Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| 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 |
| rocky mountain spotted fever in childhood. | 1981 | 6798547 | |
| rocky mountain spotted fever. serological evidence of previous subclinical infection in children. | serological tests for rocky mountain spotted fever were performed on single serum specimens from sixth graders from forsyth county, north carolina, an area highly endemic for this disease. five of 508 *.098%) sera were positive (titer greater than or equal to 1:64) using the indirect fluorescent antibody method. elevated proteus agglutination antibody titers (greater than 1:160) to ox-19, but not ot ox-2, were common (19.6%) in these children. no correlation of those with positive ox-19 titers c ... | 1982 | 6798859 |
| in vitro sensitivity of rickettsia rickettsii to doxycycline. | 1982 | 6802907 | |
| 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 |
| rocky mountain spotless fever: a dilemma for the clinician. | failure of the characteristic rash to develop during the course of illness in rocky mountain spotted fever may lead to the delay or failure of diagnosis and may result in fetal encephalopathic illness with disseminated vascular injury. four patients are described herein in whom a rash failed to develop and the diagnosis was initially incorrect. each patient was seen at least once before hospital admission by a physician and given ineffective antibiotic therapy, resulting in fatal complications. ... | 1982 | 6807231 |
| rocky mountain spotted fever in areas of high and low prevalence: survey for canine antibodies to spotted fever rickettsiae. | antibodies to rickettsia rickettsii were detected by indirect immunofluorescence in sera from 149 of 467 dogs (32%) examined from 4 military installations located in kentucky, north carolina, pennsylvania, and virginia. the prevalence at individual installations ranged from 4.3% at fort knox, ky, to 63.4% at fort bragg, nc. most of the seropositive dogs were in the working and sporting groups of dogs. the difference in antibody prevalence between sexes was not significant. serologic responses we ... | 1982 | 6808878 |
| human endothelial cell culture plaques induced by rickettsia rickettsii. | primary cultures of human umbilical vein endothelial cells were inoculated with plaque-purified rickettsia rickettsii. after adsorption of rickettsiae, monolayers were overlaid with medium containing 0.5% agarose. small plaques appeared on day 4 postinoculation, and distinct 1- to 2-mm plaques were observed on day 5. plaquing efficiency was less than that of primary chicken embryo cells in the same medium. human endothelial cell monolayers were susceptible to infection by r. rickettsii and under ... | 1982 | 6809631 |
| penicillin-induced unstable intracellular formation of spheroplasts by rickettsiae. | penicillin g (greater than or equal to 20 micrograms/ml) is rapidly rickettsiacidal for intracellular rickettsia prowazekii. light and electron microscopic examinations revealed that penicillin g in culture medium induced a predictable transformation into typical enlarging spheroplasts deficient in the internal, putative peptidoglycan layer of the outer membrane. under certain conditions, spheroplasts ruptured to discharge contents into host cell cytoplasm and to leave empty shells of defective ... | 1982 | 6809842 |
| reactivation of rickettsia rickettsii in dermacentor andersoni ticks: an ultrastructural analysis. | virulent rickettsia in dermacentor andersoni lose their pathogenicity and virulence for guinea pigs when subjected to physiological stresses, such as starvation (overwintering), of its tick vector. however, incubation of infected ticks at an elevated temperature (37 degrees c) for 24 to 48 h or feeding for a time (usually greater than 10 h) induces r. rickettsii to revert to a virulent state, a phenomenon defined as "reactivation." electron microscopy reveals that the microcapsular and slime lay ... | 1982 | 6811439 |
| 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 |
| serological cross-reaction and cross-protection in guinea pigs infected with rickettsia rickettsii and rickettsia montana. | antisera produced in guinea pigs inoculated with rickettsia rickettsii or rickettsia montana were cross-reactive but sufficiently specific to identify the primary infecting agent. guinea pigs immunized with r. montana were protected from fatal infection with r. rickettsii, although a few (25%) developed mild fever of short duration. | 1980 | 6893191 |
| the occurrence of eschars in rocky mountain spotted fever. | two patients with fatal, laboratory-confirmed rocky mountain spotted fever (rmsf) were noted early in their course to have a skin lesion characteristic of a rickettsial eschar. postmortem immunofluorescent and histopathologic studies demonstrated that the lesions were sites of extensive contiguous infection by rickettsia rickettsii with associated injury to numerous local blood vessels. rickettsial vasculitis and occlusive luminal thrombosis were associated with dermal and epidermal coagulative ... | 1981 | 7240465 |
| 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 |
| the role of cottontail rabbits (sylvilagus spp.) in the ecology of rickettsia rickettsii in the united states. | rocky mountain (sylvilagus nuttallii) and eastern (s. floridanus) cottontails were examined for their susceptibility to virulent and avirulent strains of the spotted fever agent, rickettsia rickettsii. both species of rabbits responded to inoculation of yolk sac suspensions containing 500 egg ld50 of either virulent or avirulent rickettsiae, with rickettsemias detectable as early as 3 days after inoculation and lasting up to 7 days. when fed upon by infected ticks, only one of three rocky mounta ... | 1980 | 7406116 |
| rickettsia rickettsii has proteins with cross-reacting epitopes to eukaryotic phospholipase a2 and phospholipase c. | the entry, and possibly the exit, of rickettsiae from eukaryotic cells, as well as erythrocyte lysis by some members of this group of organisms, is thought to be mediated by a phospholipase a activity even though the enzyme has not been isolated from these organisms. evidence for phospholipase c, on the other hand, has not been reported for the genus rickettsia. in this study, in a preliminary attempt to demonstrate the presence of phospholipase a2 and phospholipase c in the virulent sheila smit ... | 1994 | 7532256 |
| 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 |
