Evaluation of seven different enzyme-linked immunosorbent assays for serodiagnosis of Staphylococcus aureus bacteremia.

OBJECTIVE

Serologic assays for Staphylococcus aureus antibodies were evaluated regarding their ability to differentiate between uncomplicated and complicated S. aureus bacteremia, between S. aureus and non-S. aureus bacteremia, and between S. aureus and non-S. aureus endocarditis.

METHODS

Enzyme-linked immunosorbent assays (ELISAs) were performed to measure Ig G antibodies against seven S. aureus antigens (peptidoglycan, teichoic acid, S. aureus ultrasonicate, whole S. aureus cells, alpha-toxin, lipase and capsular polysaccharide) in 129 patients with S. aureus bacteremia (including 51 with endocarditis), 78 patients with non-S. aureus bacteremia (including 27 with endocarditis) and 100 febrile non-bacteremic controls.

RESULTS

Whole-cell ELISA was the most sensitive assay. The specificity of all assays was low. Two different combinations of ELISAs for whole cells, teichoic acid,alpha-toxin, lipase and capsular polysaccharide did distinguish between S. aureus and non-S. aureus endocarditis, but not between uncomplicated and complicated S. aureus bacteremia.