| seroepidemiological investigations in domestic ruminants from egypt, somalia and jordan for the demonstration of complement fixing antibodies against rickettsia and chlamydia (author's transl). | 1450 random serum samples of domestic ruminants from egypt, somalia and jordan were investigated for complement fixing antibodies against rickettsia and chlamydia. between 1.5 and 3.4% of the samples from the animals investigated had antibodies against the rmsf-group of rickettsia, with exception of the sera from somalian cattle and sheep from jordan. antibodies against rickettsia of the typhus-group were found in 4 cattle and 1 goat from jordan and 2 sheep from egypt; by agglutination test with ... | 1978 | 28651 |
| plaque assay and cloning of scrub typhus rickettsiae in irradiated l-929 cells. | it was demonstrated that gamma-irradiated l-929 cells support plaque formation by three strains of rickettsia tsutsugamushi and representative species of the spotted fever and typhus group rickettsiae. sensitivity of the plaque assay for detection of viable scrub typhus rickettsiae was similar to that achieved with intraperitoneal inoculation of random-bred mice. the concentration of irradiated cells and the temperature and length of incubation were all found to affect plaque size. a technique c ... | 1977 | 69632 |
| antigenic relationships between the typhus and spotted fever groups of rickettsiae. | paired sera from cases of epidemic typhus in ethiopia and from probable cases of rocky mountain spotted fever (rmsf) in the united states were examined by microagglutination (ma) and microimmunofluorescence (micro-if) tests for antibodies against rickettsia prowazekii, rickettsia typhi, rickettsia canada, rickettsia rickettsii, rickettsia conorii and ricksettsia akari. igg and igm antibodies against the various rickettsiae were titrated with specific fluorescein-conjugated anti-igg and anti-igm ... | 1978 | 99029 |
| [seroepidemiological investigations on the prevalence of rickettsial antibodies in man in the federal republic of germany (author's transl)]. | 1,600 random serum samples from inhabitants of hesse were investigated for rickettsial antibodies by complement fixation test. antibodies were found in 19 samples (1,2%) against rmsf-group antigen with titers between 1:10 and 1:640. these results confirm recent reports on natural foci of such rickettsial infections in the federal republic of germany. antibodies against rickettsia of the typhus-group or coxiella burnetii could not be detected by the complement fixation reaction. none of the sera ... | 1977 | 410727 |
| biochemical characteristics of typhus group rickettsiae with special attention to the rickettsia prowazekii strains isolated from flying squirrels. | six strains of rickettsia prowazekii, two derived from human infections and four isolated from flying squirrels, two strains of r. typhi, and the single available strain of r. canada, were characterized by several biochemical procedures. the electrophoretic patterns on polyacrylamide gels of rickettsial proteins solubilized by sodium dodecyl sulfate revealed several species differences, but strains of the same species appeared to have identical patterns. cytoplasmic fractions of the rickettsiae ... | 1978 | 415982 |
| experimental forms of infection and serological analysis of the antigenic structure of rickettsia canada. | experimental forms of rickettsia canada infection were characterized and serological analysis of the antigenic structure of r. canada was carried out. according to its pathogenicity for experimental animals, r. canada can be characterized as a poorly virulent species of rickettsiae, similar to r. prowazekii (for guinea pigs). the complement-fixing, haemagglutinating and agglutinating antigens of r. canada are fairly similar to those of the typhus group rickettsiae. the region of antigenic activi ... | 1977 | 580434 |
| recent experience with the complement fixation test in the laboratory diagnosis of rickettsial diseases in the united states. | sera from patients suspected of having rickettsial infections were tested in the complement fixation test with antigens prepared from the rickettsiae of rocky mountain spotted fever (sf), rickettsial pox (rp), murine typhus, epidemic typhus, and from rickettsia canada (rc). eight units of antigen were used in all cases and two units in man. only those patients with antibody titers of 1:16 or higher were included in the study. largely on the basis of comparative titers, the patients were divided ... | 1976 | 972194 |
| detection of rickettsia rickettsii in saliva, hemolymph and triturated tissues of infected dermacentor andersoni ticks by polymerase chain reaction. | the technique of polymerase chain reaction (pcr) is potentially superior to existing methods for detecting rickettsial infections in ticks. for this reason, we developed assays for identifying rickettsial infections in ticks by pcr. our assays amplified a 500 bp fragment from the gene encoding the romp b protein of rickettsia rickettsii. the selected primers amplified fragments of the predicted size from all spotted fever group rickettsiae (r. rickettsii, r. parkeri, r. conorii, r. sibirica) tes ... | 1992 | 1528203 |
