Adsorption of typhus rickettsiae to ghosts of sheep erythrocytes.

Rickettsial hemolysis: rapid method for enumeration of metabolically active typhus rickettsiae.

A new assay is described for enumerating biologically active typhus rickettsiae (Madrid E strain), based on adsorption of rickettsiae to erythrocytes in the presence of NaF (which allows adsorption but not lysis) and lysis in the presence of anti-Rickettsia prowazeki immune serum (which allows only a single round of lysis). The number of lysed erythrocytes is then used to estimate the number of...

Identification of cholesterol in the receptor site for rickettsiae on sheep erythrocyte membranes.

Cholesterol was identified as an essential component of the receptor on the sheep erythrocyte to which Rickettsia prowazeki adsorbs before lysing the cell. Erythrocytes or ghosts, derived by hypotonic lysis, were treated with proteolytic enzymes, sialidase, sulfhydryl reagents, and periodate without affecting their ability to adsorb rickettsiae. Lipid extracts of ghosts and erythrocytes, on the...

Rickettsial hemolysis: adsorption of rickettsiae to erythrocytes.

The hemolysis of sheep red blood cells by Rickettsia prowazeki has been characterized. A requirement for the adsorption of the rickettsia to the erythrocyte was indicated. No indication of the production of a soluble hemolysin was observed. Neither adsorption nor hemolysis can proceed at 0 C. The hemolytic process is rapid with a half-time of less than 30 min, and both the rate and extent are p...

The Phenomenon of in Vitro Hemolysis Produced by the Rickettsiae of Typhus Fever, with a Note on the Mechanism of Rickettsial Toxicity in Mice

Suspensions of yolk sac infected with rickettsiae of murine or of epidemic typhus, and indeed suspensions of liver or peritoneal washings from cotton rats infected with these organisms, when the suspensions contain a sufficient concentration of living rickettsiae, possess the capacity to hemolyze, in vitro, red cells of rabbit or sheep origin. Under the same conditions such material did not cau...

A serologically-active erythrocyte-sensitizing substance from typhus rickettsiae. I. Isolation and titration.