| rocky mountain spotted fever: a seasonal alert. | rocky mountain spotted fever occurs during seasonal tick activity. a history of exposure to tick-containing habitats within the 3- to 12-day incubation period is a key epidemiological factor. the signs of fever, headache, myalgia, nausea, vomiting, and anorexia at onset of infection are difficult to distinguish from those of self-limited viral infections. rash usually appears later and, if present, progresses through a sequence of stages and distribution that are never pathognomonic. the effects ... | 1995 | 7619984 |
| long-term sequelae of rocky mountain spotted fever. | twenty-five patients with definite or probable rocky mountain spotted fever (rmsf) who were hospitalized for > or = 2 weeks were identified from our database of 105 patients. follow-up information was collected for 20 patients, per telephone and/or medical records. the remaining five patients were lost to follow-up or died. nine patients had > or = 1 long-term sequelae (defined as complications related to an original acute infection with rickettsia rickettsii that persisted for > or = 1 year fol ... | 1995 | 7619986 |
| comparison of the rompa gene repeat regions of rickettsiae reveals species-specific arrangements of individual repeating units. | genes containing repeating units have been described for several eukaryotic and prokaryotic proteins, although none exhibit the extraordinary length and conservation seen with the rickettsia rickettsii 190-kda protein (ompa) repeat region. the genetic organization of the repeat regions of the ompa gene for r. conorii and r. akari was examined and compared to that of r. rickettsii. individual repeating units, which constitute the makeup of the repeat regions, share extensive dna homology among th ... | 1993 | 7680636 |
| e-selectin-dependent neutrophil adhesion to rickettsia rickettsii-infected endothelial cells. | increased neutrophil or hl60 cell adhesion to rickettsia rickettsii-infected endothelial cells (ecs) was observed at 6 to 8 hours after the initiation of infection, diminishing by 24 hours. similar increases were observed using formaldehyde-fixed neutrophils. cellular association and likely the intracellular presence of rickettsiae was required for enhanced neutrophil adhesion, because culture medium conditioned by infected cells or rickettsiae rendered noninfective by pretreatment with tetracyc ... | 1993 | 7683219 |
| eia with species-specific monoclonal antibodies: a novel seroepidemiologic tool for determination of the etiologic agent of spotted fever rickettsiosis. | all currently available assays for antibodies to the etiologic agents of spotted fever group rickettsioses detect reactivity with antigens of lipopolysaccharides and the major cell wall proteins, which contain epitopes that are shared among many spotted fever group rickettsiae. the hypothesis of this study was that a monoclonal antibody to a species-specific epitope of rickettsia rickettsii would be blocked from binding to the rickettsial surface if the rickettsiae were incubated previously with ... | 1993 | 7693827 |
| granulocytic ehrlichiosis and meningitis in a dog. | a 4-year-old male mixed-breed dog from the sierra nevada mountains in california was referred because of epistaxis and signs of cervical pain. dermacentor variabilis ticks were found on the dog at the time of physical examination. clinicopathologic abnormalities included nonregenerative anemia, thrombocytopenia, and rare intracytoplasmic morulae within circulating neutrophils. abnormalities of the csf included pleocytosis and intracytoplasmic morulae in approximately 9% of neutrophils. serum ant ... | 1994 | 7730122 |
| persistence of rickettsiae in the partially viable gangrenous margins of amputated extremities 5 to 7 weeks after onset of rocky mountain spotted fever. | a case of rocky mountain spotted fever complicated by gangrene of the extremities required amputation and showed persistent rickettsial infection in the margins of the gangrene at 5 and 7 weeks after onset of illness. rickettsial organisms were demonstrated by immunoperoxidase staining in the viable endothelial cells in the ischemic margins of the gangrenous tissue. we conclude that the cellular, humoral, and pharmacologic components that lead to eradication of the rickettsiae were not delivered ... | 1995 | 7748070 |
| protection of guinea-pigs from experimental rocky mountain spotted fever by immunization with baculovirus-expressed rickettsia rickettsii rompa protein. | baculovirus recombinants that express the rickettsia rickettsii rompa protein were constructed. monoclonal antibodies (mabs) against the rompa protein reacted with recombinant-infected spodoptera frugiperda (sf9) cells in indirect immunofluorescence assays. sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting of infected sf9 cell lysates with a mab against rompa showed that the recombinant-expressed rompa protein migrated slightly below rompa extracted from r. rickettsii. ... | 1995 | 7762273 |
| [the application of pcr to epidemiological study on spotted fever group rickettsiae]. | it was the first time that a primer pairs derived from the 190kda protein antigen gene of r. rickettsii were used to amplify sfgr dna in ticks, tick ova, larva, tick faeces and rodent organs which were collected in hebei, heilongjiang, hainan and beijing. a 532bp fragment was respectively amplified from above samples. the results were partially in concordance with data obtained through rickettsiae isolation. it was suggested that pcr is a rapid, specific, sensitive and practical method for detec ... | 1995 | 7767922 |
| genomic identification of rickettsia slovaca among spotted fever group rickettsia isolates from dermacentor marginatus in armenia. | restriction fragment length polymorphism (rflp) analysis of polymerase chain reaction (pcr) amplified genes was used for genomic identification of armenian isolates of the spotted fever group (sfg) rickettsiae with unclear taxonomic position. analysis was performed by using one genus-specific primer pair derived from r. prowazekii citrate synthase gene and two species-specific primer pairs derived from r. rickettsii genes for 190 k and 120 k antigens following alui, psti and rsai digestion of am ... | 1994 | 7793355 |
| detection of dna of causative agent of spotted fever group rickettsiosis in japan from the patient's blood sample by polymerase chain reaction. | the polymerase chain reaction (pcr) was applied for the etiological diagnosis of spotted fever group (sfg) rickettsiosis in japan. nucleotide primers derived from the 17-kda antigen gene of rickettsia rickettsii primed a rickettsia-specific 246-base-pair product for all of the katayama, abe, misaka and kojima strains, which we had isolated previously. moreover, we were able to detect the same product by pcr amplification from the peripheral blood of a patient in the acute stage of the illness. t ... | 1994 | 7799840 |
