DIFFERENTIAL-DIAGNOSIS OF STAPHYLOCOCCUS-AUREUS FROM STAPHYLOCOCCUS-EPIDERMIDIS AND STAPHYLOCOCCUS-SAPROPHYTICUS BY ALPHAZURINE-A DYE

Staphylococcal bacterial suspensions were streaked on Trypticase soy agar with 5% sheep blood culture plates. Paper discs containing alphazurine A, a triphenylmethane dye, were placed on the inoculated plates which were incubated at 37-degrees-C for 24 hours. A wide zone of inhibition of growth of Staphylococcus aureus was present around the paper discs. Growth of Staphylococcus epidermidis and Staphylococcus saprophyticus was not inhibited.