| a case of murine typhus in queensland. | to present a case of murine (endemic) typhus, the first to be reported within the last 30 years in australia. | 1992 | 1625620 |
| typhus and typhuslike rickettsiae associated with opossums and their fleas in los angeles county, california. | the recent discovery of cat fleas (ctenocephalides felis) infected with a typhuslike rickettsia (designated the elb agent) raises the question of whether similar rickettsial infections exist in wild cat flea populations. we verified the presence of the elb agent and rickettsia typhi in urban and suburban areas of los angeles, calif. opossums trapped in close proximity to the residences of human murine typhus cases in los angeles county and other areas within the city of los angeles were tested f ... | 1992 | 1629332 |
| immunoblot studies to analyze antibody to the rickettsia typhi group antigen in sera from patients with acute febrile cerebrovasculitis. | in 1986, an unusual syndrome of acute febrile cerebrovasculitis in the piedmont region of virginia was reported. all patients had encephalopathy and prior exposure to both a sylvan environment and flea-infested animals. the initial serological studies suggested a rickettsial origin, corroborating clinical, epidemiological, and histopathological findings. sera from four of five patients were subsequently studied by immunoblotting. unabsorbed and absorbed sera were tested with electrophoresed and ... | 1991 | 1723073 |
| flinders island spotted fever: a newly recognised endemic focus of tick typhus in bass strait. part 2. serological investigations. | twenty-six cases of a spotted-fever-like illness have been identified on flinders island, tasmania, over a 17 year period. these patients and 335 healthy persons from the island were investigated serologically using the weil-felix agglutination test (proteus sp. antigens ox2, ox19, oxk) and rickettsia-specific microimmunofluorescence. the antigens used in these latter tests comprised one member of the typhus group (rickettsia typhi) and three members of the spotted fever group (rickettsia ricket ... | 1991 | 1898756 |
| antigenic relationships among the rickettsiae of the spotted fever and typhus groups. | using immunoblots to analyze antigenic relationships among the pathogenic spotted fever and typhus group rickettsiae, i found that the rickettsial lipopolysaccharide (lps) was a group-specific antigen. all the rickettsiae examined had 135-kda and 58-kda protein antigens. the spotted fever rickettsiae and rickettsia canada had, in addition, 190-kda protein antigens which were antigenic analogs of previously described protective antigens of r. conorii and r. rickettsii. | 1991 | 1916232 |
| molecular cloning and sequence analysis of the sta58 major antigen gene of rickettsia tsutsugamushi: sequence homology and antigenic comparison of sta58 to the 60-kilodalton family of stress proteins. | the scrub typhus 58-kilodalton (kda) antigen (sta58) of rickettsia tsutsugamushi is a major protein antigen often recognized by humans infected with scrub typhus rickettsiae. a 2.9-kilobase hindiii fragment containing a complete sta58 gene was cloned in escherichia coli and found to express the entire sta58 antigen and a smaller protein with an apparent molecular mass of 11 kda (stp11). dna sequence analysis of the 2.9-kilobase hindiii fragment revealed two adjacent open reading frames encoding ... | 1990 | 2108930 |
| similarity in pathogenic features in lung and peritoneal infection by coxiella burnetii, typhus group rickettsiae, and chlamydiae. | | 1990 | 2198836 |
| [characteristics of monoclonal antibodies directed to species specific and group specific antigens of rickettsia prowazekii]. | a number of hybridomas against different determinants of r. prowazekii were obtained by hybridization of splenocytes from balb/c mice immunized with whole cells or soluble antigens of the organism. some of the monoclonal antibodies bound to thermolabile species specific protein of r. prowazekii and did not react with r. mooseri antigens (monoclonal antibodies series b4/4 and a3). monoclonal antibodies c5/2 and a3/2 reacted with group specific thermostabile antigen which is common for both r. pro ... | 1989 | 2485302 |
| production of antibody to and cellular localization of erythrocyte-sensitizing substance from rickettsia rickettsii. | antibodies to rickettsia rickettsii erythrocyte-sensitizing substance (ess) were raised in rabbits by using a derivatized ess. the resulting antibodies reacted with r. rickettsii and cross-reacted with rickettsia conorii, a member of the spotted fever group rickettsiae, but did not react with rickettsia typhi, a member of the typhus group rickettsiae, legionella bozemanii, or proteus vulgaris ox19 or ox2. immunoblot analysis indicated that ess was present in more than one fraction and that the m ... | 1989 | 2497137 |
| lymphokine-activated-killer-mediated lysis of cells infected with typhus group rickettsiae can be inhibited by okt3 monoclonal antibody. | we examined the ability of monoclonal antibodies directed against lymphocyte surface antigens to block the lysis of typhus group rickettsia-infected cells by lymphokine-activated killer effectors. lysis was significantly inhibited by okt3 monoclonal antibody but not by okt4 or okt8 monoclonal antibody. | 1986 | 3087881 |