| differential activity of rickettsia rickettsii opma and ompb promoter regions in a heterologous reporter gene system. | the outer membrane of the gram-negative obligate intracellular parasite rickettsia rickettsii contains two large surface protein antigens with approximate molecular masses of 200 and 135 kda termed rompa and rompb, respectively. rompb is the most abundant protein in the outer membrane, while rompa is a relatively minor constituent. densitometry of intrinsically radiolabelled protein profiles from r. rickettsii-infected vero cells indicated a molar ratio of approximately 1:9 between rompa and rom ... | 1994 | 7812435 |
| nucleotide sequence of polymerase chain reaction product amplified from rickettsia japonica dna using rickettsia rickettsii 190-kilodalton surface antigen gene primers. | the pcr product amplified from rickettsia japonica with the primer pair rr 190.70p and rr 190.602n of r. rickettsii 190-kda antigen gene was cloned into m13mp19 rf dna at the eco ri site and sequenced by chemiluminescent dna sequencing. the sequence revealed a molecular size of 533 base pairs (bp). the primer-flanking region of 491 bp, an open reading frame, was compared with the corresponding region of r. rickettsii, demonstrating 35 nucleotide substitutions in r. japonica. the sequence of prim ... | 1994 | 7898385 |
| differentiation of rickettsia japonica by restriction endonuclease fragment length polymorphism using products of polymerase chain reaction amplification with rickettsia rickettsii 190-kilodalton surface antigen gene primers. | restriction fragment length polymorphism of polymerase chain reaction (pcr) amplification products differentiated rickettsia japonica, a causative agent of oriental spotted fever, from other spotted fever group (sfg) rickettsiae. primer pair rr190. 70p and rr190. 602n of r. rickettsii 190-kda antigen gene sequence primed genomic dnas obtained from r. japonica, type strain yh and strains nt, nk, yki, and tkn. the products were cleaved by psti but not by afai restriction endonuclease. the psti dig ... | 1993 | 7901739 |
| dna typing of rickettsiae in naturally infected ticks using a polymerase chain reaction/restriction fragment length polymorphism system. | we used the polymerase chain reaction/restriction fragment length polymorphism (pcr/rflp) rickettsial typing system of regnery and others to rapidly identify rickettsiae in naturally infected ticks. unlike previously described methods, our pcr assays type rickettsiae directly from tick tissues without first isolating the organisms. we collected 226 adult dermacentor andersoni ticks in the bitterroot mountains of western montana and analyzed them for possible rickettsial infection by hemolymph te ... | 1994 | 7906924 |
| identification of rickettsia conorii infection by polymerase chain reaction in a soldier returning from somalia. | a soldier developed characteristic manifestations of boutonneuse fever shortly after leaving somalia. rickettsial dna was detected in a biopsy sample of the tache noire by a polymerase chain reaction (pcr) in which primers derived from the 190-kd antigen gene of rickettsia rickettsii were used. the source of this dna was identified as rickettsia conorii by restriction fragment length polymorphism (rflp) analysis of the pcr product. r. conorii was also isolated from the skin biopsy specimen. the ... | 1994 | 7948564 |
| rickettsialpox in a new york city hospital, 1980 to 1989. | rickettsialpox is caused by rickettsia akari, which is transmitted from rodents to humans by bloodsucking mites. the initial skin lesion forms an eschar and is followed by the development of fever, malaise, myalgia, and 5 to 40 maculopapules and papulovesicles. the disease, which responds to tetracycline, can be mistaken for chickenpox. the diagnosis has been based on an increase in serum antibody titers against r. akari over a period of three to eight weeks. we discuss a more rapid technique th ... | 1994 | 7969341 |
| 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 |
| sequence analysis of the sbsa gene encoding the 130-kda surface-layer protein of bacillus stearothermophilus strain pv72. | bacillus stearothermophilus (bs) contains a surface-layer (s-layer) protein (sbsa), which forms a hexagonal array on the cell wall. in order to understand the structural/functional relationship of sbsa from bs pv72, the entire nucleotide (nt) sequence of the sbsa gene was determined from three overlapping fragments. the 3'-end was cloned and expressed in escherichia coli, whereas the 5'-region was amplified from the genome of bs pv72 by the polymerase chain reaction using two overlapping fragmen ... | 1994 | 8045409 |
| species-specific balb/c mouse antibodies to rickettsiae studied by western blotting. | balb/c mice were inoculated intraperitoneally either once only, or up to four times at weekly intervals, with viable rickettsia rickettsii, rickettsia conorii or the israeli spotted fever group rickettsia. sera collected one week after the last inoculation were tested for the presence of antibodies reactive with the above organisms by indirect fluorescent antibody testing and western blot. with repeated inoculations there was a general progressive rise in homologous and heterologous immunofluore ... | 1994 | 8050715 |
| in vitro susceptibilities of spotted fever group rickettsiae and coxiella burnetti to clarithromycin. | the in vitro bacteriostatic activity of clarithromycin, a new macrolide derivative, against rickettsia rickettsii, rickettsia conorii, and "rickettsia israeli" was determined by the plaque assay and the dye uptake assay. both bacteriostatic and bactericidal activities of clarithromycin against the nine mile, q212, priscilla, and me9 strains of coxiella burnetti were evaluated by using three cell culture systems. clarithromycin showed improved antibacterial activity compared with that of erythrom ... | 1993 | 8109928 |
| rickettsia rickettsii infection of cultured human endothelial cells induces tissue factor expression. | microvascular thrombi underlie many of the clinical manifestations of rocky mountain spotted fever (rmsf), a disease characterized by rickettsia rickettsii infection of vascular endothelial cells. studies were designed to determine whether r rickettsii-infection of cultured human umbilical vein endothelial cells results in tissue factor (tf) induction, a process that could directly activate coagulation in infected vessels. whereas uninfected endothelial cell cultures showed essentially undetecta ... | 1994 | 8123842 |
