Study of the staphylococcal affinity to fibrinogen by passive hemagglutination: a tool for the Staphylococcus aureus identification.

Cadness-Graves et al. used a slide agglutination reaction with human plasma to identify Staphylococcus aureus. The clumping factor (CF) is responsible for this reaction by reacting directly with the fibrinogen. To increase the sensitivity and the specificity of the reaction and the taxonomic value of the test based on the CF detection, a passive hemagglutination has been developed and applied on 580 staphylococcal strains. Formolized sheep red cells were sensitized with human fibrinogen. This reaction has been compared to the classic plasma slide test. The hemagglutination test is more suitable and more precise than the plasma slide test. The detection of staphylococcal affinity to fibrinogen using the passive hemagglutination reaction is a method which is simple and specific, and therefore of obvious interest in taxonomic studies.