Staphylococcus epidermidis biotype 4: epidemiological conclusions from five different typing methods.

There is presently no accepted method for marking individual strains of Staphylococcus epidermidis. Consequently, five parameters for distinguishing such strains were examined and compared for their epidemiological efficacy: biotyping, serotyping, proteinase grouping, aminopeptidase profiles and antibiograms. Both biotyping and proteinase grouping were of limited use in identifying a particular strain, although they were helpful in initially categorizing such strains. Antibiograms were least useful because of similarities in susceptibility patterns among isolates. Serotyping and amino-peptidase profiles provided the best means of identifying an individual strain for epidemiological use. The applicability of these typing methods was demonstrated during a one year epidemiological study at a chronic disease hospital.