| characterization of a rickettsia rickettsii dna fragment analogous to the fir a-orf17-lpxa region of escherichia coli. | the fira and lpxa genes, as well as an orf coding for a putative 16-kda protein of unknown function, have been identified and characterized in the obligate intracellular bacterium. rickettsia rickettsii. this is the first description of these genes, which code for enzymes involved in the biosynthesis of lipid a, in a species outside of the enterobacteriaceae. the deduced amino acid (aa) sequences of fira, orf16 and lpxa of r. rickettsii, when compared to their escherichia coli analogs, exhibited ... | 1994 | 8125326 |
| infection of human endothelial cells by rickettsia rickettsii causes a significant reduction in the levels of key enzymes involved in protection against oxidative injury. | the activities of glucose-6-phosphate dehydrogenase, catalase, and glutathione peroxidase were significantly decreased in human endothelial cells infected with the obligate intracellular bacterium rickettsia rickettsii, the causative agent of rocky mountain spotted fever. this observation lends additional support to our hypothesis implicating oxidative damage in endothelial cell injury caused by this microorganism. | 1994 | 8188386 |
| evaluation of immunoperoxidase techniques to detect rickettsia rickettsii in fixed tissue sections. | standard immunoperoxidase techniques were evaluated in the diagnosis of rocky mountain spotted fever (rmsf). formalin-fixed, paraffin-embedded tissue was tested to detect rickettsia rickettsii using the same antibody provided by the centers for disease control and prevention that is used for direct immunofluorescence (dif). tissues from 23 patients with suspected rmsf were divided: some were snap-frozen for dif; the remainder were fixed in formalin, processed routinely, and embedded in paraffin ... | 1994 | 8209863 |
| preliminary evaluation of the indx dip-s-ticks with positive rickettsial samples in malaysia. | forty-four serum samples of various reactivities to rickettsial antigens demonstrated by the indirect immunoperoxidase technique were tested with indx dip-s-ticks (indx integrated diagnostics inc., usa) kit for the detection of tick borne diseases. the kit utilised rickettsia rickettsii the causative agent of rocky mountain spotted fever (rmsf) as antigens. the samples positive for endemic typhus were also tested against r. typhi, the agent for endemic typhus by the same method. the aim of this ... | 1993 | 8277794 |
| human endothelial cells as an alternative to dh82 cells for isolation of ehrlichia chaffeensis, e. canis, and rickettsia rickettsii. | ehrlichia chaffeensis, etiologic agent of human ehrlichiosis, and rickettsia rickettsii, etiologic agent of rocky mountain spotted fever (rmsf), are both tick-borne agents that cause nonspecific symptoms that may be indistinguishable from each other early in the course of infection. e. canis is a canine pathogen closely related to e. chaffeensis and was initially suspected of being the causative agent of human ehrlichiosis. if a febrile illness is reported, after tick exposure, neither ehrlichio ... | 1993 | 8297496 |
| the use of a polymerase chain reaction as a diagnostic test for rocky mountain spotted fever. | a polymerase chain reaction (pcr) for amplifying ribosomal dna of rickettsia rickettsii was performed on blood clots and urine samples from 10 patients with suspected rocky mountain spotted fever (rmsf) and five controls with nonrickettsial diseases. the results of this pcr-based procedure were positive in four of the five patients with probable rmsf, but reamplification was required in three patients. rickettsia rickettsii was grown from the blood of two of these four patients. the urine from o ... | 1994 | 8304573 |
| brazilian spotted fever in espirito santo, brazil: description of a focus of infection in a new endemic region. | although brazilian spotted fever is known to occur in several adjacent states, infection with spotted fever group (sfg) rickettsiae has not previously been documented in the brazilian state of espirito santo. we report a cluster of two proven and four suspected cases of brazilian spotted fever in a small valley near colatina, espirito santo. four patients died without confirmatory serologic or pathologic studies. the two surviving patients had serologic and/or pathologic evidence of infection wi ... | 1993 | 8357085 |
| comparison of latex agglutination, indirect immunofluorescent antibody, and enzyme immunoassay methods for serodiagnosis of rocky mountain spotted fever in dogs. | indirect immunofluorescent antibody (ifa), latex agglutination (la), and enzyme immunoassay (eia) methods were compared for evaluation of the serum antibody responses of dogs experimentally and naturally exposed to spotted fever-group rickettsiae. selected sera (obtained on days 1, 42, 53, 124, 145, 236, 255, 264, and 292) were examined from three 8-month-old female beagles inoculated with rickettsia rickettsii on days 34 and 250 of the study. a second group of dogs comprised three 8-month-old f ... | 1993 | 8427468 |
| 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 |
| rocky mountain spotted fever complicated by gangrene: report of six cases and review. | although mortality due to fulminant rocky mountain spotted fever (rmsf) is well appreciated, the ability of the disease to cause survivors to become permanently disabled is not as widely known. we report six cases of rmsf complicated by gangrene. although four patients required multiple limb and/or digital amputations, only one death resulted. our review of the english-language literature revealed 23 additional cases of rmsf complicated by gangrene. pathophysiologically, gangrene is most likely ... | 1993 | 8507753 |
| rocky mountain spotted fever in an endemic area in minas gerais, brazil. | only one species of spotted fever-group rickettsiae that is pathogenic for humans has been isolated in brazil, where few physicians are familiar with this disease. in order to obtain information on tick-borne rickettsiosis, a study was performed in the county of santa cruz do escalvado, state of minas gerais, brazil, where a fatal clinical case confirmed by specific immunofluorescence had been reported. serum samples obtained from 679 humans and 96 dogs were tested by indirect immunofluorescence ... | 1994 | 8524052 |
| tissue factor mrna expression in the endothelium of an intact umbilical vein. | tissue factor (tf) mrna expression was measured by in situ hybridization in the endothelium of the intact human umbilical vein after infection with rickettsia rickettsii. at 4 hours, r rickettsii organisms were clearly visible within approximately 70% of endothelial cells by immunocytochemical staining. quantitation of tf mrna expression revealed that the level within endothelial cells of the infected vein was significantly greater (3.7-fold, p < .0001) than that detected in uninfected endotheli ... | 1996 | 8547639 |
