O antigens of Proteus mirabilis and Proteus vulgaris strains isolated from patients with bacteremia.

During the period of 1971 to 1979, 172 Proteus mirabilis and 17 Proteus vulgaris strains were collected from blood cultures. Of these strains, 144 could be grouped into 25 O antigens. The most common antigens were O3, O23, O10, O30, and O24, which represented 46.1% of all strains. The O antigen distribution of strains isolated from blood cultures did not differ significantly from that of fecal and urinary strains. No particular O antigen could thus be defined as a virulence factor in bacteremia.