Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| the typhus-rocky mountain spotted fever group of infections in the eastern and southeastern states. | 1931 | 18013262 | |
| a toxic substance associated with the rickettsias of the spotted fever group. | 1953 | 13052922 | |
| [rickettsia of the rocky mountain spotted fever group and the agent of siberian tick typhus]. | 1953 | 13150106 | |
| recovery of a rickettsia of the spotted fever group from microtus pennsylvanicus from virginia. | 1954 | 13167137 | |
| erythrocyte-sensitizing substances from rickettsiae of the rocky mountain spotted fever group. | 1954 | 13184127 | |
| [serological diagnosis of rickettsial diseases of typhus and tick spotted fever group by the hemagglutination method. i. technic for preparing antigen and conducting the test]. | 1957 | 13423199 | |
| immunologic relationships among the spotted fever group of rickettsias determined by toxin neutralization tests in mice with convalescent animal serums. | 1960 | 13798490 | |
| factors affecting the growth of rickettsias of the spotted fever group in fertile hens' eggs. | 1962 | 13917322 | |
| nonpathogenic rickettsias related to the spotted fever group isolated from ticks, dermacentor variabilis and dermacentor andersoni from eastern montana. | 1963 | 14053295 | |
| the rocky mountain spotted fever group of rickettsias. | 1965 | 14318051 | |
| glomerular response in human and experimental rickettsial disease (rocky mountain spotted fever group). a light and electron microscopy study. | 1968 | 5684481 | |
| two strains of rickettsiae of rocky mountain spotted fever group recovered from dermacentor marginatus ticks in czechoslovakia. results of preliminary serological identification. | 1969 | 4389040 | |
| tick-borne rickttsiae of the spotted fever group in west pakistan. i. isolation of strains from ticks in different habitats. | 1970 | 5536972 | |
| localization of coxiella burneti and rickettsiae of the rocky mountain spotted fever group in ticks. | 1972 | 4110513 | |
| the pathogenesis of the vascular lesions in experimental rickettsial disease of the guinea pig (rocky mountain spotted fever group). a light, immunofluorescent and electron microscopic study. | 1973 | 4119475 | |
| a search for the epidemic typhus agent in ethiopian ticks. | the presence of antibodies to rickettsia prowazeki in domestic animals from several parts of africa, and the isolation of this rickettsia from the blood of goats and sheep and from ticks off cattle or camels in ethiopia, led to the hypothesis that r. prowazeki in nature may occur in an extrahuman cycle involving ticks and domestic animals. this study attempted to recover r. prowazeki from 2 624 ticks (4 genera, 10 species) collected in central and southern ethiopia. the ticks were examined by th ... | 1973 | 4204491 |
| tick-borne rickettsiae of the spotted fever group in west pakistan. ii. serological classification of isolates from west pakistan and thailand: evidence for two new species. | 1973 | 4734280 | |
| the isolation of strains of rickettsiae of the spotted fever group in israel and their differentiation from other members of the group by immunofluorescence methods. | 1974 | 4208205 | |
| plaque assay of rickettsiae in a mammalian cell line. | clear-cut and repeatable plaque assays were obtained for three rickettsiae of the spotted fever group (rickettsia rickettsi, r. conori, and r. montana) in vero cells used in a manner similar to that for arboviruses. in addition, three typhus group agents (r. typhi, r. canada, r. prowazeki) induced plaques in these cells. in preliminary tests coxiella burneti (nine mile strain) failed to produce plaques. comparable results were obtained in plastic flasks and plastic culture trays incubated in amb ... | 1974 | 4208640 |
| isolation of spotted fever group and wolbachia-like agents from field-collected materials by means of plaque formation in mammalian and mosquito cells. | three isolations from ticks (dermacentor occidentalis) of a rickettsia of the spotted fever group and 5 isolations from chipmunk (eutamias rugicaudus) blood of a wolbachia-like agent were obtained from plaques formed in singh's aedes albopictus (mosquito) and vero (african green monkey kidney) cell cultures. these organisms could not be isolated by injection of the infected ticks or blood into embryonated chicken eggs, guinea pigs, or voles (microtus pennsylvanicus), but fluid cultures of grace' ... | 1975 | 241251 |
| rhipicephalus sanguineus: vector of a new spotted fever group rickettsia in the united states. | a rickettsia related to but distinct from the spotted fever agent, rickettsia rickettsii, has been detected in 167 (18.9%) of 884 rhipicephalus sanguineus taken off dogs in central and northern mississippi. the organisms could readily be isolated in male meadow voles (microtus pennsylvanicus), where it produced massive infections in the tissues of tunica vaginalis. it was practically nonpathogenic for male guinea pigs, although inoculation of these animals with infected tunica vaginalis of voles ... | 1975 | 806533 |
