Significance of Gardnerella vaginalis in urine cultures

During a 15-month period, 12,343 consecutive routine urine cultures from female patients were screened for the presence of Gardnerella vaginalis. Of the positive urine cultures, Escherichia coli was found in 1,256 (57%) and presumptive G. vaginalis in 163 (5%). Of the 163 presumptive G. vaginalis isolates, 115 were present in quantitative categories sufficient to suggest the diagnosis of probable urinary tract infection. Of these 115 isolates, 92 were available for specific identification, of which 69 (75%) proved to be G. vaginalis. Comparison of clinical urinary tract diagnoses for the 69 G. vaginalis patients and a matched cohort of E. coli patients showed a significant correlation of E. coli recovery with the diagnosis of urinary tract infection and a significant correlation of G. vaginalis recovery with no urinary tract infection. G. vaginalis was frequently recovered from nonsymptomatic pregnant patients. G. vaginalis appeared at best to be an uncommon urinary tract pathogen.