| lysis of cells infected with typhus group rickettsiae by a human cytotoxic t cell clone. | cytolytic human t cell clones generated in response to the intracellular bacterium rickettsia typhi were characterized. growing clones were tested for their ability to proliferate specifically in response to antigens derived from typhus group rickettsiae or to lyse targets infected with r. typhi or rickettsia prowazekii. two clones were able to lyse targets infected with typhus group rickettsiae. one of these clones was more fully characterized because of its rapid growth characteristics. this c ... | 1987 | 3121731 |
| 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 |
| deoxyribonucleic acid base composition of members of the typhus group of rickettsiae. | | 1972 | 4404107 |
| [the relationship between the hemolytic, toxic and glutamate oxidase activity of typhus group rickettsia under conditions disturbing their contact with glutamic acid]. | | 1969 | 4977508 |
| plaque assay for q fever and scrub typhus rickettsiae. | the plaque assay procedure developed for spotted fever and typhus group rickettsiae is also appropriate for scrub typhus and q fever rickettsiae. the plaque titers of suspensions of rickettsia tsutsugamushi and coxiella burnetii compared favorably with end points obtained by titrations in mice. | 1970 | 4989539 |
| rickettsia canada: a new member of the typhus group of rickettsiae isolated from haemaphysalis leporispalustris ticks in canada. | | 1967 | 6039198 |
| acute febrile cerebrovasculitis: a syndrome of unknown, perhaps rickettsial, cause. | in late 1983, five patients living near charlottesville, virginia, were treated for an unusual syndrome of fever, headache, altered mentation, multifocal neurologic signs, and cerebrospinal fluid pleocytosis. clinical signs of brainstem disease developed in four patients. all five had had recent exposure to forests or wood and contact with flea-infested dogs. two patients died; one survivor has had recurrent seizures. brain biopsy samples in two patients and autopsy findings in another showed ce ... | 1986 | 3963661 |
| recognition of typhus group rickettsia-infected targets by human lymphokine-activated killer cells. | lymphokine-activated killer cells caused significant lysis of target cells infected with typhus group rickettsiae (tgr) but not cells infected with rickettsia tsutsugamushi. monoclonal and polyclonal antibodies against tgr or tgr-infected cells failed to bind specifically to infected targets, as determined by flow cytometry or by immunoprecipitation of radiolabeled cell surface proteins. major unaltered antigenic determinants of tgr therefore cannot be detected on the surface of infected targets ... | 1988 | 3137174 |
| characterization of human cytotoxic lymphocytes directed against cells infected with typhus group rickettsiae: evidence for lymphokine activation of effectors. | an in vitro culture and assay system was used to determine whether cytotoxic lymphocytes are generated in humans after rickettsial infection. peripheral blood mononuclear cells (pbmc) were obtained from six individuals with serologic evidence of prior infection with typhus group rickettsiae and from six nonimmune individuals. after pbmc from immune individuals were stimulated in vitro for 7 days with rickettsial antigen, they were capable of lysing typhus group rickettsia-infected, autologous ph ... | 1986 | 3081648 |
| human t helper cells specific for antigens of typhus group rickettsiae enhance natural killer cell activity in vitro. | the peripheral blood mononuclear cells (pbmc) from 5 individuals immune to typhus group rickettsiae and from 13 nonimmune individuals were stimulated in vitro for 7 days with typhus group rickettsial antigen (tgra). at the end of day 7, lysis of the natural killer (nk)-susceptible target k562 by these pbmc was determined. as controls, pbmc from both groups of donors were cultured in vitro for 7 days without antigen or were freshly isolated, and lysis of the k562 target was determined. there was ... | 1986 | 2945787 |
| [luminescent-serologic analysis of the antigenic interrelationship between r. canada and classic representatives of rickettsiae of the typhus group]. | the results of studying the antigenic relationships of r. canada, a new rickettsia species, and classical rickettsia species of the typhus group are presented. the study was carried out by luminescent serological analysis with the use of corpuscular antigens and the live infectious agent cultures. r. canada and rickettsiae of the typhus group were similar in their antigenic structures; this, however, could be revealed only in the study of the live cultures of the infectious agents. the study of ... | 1981 | 6785945 |