| hemocytic rickettsia-like organisms in ticks: serologic reactivity with antisera to ehrlichiae and detection of dna of agent of human granulocytic ehrlichiosis by pcr. | ixodid ticks were collected from connecticut, massachusetts, missouri, pennsylvania, rhode island, and british columbia (canada) during 1991 to 1994 to determine the prevalence of infection with hemocytic (blood cell), rickettsia-like organisms. hemolymph obtained from these ticks was analyzed by direct and indirect fluorescent antibody (fa) staining methods with dog, horse, or human sera containing antibodies to ehrlichia canis, ehrlichia equi, or rickettsia rickettsii. of the 693 nymphal and a ... | 1995 | 8567911 |
| rocky mountain "spotless" fever with an erythema migrans-like skin lesion. | we report a case of rocky mountain "spotless" fever with a localized rash at the site of the tick bite that resembled the erythema migrans rash of lyme borreliosis. physicians who practice in geographic areas where rocky mountain spotted fever occurs should be aware of this unusual presentation. | 1995 | 8589170 |
| interleukin-1 alpha production during rickettsia rickettsii infection of cultured endothelial cells: potential role in autocrine cell stimulation. | rickettsia rickettsii infection results in numerous responses by cultured endothelial cells, among them a rapid, transient increase in steady-state levels of tissue factor mrna (l.a. sporn, p.j. haidaris, r.-j. shi, y. nemerson, d.j. silverman, and v.j. marder, blood 83:1527-1534, 1994). in this study, production of interleukin-1 (il-1) was measured during infection and its potential role in autocrine cell stimulation was investigated. a fivefold increase in levels of il-1 alpha antigen was meas ... | 1996 | 8613368 |
| deletion in the 190 kda antigen gene repeat region of rickettsia rickettsii. | the 190 kda outer membrane protein of rickettsia rickettsii is a major immunodominant protective antigen which contains 13 tandem nearly identical repeating sequences. we have identified a deletion in the 190 kda antigen gene of r. rickettsii strain smith maintained in the laboratory. the deletion occurred within the repeat region of this gene and the mutated repeat region corresponded to one repeating unit in size. | 1996 | 8692010 |
| tick-borne illness increasing in oklahoma. | 1996 | 8720556 | |
| detection of spotted fever group rickettsiae in ticks and rodents by polymerase chain reaction technique in people's republic of china. | the polymerase chain reaction (pcr) technique for amplification of genomic fragments of spotted fever group (sfg) rickettsiae directly from field samples of ticks, tick ova, tick larvae, tick faeces and organs of wild mice was employed for the first time in p.r. of china. ticks and rodents were collected in beijing and heilongjiang, hainan and hebei provinces. the pcr primers were designed from the dna sequence encoding the 190 k protein of r. rickettsii for a 532 bp long product. seven of ten t ... | 1995 | 8722295 |
| rocky mountain spotted fever. | 1996 | 8727127 | |
| laboratory diagnosis of rickettsial diseases. | 1996 | 8727134 | |
| genetic variation in australian spotted fever group rickettsiae. | rickettsiae were isolated by cell culture of buffy coat blood from six patients with spotted fever from southeastern australia and flinders island in bass strait. the isolates were genetically compared with two previous rickettsia australis patient isolates. the genus-specific 17-kda genes from the isolates were compared after dna amplification and restriction fragment analysis of the amplified dna. this comparison revealed that mainland rickettsial isolates from southeastern australia were iden ... | 1996 | 8735110 |
| [spotted fever group rickettsiosis and vectors in kanagawa prefecture]. | primer pairs for pcr were designed from the gene encoding the 17,000-molecular-weight genus-common antigen of rickettsia japonica, rickettsia rickettsii, rickettsia conorii, rickettsia typhi and rickettsia prowazekii. primers r1, r2 were designed for amplifying the genomic dna from spotted fever group (sfg) rickettsiae and epidemic typhus rickettsiae. primers rj5, rj10 were designed for amplifying the genomic dna from only r. japonica. using the primers r1, r2, about a 540-bp fragment was observ ... | 1996 | 8741704 |
| increased expression of plasminogen activator inhibitor-1 in r. rickettsii-infected endothelial cells. | changes in pai-1 expression in human umbilical vein endothelial cells (huvec) were studied following in vitro infection with rickettsia rickettsii. a 1.8-fold increase in secreted pai-1 activity occurred in infected versus control cultures (p = 0.03) at 24 h but not at earlier timepoints. a similar increase (1.4-fold) in secreted pai-1 antigen (p < 0.005) was measured by elisa. to determine whether this increase was due to increased synthesis of pai-1, huvec were metabolically labeled with 35s-m ... | 1996 | 8743186 |
| unrecognized spotted fever group rickettsiosis masquerading as dengue fever in mexico. | although rocky mountain spotted fever was documented in northern mexico during the 1940s, spotted fever group (sfg) rickettsioses have subsequently received little attention in mexico. in this study, sera collected in 1993 from 50 patients from the mexican states of yucatan and jalisco, who were suspected clinically to have dengue fever but had no antibodies to dengue virus, were examined by indirect immunofluorescence for igm antibodies reactive with rickettsia rickettsii, r. akari, and r. typh ... | 1996 | 8780453 |
| reliving a nightmare: a hard (and tragic) lesson in humility. | 1996 | 8816145 | |
| remember rocky mountain spotted fever--a lesson in ethical principles. | 1996 | 8816146 | |
| parasites and selected diseases of collared peccaries (tayassu tajacu) in the trans-pecos region of texas. | fifty-five collared peccaries (tayassu tajacu) were collected from october 1988 through april 1991 from five counties within the trans-pecos region of texas (usa) to monitor for diseases and parasites. no endoparasites were recovered on gross examination. antibody to borrelia burgdorferi was documented in one (2%) of 55 specimens. three (6%) of 54 collared peccaries were positive for yersinia pestis antibodies. all collared peccaries were negative for antibodies against brucella spp., francisell ... | 1996 | 8827690 |
| differentiation of spotted fever group rickettsiae by sequencing and analysis of restriction fragment length polymorphism of pcr-amplified dna of the gene encoding the protein rompa. | currently, the genotypic identification of the spotted fever group (sfg) rickettsiae is based on restriction fragment length polymorphism analysis of pcr-amplified genes coding for the enzyme citrate synthase and the surface proteins rompa and rompb. a set of useful restriction endonucleases was found following comparison of rickettsia rickettsii and r. prowazekii sequences. however, by using three pcr amplifications and four enzyme digestions with this set, it was impossible to differentiate be ... | 1996 | 8862558 |
