Abstract
During the period of 1971-1979, 172 P. mirabilis and 17 P. 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.