isolates recovered from various species of ticks in portugal. | twelve rickettsial isolates, from rhipicephalus sanguineus, r. turanicus, dermacentor marginatus and hyalomma marginatus, were subjected to genotypic analysis. amplification of specific dna sequences, restriction endonuclease digestion of amplified dna products, and gel electrophoresis were used to identify specific dna fragment-banding patterns. five patterns were resolved. four were homologous with those of previously described rickettsial genotypes, r. conorii, r. slovaca, r. rhipicephali and ... | 1995 | 7867736 |
| infestation by ticks and detection of antibodies to spotted fever group rickettsiae in wild animals captured in the state of são paulo, brazil. a preliminary report. | | 1996 | 9283648 |
| dot-elisa for rapid detection of q fever and spotted fever group antirickettsial antibodies. | | 1993 | 8105670 |
| proteinic and genomic identification of spotted fever group rickettsiae isolated in the former ussr. | sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page), restriction fragment length polymorphism of polymerase chain reaction-amplified genes (rflp-pcr), and pulsed-field gel electrophoresis (pfge) were used to identify 25 isolates of spotted fever group rickettsia collected in the former ussr. six rickettsia akari isolates which were identical to the mk reference strain from the american type culture collection were found. also, 14 isolates were found to be rickettsia sibirica and ... | 1993 | 7902843 |
| japanese spotted fever: report of 31 cases and review of the literature. | spotted fever group (sfg) rickettsioses, which are transmitted by ticks, were long thought not to exist in japan. three clinical cases of japanese spotted fever (jsf) were first reported in 1984. the causative agent was isolated and named rickettsia japonica. through october 1996, 31 cases were diagnosed as jsf in tokushima prefecture. infected patients typically had acute high fever, headache, and characteristic exanthema; eschar was observed in 90%. after the discovery of jsf, more than a hund ... | 1997 | 9204291 |
| sequence analysis and comparison of 190 k surface antigen gene fragment of a new species of spotted fever group rickettsiae. | a 533 bp long pcr product amplified from rickettsial strain hl-93 dna with the primer pair rr 190.70p and rr 190.602n, designed from dna sequence encoding 190 k protein antigen of r. rickettsii, was cloned into plasmid vector pgem-t and sequenced. the primer-flanking region of the product, an open reading frame, was 491 bp long. the sequence of the product was compared with those of the corresponding regions of dnas of r. rickettsii (strain r), r. japonica (strain vr 1363) and r. conorii (strain ... | 1997 | 9199714 |
| [clinical characteristics and therapeutic perspectives of boutonneuse fever. assessment of a caseload of 39 patients]. | rickettsia conorii is the etiologic agent of boutonneuse fever, a rickettsiosis of the spotted fever group that is endemic in southern italy. chloramphenicol or tetracyclines are still the treatment of choice for this disease, and recently quinolones have also been utilized with success. in 1994-95, 39 otherwise healthy patients were admitted to our unit for boutonneuse fever. they were treated, in random order, with quinolones (10 subjects received ciprofloxacin, 500 mg/12 h per os; 8 subjects ... | 1997 | 9409946 |
| prevalence of antibodies to rickettsiae in the human population of suburban bangkok. | following a report of three cases of scrub typhus in suburban bangkok, we performed a serosurvey in the patients' communities. both igg and igm antibodies were measured in an indirect immunoperoxidase assay, using separate spots of antigen from rickettsia tsutsugamushi (scrub typhus), r. typhi (murine typhus), and tt-118 spotted fever group rickettsiae. of 215 people donating blood, antibody levels indicative of most recent exposure to r. tsutsugamushi were most prevalent (21%), followed by r. t ... | 1994 | 8074248 |
| role of t lymphocyte subsets in immunity to spotted fever group rickettsiae. | to evaluate the roles of cd4 and cd8 t lymphocytes in immunity to disseminated endothelial infection with rickettsia conorii (malish 7 strain), these t cell subsets were depleted or adoptively transferred into subsequently infected c3h/hen mice. cd4 t lymphocyte-depleted and sham-depleted mice underwent a similar course of illness with a sublethal rickettsial dose, cleared the infection by day 10, and recovered on days 10 to 11. in contrast, mice depleted of cd8 lymphocytes or cd4 and cd8 lympho ... | 1997 | 9164951 |
| phylogenetic placement of rickettsiae from the ticks amblyomma americanum and ixodes scapularis. | a rickettsial isolate (isolate moaa) belonging to the spotted fever group (sfg) was obtained from the lone star tick amblyomma americanum. we used pcr to characterize the genes for the rickettsial outer membrane proteins rompa and rompb. we sequenced the pcr products (domains i of both the rompa gene and the rompb gene) of moaa and wb-8-2, another rickettsial isolate from a. americanum. to place moaa and wb-8-2 and two other nonpathogenic isolates (rickettsia rickettsii hip2 and rickettsia monta ... | 1998 | 9574696 |