| rocky mountain spotted fever (tick-borne typhus) in south carolina: an educational program and tick/rickettsial survey in 1973 and 1974. | because the incidence of spotted fever is increasing in south carolina, campaigns were carried out in 1973 and 1974 to provide the public and medical practitioners, through pamphlets and news media, with information about spotted fever and the ticks which transmit the causative agent, rickettsia rickettsii. people were also invited to save and submit live ticks removed from vegetation, animals and humans, for examination by the hemolymph test. a total of 1,186 ticks consisting of 987 dermacentor ... | 1975 | 811127 |
| indirect hemagglutination test for human antibody to typhus and spotted fever group rickettsiae. | an indirect hemagglutination (iha) test is described that uses glutaraldehyde-stabilized erythrocytes treated with a rickettsial erythrocyte-sensitizing substance obtained from rickettsia typhi or rickettsia rickettsii. the serological reagent was stable for at least 3 months at room temperature and 6 months at 4 c. it exhibited group specificity and no group cross-reactivity. at a minimum dilution of 1:40, acute and early convalescent epidemic and murine typhus antisera showed 86% positive reac ... | 1975 | 811685 |
| rocky mountain spotted fever in mississippi: survey for spotted fever antibodies in dogs and for spotted fever group reckettsiae in dog ticks. | during epidemiologic studies of rocky mountain spotted fever in mississippi in 1973, dogs were surveyed for antibodies tp spotted fever group antigens and for tick parasites infected with rickettsiae of the spotted fever group. fifty-three (46%) of 116 serum samples had complement-fixing antibody titers greater than or equal to 1:8 as compared to only one (5%) of 21 samples from a group of dogs obtained from metropolitan chicage. fifty-two per cent of the dogs tested from mississippi had microag ... | 1976 | 814809 |
| 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 |
| rickettsiae belonging to the spotted fever group from ticks in the tribec mountains. | rickettsiae of the spotted (sf) group were found in a selected locality of the tribec mountains in southern slovakia in 1974. the rickettsiae were found in 10.8% of females and 6.1% of males of haemaphysalis inermis and 7.3% of females and 4.8% of males of ixodes ricinus. no significant differences in the incidence were observed during the year. coxiella burneti was found in 1 male and 4 females of h. inermis and 1 male of i. ricinus in ad adjacent locality. antibodies against rickettsiae of the ... | 1976 | 820614 |
| proteins of typhus and spotted fever group rickettsiae. | purified radioactive rickettsiae were obtained from irradiated and cycloheximide-inhibited l cells, and their proteins were analyzed by polyacrylamide gel electrophoresis. rickettsial species could be distinguished by comparing the relative mobilities of constituent proteins after migration of two differentially labeled preparations in a single gel. distinct differences were observed in gel patterns of rickettsiae from the typhus and spotted fever groups, as well as with different species within ... | 1976 | 820639 |
| ricettsioses studies. 2. natural foci of rickettsioses in east slovakia. | natural foci of q fever and of spotted fever group rickettsiae in the kosice district of east slovakia are described and discussed. it was established that the natural focus of q fever was a secondary one. cattle were observed to be the main source of human infection and a high proportion of synanthropic rodents was found to be infested with coxiella burnetii. the natural focus of spotted fever group rickettsiae was shown to be of a primary character, such rickettsiae circulating among ticks and ... | 1976 | 1085666 |
| rickettsioses studies. 1. natural foci of rickettsioses in the armenian soviet socialist republic. | ixodid ticks collected in the armenian ssr during 1971 and 1974 were positive for rickettsiae of the spotted fever group, as confirmed by haemocyte tests and by isolation experiments. serum specimens collected from human beings and from domestic and wild animals in the same areas contained antibodies against such rickettsiae and against coxiella burnetii. these results indicate the existence of mixed natural foci of rickettsioses of the spotted fever group and of q fever in the armenian ssr. | 1976 | 134846 |
| isolation of a spotted fever group rickettsia from the pacific coast tick, ixodes pacificus, in oregon. | a rickettsia of the spotted fever group was isolated on three occasions from ixodes pacificus in western oregon. these isolations, and additional evidence furnished by complement fixation tests on guinea pigs inoculated with other oregon ticks of this species, indicate that the association of this rickettsia with the pacific coast tick may be widespread. this is the first isolation of a spotted fever group rickettsia from i. pacificus. because the oregon isolates are mildly virulent for guinea p ... | 1976 | 937637 |
