Hemagglutination Test for Epidemic and Murine Typhus Fever using Sheep Erythrocytes Sensitized with Proteus OX19 Extracts

Abstract

In recent years the hemagglutination test has been used as an aid in the diagnosis of various diseases (9–19). This test is based upon the specific agglutination by homologous immune serum of erythrocytes which have been sensitized with bacterial filtrates or carbohydrate fractions (32). It has long been recognized that rickettsiae possess a non-specific antigen in common with certain strains of Proteus, making possible the Weil-Felix Reaction (1–8, 20–30). This study deals with the application of the hemagglutination test to epidemic and murine typhus fever, using as antigen sheep erythrocytes which have been sensitized with extracts from Proteus OX19. MATERIALS AND METHODS A Proteus OX19 culture, No. 7484 of the American Type Culture Collection, was used in this study. The various antigens were prepared in the following manner: 1. W-antigen. 200 ml. of a 10 per cent suspension of Proteus in distilled water was shaken for one-half hour and the bacterial debris removed by centrifugation.