ANTIBODY RESPONSE TO WHOLE CELLS AND TEICHOIC ACID OF STAPHYLOCOCCUS AUREUS STRAIN E 1369 IN HUMAN SERA

A whole cell Staphylococcus aureus enzyme-linked immunosorbent assay (ELISA) using the protein A-deficient strain E 1369 as antigen was compared to an ELISA with cell-wall teichoic acid, extracted from the same strain, as antigen for the detection of IgG antibodies against S. aureus in human sera. A total of 178 serum samples from 119 patients with S. aureus endocarditis, complicated and uncomplicated septicaemia, non-S. aureus endocarditis and septicaemia were investigated together with sera from 155 healthy controls. The sensitivity in diagnosing S. aureus endocarditis was better for the whole cell-ELISA (83%) as compared to the teichoic acid-ELISA (61%), and the same was true for complicated septicaemia (41% vs 29%). The whole cell ELISA was also more specific for S. aureus infections with only 3.6% false positive test values compared to 7.1% for the teichoic acid-ELISA. The differences were however, not statistically significant. None of the assays were able to distinguish between complicated and uncomplicated S. aureus septicaemia.