| massive occurrence of rickettsiae of the spotted fever group in fowl tampan, argas persicus, in the armenian s.s.r. | fowl tampans (argas persicus) collected in oktemberyan in the armenian s.s.r. in 1974 were found to be massively infected with rickettsiae of the spotted fever (sf) group. one isolated rickettsial strain, designated armenia 9, is antigenically related to, and probably identical with, strain armenia 11 and strain b of rickettsia slovaca, isolated from dermacentor marginatus ticks. strain armenia 9 grows readily in chick embryo yolk sacs and in chick embryo cell (cec) and l-cell cultures. it cause ... | 1977 | 22239 |
| antigenic relations of rickettsia prowazekii and rickettsia canada, established in the study of sera of patients with brill's disease. | sera of patients with brill's disease and of healthy persons with spotted fever in their past history were examined in the complement fixation reaction (cfr) to determine antigenic relations between r. prowazekii and r. canada. r. canada was found to have common antigenic determinants with r. prowazekii and r. mooseri. however, the antigenic determinants of r. canada differed from those of the mentioned rickettsiae. the titres of complement-fixing antibodies in the sera of patients with brill's ... | 1977 | 560410 |
| rickettsiae of the spotted fever group in slovakia. | 1977 | 408981 | |
| [isolation of rickettsia of the spotted fever group (sf group) from dermacentor marginatus ticks in tirol, austria]. | 1977 | 410728 | |
| susceptibility of laboratory animals to infection by spotted fever group rickettsiae. | an attempt was made to find a suitable animal model for studies of spotted fever group rickettsiae. inbred and outbred mice, the guinea pig, ferret, gerbil, hamster, wild rabbit, cotton rat, sheep, and miniature swine were tested. of these, only certain strains of the mouse [mai:(s) and balb/cj] and the guinea pig [hla:(ha)] exhibited, overtly, the desired characteristics of disease. other laboratory animals (such as sheep or rabbits) can be used for the production of antiserum against the spott ... | 1977 | 857087 |
| rickettsioses studies. 3. natural foci of rickettsioses in south bohemia. | antibodies against coxiella burnetii and against rickettsiae of the spotted fever group were found in human sera and in sera from domestic and wild animals collected in south bohemia. spotted fever group rickettsiae were also discovered in the tick ixodes ricinus. these results indicate the presence of both types of rickettsiae in this part of czechoslovakia. as no epizootics or epidemics of q fever have as yet been reported in the area, it can be assumed that c. burnetii occurs in the latent st ... | 1977 | 304389 |
| rickettsiae of the spotted fever isolated from dermacentor marginatus ticks in south germany. | rickettsiae of the spotted fever group were detected by haemocyte test in 8 (12%) of 51 partially engorged dermacentor marginatus females collected in march/april 1975 in south germany. four strains of rickettsiae were isolated from ticks positive in haemocyte test. it was concluded with isolated strain brd-1 and homologous immune guinea pig, hamster and mouse sera in cf cross reactions with antigens and immune sera against other members of the sf group, that the newly isolated strains are simil ... | 1977 | 930478 |
| presence of complement fixing (cf) antibody against spotted fever group of rickettsiae in human beings from kerala, south india. | 1978 | 730266 | |
| suppression of cellular immune responses in guinea pigs infected with spotted fever group rickettsiae. | using a guinea pig model, we demonstrated that infections with pathogenic species of spotted fever group rickettsiae transiently and nonspecifically suppress established cellular immune responses as measured by in vitro lymphocyte transformation and in vivo delayed cutaneous hypersensitivity responses to unrelated, nonrickettsial antigens. the correlation of the duration of this immunosuppression with the virulence of the infecting rickettsial species suggests that this suppression is a patholog ... | 1978 | 730362 |
| comparative electrophoresis of spotted fever group rickettsial proteins. | 1978 | 415197 | |
| 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 |
| [antigenic structure of rickettsia of the tick-borne spotted fever group isolated in the armenian ssr]. | the authors present data concerning the study of the antigenic properties of rickettisa of the tick-borne spotted fever group isolated from the ixodes ticks in the armenain ssr. in order to determine the species of the isolated strains a method of serological identification of rickettsia in the complement fixation reaction with the species-specific immune sera of albino mice was used. the results obtained permitted to refer the armenia-74, no. 11, 29, and 57 species to the r. sibricia species. | 1978 | 151462 |
