Evaluation of a new commercial kit (UROBACT) for detection of bacteriuria

A new commercially available method (UROBACT, AB Dermaci, Sweden) for detection of bacteriuria was compared to a conventional semiquantitative bacteriological method. The kit consisted of two tubes, which were inoculated with urine in two different dilutions. Positive tests were recorded as a colour change from red to yellow in both tubes, and the test was considered negative if one or both tubes remained red. When studying 556 urine samples, the test detected 153 of 163 samples with greater than or equal to 10(5) colony forming units (CFU) of bacteria per ml, i.e. the sensitivity was 93.9%. Among the samples containing less than 10(5) CFU/ml, 347 of 357 were recorded as negative, giving a specificity of 97.2%. Although relatively few urine samples containing Staphylococcus saprophyticus and Pseudomonas pyoceanea were tested the results indicated that the method was less reliable for these species. However, compared to dip-slides, which also give poor results with S. saprophyticus, the new test has several advantages, including a more simple interpretation, i.e. a distinct colour change.