| genotypic identification of an undescribed spotted fever group rickettsia in ixodes ricinus from southwestern spain. | an undescribed rickettsia was directly analyzed with specific rickettsial molecular biology tools on ixodes ricinus l. collected in different localities of the province of cadiz (southwestern spain). on the basis of the results of the citrate synthase (glta) gene, 190 kd-outer membrane protein (rompa) gene, and 16s ribosomal rna (16s rrna) gene partial sequence data, it was found that this rickettsia is sufficiently genetically distinct from other rickettsia to be considered a distinct taxonomic ... | 1998 | 9598443 |
| detection of spotted fever group (sfg) rickettsia in ixodes ricinus ticks in austria. | | 1997 | 9607097 |
| rickettsialpox. | rickettsialpox is a member of the spotted-fever group of the rickettsioses and results from an infection with rickettsia akari. this microbe is transmitted by the bite of the house-mouse mite liponyssoides sanguineus. patents experience fevers, sweats, headaches, and a vesicular eruption over the trunk and extremities. the palms and soles are spared. an eschar results at the spot of the mite bite. tetracycline is the treatment of choice. | 1997 | 9098640 |
| detection of cowdria ruminantium by means of a dna probe, pcs20 in infected bont ticks, amblyomma hebraeum, the major vector of heartwater in southern africa. | a dna probe, pcs20, previously described for use in detection of cowdria ruminantium infections in amblyomma variegatum (the principal vector of heartwater) hybridized with c. ruminantium dna in organs of laboratory-infected a. hebraeum adult ticks (the major southern african vector of heartwater). the probe hybridized with c. ruminantium dna in 46/49 midguts from male ticks and 26/29 from females, thus indicating infection. corresponding salivary glands were less heavily infected, but infection ... | 1993 | 8432329 |
| first isolation of rickettsia helvetica from ixodes ricinus ticks in france. | two rickettsial isolates recovered from ixodes ricinus ticks in puy-de-dôme (central france) were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, western blot immunoassay, restriction fragment length polymorphism analysis, and sequencing of a portion of the citrate-synthase gene. by these methods, the isolates appeared to be identical to a member of the spotted fever group rickettsiae, rickettsia helvetica. this first isolation of rickettsia helvetica in france has ep ... | 1998 | 9629973 |
| taxonomic position of the rickettsiae: current knowledge. | the term rickettsiae initially encompassed all intracellular bacteria. early rickettsial taxonomy was based on a comparison of a few phenotypic characteristics and recently, molecular studies brought new bases for rickettsial taxonomy. all rickettsial species studied so far belong to the alpha and gamma groups of the proteobacteria. ehrlichiae complex groups cowdria ruminantium, anaplasma marginale and wolbachia pipientis and the related parthenogenesis and cytoplasmic incompatibility bacteria, ... | 1994 | 8117465 |
| antigens of rickettsia conorii recognized by seropositive healthy people from salamanca (central-west spain). | the antigenic reactivity in western immunoblotting assay of individual rickettsia conorii components with sera of healthy people living in salamanca province, an endemic zone of mediterranean spotted fever, is evaluated. polypeptides of molecular weights 100 kda (92.7%), 135 kda (75.6%), 160 kda (70.7%) and 115 kda (48.8%) were recognized by a higher proportion of sera with indirect immunofluorescent antibody test titers > or = 1:80. reaction with apparent rickettsial lipopolysaccharide was foun ... | 1993 | 8472802 |
| genetic analysis of isolates of the spotted fever group of rickettsiae belonging to the r. conorii complex. | the cytoplasmic 120 kda antigen genes of 9 isolates of rickettsia conorii (rc), 12 isolates of r. africae (ra), and 3 isolates of israeli tick typhus rickettsiae (istt) were compared for restriction fragment length polymorphisms (rflp) present in portions of the open reading frame amplified by polymerase chain reaction (pcr). initially, dnas from 13 species or serotypes of spotted fever group rickettsiae were used to select restriction enzymes (re) that detected rflp in gene fragments amplified ... | 1998 | 9668445 |
| dual infection with ehrlichia chaffeensis and a spotted fever group rickettsia: a case report. | well-documented cases of simultaneous human infection with more than one tick-borne pathogen are rare. to our knowledge only two dual infections have been reported: simultaneous human infection with the agent of human granulocytic ehrlichiosis and borrelia burgdorferi and simultaneous human infection with b. burgdorferi and babesia microti (1-2). rocky mountain spotted fever has long been known to be endemic in north carolina; cases of human ehrlichial infection were recognized there soon after ... | 1998 | 9621205 |
| ultrastructure of spotted fever rickettsialike microorganisms observed in tissues of dermacentor taiwanensis (acari: ixodidae). | tissues of midguts, malpighian tubules, salivary glands, and ovaries of female dermacentor taiwanensis sugimoto collected in an area endemic for japanese spotted fever were examined with an electron microscope, and the presence of two kinds of rickettsialike microorganisms was confirmed in japan. based on ultrastructural findings, a rod-shaped organism detected in all the tissues is a rickettsia; another, irregularly shaped organism that was found only in the ovary, is a wolbachia. a hemolymph t ... | 1993 | 8510117 |