PRIOR CONCURRENT THERAPY: Biologic therapy: See Disease Characteristics Chemotherapy: Not specified Endocrine therapy: Not specified Radiotherapy: Not specified Surgery: Not specified Other: At least 4 days since prior intravenous antibacterial agents Oral antibiotics for prophylaxis of bacterial infection allowed At least 30 days since prior treatment with any other investigational antibiotic No other concurrent antibiotics except trimethoprim-sulfamethoxazole for the prevention of Pneumocystis carinii pneumonia