Immune response to Bacteroides ureolyticus in a patient with brain abscess

A high titer (1:256) of agglutinating antibodies against Bacteroides ureolyticus was demonstrated in a 35-year-old woman with brain abscess, using a microagglutination test. Tests done with B. ureolyticus and heterologous sera as well as with heterologous strains and the patient's serum were negative. Circulating antibody to B. ureolyticus has not been reported previously.