Publications

rocky mountain spotted fever in clermont county, ohio. ii. distribution of population and infected ticks in an endemic area.	the epidemiology of rocky mountain spotted fever (rmsf) in relation to the distribution of the human population and infected ticks has not been defined. a study was undertaken in clermont county, ohio, to describe the distribution of population in a highly endemic focus of rmsf and to determine the prevalence of ticks infected with rickettsiae of the spotted fever group. this area was compared to another area of similar size in the same county where the incidence of rmsf was much lower. the popu ...	1980	7352458
sexual transmission of spotted fever group rickettsiae by infected male ticks: detection of rickettsiae in immature spermatozoa of ixodes ricinus.	electron microscopic evidence is provided showing that the newly described "swiss agent," a spotted fever group rickettsia, is incorporated into the reproductive cells of its male tick vector, ixodes ricinus. rickettsiae were found in spermatogonia, spermatocytes, and maturing spermatids. the potential significance of these observations is briefly discussed in relation to published data on sexual transmission of rickettsiae by ticks.	1980	7380544
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
the ultrastructure of rickettsia slovaca in naturally infected females of the tick dermacentor marginatus.	the ultrastructure of rickettsia slovaca in naturally infected females of the tick dermacentor marginatus is similar to that of other members of the spotted fever group rickettsiae. r. slovaca was found to multiply in all organs, tissues and cells examined. it is primarily found free in the cytoplasm; occasionally it may also invade the cell nucleus. special attention was paid to the rickettsiae in the salivary gland. they multiply in all cells of the three acini types i-iii and also in the duct ...	1980	7406420
demonstration of heat-labile and heat-stable epitopes of rickettsia japonica on ultrathin sections.	spotted fever group rickettsiae including rickettsia japonica have two major polypeptides and lipopolysaccharide (lps)-like antigen on the surface. the major part of the antibodies to these polypeptides generated by immunization with live rickettsiae are reactive with heat-labile and conformation-dependent epitopes.	1994	7523765
isolation, cultivation, and partial characterization of the elb agent associated with cat fleas.	elb rickettsiae from cat flea homogenates were recovered in tissue culture cells following sequential passage through laboratory rats and the yolk sacs of embryonated chicken eggs. seven days after inoculation of elb from the infected yolk sacs, vero cells and l929 cells were observed to contain intracellular bacteria as demonstrated by diff quik and indirect immunofluorescence assay staining. the rickettsial and elb identity of the cultured agent was confirmed by pcr detection of the 16s rrna a ...	1995	7591142
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
[serosurvey for spotted fever group rickettsial infection in vertebrates in shimane prefecture].	we carried out a survey for the prevalence of antibodies to the spotted fever group (sfg) rickettsia in vertebrates such as dogs, cattle, deer, and mice in shimane prefecture. rickettsia japonica was employed as antigen in indirect immunofluorescence (if) tests. the experiment for natural infections using decoy animals was performed in the field of the endemic area. 1. among 115 street dogs, 18.3% possessed the antibodies against sfg rickettsia, while all of the 8 hunting dogs had the antibodies ...	1995	7602185
comparative antigenic analysis of spotted fever group rickettsiae from israel and other closely related organisms.	spotted fever rickettsiosis in israel has been considered as possibly somewhat more severe than boutonneuse fever, from which it also differs in having a very low proportion of cases with a tick-inoculation site eschar. this investigation was undertaken to determine whether the israeli spotted fever group (sfg) rickettsiae differed sufficiently from rickettsia conorii to be considered as a distinct species. strains of rickettsia conorii from morocco and south africa, four sgf rickettsial isolate ...	1995	7611567
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
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
specific amplification of rickettsia japonica dna from clinical specimens by pcr.	the gene encoding the 17,000-molecular-weight genus-common antigen (17k genus-common antigen) has been cloned and sequenced from rickettsia japonica. the primer pair used for pcr was designed from this sequence. a 357-bp fragment was observed by amplifying the genomic dna from r. japonica and also the dna from blood clots of patients with spotted fever group rickettsiosis. the results indicated that this method is suitable for the diagnosis of spotted fever group rickettsiosis in japan.	1995	7714214
granulocytic ehrlichiosis and meningitis in a dog.	a 4-year-old male mixed-breed dog from the sierra nevada mountains in california was referred because of epistaxis and signs of cervical pain. dermacentor variabilis ticks were found on the dog at the time of physical examination. clinicopathologic abnormalities included nonregenerative anemia, thrombocytopenia, and rare intracytoplasmic morulae within circulating neutrophils. abnormalities of the csf included pleocytosis and intracytoplasmic morulae in approximately 9% of neutrophils. serum ant ...	1994	7730122
