Biochemical Characteristics of Typhus Group Rickettsiae with Special Attention to the
            <i>Rickettsia prowazekii</i>
            Strains Isolated from Flying Squirrels

Dasch, Gregory A.; Samms, J R; Weiss, Emilio

doi:10.1128/iai.19.2.676-685.1978

Cited by 36 publications

(16 citation statements)

References 22 publications

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“…For lactoperoxidase-catalyzed radioiodination, carrier-free 125I was diluted with phosphate buffer to an iodide concentration of 0.6 jg/ml. Sucrose gradientpurified (0.03 ml) were mixed for 30 mi at 260C with 0.01 nil of lactoperoxidase (1…”

Section: Methodsmentioning

confidence: 99%

Surface proteins of typhus and spotted fever group rickettsiae

Osterman¹,

Eisemann²

1978

Infect Immun

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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 !LM 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 ,uM iodide, all six major proteins were radiolabeled. Similar selective labeling was not achieved with R. conorii. Analysis of both typhus and spotted fever group organisms radiolabeled with galactose suggested that carbohydrate was associated with proteins 1, 3, and 4. Typhus soluble antigen included all major proteins except protein 2, which remained attached to particulate rickettsiae after ether extraction. Protein 4 appeared to be prominent in the surface topography of R. prowazekii, was a component of soluble antigen and may have an important role in rickettsiae-host interactions.

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Section: Methodsmentioning

confidence: 99%

Surface proteins of typhus and spotted fever group rickettsiae

Osterman¹,

Eisemann²

1978

Infect Immun

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“…The evolutionary, taxonomic, and clinical significance of these observations is not apparent. We were disappointed that none of these monoclonal antibodies could distinguish among the various strains of R. prowazekii, but this was not particularly surprising in view of the known homogeneity of the surface proteins of reference strains (6). Regardless, the interesting array of monoclonal antibodies that were produced should be of value in the study of rickettsial diseases.…”

Section: Discussionmentioning

confidence: 99%

Detection and characterization of mouse monoclonal antibodies to epidemic typhus rickettsiae

Black¹,

Tzianabos²,

Roumillat³

et al. 1983

J Clin Microbiol

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A solid-phase immunofluorometric assay was used to detect mouse monoclonal antibodies to epidemic typhus rickettsiae, Rickettsia prowazekii (the immunizing antigen), and to murine typhus rickettsiae, Rickettsia typhi, a related antigen. Of the 649 hybridoma cultures obtained, 628 contained antibodies either to R. prowazekii or to both R. prowazekii and R. typhi. A total of 72 cultures were cloned by limiting dilution and yielded 137 antibody-producing clones. Of these, 104 produced antibodies specific for R. prowazekii, 22 produced antibodies that reacted with R. prowazekii and R. typhi, and 11 produced antibodies that reacted with R. prowazekii, R. typhi, and R. canada. The immunoglobulin isotypes of the mouse monoclonal antibodies produced were identified by a related indirect immunofluorometric assay technique with fluorescein isothiocyanate-conjugated antisera specific for each isotype. Antibodies were also evaluated by indirect fluorescent antibody tests, and antibodies from selected clones were found to neutralize rickettsial toxic activity in mice.

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“…MICROBIOL. sial strains used in this investigation have been described elsewhere (3,29). All rickettsiae were purified from frozen pools of infected yolk sacs of embryonated chicken eggs by two cycles of Renografin density gradient centrifugation in K36 buffer and filtration through a glass filter as described previously (5,28).…”

Section: Methodsmentioning

confidence: 99%

Isolation of species-specific protein antigens of Rickettsia typhi and Rickettsia prowazekii for immunodiagnosis and immunoprophylaxis

Dasch¹

1981

J Clin Microbiol

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A simple procedure for the selective isolation of the protective species-specific protein antigens (SPAs) of Rickettsia typhi and Rickettsia prowazekii was developed to permit use of the SPAs in the immunodiagnosis and immunoprophylaxis of typhus infections. Although the SPAs were readily extracted from lysozyme- or detergent-treated rickettsiae, as measured by rocket immunoelectrophoresis, other polypeptides were also present, as shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In contrast, both water and seven buffers, each at a 10 mM concentration and pH 7.6, were nearly equally effective in the selective release of the SPAs from whole cells by extraction for 30 min at 45 degrees C. High-ionic-strength buffers and MgCl2 abolished this SPA release, thus suggesting that divalent cations were important in the binding of the SPAs to the cell envelope. The efficacy of the dilute buffer extraction procedure for isolation of large amounts of SPAs was tested by further characterization of the supernatants obtained by centrifugation (200,000 x g) of two successive tris-(hydroxymethyl)aminomethane-hydrochloride buffer (Tris) extracts. With this procedure, between 10 and 15 mg of SPA was obtained from 100 mg of purified rickettsiae. Although low-molecular-weight ribonucleic acid fragments were released into the Tris extracts in significant amounts, only the SPAs were detected, in significant quantities, as measured by polyacrylamide gel electrophoresis and rocket immunoelectrophoresis. The Tris extracts contained the same major and minor SPA polypeptides as those observed previously in SPA preparations obtained by extensive diethylaminoethyl-cellulose column chromatography, but the Tris SPAs were more satisfactory antigens in an enzyme-linked immunosorbent assay.

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Biochemical Characteristics of Typhus Group Rickettsiae with Special Attention to the Rickettsia prowazekii Strains Isolated from Flying Squirrels

Cited by 36 publications

References 22 publications

Surface proteins of typhus and spotted fever group rickettsiae

Surface proteins of typhus and spotted fever group rickettsiae

Detection and characterization of mouse monoclonal antibodies to epidemic typhus rickettsiae

Isolation of species-specific protein antigens of Rickettsia typhi and Rickettsia prowazekii for immunodiagnosis and immunoprophylaxis

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