A simple and inexpensive method for the identification of Staphylococcus epidermidis and Staphylococcus hominis.

Eight hundred and ninety-two strains of Staphylococcus species were identified by means of desferrioxamine susceptibility and fermentation results of three carbohydrates, with the API Staph system (bioMérieux, France) as reference method. No identification could be obtained for 34 strains with API Staph. Of the remaining 858 strains, identical identification was obtained with 842 (98.1%). All 707 strains identified as Staphylococcus epidermidis or Staphylococcus hominis by the API Staph system were found to be desferrioxamine susceptible, and all but 5 (3.3%) of 151 strains identified as other staphylococcal species were found to be resistant, yielding an identification correlation of 99.4% for desferrioxamine. The five additional strains which were susceptible to desferrioxamine were identified as Staphylococcus capitis (2 strains), Staphylococcus lugdunensis (2 strains), and Staphylococcus warneri (1 strain) by API Staph, and as Staphylococcus epidermidis (1 strain), Staphylococcus hominis (3 strains), and one other staphylococcal species by the experimental system.