| prednisolone at anti-inflammatory or immunosuppressive dosages in conjunction with doxycycline does not potentiate the severity of rickettsia rickettsii infection in dogs. | dogs were experimentally inoculated with rickettsia rickettsii to determine if anti-inflammatory or immunosuppressive dosages of prednisolone, when administered in conjunction with an antirickettsial antibiotic (doxycycline), induced therapeutically relevant pathophysiological consequences that ultimately influence disease outcome. although the duration of rickettsemia was prolonged in dogs receiving immunosuppressive, but not anti-inflammatory, corticosteroids, concurrent administration of doxy ... | 1997 | 8980770 |
| predictors of prognosis and risk of acute renal failure in patients with rocky mountain spotted fever. | acute renal failure has long been associated with severe rocky mountain spotted fever (rmsf). despite many descriptions of the protean manifestations of this disease, relatively little is known concerning the risk factors for acute renal failure. only a few studies have examined the outcome of patients infected with rickettsia rickettsii who develop renal insufficiency, and these studies had methodological problems. | 1996 | 9003109 |
| [spotted fever in the municipality of pedreira, ps, brazil. serologic survey]. | cases of brasilian spotted fever (bsf) have been occurred since 1985, in the rural area of pedreira town, situated 160 km away from the city of são paulo (longitude 46 degrees 54'07", latitude 22 degrees 44'21"). aiming at evaluating the prevalence of brasilian spotted fever in this endemic area, single-serum samples were collected from 473 healthy persons, amongst city-dwellers and the local china industry workers. the obtained samples were tested by indirect immunofluorescence (ifa), in order ... | 1996 | 9026831 |
| primary isolation of spotted fever group rickettsiae from amblyomma cooperi collected from hydrochaeris hydrochaeris in brazil. | this paper reports the first isolation of a spotted fever group rickettsia from an amblyomma cooperi ixodid collected from a capybara (hydrochaeris hydrochaeris) in an endemic area of spotted fever in the county of pedreira, state of são paulo, brazil. isolation was performed in vero cell culture and submitted to immunofluorescence, using antibody from rickettsia rickettsii-positive human serum. | 1996 | 9040845 |
| in vitro susceptibilities of bartonella henselae, b. quintana, b. elizabethae, rickettsia rickettsii, r. conorii, r. akari, and r. prowazekii to macrolide antibiotics as determined by immunofluorescent-antibody analysis of infected vero cell monolayers. | the in vitro susceptibilities of bartonella (rochalimaea) henselae, b. quintana, b. elizabethae, rickettsia akari, r. conorii, r. prowazekii, and r. rickettsii to different concentrations of azithromycin, clarithromycin, dirithromycin, erythromycin, and roxithromycin in vero cell cultures were evaluated. bartonella and rickettsia spp. were allowed to initiate infection of the antibiotic-free vero cell monolayers, which were maintained in 16-chamber microscope slides in the absence of antibiotics ... | 1997 | 9055996 |
| clinical and clinicopathologic abnormalities in greyhounds with cutaneous and renal glomerular vasculopathy: 18 cases (1992-1994) | to determine clinical signs and clinicopathologic abnormalities in greyhounds with cutaneous and renal glomerular vasculopathy and to determine whether there were any differences between dogs with and without renal azotemia. | 1997 | 9074681 |
| clinical features and serology of 14 dogs affected by granulocytic ehrlichiosis in sweden. | the clinical features and the titres to ehrlichia equi, e canis, e risticii, rickettsia rickettsii and borrelia afzelii in 14 swedish dogs, in which ehrlichiosis was diagnosed on the basis of the presence of inclusions in granulocytes, are reported. most of the dogs were moderately ill but made a rapid recovery after treatment with doxycycline. the dogs with inclusions were thrombocytopenic. analysis of the antibody titres indicates that serology to e equi will remain the most appropriate serolo ... | 1997 | 9076917 |
| citrate synthase gene comparison, a new tool for phylogenetic analysis, and its application for the rickettsiae. | using pcr and an automated laser fluorescent dna sequencer, we amplified and sequenced a 1,234-bp fragment of the citrate synthase-encoding gene (glta) of 28 bacteria belonging to the genus rickettsia. comparative sequence analysis showed that most of the spotted fever group (sfg) rickettsiae belonged to one of two subgroups. the first subgroup included rickettsia massiliae, strain bar 29, rickettsia rhipicephali, "rickettsia aeschlimanni," and rickettsia montana, which have been isolated only f ... | 1997 | 9103608 |
| rickettsia peacockii sp. nov., a new species infecting wood ticks, dermacentor andersoni, in western montana. | rickettsia peacockii, a new species of spotted fever group rickettsiae, was identified from rocky mountain wood ticks (dermacentor andersoni) collected in the sapphire mountain range on the eastern side of bitterroot valley, montana. dna from r. peacockii skalkahot (t = type strain) in naturally infected tick tissue was amplified by a pcr assay with primer sets derived from eubacterial 16s ribosomal dna (rdna), rickettsial citrate synthase, and 190-kda surface antigen (rompa) genes. partial 16s ... | 1997 | 9103635 |
| detection of colorado tick fever virus by using reverse transcriptase pcr and application of the technique in laboratory diagnosis. | colorado tick fever (ctf) virus elicits an acute illness in humans, producing nonspecific flu-like symptoms and a biphasic fever in approximately 50% of patients. the disease is transmitted by the adult rocky mountain wood tick (dermacentor andersoni), and therefore incidence is limited by the habitat and life cycle of that vector. the early symptoms of infection are difficult to distinguish from those of several other agents, especially rickettsia rickettsii. serologic testing is usually unable ... | 1997 | 9114408 |
| rickettsia rickettsii infection of cultured human endothelial cells induces nf-kappab activation. | rickettsia rickettsii, the etiologic agent of rocky mountain spotted fever, is an obligate intracellular bacterial organism that infects primarily the vascular endothelial cells (ec). a component of the ec response to infection is transcriptional activation, which may contribute to the thrombotic and inflammatory consequences of disease. in this study, we explore r. rickettsii-induced activation of the nuclear factor-kappab/rel (nf-kappab) family of transcription factors involved in early transc ... | 1997 | 9199451 |