| anticomplementarity in complement-fixation test with soluble antigens of the spotted fever group rickettsiae. | anticomplementarity occurring in the complement-fixation (cf) test with soluble antigens of rickettsiae of the spotted fever (sf) group is caused by interaction of soluble antigens with guinea pig sera serving as the source of complement. the serum factor responsible for anticomplementarity is thermostable and cannot be removed by treatment of guinea pig serum with co2 or nitrogen. an adverse effect of such serum was also observed upon its mixing with other guinea pig sera lacking anticomplement ... | 1978 | 219638 |
| 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 |
| an apparent outbreak of rickettsial illness in costa rica, 1974. | a focal outbreak of highly fatal disease occurred in eastern costa rica in 1974. no rickettsial spotted fevers have previously been reported in costa rica. nevertheless, the available evidence points to an unidentified rickettsial pathogen, probably of the spotted fever group, as the agent responsible for this outbreak. | 1978 | 100162 |
| surface proteins of typhus and spotted fever group rickettsiae. | six proteins, previously established as major constituents of intact organisms, were identified in cell envelopes obtained from intrinsically radiolabeled rickettsia prowazekii. extrinsic radioiodination of intact organisms conducted at 0.5 micronm iodide indicated that protein 4 was the most peripheral, although protein 1 also had reactive groups exposed on the surface of the organisms. a 10-fold increase in iodide concentration resulted in labeling of protein 2, and at 50 micronm iodide, all s ... | 1978 | 101466 |
| serologic typing of rickettsiae of the spotted fever group by microimmunofluorescence. | 1978 | 101593 | |
| distribution and prevalence of spotted fever group rickettsiae in ticks from south carolina, with an epidemiological survey of persons bitten by infected ticks. | live ticks removed from human hosts were tested for the presence of spotted fever group rickettsiae from 1974 through 1976. spotted fever group rickettsiae were detected in dermacentor variabilis, amblyomma americanum, amblyomma maculatum, and ixodes scapularis. persons from whom positive ticks were removed in 1974 and 1975 were questioned about ensuing illness. eleven of 51 persons from whom rickettsia-positive d. variabilis were removed reported some unexplained combination of symptoms compati ... | 1978 | 103448 |
| rocky mountain spotted fever in connecticut: human cases, spotted-fever group rickettsiae in ticks, and antibodies in mammals. | three parameters were used in 1976 and 1977 to assess the status of rocky mountain spotted fever (rmsf) in connecticut--compilation and review of clinical data on suspected human cases for the 13-year period 1965--1977, examination of tick tissues for spotted fever-group rickettsiae by the hemolymph test and direct immunofluorescence, and analyses of mammalian sera for antibodies against rickettsia rickettsii. there were six presumptive rmsf cases which probably originated in connecticut. four o ... | 1979 | 111543 |
| ixodes ricinus: vector of a hitherto undescribed spotted fever group agent in switzerland. | a tick/rickettsial survey in various parts of switzerland revealed the presence of a new, hitherto undescribed spotted fever group rickettsia ("swiss agent") in up to 11.7% of i. ricinus collected off vegetation. infection in ticks was found to be generalized with rickettsiae developing intracellularly and occasionally also intranuclearly. as a result of massive growth in ovarial tissues, including the germinative cells, the rate of transovarial and filial infection was 100%. the "swiss agent" a ... | 1979 | 44100 |
| 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 |
| rickettsiae of the spotted fever group in hungary. | rickettsiae were detected by haemocyte test in 7.2% of dermacentor marginatus and 4.7% of d. reticulatus ticks collected in hungary. six strains of rickettsiae were isolated from positive specimens. these rickettsiae according to cfr are closely related, probably identical with r. slovaca and they represent the first rickettsiae of the spotted fever group found in that country. | 1979 | 544393 |
| properties of selected rickettsiae of the spotted fever group. | eight strains of spotted fever group rickettsiae were studied to gain insight into the extent of variation of their properties. two standard strains of rickettsia rickettsii and one strain of rickettsia conorii were included among the eight for comparison. the molar percentage of guanine plus cytosine for each strain did not differ significantly from that for r. rickettsii, 32.6 +/- 0.7%. two strains caused extended fever in guinea pigs, one strain caused fever of short duration, and the other s ... | 1980 | 6769801 |
| 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 |