genotype characterization of the bacterium expressing the male-killing trait in the ladybird beetle adalia bipunctata with specific rickettsial molecular tools.	the male-killing ladybird beetle (lb) bacterium (ab bacterium) was analyzed with specific rickettsial molecular biology tools in the lb adalia bipunctata strains. eight phenotype-positive lb strains showing mortality of male embryos were amplified with rickettsial genus-specific primers from the gene for citrate synthase (cs) and the gene for a 17-kda protein and spotted fever group-specific primers from the gene for the 120-kda outer membrane protein (ompb). the specificity of amplification was ...	1995	7747963
seroepidemiology of infections due to spotted fever group rickettsiae and ehrlichia species in military personnel exposed in areas of the united states where such infections are endemic.	a prospective, seroepidemiologic study of spotted fever group rickettsiae (sfgr) and ehrlichia infections was done among 1194 us military personnel exposed in a heavily tick-infested area of arkansas in 1990. seroconversion (4-fold) and seroprevalence rates were determined by indirect immunofluorescent antibody assays. seroconversions to sfgr occurred in 30 persons (2.5%), whereas seroconversion to ehrlichia species occurred in 15 (1.3%). the majority of seroconverters did not report symptoms (2 ...	1995	7751702
[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
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
genomic identification of rickettsia slovaca among spotted fever group rickettsia isolates from dermacentor marginatus in armenia.	restriction fragment length polymorphism (rflp) analysis of polymerase chain reaction (pcr) amplified genes was used for genomic identification of armenian isolates of the spotted fever group (sfg) rickettsiae with unclear taxonomic position. analysis was performed by using one genus-specific primer pair derived from r. prowazekii citrate synthase gene and two species-specific primer pairs derived from r. rickettsii genes for 190 k and 120 k antigens following alui, psti and rsai digestion of am ...	1994	7793355
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
the role of tumor necrosis factor in host defense against scrub typhus rickettsiae. ii. differential induction of tumor necrosis factor-alpha production by rickettsia tsutsugamushi and rickettsia conorii.	the present study was undertaken to investigate the ability of members of two different groups of rickettsia to stimulate macrophages or immune lymphocytes to produce tnf. it was found that r. conorii, a spotted fever group rickettsia, readily induced murine peritoneal macrophages or the macrophage-like cell line p388d1 to produce relatively high levels of tnf. the interaction of macrophages with viable organisms or heat-killed organisms resulted in tnf production. in contrast, viable or killed ...	1994	7854212
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
purification of rickettsial cultures contaminated by mycoplasmas.	an experimental biological model is proposed for purification of rickettsiae-infected cell cultures from mycoplasma contamination using intravenous mouse infection and subsequent passages on vero cell monolayers. mycoplasma-free rickettsial cultures were obtained in mouse brain or spleen suspension within 3 hrs or 3 days, respectively, after mouse inoculation. ten strains of spotted fever group rickettsiae were purified from mycoplasmas by this procedure.	1994	7879714
nucleotide sequence of polymerase chain reaction product amplified from rickettsia japonica dna using rickettsia rickettsii 190-kilodalton surface antigen gene primers.	the pcr product amplified from rickettsia japonica with the primer pair rr 190.70p and rr 190.602n of r. rickettsii 190-kda antigen gene was cloned into m13mp19 rf dna at the eco ri site and sequenced by chemiluminescent dna sequencing. the sequence revealed a molecular size of 533 base pairs (bp). the primer-flanking region of 491 bp, an open reading frame, was compared with the corresponding region of r. rickettsii, demonstrating 35 nucleotide substitutions in r. japonica. the sequence of prim ...	1994	7898385
differentiation of rickettsia japonica by restriction endonuclease fragment length polymorphism using products of polymerase chain reaction amplification with rickettsia rickettsii 190-kilodalton surface antigen gene primers.	restriction fragment length polymorphism of polymerase chain reaction (pcr) amplification products differentiated rickettsia japonica, a causative agent of oriental spotted fever, from other spotted fever group (sfg) rickettsiae. primer pair rr190. 70p and rr190. 602n of r. rickettsii 190-kda antigen gene sequence primed genomic dnas obtained from r. japonica, type strain yh and strains nt, nk, yki, and tkn. the products were cleaved by psti but not by afai restriction endonuclease. the psti dig ...	1993	7901739
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
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
differentiation among spotted fever group rickettsiae species by analysis of restriction fragment length polymorphism of pcr-amplified dna.	restriction fragment length polymorphism (rflp) analysis of pcr-amplified genes was used to study spotted fever group (sfg) rickettsiae, extending the previous work of regnery et al. (r.l. regnery, c.l. spruill, and b.d. plikaytis, j. bacteriol. 173:1576-1589, 1991). twenty-six strains of sfg rickettsia were studied, including several recognized species which have never been studied (r. parkeri, r. helvetica, and r. japonica) as well as strains which are not currently classified. two previously ...	1994	7910831
