Detection of bladder bacteriuria in patients with acute urinary symptoms

Quantitative culture of midstream urine fails to yield a significant microorganism in many patients with acute urinary symptoms. We cultured bladder urine, obtained by aspiration, from symptomatic adults with equivocal findings on standard testing of midstream urine for low numbers of conventional uropathogens and fastidious bacteria. We found 561 (31%) of 1817 women and 36 (12%) of 300 men to be culture positive. Five hundred eighty-one (70%) of 830 isolates were fastidious bacteria; 191 (34%) of 561 culture positive women and 0 of 36 culture-positive men had polymicrobic bacteriuria. Bacterial counts were less than 10(5) colony-forming units/mL in 67% of samples; 204 of 406 patients with single-species infections had increased leukocyte counts in urine. Patients with symptoms of urinary tract infection who are culture negative on standard testing may harbor fastidious bacteria or low numbers of conventional uropathogens in the bladder. In these patients, culture of bladder aspiration urine for low counts and fastidious species is necessary to diagnose bacteriuria.