| spotted fever group rickettsiae in dermacentor variabilis from cape cod, massachusetts. | spotted fever group (sfg) rickettsiae were identified by indirect immunofluorescent antibody tests in 1.1% of 6,956 specimens of dermacentor variabilis collected on cape cod, massachusetts. forty-one of 45 rickettsial isolates were serotyped as rickettsia montana, one as rickettsia rickettsii, and three were unidentified. studies of canines and humans with clinical evidence of spotted fever, and of healthy dogs with antibody to sfg rickettsiae, indicated that exposure of the canine population to ... | 1980 | 6773430 |
| serological evidence of infection by spotted fever group rickettsiae in karnataka state. | 1980 | 6780455 | |
| natural occurrence of spotted fever group rickettsiae in the dog flea ctenocephalides canis in karnataka. | 1980 | 7191408 | |
| 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 |
| ecology of tick-borne agents in california. i. spotted fever group rickettsiae. | 1981 | 7212168 | |
| importation into the united states from africa of rhipicephalus simus on a boutonneuse fever patient. | rhipicephalus simus koch was removed from a human upon his return to connecticut, u.s.a. from kenya, africa. this person became ill in africa, exhibited clinical manifestations of boutonneuse fever and had a significant rise (greater than or equal to 8-fold) in igm titer against spotted fever-group rickettsiae. rickettsia conorii was probably the infectious agent. | 1981 | 7258502 |
| rickettsialpox: report of an outbreak and a contemporary review. | rickettsialpox is a mild illness characterized by the appearance of a primary eschar at the site of a mite bite followed by fever, headache, and a papulovesicular rash. it can be confused with a variety of illnesses including several other rickettsial diseases and chickenpox. r. akari, the etiologic agent, is a rickettsia belonging to the spotted fever group (sfg) of rickettsial illnesses. in spite of significant serologic cross-reactivity with other sfg agents, there is no convincing evidence o ... | 1981 | 7278620 |
| a rickettsia-like organism showing positive immunofluorescence with antisera to coxiella burnetii in haemaphysalis inermis ticks. | a rickettsia-like organism (rlo) was detected in the oocytes of haemaphysalis inermis ticks. the rlos were about 5 microns long bent rods with a definite inner structure. they were gram-negative and could be visualized by giemsa but not by gimenez staining. attempts to cultivate the rlo in chick embryo yolk sacs, various types of cell culture and tick body cavities were unsuccessful. the rlo displayed a bright immunofluorescence with antisera to coxiella burnetii, but no immunofluorescence was o ... | 1981 | 6118050 |
| serotypes of spotted fever group rickettsiae isolated from dermacentor andersoni (stiles) ticks in western montana. | adult dermacentor andersoni ticks were collected by flagging vegetation in 18 canyons bordering the bitterroot valley, montana, an area where nearly 400 cases of rocky mountain spotted fever (rmsf) have occurred since 1900. three hundred and nine (8.3%) of the 3,705 ticks collected contained hemocyte-associated rickettsia-like organisms of three morphologic types, coccobacillary, fine bacillary, and coarse bacillary (long forms). only the coccobacillary and fine bacillary organisms stained with ... | 1981 | 6782899 |
| endemicity of spotted fever group rickettsiae in connecticut. | to compare rickettsial infectivity and seropositivity rates against spotted fever group (sfg) rickettsiae, ticks and wild mammals were collected from three areas where rickettsia rickettsii was thought to be enzootic in connecticut during 1978-1979, and from four additional sites (with no reported human cases) between 1976 and 1979. of the 1,001 dermacentor variabilis examined by the hemolymph test, 59 (5.9%) contained rickettsia-like organisms; direct immunofluorescence tests verified the prese ... | 1981 | 6789690 |
| serotypes of tick-borne spotted fever group rickettsiae from western california. | a rickettsial survey of ixodid ticks known to bite man was conducted in 1979 in four coastal counties of california to obtain isolates from tick species that might be involved in the transmission of spotted fever-like illnesses, and to examine serologic characteristics of the rickettsiae relative to defined members of the spotted fever group (sfg). one hundred and seventy (19.4%) of 877 ticks comprising three species were shown by hemolymph test to harbor rickettsia-like organisms. a total of 85 ... | 1981 | 6789691 |
| [epidemiological survey in a natural focus of rickettsia transmitted by ixodes ricinus in switzerland (author's transl)]. | a spotted fever group rickettsia referred to as "swiss agent" was detected in 8.5% of ixodes ricinus collected in a marshy forest of the swiss plateau. this organism, in its tick vector, was found to be transmitted stadially as well as ovarially; of 433 larval, nymphal or adult ticks from 17 parental tick females, all were infected. a total of 3,612 larval i. ricinus were collected from 168 small mammals including 127 clethrionomys glareolus, 29 apodemus sylvaticus and flavicolis, 7 microtus agr ... | 1981 | 7020557 |