| sequence analysis and comparison of 190 k surface antigen gene fragment of a new species of spotted fever group rickettsiae. | a 533 bp long pcr product amplified from rickettsial strain hl-93 dna with the primer pair rr 190.70p and rr 190.602n, designed from dna sequence encoding 190 k protein antigen of r. rickettsii, was cloned into plasmid vector pgem-t and sequenced. the primer-flanking region of the product, an open reading frame, was 491 bp long. the sequence of the product was compared with those of the corresponding regions of dnas of r. rickettsii (strain r), r. japonica (strain vr 1363) and r. conorii (strain ... | 1997 | 9199714 |
| bacteriostatic and bactericidal activity of levofloxacin against rickettsia rickettsii, rickettsia conorii, 'israeli spotted fever group rickettsia' and coxiella burnetii. | levofloxacin, the l-isomer of ofloxacin, is approximately twice as active as ofloxacin against most gram-positive and gram-negative bacteria, and has improved intracellular pharmacokinetic and pharmacodynamic properties. the present work deals with the in-vitro activity of levofloxacin against the obligate intracellular bacteria rickettsia rickettsii, rickettsia conorii, 'israeli spotted fever group rickettsia' (israeli sfgr) and coxiella burnetii. fluoroquinolones, including ofloxacin, have pre ... | 1997 | 9222041 |
| pcr amplification and comparison of nucleotide sequences from the groesl heat shock operon of ehrlichia species. | degenerate pcr primers derived from conserved regions of the eubacterial groesl heat shock operon were used to amplify groesl sequences of ehrlichia equi, ehrlichia phagocytophila, the agent of human granulocytic ehrlichiosis (hge), ehrlichia canis, bartonella henselae, and rickettsia rickettsii. the groesl nucleotide sequences were less conserved than the previously determined 16s rrna gene sequences of these bacteria. a phylogenetic tree derived from deduced groel amino acid sequences was simi ... | 1997 | 9230387 |
| thoracic radiographic findings in dogs infected with rickettsia rickettsii. | sixteen beagle dogs were injected intradermally with rickettsia rickettsii. the dogs were divided into four groups (n = 4): 1) infected, non-treated control; 2) infected, treated with doxycycline; 3) infected, treated with doxycycline and an anti-inflammatory dose of corticosteroid; and 4) infected, treated with doxycycline and an immunosuppressive dose of corticosteroid. thoracic radiographs were made and ocular fluorescein angiography was performed on days 6, 10, 17 post-inoculation. a mild in ... | 1997 | 9262680 |
| immunoperoxidase and immunofluorescent staining of rickettsia rickettsii in skin biopsies. a comparative study. | to compare immunofluorescent and immunoperoxidase staining of rickettsia rickettsii in skin biopsies of patients suspected of having rocky mountain spotted fever (rmsf). | 1997 | 9278621 |
| the great imitator: rocky mountain spotted fever occurring after hospitalization for unrelated illnesses. | we describe two patients who had rocky mountain spotted fever after they were admitted to the hospital for emergency and elective surgical procedures. we initially thought one patient had a hospital-acquired infection; the correct diagnosis was deduced from epidemiologic clues elicited by consultants. these two cases were also unusual in that one patient had a recurrent rash after an abbreviated course of low-dose doxycycline therapy and the other patient had transient and self-limiting postinfe ... | 1997 | 9305309 |
| rickettsia rickettsii growth and temperature-inducible protein expression in embryonic tick cell lines. | rickettsia rickettsii has limited adverse effects on its arthropod vector, but causes severe disease in man. to model differences in host-parasite interaction, r. rickettsii growth and protein expression were examined at temperatures reflective of host environment in the tick cell lines dalbe3 and ide2, the human endothelial cell line ecv304, and the african green monkey kidney cell line vero76. at low multiplicities of infection, rickettsial titres increased 10(2)-10(3)-fold in all cell lines a ... | 1997 | 9364140 |
| cutaneous histopathology of rocky mountain spotted fever. | the dermatologic diagnosis of rocky mountain spotted fever (rmsf) is often presumptive; the clinical presentation includes skin rash and febrile illness with or without a clear history of tick bite. the characteristic cutaneous manifestations include a generalized skin eruption with purpuric, blanching or non-blanching macules and papules usually involving the extremities. although skin biopsies are often performed to confirm the diagnosis, the spectrum of cutaneous histopathology in rmsf has no ... | 1997 | 9449487 |
| transcriptional regulation of endothelial cell tissue factor expression during rickettsia rickettsii infection: involvement of the transcription factor nf-kappab. | the vascular endothelial cell (ec) is a primary target of infection with rickettsia rickettsii, the etiologic agent of rocky mountain spotted fever. changes in gene transcription elicited by intracellular infection, including ec expression of the coagulation pathway initiator known as tissue factor (tf), may contribute to the vascular pathology observed during disease. nuclear run-on analysis of uninfected and infected, cultured human endothelial cells revealed that the rate of tf mrna transcrip ... | 1998 | 9488397 |
| superoxide dismutase-dependent, catalase-sensitive peroxides in human endothelial cells infected by rickettsia rickettsii. | the generation and intracellular accumulation of reactive oxygen species have been shown to be associated with the infection of human umbilical vein endothelial cells (huvec) by rickettsia rickettsii. in response to the oxidant superoxide, the activity of the enzyme superoxide dismutase (sod) increases following infection by this obligate intracellular bacterium. other oxidants which are capable of oxidizing the fluorescent probe 2',7'-dichlorofluorescin (dcfh) also accumulate intracellularly wi ... | 1998 | 9529045 |
| erythema migrans-like rash illness at a camp in north carolina: a new tick-borne disease? | borrelia burgdorferi, the causative agent of lyme disease, has never been isolated from a patient thought to have acquired lyme disease in any southeastern state. | 1997 | 9531233 |
