The presence of antibody-coated anaerobic bacteria in asymptomatic bacteriuria during pregnancy.

Quantitative anaerobic culture of urine samples obtained from 593 pregnant women by suprapubic bladder aspiration was performed to establish the involvement of anaerobic bacteria in asymptomatic urinary tract infections. The fluorescent antibody (FA) test was applied to the sediments of bladder aspirates to determine the site of infection. Anaerobic bacteriuria (greater than or equal to 10(4) microorganisms/ml of urine) was found in 34 patients, of whom five were FA-positive. These anaerobes were identified as Lactobacillus minutus, Veillonella parvula (two patients). Clostridium putrefaciens, and Peptostreptococcus anaerobius. Aerobic bacteriuria (greater than 10(4) microorganisms/ml of urine) was detected in 27 patients, of whom 13 were FA-positive. In 10 women with mixed aerobic/anaerobic bacteriuria, no FA-positive bacteria were found. The finding of FA-positive anaerobes may indicate that these organisms are involved in silent renal infection.