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
genotypic and biological characteristics of non-identified strain of spotted fever group rickettsiae isolated in crimea.	a strain of rickettsiae, designated crimea-108, was isolated from ticks dermacentor marginatus in the crimea in 1977. its immunobiological characteristics involve low pathogenicity for experimental animals, moderate infectivity for chick embryos, and antigenic relatedness to spotted fever group (sfg) rickettsiae (r. sibirica, r. conorii, r. akari), especially to r. sibirica. the genotypic characterization of the strain crimea-108 was carried out in comparison with sfg and typhus group rickettsia ...	1993	7912040
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 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
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
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
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
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
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
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
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
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
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
dot-elisa for rapid detection of q fever and spotted fever group antirickettsial antibodies.		1993	8105670
in vitro susceptibilities of spotted fever group rickettsiae and coxiella burnetti to clarithromycin.	the in vitro bacteriostatic activity of clarithromycin, a new macrolide derivative, against rickettsia rickettsii, rickettsia conorii, and "rickettsia israeli" was determined by the plaque assay and the dye uptake assay. both bacteriostatic and bactericidal activities of clarithromycin against the nine mile, q212, priscilla, and me9 strains of coxiella burnetti were evaluated by using three cell culture systems. clarithromycin showed improved antibacterial activity compared with that of erythrom ...	1993	8109928
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
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
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
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
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
transfiguration of rickettsial diseases: tsutsugamushi disease and spotted fever group rickettsiosis in japan.		1993	8204977
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
[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
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
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
prevalence of antibodies to spotted fever group rickettsiae along the eastern coast of the adriatic sea.	a seroepidemiological survey in coastal croatia detected antibodies reactive with rickettsia conorii in 4.2% of sera by immunofluorescence assay and in 5.0% of sera by enzyme immunoassay. western immunoblotting demonstrated antibodies to the 120-kda surface protein in all 20 positive serum samples examined and to rickettsial lipopolysaccharide in 3 of these serum samples. humans in this area are clearly being exposed to spotted fever rickettsiae.	1993	8370756
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
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
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
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
ecological studies on the brown dog tick rhipicephalus sanguineus (acari: ixodidae) in southern israel and its relationship to spotted fever group rickettsiae.	an outbreak of spotted fever group rickettsiae (sfgr) was investigated by studying free-living and parasitic stages of ticks in two settlements of equal size and population located 20 km apart in the negev desert. although high morbidity from sfgr was found in one of the settlements (kibbutz ze'elim), no clinical cases were observed in the second (kibbutz re'im). using flagging and co2-trapping, approximately 9 times more ticks were collected in ze'elim than in re'im. rhipicephalus sanguineus (l ...	1993	8433318
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
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
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
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
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
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
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
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
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
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
genomic and proteinic characterization of strain s, a rickettsia isolated from rhipicephalus sanguineus ticks in armenia.	strain s, a spotted fever group (sfg) rickettsia isolated from rhipicephalus sanguineus ticks collected in armenia, was identified. microimmunofluorescence, sodium dodecyl sulfate-polyacrylamide gel protein electrophoresis and western immunoblotting, pcr and then restriction fragment length polymorphism analysis, pulsed-field gel electrophoresis, and 16s rrna gene sequencing were used to compare strain s with reference isolates. strain s was found to possess proteinic, antigenic, and genomic pat ...	1995	8567916
