Identification ofStaphylococcus epidermidis andStaphylococcus hominis from blood cultures by testing susceptibility to desferrioxamine

Abstract
Testing susceptibility to desferrioxamine has recently been described as a method for the identification ofStaphylococcus epidermidis. This method was compared to a commercial test and the tube coagulase test for the identification of staphylococci from blood cultures and other fluid specimens. A total of 216 isolates was tested over a 13-month period. Sensitivity of the desferrioxamine test in identifying isolates ofStaphylococcus epidermidis andStaphylococcus hominis was 97.3 %, while specificity was 91.8 %. When isolates displaying discrepant desferrioxamine results were characterized using recently described interpretive criteria, sensitivity and specificity of the desferrioxamine test improved to 100 %. The desferrioxamine test was reliable, inexpensive and simple to perform, and should prove useful in the diagnostic laboratory.