| antibodies to spotted fever-group rickettsiae in dogs and prevalence of infected ticks in southern connecticut. | blood samples and ticks were obtained from dogs to assess canine exposure to spotted fever-group (sfg) rickettsiae during 1978-1980 in southern connecticut. of the 1,576 dog sera screened by microimmunofluorescence. 174 (11.0%) contained specific antibodies at titers greater than or equal to 1:64 against rickettsia montana (n = 34), r rickettsii (n = 31), r rhipicephali (n = 19), or the unclassified 369-c rickettsia (n = 90). end points greater than or equal to 1:8,192 to r rickettsii and to r r ... | 1982 | 6803626 |
| establishment of cell cultures persistently infected with spotted fever group rickettsiae. | a cell line was established from the tunica vaginalis of meadow voles, microtus pennsylvanicus, which could be persistently infected with the spotted fever group rickettsiae, rickettsia rickettsii, r. rhipicephali, and r. slovaca. as determined by light and electron microscopy, all cells in the cultures became infected and remained so even after 20 serial passages over a period of months. the rickettsiae-infected vole cell line is an excellent experimental model to study the noncytolytic host-ce ... | 1982 | 6820331 |
| biological properties of rabbit antibodies to a surface antigen of rickettsia rickettsii. | because of the potential significance of external components of the obligate intracellular parasite rickettsia rickettsii in host-parasite interactions, we have begun the first phase of a study to isolate and characterize surface antigens of this organism. an antiserum to a rickettsial surface component was obtained from rabbits inoculated with immune precipitates prepared by crossed immunoelectrophoresis of triton x-100 extracts of r. rickettsii strain r. this antiserum (i) protected guinea pig ... | 1983 | 6403467 |
| [survey of natural infection of ticks with rickettsia of the spotted fever group in the northwestern section of xinjiang province]. | 1983 | 6411346 | |
| rickettsial antibody prevalence in southern israel: igg antibodies to coxiella burnetii, rickettsia typhi, and spotted fever group rickettsiae among urban- and rural-dwelling and bedouin women. | a retrospective serological survey was carried out using sera obtained from women at childbirth in the southern desert region of israel to determine exposure experience to three rickettsial agents: coxiella burnetii, rickettsia typhi, and spotted fever group rickettsiae. using the indirect fluorescent antibody method for determining igg antibodies, it was found that about 40% of all sera examined demonstrated antibodies to one or more rickettsiae. bedouin women appeared to be at greater risk of ... | 1983 | 6418016 |
| susceptibility of inbred mice to rickettsiae of the spotted fever group. | a mouse strain susceptible to lethal infection with rickettsia conorii was required for testing vaccine efficacy and for studying the immunology and pathogenesis of infection. among 20 strains of inbred mice inoculated intraperitoneally with the malish strain of r. conorii, the c3h/hej mouse strain was the most susceptible, with a 50% lethal dose of approximately 10 pfu. infection of all mouse strains resulted in a measurable antibody response; the highest titers correlated with the greatest deg ... | 1984 | 6418657 |
| rocky mountain spotted fever vaccine: a regional need. | because the killed rickettsia vaccines have failed to provide protection against rocky mountain spotted fever, we approached the problem of protective immunity to rickettsia rickettsii with a closely related, live, less pathogenic spotted fever rickettsia. guinea pigs vaccinated with r conorii produced antibodies to spotted fever group rickettsiae and did not have fever or other signs of illness after challenge with r rickettsii. a vaccine against rocky mountain spotted fever would be useful in ... | 1984 | 6424239 |
| epidemiology of rocky mountain spotted fever in ohio, 1981: serologic evaluation of canines and rickettsial isolation from ticks associated with human case exposure sites. | a survey for the prevalence of rocky mountain spotted fever (rmsf) antibodies in dogs associated with confirmed human cases in ohio was conducted during 1981. twelve of 14 confirmed cases (85%) had a history of dog association prior to onset of rmsf. a total of 29 dogs were included in the study, with 16 dogs providing serum samples for antibody testing and the remainder providing tick samples. serum samples tested by indirect microimmunofluorescence techniques revealed 12/16 dogs (75%) to be se ... | 1984 | 6435461 |
| the occurrence of the brown dog tick, rhipicephalus sanguineus (latr. 1806), a possible vector of the spotted fever group rickettsiae, on sheep in the negev region in israel. | 1984 | 6546817 | |
| susceptibility and reservoir potential of the dog to spotted fever-group rickettsiae. | this study was initiated to determine the degree of susceptibility of dogs to virulent and nonvirulent spotted fever-group rickettsiae and to evaluate dogs as sources of infection for ticks. dogs were exposed either by inoculation (syringe) or by infective tick bite to the following rickettsial serotypes: (1) rickettsia rickettsii (wachsmuth and sawtooth female 2 strains), (2) r montana (m/5-6 b strain), and (3) r rhipicephali (3-7-female 6 strain). results indicated that dogs inoculated with 1, ... | 1984 | 6548617 |