prevalence of antibodies to coxiella burnetti, rickettsia conorii, and rickettsia typhi in seven african countries.	the prevalences of antibodies reactive with coxiella burnetti, rickettsia conorii, and rickettsia typhi were determined by indirect fluorescent antibody testing of sera from seven african countries. the seroprevalences of antibodies reactive with c. burnetti and r. conorii in countries from north africa were similar to those reported from southern europe. in countries of sub-saharan africa, the seroprevalence of antibodies reactive with c. burnetti varied greatly; the generally higher figures fo ...	1995	8589132
antibodies to spotted fever group rickettsiae and coxiella burnetii among domestic animals in southern croatia.	the sera of dogs, goats, sheep and cattle (total 153) from the kastelas' bay area (middle part of the eastern coast of the adriatic sea) were tested for antibodies against rickettsia conorii and coxiella burnetii by a complement fixation test. the overall percentages of positive sera among the tested animals were 23.9% for r. conorii and 16.4% for c. burnetii. the results show that animals in this area are clearly being exposed to spotted fever group rickettsiae as well as to c. burnetii. for co ...	1995	8689084
a new spotted-fever-group rickettsiosis.		1996	8709763
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
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
[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
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
serosurvey for cowdria ruminantium, coxiella burnetii, and spotted fever group rickettsiae in ostriches (struthio camelus) from zimbabwe.	sera from 216 ostriches on nine farms around zimbabwe were examined by indirect fluorescent antibody (ifa) testing for the presence of antibodies reactive with cowdria ruminantium, coxiella burnetii, and rickettsia africae, a spotted fever group rickettsia. although no reactive antibodies could be detected to c. ruminantium or c. burnetii, 51/216 (35%) sera reacted with r. africae. the seroprevalence in ostriches from the south of zimbabwe was significantly higher than in birds from the north (p ...	1996	8790897
molecular phylogeny and in situ detection of the etiologic agent of necrotizing hepatopancreatitis in shrimp.	necrotizing hepatopancreatitis (nhp) is a severe disease of farm-raised penaeus vannamei that has been associated with mortality losses ranging from 20 to 95%. nhp was first recognized in texas in 1985 (s. k. johnson, p. 16, in handbook of shrimp diseases, 1989) and is an economically important disease that has limited the ability to culture shrimp in texas. the putative cause of nhp is a gram-negative, pleomorphic, intracellular, rickettsia-like bacterium that remains uncultured in part because ...	1996	8795235
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
serological examination of human and animal sera from six countries of three continents for the presence of rickettsial antibodies.	forty samples each of human sera collected in guinea bissau, cape verde, el salvador and iran, and animal sera (goat and cattle from sri lanka and sheep from tanzania) were examined for the presence of antibodies to typhus group (tg) rickettsiae, spotted fever group (sfg) rickettsiae and coxiella burnetii by enzyme-linked immunosorbent assay (elisa) and indirect fluorescent antibody (ifa) test. of human sera tested, a higher proportion of positive sera were found with elisa and ifa test for tg, ...	1996	8817184
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
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
phenotypic and genotypic characterization of spotted fever group rickettsiae isolated from catalan rhipicephalus sanguineus ticks.	eighty-nine rhipicephalus sanguineus ticks and 21 rhipicephalus bursa ticks collected in catalonia were tested by the hemolymph test to establish their infection rate with spotted fever group rickettsiae. by giménez staining, 11.2% of the r. sanguineus isolates and 0% of the r. bursa isolates were found to contain rickettsia-like organisms. six spotted fever group rickettsial strains (bar29, bar31, gir4, tar1, tar2, and tar3) were isolated from these ticks and were characterized by phenotypic an ...	1996	8897166
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
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
prevalence of spotted fever group rickettsiae in ticks from southern israel.	the prevalence of spotted fever group rickettsiae was studied in questing ticks collected from southern israel. ticks were examined from an agricultural settlement (kibbutz ze'elim), an endemic site for mediterranean spotted fever, and from another kibbutz (re'im) in an adjacent area where the disease has not been reported. ticks were collected by flagging and co2 traps from vegetation inside and outside the settlements during 1989/1990 and 1994. in ze'elim, 98% of the ticks collected were brown ...	1996	8961650
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
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
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
genotypic identification of three new strains of spotted fever group rickettsiae isolated in china.	polymerase chain reaction (pcr) and restriction endonuclease fragment length polymorphism (rflp) analysis were used to characterize the genotypic diversity of three isolates of spotted fever group (sfg) rickettsiae isolated from ticks in china. a primer pair designed from dna sequence encoding 190 k protein antigen of r. rickettsii and genomic dnas obtained from the isolates were used in pcr. the pcr products were cleaved with restriction endonucleases psti and rsai, and the digestion patterns w ...	1996	9014012
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