Simple Disposable Method for Quantitative Cultures of Urine

A disposable kit was tested as a means of detecting significant bacteriuria by quantitative culture of urine. The total error in 3,563 specimens tested by five investigators was less than 1%. The method was very effective in differentiating significant bacteriuria, i.e., more than 100,000 bacteria per ml of urine from uninfected urine. In specimens from patients with urinary tract abnormalities who had mixed bacterial flora, the absolute numbers obtained with the dip-inoculum method had a 10% variation when compared to results obtained by calibrated loop or dilution pour plate methods. Therefore, the main utility of the kit is for screening and following patients after therapy. A significant delay in time between inoculation of the medium in the kit with the freshly voided urine and incubation of the kit to promote growth did not affect the reliability of the kit as a method of doing quantitative urine cultures to detect bacteriuria.