| nf-kappa b-dependent inhibition of apoptosis is essential for host cellsurvival during rickettsia rickettsii infection. | the possibility that bacteria may have evolved strategies to overcome host cell apoptosis was explored by using rickettsia rickettsii, an obligate intracellular gram-negative bacteria that is the etiologic agent of rocky mountain spotted fever. the vascular endothelial cell, the primary target cell during in vivo infection, exhibits no evidence of apoptosis during natural infection and is maintained for a sufficient time to allow replication and cell-to-cell spread prior to eventual death due to ... | 1998 | 9539792 |
| proteasome-independent activation of nuclear factor kappab in cytoplasmic extracts from human endothelial cells by rickettsia rickettsii. | interaction of many infectious agents with eukaryotic host cells is known to cause activation of the ubiquitous transcription factor nuclear factor kappab (nf-kappab) (u. siebenlist, g. franzoso, and k. brown, annu. rev. cell biol. 10:405-455, 1994). recently, we reported a biphasic pattern of nf-kappab activation in cultured human umbilical vein endothelial cells consequent to infection with rickettsia rickettsii, an obligate intracellular gram-negative bacterium and the etiologic agent of rock ... | 1998 | 9573057 |
| effects of the antioxidant alpha-lipoic acid on human umbilical vein endothelial cells infected with rickettsia rickettsii. | rickettsia rickettsii infection of endothelial cells is manifested in very distinctive changes in cell morphology, consisting of extensive dilatation of the membranes of the endoplasmic reticulum and outer nuclear envelope and blebbing of the plasma membrane, as seen by transmission electron microscopy (d. j. silverman, infect. immun. 44:545-553, 1984). these changes in cellular architecture are thought to be due to oxidant-mediated cell injury, since their occurrence correlates with dramatic al ... | 1998 | 9573120 |
| phylogenetic placement of rickettsiae from the ticks amblyomma americanum and ixodes scapularis. | a rickettsial isolate (isolate moaa) belonging to the spotted fever group (sfg) was obtained from the lone star tick amblyomma americanum. we used pcr to characterize the genes for the rickettsial outer membrane proteins rompa and rompb. we sequenced the pcr products (domains i of both the rompa gene and the rompb gene) of moaa and wb-8-2, another rickettsial isolate from a. americanum. to place moaa and wb-8-2 and two other nonpathogenic isolates (rickettsia rickettsii hip2 and rickettsia monta ... | 1998 | 9574696 |
| rompa is a critical protein for the adhesion of rickettsia rickettsii to host cells. | rompa and rompb are immunodominant, surface-exposed proteins of rickettsia rickettsii. prior evidence suggests that adhesion of r. rickettsii to the host cell is mediated by a rickettsial protein. five monoclonal antibodies to rompa, five to rompb, and one to the rickettsial lipopolysaccharide (lps) were tested for inhibition of rickettsial attachment. all the monoclonal antibodies to rompa inhibited adhesion of rickettsiae to the l-929 cells with some inhibition rates as high as 90%. in contras ... | 1998 | 9600861 |
| immunodiagnosis of human granulocytic ehrlichiosis by using culture-derived human isolates. | human granulocytic ehrlichiosis (hge) is an emerging infection caused by an ehrlichia species closely related to ehrlichia equi and ehrlichia phagocytophila. recent advances in the isolation and cultivation of this organism have allowed us to develop an immunofluorescence assay (ifa), enzyme immunoassay (eia), and western immunoblotting (wb) using hl-60 cell culture-derived human isolates. antibody was detected in sera from culture-confirmed hge patients by ifa and eia, and these samples were re ... | 1998 | 9620365 |
| dual infection with ehrlichia chaffeensis and a spotted fever group rickettsia: a case report. | well-documented cases of simultaneous human infection with more than one tick-borne pathogen are rare. to our knowledge only two dual infections have been reported: simultaneous human infection with the agent of human granulocytic ehrlichiosis and borrelia burgdorferi and simultaneous human infection with b. burgdorferi and babesia microti (1-2). rocky mountain spotted fever has long been known to be endemic in north carolina; cases of human ehrlichial infection were recognized there soon after ... | 1998 | 9621205 |
| rickettsia rickettsii infection of the ea.hy 926 endothelial cell line: morphological response to infection and evidence for oxidative injury. | ea.hy 926 is a permanent human cell line that expresses highly differentiated functions characteristic of human vascular endothelium. rickettsia rickettsii can efficiently infect and cause a cytopathic effect in ea.hy 926 cells. r. rickettsii produced visible lytic plaques in ea.hy 926 cells at 10 d post-infection (p.i.) following application of a secondary agarose overlay containing 2 micrograms emetine ml-1 and 40 micrograms naf ml-1 on day 2. rickettsial growth in ea.hy 926 cells had a simila ... | 1998 | 9720025 |
| phylogenetic analysis of spotted fever group rickettsiae by study of the outer surface protein rompa. | rickettsiae are classified in the order rickettsiales and have been included in the alpha subclass of the class proteobacteria on the basis of 16s rrna gene sequence comparison. to estimate the evolutionary forces that have shaped the members of the spotted fever group (sfg) rickettsiae, the ompa gene (apart from the tandem repeat units), encoding an antigenic high-molecular-mass membrane protein specific for the group, was amplified and sequenced from 21 isolates. the phylogenetic relationship ... | 1998 | 9734038 |
| [a molecular epidemiologic investigation of north asia fever in scenic spots of beijing suburb]. | pcr/rflp technique was used to detect spotted fever group rickettsiae (sfgr) in ticks and small mammals collected in eleven scenic spots of beijing suburb. we not only detected rickettsia sibirica in d. sinicus and hedgehog collected nearby the museum of aviation, but also isolated two strains of sfgr from them, named as bj-95 strain and bjh-95 strain respectively. the two strains were identified as r. sibirica by sds-page, western blot and pcr/rflp. the results demonstrated the existence of hor ... | 1997 | 9812516 |
| characterization of human immunoglobulin (ig) isotype and igg subclass response to bartonella henselae infection. | serologic parameters of cat scratch disease (csd) were evaluated by western blot analysis. sera from patients with serologically confirmed csd antigen were screened for immunoglobulin (ig) isotype-specific as well as igg subclass-specific reactivity against bartonella henselae whole-cell antigen. bartonella-negative control sera were used to determine baseline antibody activity. heterogeneous b. henselae-specific igg reactivity with numerous protein bands, ranging from >150 to <17 kda, was obser ... | 1998 | 9826373 |