| immunoblot cross-reactions among rickettsia, proteus spp. and legionella spp. in patients with mediterranean spotted fever. | sera from patients suffering from mediterranean spotted fever (i.e. an infection due to rickettsia conorii) were studied by immunoblot to investigate cross-reactivity. a prevalence of igm antibodies to proteus ox 19, proteus ox 2, to the rickettsia typhus group, to legionella pneumophila serovars 4 and 5, to l. bozemanii wiga and to l. micdadei tatlock was found. western blot confirmed that the antibodies were directed against the lipopolysaccharide as demonstrated by proteinase k digestion of t ... | 1995 | 7541270 |
| in vitro antigen-specific antibody response to the species-specific surface protein antigens of typhus group rickettsiae by human peripheral blood mononuclear cells: generation of an antigen-dependent suppressor t cell. | we defined conditions suitable for in vitro synthesis of rickettsia-specific antibody by human pbmc cultured with the spa of rickettsia typhi or r. prowazekii and without addition of mitogens or polyclonal stimulators. antibody synthesis, as measured by an enzyme-linked immunosorbent assay, was cycloheximide-inhibitable and antigen-specific. pbmc from individuals with prior rickettsial infection made antibody, whereas pbmc from those receiving vaccine or with undetectable levels of serum anti-sp ... | 1985 | 2579151 |
| 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 |
| 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 |
| [detection of antibodies to rickettsia prowazekii using 3 serologic tests]. | commercial antigens of r. prowazekii may be used for the diagnosis of the typhus group rickettsiosis by the new solid-phase indirect enzyme immunoassay (spi eia). high sensitivity of the test makes the diagnosis of rickettsioses more effective and ensures an earlier detection of typhus patients. the authors have employed spi eia modification with polyethylene glycol, permitting a change in the incubation regimen (20 degrees c instead of 37 degrees c) and more rapid reaction; this recommends the ... | 1989 | 2467065 |
| heterogeneity of cd4-positive human t-cell clones which recognize the surface protein antigen of rickettsia typhi. | immunity to the typhus group of rickettsiae is largely dependent on the effector function of several classes of t lymphocytes, including those which produce gamma interferon. since the surface protein antigen (spa) derived from typhus group rickettsiae has been shown to be an effective immunogen in animal models, human t-cell clones specific for the spa of rickettsia typhi were isolated and tested for their antigenic specificity, as well as for their ability to produce gamma interferon. eighteen ... | 1989 | 2466795 |
| reactivity of monoclonal antibodies to rickettsia rickettsii with spotted fever and typhus group rickettsiae. | analysis of 15 spotted fever group (sfg) and 2 typhus group strains of rickettsiae with a panel of monoclonal antibodies revealed a number of shared and unique epitopes of the 120- and 155-kilodalton surface proteins. all of the sfg strains but neither of the typhus group strains reacted with antibody to the lipopolysaccharidelike antigen of rickettsia rickettsii; possibly the lipopolysaccharidelike antigen is the common antigen which defines the sfg. north carolina and montana strains of r. ric ... | 1987 | 2432081 |
| identification of strain-specific and group-reactive antigenic determinants on the karp, gilliam and kato strains of rickettsia tsutsugamushi. | hybridoma antibodies (hab) were prepared against the karp, gilliam and kato strains of rickettsia tsutsugamushi and were examined for homologous and heterologous reactivity using an indirect immunofluorescence assay. strain-specific hab demonstrated homologous ifa titers ranging from 1/320 to 1/1,280 and did not react (less than 1/10) with the heterologous strains. the cross-reactive hab generally reacted equally with all three strains in the scrub typhus group; however, there were some hab that ... | 1985 | 2422967 |
| 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 |
| 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 |
| prevalence of antibodies to rickettsia conorii coxiella burnetii and rickettsia typhi in salamanca province (spain). serosurvey in the human population. | the salamanca province of spain is an endemic zone for mediterranean spotted fever. in this area, only one case of q fever has been reported and typhus group rickettsial diseases have never been diagnosed. to obtain a panoramic view of the presence of antibodies to the most ubiquitous rickettsial agents, 400 sera specimens from a statistically representative sample of the human population of salamanca city and its surrounding province were subjected to indirect microimmunofluorescent test for an ... | 1990 | 2123799 |
| emerging bacterial zoonotic and vector-borne diseases. ecological and epidemiological factors. | among the etiologic agents of emerging infectious diseases are several bacterial organisms that naturally reside in animal and arthropod hosts. the most compelling emerging bacterial zoonotic and vector-borne diseases in the united states are lyme disease; a southern erythema migrans-like illness; human monocytic ehrlichiosis; human granulocytic ehrlichiosis; a novel cat flea-associated typhus group rickettsiosis; bartonelloses of immunocompetent and immunocompromised persons, particularly with ... | 1996 | 8627968 |