| spotted fever and murine typhus in the negev desert region of israel, 1981. | during 1981, 52 cases of rickettsiosis caused by the spotted fever group of rickettsiae were reported in a population of 250 000 living in the negev desert region of israel. retrospectively, at least 5 of these cases were serologically shown to have been caused by rickettsia typhi, the agent of murine typhus. most cases of rickettsial disease occurred in the summer months and one half of all cases occurred in children aged 9 years or less. while the specificity of a physician's diagnosis of the ... | 1984 | 6610498 |
| injury restricted to cells infected with spotted fever group rickettsiae in parabiotic chambers. | one chamber of paired parabiotic chambers separated by 0.2 micron poresized membrane filters which prevented passage of rickettsiae were infected with either rickettsia rickettsii or r. conorii. infected vero cell monolayers underwent necrosis. uninfected monolayers in adjoining chambers which shared the same extracellular milieu including soluble rickettsial products did not undergo necrosis. | 1984 | 6152112 |
| production and characterization of monoclonal antibodies to rickettsia rickettsii. | five mouse ascitic fluids (mafs) containing monoclonal antibody to rickettsia rickettsii were produced from three original fusions by murine hybridoma technology. the five mafs were fractionated and purified; each contained monoclonal antibody of the immunoglobulin g2a subclass. each monoclonal antibody-containing maf was titrated by indirect immunofluorescence against three r. rickettsii isolates from humans and four other spotted fever group rickettsiae. each maf was also titrated in the compl ... | 1984 | 6209219 |
| demonstration of spotted fever group rickettsiae in the tache noire of a healthy person in sicily. | a human case of rickettsial infection occurred in sicily following tick bite. the patient did not have fever, the typical nodular rash, or other symptoms of illness other than development of a tache noire containing spotted fever group rickettsiae, which were demonstrated by immunofluorescence. a high titer of antibodies of the igg class suggests that the patient may have had previous exposure to rickettsia conorii or a related spotted fever group rickettsia. an anamnestic response may be hypoth ... | 1984 | 6375408 |
| canine rocky mountain spotted fever: a kennel epizootic. | within a period of 5 consecutive days after the initial observation of illness was made, 7 of 12 siberian husky dogs developed clinical signs of rickettsia rickettsii infection. one dog died and was necropsied. clinical signs of infection consisted of lethargy, anorexia, ocular and nasal discharges, and neurologic disorder (incoordination and rolling). scleral blood vessel injection, fever, lymphadenomegaly, splenomegaly, and increased bronchovesicular lung sounds were prominent findings. clinic ... | 1985 | 4062017 |
| susceptibility of small mammals to nonvirulent spotted fever group rickettsiae. | 1985 | 3838556 | |
| [serological approach to the occurrence of rickettsioses in the central african republic]. | a serosurvey for evidence of human rickettsial infections was carried out in the republic of central africa on 144 sera by indirect immunofluorescence (iif) and microagglutination tests (ma). there was no serological evidence of epidemic typhus and only two sera were positive for murine typhus. approximately 15% of the surveyed population was serologically positive by ma for r. conorii antibodies. however, 48% of this population had spotted fever group antibodies as detected by iif but were nega ... | 1985 | 3896545 |
| rickettsia-like organisms in ticks and antibodies to spotted fever-group rickettsiae in mammals from northern mississippi. | studies were conducted from april through august during 1974 and 1975 on 30 randomly selected trapping sites in wall doxey state park, holly springs national forest, and 1.6 km south of the park in marshall county, mississippi to provide information on the occurrence of ticks involved in the maintenance and transmission of spotted fever-group rickettsiae in nature. of 365 animals (14 species) collected, 186 (51%) were parasitized by 4,169 ticks. species of ticks collected included: dermacentor v ... | 1985 | 3923212 |
| [preliminary studies on the occurrence of rickettsiae of the spotted fever group in rhipicephalus sanguineus captured in suburban areas]. | in the urban periphery of rome, two sub-zones could be distinguished, characterized by uncultivated steppeland and by small shacks with large quantities of domestic refuse, respectively. rhipicephalus sanguineus appeared to be typical of this second sub-zone. r. sanguineus adults and nymphae were captured in different seasonal periods and were checked for the prevalence of rickettsiae of the spotted fever (sf) group. moreover, larvae from hatched eggs, laid by captured r. sanguineus females, wer ... | 1985 | 3924079 |
