Presumptive Identification of Staphylococcus saprophyticus from Urine Specimens by Colony Appearance and Coagulase Testing: An Evaluation

Two hundred one urine specimens with pure or nearly pure cultures (greater than 5 X 10(4) CFU/mL) of coagulase-negative staphylococcus were identified in reviewing all significant urine isolates over a ten-month period. The majority of these were from young female adult outpatients with Staphylococcus saprophyticus constituting 88.9% of isolates determined with the API Staph-Ident System. For urine specimens, particularly for outpatients, coagulase-negative, nonhemolytic staphylococcal colonies with yellow pigmentation could be identified presumptively as S. saprophyticus with a sensitivity of 97.8% and a specificity of 98.3%, compared with novobiocin susceptibility testing with a sensitivity of 100% and a specificity of 96.9%.