| structural analyses of the 120-kda serotype protein antigens of typhus group rickettsiae. comparison with other s-layer proteins. | | 1990 | 2116106 |
| the 17-kilodalton protein antigens of spotted fever and typhus group rickettsiae. | | 1990 | 2116105 |
| 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 |
| 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 |
| possible typhus-group infection in new york state: presentation of four suspect cases. | epidemiologic investigations were recently conducted on four cases which were reported in new york state in 1986 and 1987, three of which were within one family. these included hospital chart reviews, case or family interviews, animal trappings, and ectoparasite surveys. serologic tests and immunoblots were performed on blood samples obtained from these patients. all four patients had acute febrile illnesses; two required hospitalization and one died. microimmunofluorescence test results using r ... | 1990 | 2116104 |
| 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 |
| domestic cats as indicators of the presence of spotted fever and typhus group rickettsiae. | using indirect immunofluorescence assays, sera from cats in zimbabwe (n = 119) and south africa (n = 52) were found to contain antibodies reactive with rickettsia conorii (34% and 19% respectively) and r. typhi (7% and 10% respectively). these results indicate that cats may become infected with members of the spotted fever and typhus groups of rickettsiae and that cats can, therefore, be used as indicators of the presence of these organisms. | 1997 | 9062789 |
| evidence supporting the hypothesis that rickettsial virulence factors determine the severity of spotted fever and typhus group infections. | | 1990 | 2116102 |
| [monoclonal antibodies to the species-specific and group antigens of rickettsia prowazekii]. | a number of hybridomas to different r. prowazekii determinants were obtained by the hybridization of spleen cells of balb/c mice immunized with r. prowazekii corpuscular and soluble antigens. some of the monoclonal antibodies (mcab) reacted with r. prowazekii thermolabile species-specific protein and did not react with r. typhi antigens (mcab of batches b4/4 and a-d3). mcab c5/2 and a3/2 reacted with the group thermostable antigen, common for r. prowazekii and r. typhi. mcab to the species-speci ... | 1990 | 1695051 |
| restriction fragment length polymorphism of the dna of typhus group rickettsiae. | the dna of 10 strains of rickettsia prowazekii, 5 strains of rickettsia typhi and 1 strain of rickettsia canada was investigated by restriction fragment length polymorphism analysis. interspecies differences were characterized by a great number of noncomigrating bands. using the endonuclease hindiii and psti fragments comigration as a quantitative criterion, genetic similarity coefficient was calculated for the pair rickettsia prowazekii/rickettsia typhi-32.0%, for rickettsia prowazekii/ricketts ... | 1991 | 1687635 |
| intracytoplasmic localization of antigenic heat-stable 120- to 130-kilodalton proteins (ps120) common to spotted fever group rickettsiae demonstrated by immunoelectron microscopy. | immunoelectron microscopy demonstrated antigenic heat-stable 120- to 130-kilodalton proteins (ps120) of spotted fever group (sfg) rickettsiae with antiserum against recombinant ps120 of rickettsia japonica. in the case of r. japonica, a major part of the protein was shown to be localized outside the electron-lucent nucleoid-like region in the cytoplasm of the organisms. the other sfg rickettsiae represented a similar localization of the ps120 antigens cross-reactive to that of r. japonica. on th ... | 1997 | 9403508 |
| structural properties of lipopolysaccharides from rickettsia typhi and rickettsia prowazekii and their chemical similarity to the lipopolysaccharide from proteus vulgaris ox19 used in the weil-felix test. | the lipopolysaccharides (lpss) isolated from typhus group (tg) rickettsiae rickettsia typhi and rickettsia prowazekii were characterized by chemical analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page) followed by silver staining. lpss from two species of tg rickettsiae contained glucose, 3-deoxy-d-manno-octulosonic acid, glucosamine, quinovosamine, phosphate, and fatty acids (beta-hydroxylmyristic acid and heneicosanoic acid) but not heptose. the o-polysaccharides o ... | 1998 | 9488376 |
| [tropical animal and human rickettsial infections]. | advances in molecular biology have provided tools that have greatly clarified our knowledge of rickettsial diseases. most rickettsias have been reclassified in the alpha subgroup of proteobacteria. four groups of rickettsias have been identified: the spotted fever group, the typhus group, ehrlichia, and bartonella. although still considered as a rickettsia, coxiella burnetti, the agent causing q fever, has been reclassified separately in the gamma subdivision of proteobacteria. recognition of ri ... | 1997 | 9513175 |
