[Comparison of direct and standardized disk diffusion susceptibility testing of urine and other clinical specimens...

A comparison between direct and standardized disk diffusion tests was made on a total of 116 urine specimens containing greater than or equal to 10(5) organism/ml and on a total of 229 clinical specimens others than urine. The number of major discrepancies per organism tested in pure culture was 31 (39.7%) for urine and 102 (59.6%) for other specimens. Although this procedure may be of value in selected cases with pure cultures of organism, its use on a routine basis is not recommended.