Anaerobic bacteriuria in a male urologic outpatient population.

We screened 517 urine samples from male outpatients, many of whom had underlying urinary tract pathology, for anaerobic and aerobic bacteriuria. Of the 153 specimens containing greater than 10(5) bacteria per ml. 20% yielded anaerobes only and an additional 6% revealed mixed anaerobic and aerobic growth. Pyuria was found more frequently in samples containing anaerobic bacteriuria than in those containing no growth but not as frequently as when aerobic bacteria were present. The high counts of anaerobic bacteria in first-voided specimens compared to midstream and post-prostatic massage aliquots suggested a urethral source for most bacteria. However, suprapubic aspiration of bladder urine demonstrated the organism in 2 of 10 patients with high numbers of anaerobes and pyuria in voided samples.