Five-hour novobiocin test for differentiation of coagulase-negative staphylococci.

A 5-h broth disk test, read visually for growth or no growth to determine resistance of coagulase-negative staphylococci to 1.6 micrograms of novobiocin per ml, was evaluated as a rapid test for the presumptive identification of Staphylococcus saprophyticus. The correlation with an overnight disk diffusion test was 100%.