| susceptibility of some species of rodents to rickettsiae. | the present study was designed to test the susceptibility of free-living rodents, viz apodemus flavicollis, microtus arvalis, clethrionomys glareolus, mus musculus, and outbred white mice from dobrá voda farm, csfr, to coxiella burnetii, rickettsiae of the spotted fever group (rickettsia sibirica, r. conorii, r. slovaca and r. akari) and rickettsiae of typhus group (r. typhi and r. prowazekii) by various routes of administration. the highest levels of antibodies to c. burnetii were found in a. f ... | 1992 | 1427494 |
| [the complex technology of producing rickettsial diagnostic immunoglobulin preparations and comparative technico-economic indices]. | the author elaborated a complex technology of production of a number of rickettsial diagnostic immunoglobulin preparations with a different action spectrum on the basis of a single initial raw material--horse immune serum. horses immunized and reimmunized according to the original combined scheme served as producers of high-quality immune sera for multi-directed purposes. on the basis of such sera there were prepared dry fluorescent antibodies, immunoglobulin erythrocytic diagnostic agents, diag ... | 1976 | 821272 |
| microimmunofluorescence test for the serological study of rocky mountain spotted fever and typhus. | a microimmunofluorescence test was used to study antibody responses to various spotted fever group and typhus group rickettsiae during rocky mountain spotted fever (rmsf) and epidemic typhus (et). patients with rmsf reacted most strongly to rickettsia rickettsii; those with et reacted predominantly to r. prowazekii. the degree of cross-reaction to other rickettsial strains varied from patient to patient, but a particular pattern of cross-reaction was consistently observed in serial sera from the ... | 1976 | 815267 |
| identification and molecular analysis of the gene encoding rickettsia typhi hemolysin. | rickettsia typhi, the causative agent of murine typhus, grows directly within the host cell cytoplasm, accumulating a large number of progeny, and eventually lyses the cells. typhus group rickettsiae (r. typhi and r. prowazekii) adhere to and lyse human and sheep erythrocytes. however, the molecular mechanism underlying erythrocyte lysis by r. typhi has not been defined. here we describe the cloning and nucleotide sequence analysis of the gene (tlyc) encoding a hemolysin from r. typhi. dna seque ... | 1999 | 10531273 |
| sequence analysis of the gene encoding the major outer membrane protein romp b of rickettsia japonica. | the complete nucleotide sequence of the gene encoding romp b (ompb), one of the two major outer membrane antigen proteins, of rickettsia japonica was determined and compared to those of the other spotted fever group and typhus group rickettsiae. open reading frame of the ompb gene of r. japonica consisted of 4,968 nucleotides coding for a putative precursor protein with 1,656 amino acids (aa) in which the n-terminal 1,363 aa and the c-terminal 293 aa encode 135-kilodalton romp b and 32-kilodalto ... | 1999 | 10609616 |
| rickettsial diseases: the typhus group of fevers--a review. | | 2000 | 10775278 |
| ultrastructure of rickettsia rickettsii actin tails and localization of cytoskeletal proteins. | actin-based motility (abm) is a mechanism for intercellular spread that is utilized by vaccinia virus and the invasive bacteria within the genera rickettsia, listeria, and shigella. within the rickettsia, abm is confined to members of the spotted fever group (sfg), such as rickettsia rickettsii, the agent of rocky mountain spotted fever. infection by each agent induces the polymerization of host cell actin to form the typical f (filamentous)-actin comet tail. assembly of the actin tail propels t ... | 2000 | 10899876 |
| ultrastructure of rickettsia rhipicephali, a new member of the spotted fever group rickettsiae in tissues of the host vector rhipicephalus sanguineus. | rickettsia rhipicephali is similar in ultrastructure to r. rickettsii while differing from other rickettsiae of the typhus group and of q fever and others by its lack of a prominently reticulated cytoplasmic matrix and in the thickness of the inner osmophilic layer of the cell wall. in tissues of the tick vector rhipicephalus sanguineus, r. rhipicephali had a mean length and width of 1.2 and 0.46 micrometer, respectively. it possessed a trilaminar cell wall with an adhering capsule-like layer. t ... | 1979 | 570191 |
| sensitive enzyme-linked immunosorbent assay for detection of antibodies against typhus rickettsiae, rickettsia prowazekii and rickettsia typhi. | an enzyme-linked immunosorbent assay (elisa) has been developed for the titration of rickettsial antibodies in human and animal sera. two preparations of soluble typhus-group antigens were obtained from rickettsia typhi and rickettsia prowazekii by ether extraction: a standard antigen from infected yolk sacs (ys antigen) and one free of yolk sac contaminants from renografin-purified rickettsiae (pr antigen). rabbit, mouse, and guinea pig sera were obtained by immunization with viable purified r. ... | 1977 | 408372 |
