Abstract
A 67-year-old woman with a liver abscess due to Bacteroides fragilis was treated with metronidazole 0.4 g orally every 8 h for 6 weeks. There was a rapid clinical improvement even though no surgical drainage was performed. By the indirect immunofluorescence technique using the patient's own strain as an antigen the antibody titer declined from 5120 to 80 in 6 months, suggesting eradication of the infecting agent.