Recognition of immunologically important antigens in Bacteroides fragilis infection -an experimental study in mice.

When the outer membrane proteins (OMP) of Bacteroides fragilis ATCC 23745 grown under seven different culture conditions were analysed by SDS-PAGE, five of the seven preparations showed similar protein profiles. When the three different OMP preparations were subsequently analysed by Western blotting, that from B. fragilis grown in brain heart infusion broth supplemented with haemin and menadione alone showed more immunodominant bands than those grown with additional cholesterol and methionine or cholesterol and cysteine. Only the former showed immunodominant proteins around 45.6 kDa and 66.2 kDa throughout the course of infection in mice. A protein corresponding to 97.4 kDa was found under all culture conditions. The results emphasise the importance of culture conditions in the expression of immunologically reactive antigens and also the possible use of such antigens in the serodiagnosis of B. fragilis infection.