| enzyme immunoassay of antibody to rochalimaea quintana: diagnosis of trench fever and serologic cross-reactions among other rickettsiae. | enzyme immunoassay (eia) tests were used to diagnose trench fever and to determine cross-reactions of rochalimaea quintana with other rickettsiae. the results were compared with those obtained by counterimmunoelectrophoresis (cie). all sera from cases of primary or relapsed forms of trench fever were positive both in eia, with serum antibody titers of 1:20-1:640, and in cie, giving one to three precipitin lines. sera from patients with other rickettsial infections were also tested for reactivity ... | 1978 | 351072 |
| phylogenetic analysis of the rompb genes of rickettsia felis and rickettsia prowazekii european-human and north american flying-squirrel strains. | the rickettsial outer membrane protein b (rompb) gene encodes the major surface antigens of rickettsia species. we undertook sequencing and molecular analysis of the rompb gene of rickettsia felis and a comparison with its homologs in spotted fever group (sfg) and typhus group (tg) rickettsiae, including the complete sequences of two north american flying squirrel strains and two european human strains of rickettsia prowazekii. we sequenced 5,226 base pairs (bp) of the r. felis rompb, encoding a ... | 2000 | 11289671 |
| some biological properties of an endotoxic lipopolysaccharide from the typhus group rickettsiae. | a lipophilic thermostable lipopolysaccharide (lps) complex was isolated by phenol extraction from purified suspensions of the typhus group rickettsiae. the lps complex is antigenic and possesses some endotoxic properties such as toxicity for actinomycin d-treated mice, pyrogenicity for rabbits and guinea pigs, ability to elicit hypothermia in white rats and local schwartzman reaction and active cutaneous anaphylaxis in rabbits. | 1977 | 22240 |
| in vitro stimulation of human peripheral blood lymphocytes by soluble and membrane fractions of renografin-purified typhus group rickettsiae. | cell-free extracts of disrupted renografin-purified rickettsia typhi and r. prowazekii were evaluated as antigens in lymphocyte transformation assays for cell-mediated immunity to typhus group rickettsiae in 19 individuals with and 9 without histories of exposure to these organisms. exposure consisted of clinical disease, vaccination with epidemic typhus vaccine, or occupational exposure to these agents. both the soluble and membrane fractions of disrupted purified rickettsiae were used, and tra ... | 1980 | 6769803 |
| observations on rickettsia canada a recently described member of the typhus group rickettsiae. | | 1968 | 4975527 |
| 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 |
| detection of typhus antibodies by latex agglutination. | a latex test for assay of antibodies to endemic and epidemic typhus rickettsiae is simple, group-specific, sensitive, and reproducible. cross-reactivity within the typhus group was extensive. | 1981 | 6780601 |
| use of a sensitive microplate enzyme-linked immunosorbent assay in a retrospective serological analysis of a laboratory population at risk to infection with typhus group rickettsiae. | a microplate enzyme-linked immunosorbent assay (elisa), developed for the detection of antibodies to typhus group rickettsiae, was used to analyze human sera from individuals engaged directly or indirectly in rickettsial research. the earliest serum available from each of 112 individuals was tested for immunoglobulin m (igm) and igg antibodies against rickettsia typhi and rickettsia prowazekii by elisa at a 1:500 dilution. in at least one assay, nine sera had elisa optical densities of greater t ... | 1980 | 6783677 |
| 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 |
| polymerase chain reaction-based diagnosis of mediterranean spotted fever in serum and tissue samples. | a nested polymerase chain reaction (pcr) assay has been developed and used in the diagnosis of fatal and benign cases of mediterranean spotted fever (msf). the test was based on specific primers derived from a rickettsia conorii 17-kd protein gene. a positive signal was obtained from spotted fever group (sfg) and typhus group (tg) rickettsiae. discrimination between sfg and tg rickettsiae was based on a restriction fragment length polymorphism test. other gram-negative bacterial species tested d ... | 2002 | 12389942 |
| 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 |
| detection of antibodies against spotted fever group rickettsia (sfgr), typhus group rickettsia (tgr), and coxiella burnetii in human febrile patients in the philippines. | a total of 157 sera from febrile patients in the philippine general hospital in manila, luzon, and the northern samar provincial hospital, the philippines, were used. serum antibodies against spotted fever group rickettsia (sfgr) and typhus group rickettsia (tgr) were detected by indirect immunofluorescence test. antibody positive rates were 1.3% for sfgr (rickettsia japonica) and 2.5% for tgr (r. typhus), respectively. rickettsial antibodies in humans in the philippines were found for the first ... | 2003 | 12711823 |
| rickettsioses in swedish travellers, 1997-2001. | from laboratory records, information was collected on all 77 cases of rickettsioses diagnosed in sweden during 1997-2001, 14 of which were diagnosed as belonging to the typhus group and 63 to the spotted fever group. signs of hepatic involvement occurred more frequently in the typhus group. denominators for the number of journeys to different parts of the world were retrieved from a commercial swedish tourist database. the estimated risk of rickettsioses in destinations outside europe varied fro ... | 2003 | 12839153 |
