[Rapid agglutination tests for the identification of Staphylococcus aureus]

The article deals with rapid agglutination tests for Staphylococcus aureus identification which detect clumping factor and protein A. The tests were compared with standard diagnostic methods: free coagulase, bound coagulase and thermostable deoxyribonuclease, 190 Staphylococcus aureus strains have been examined of which, 105 methicillin susceptible strains, 85 methicillin resistant strains, and 32 coagulase negative staphylococci strains strains. The presence of clumping factor was detected in 100% of examined Staphylococcus aureus strains. No difference between methicillin susceptible strains and methicillin resistant strains was observed. Protein A was present in 96.1% of methicillin susceptible strains and in 90.6% of methicillin resistant Staphylococcus aureus strains. The same test showed false negative results in 12 strains: 4 of which methicillin susceptible and 8 methicillin resistant strains. Coagulase test slide method and protein A detecting test hand one false positive result each for coagulase negative staphylococci examined. The specificity of all tests used was 100% and 99.5% respectively. The authors suggest latex or hemagglutination tests detecting clumping factor and/or protein A for rapid Staphylococcus aureus strains identification in hospital environment. It is important to point out the possibility of getting false negative protein A detecting results in methicillin resistant strains.