| spotted fever group rickettsiosis in japan. | the acute febrile disease with characteristic rash encountered in tokushima prefecture was proved to be a spotted fever group rickettsiosis, which showed a significant rise in agglutinins to both proteus ox2 and ox19 and significantly high levels of cf antibodies to rickettsia akari and rickettsia rickettsii. | 1985 | 3934436 |
| spotted fever group rickettsiae in immature and adult ticks (acari: ixodidae) from a focus of rocky mountain spotted fever in connecticut. | immature and adult ixodid ticks were collected during 1983 and 1984 in newtown, connecticut, an area endemic for rocky mountain spotted fever (rmsf), to determine prevalence of infection by spotted fever group (sfg) rickettsiae. direct fluorescent-antibody (fa) staining revealed sfg organisms in 6 (1.8%) of 332 dermacentor variabilis larvae, 5 (7.8%) of 64 d. variabilis nymphs, and in 2 (40%) of 5 ixodes cookei nymphs removed from small- and medium-sized mammals. hemolymph tests detected rickett ... | 1985 | 3938341 |
| [evaluation of weil-felix test results by comparing the agglutinability of proteus ox2 and ox19 commercial antigens: basis for the presumption of a spotted fever group rickettsiosis]. | 1985 | 3938464 | |
| [the first report of the rickettsial infections of spotted fever group in japan: three clinical cases]. | 1985 | 3938467 | |
| rickettsiae and hosts. | protective immunity to rickettsia tsutsugamushi in a murine model is dependent upon the development of cell mediated immunity, as demonstrated by lymphocyte transfer, production of lymphokines and -interferon by thymus-derived lymphocytes, activation of macrophages by lymphokines and demonstration of delayed-type hypersensitivity response following exposure to these organisms. infection of mice with small numbers of rickettsia typhi inoculated by a peripheral route leads to a more complex patter ... | 1985 | 2408453 |
| prevalence and distribution of spotted fever and typhus infections in sierra leone and ivory coast. | a serosurvey for evidence of rickettsial infections was conducted in the rural populations of several tropical rain forest areas in sierra leone and ivory coast. seropositivity rates were surprisingly high in both countries, with more than 7% of the individuals in some districts having antibodies to spotted fever-group rickettsiae. no significant difference was found in the overall prevalence of diagnostic antibody titers to spotted fever-group rickettsiae in sierra leone (5.3%) and ivory coast ... | 1986 | 3025125 |
| ecological study of rocky mountain spotted fever in costa rica. | since rocky mountain spotted fever (rmsf) was recognized in costa rica, ecological studies have been undertaken to discern its distribution and the natural cycle of rickettsia rickettsii. the population of ticks parasitizing animals and vegetation was scarce. rickettsiae were not isolated from pools of ticks nor from spleens of the animals studied. however, the active circulation of rickettsiae was evidenced through the demonstration of spotted fever group antibodies in humans, dogs, and wild ra ... | 1986 | 3080917 |
| production and characterization of cloned t-cell hybridomas that are responsive to rickettsia conorii antigens. | t-cell hybridomas produced by the fusion of rickettsia conorii immune t cells to the akr thymoma bw 5147 produced interleukin-2 when stimulated with the antigens of three different r. conorii strains. one cloned hybridoma responded only to r. conorii antigens, whereas a second and third cloned hybridoma also responded to the antigens of rickettsia rickettsii sheila smith and rickettsia sibirica 246, respectively. antigen responses required antigen-presenting cells, and this interaction was major ... | 1986 | 3082761 |
| [serologic studies of spotted fever group rickettsiosis occurring in muroto-city, kochi prefecture]. | 1986 | 3090165 | |
| epidemiology of boutonneuse fever in western sicily. distribution and prevalence of spotted fever group rickettsial infection in dog ticks (rhipicephalus sanguineus). | the distribution and prevalence of spotted fever group rickettsial infection in the ixodid dog tick rhipicephalus sanguineus were found to occur at a rate of 19.7% with variation related to geographic and sociooccupational factors. a higher rate of infection was demonstrated in ticks removed from dogs associated with documented cases of boutonneuse fever. the results fit into available clinical and seroepidemiologic data on rickettsia conorii infection in western sicily. | 1986 | 3513550 |
| immunofluorescence test with rickettsia montana for serologic diagnosis of rickettsial infection of the spotted fever group in shikoku, japan. | 1986 | 3540537 | |
| isolation of a spotted fever group rickettsia from a patient with febrile exanthematous illness in shikoku, japan. | 1986 | 3553872 |