| differentiation of rickettsiae by groel gene analysis. | the nucleotide sequences (534 to 546 bp) of the groel gene, which encodes the 60-kda heat shock protein groel, from 15 rickettsial strains were determined and compared. in the phylogenetic tree created by the unweighted pair group method with arithmetic averages and the neighbor-joining method, rickettsial strains could be distinguished from ehrlichia strains. five spotted fever group strains, four typhus group strains, and six scrub typhus group (stg) strains were differentiated as distinct ent ... | 2003 | 12843026 |
| rickettsial actin-based motility: behavior and involvement of cytoskeletal regulators. | actin-based motility (abm) is employed by spotted fever group (sfg) rickettsiae, such as rickettsia rickettsii, to promote cell-to-cell spread. time-lapse video microscopy revealed that abm is not strictly confined to sfg rickettsiae as typhus group r. typhi moved at approximately the same rate as r. rickettsii (approximately 4 micro m/min), but in a highly erratic fashion. a number of common behaviors were observed between abm of r. typhi and r. rickettsii, such as entrance into plasma membrane ... | 2003 | 12860687 |
| the typhus group of fevers. | | 1952 | 12978349 |
| refresher course for general practitioners; the typhus group of fevers. ii. | | 1952 | 12978371 |
| summary of recent abstracts. viii. typhus group of fevers. | | 1952 | 13005697 |
| [exanthematous fever of the tick typhus group at bobo-dioulasso, upper volta]. | | 1952 | 13032749 |
| 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 |
| typhus group of fevers. | | 1955 | 13312073 |
| [diseases of the exanthematous typhus group in brazil]. | | 1955 | 13369126 |
| [exanthematic typhus group diseases in brazil]. | | 1956 | 13369156 |
| typhus group of fevers. | | 1957 | 13486635 |
| [contribution to the study of diseases of the exanthematous typhus group in brazil (neotropical exanthematous typhus)]. | | 1957 | 13551935 |
| 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 |
| typhus group of fevers. | | 1960 | 13785221 |
| [on the method of titration of rickettsia of the typhus group and q fever on chick embryos]. | | 1960 | 13852636 |
| [complement fixing antibody against typhus group rickettsiae in sera of healthy korean]. | | 1962 | 13879394 |
| typhus group of fevers. | | 1962 | 14000653 |
| activation and enhanced contact of human t-lymphocytes with autologous red blood cells are required for their stable adherence at 37 degrees. | the adherence of human red blood cells (rbc) to autologous t-cells does not occur in the body, and in vitro is elicited at 4 degrees. autologous e-rosetting at 37 degrees has not previously been described. in this work, lymphocyte-rbc adherence has been studied in mixed leukocyte-rbc cultures and in whole blood from healthy donors. vital, cytochemical and electron microscopic studies have shown that t-cells may form stable e-rosettes with autologous rbc at 37 degrees. as in the previously report ... | 1993 | 8148955 |
| [effect of cortisone on the course of infections of the typhus group in experimental animals. iii. effect of cortisone on the course of epidemic typhus in experimental animals]. | | 1959 | 14446098 |
| [effect of cortisone on the course of rickettsial infections from the typhus group in experimental animals. i. effect of cortisone on the course of murine typhus in guinea pigs]. | | 1959 | 14446099 |
| gene sequence-based criteria for identification of new rickettsia isolates and description of rickettsia heilongjiangensis sp. nov. | we propose genetic guidelines for the classification of rickettsial isolates at the genus, group, and species levels by using sequences of the 16s rrna (rrs) gene and four protein-coding genes, the glta, ompa, and ompb genes and gene d. to be classified as a member of the genus rickettsia, an isolate should exhibit degrees of rrs and glta homology with any of the 20 rickettsia species studied of >/=98.1 and >/=86.5%, respectively. a member of the typhus group should fulfill at least two of the f ... | 2003 | 14662925 |
| evaluation of a pcr assay for quantitation of rickettsia rickettsii and closely related spotted fever group rickettsiae. | a spotted fever rickettsia quantitative pcr assay (sq-pcr) was developed for the detection and enumeration of rickettsia rickettsii and other closely related spotted fever group rickettsiae. the assay is based on fluorescence detection of sybr green dye intercalation in a 154-bp fragment of the rompa gene during amplification by pcr. as few as 5 copies of the rompa gene of r. rickettsii can be detected. sq-pcr is suitable for quantitation of r. rickettsii and 10 other genotypes of spotted fever ... | 2003 | 14662926 |
| [standardization of serologic tests in the diagnosis of fevers of the typhus group]. | | 1950 | 14798506 |
| summary of recent abstracts. viii. typhus group of fevers. | | 1950 | 14798658 |