The CLED agar option in urine culture routine. A prospective and comparative evaluation

Current recommendations for routine urine culture are still inoculation of specimens in a combination of solid media, usually blood agar (BA) plus MacConkey agar (MK). We have performed a prospective blind study comparing the accuracy of CLED agar (C), as the sole medium, with classic procedure (BA+MK). We included 1157 urine samples plated on the three culture media simultaneously. After incubation for 20-22 hr at 37 degrees C, the cultures were read by two of the authors independently. The cultures were evaluated according to standard criteria (BA+MK) considering a count above 10(4) CFU/ml as significant. The numbers of positive, negative, and contaminated cultures were 233, 764, and 160, respectively. Sensitivity and specificity of CLED were 98% and 99%, respectively. Fastidious microorganisms were accurately detected on C agar as well as on BA+MK. Morphologic differentiation of colonies was easier with C agar, and time required for inoculating and reading the plates was logically less in the C group. As the productivity of C is similar to that of standard procedures, its economy and convenience make it a medium worth using for routine culture of urine samples.