Diagnosing Staphylococcus aureus Endocarditis by Detecting Antibodies against S. aureus Capsular Polysaccharide Types 5 and 8

Abstract

Consecutive serum samples from patients with Staphylococcus aureus endocarditis or septicemia or non-S. aureus endocarditis and febrile nonsepticemic controls were tested for antibodies against S. aureus capsular polysaccharide (CP) types 5 and 8 by ELISA. The upper normal antibody levels were defined as the upper 99.5% confidence limits of the values from the febrile controls. All available patient isolates were tested for the presence of CP type 5 or 8 (85% of the isolates expressed either serotype), and all five patients with S. aureus endocarditis had positive antibody levels against the corresponding serotype within the first 10 days of infection. Three other endocarditis patients lacked isolates for CP testing but two of these were positive. Positive antibody levels were found in 0 of 28 septicemia patients, in 1 of 12 non-S. aureus endocarditis patients, and in 3 of 37 febrile controls. Thus, testing for anti-CP 5 or 8 antibodies, especially together with CP serotyping of the patient's isolate, seems to provide important information in the differential diagnosis of endocarditis in patients with S. aureus septicemia.

Levels of Antibody against 11 Staphylococcus aureus Antigens in a Healthy Population

“…In fact, as can be seen in Fig. 1, there were individuals who did not show any antibody response against individual antigens, notably Bsp, Eap, ClfB, and SSS, but in general, most individuals showed antibodies against all antigens tested and all individuals showed antibodies against at least some staphylococcal antigens, although at different levels (3,4,11,13,17,20,23). This indicates that most healthy adult individuals have been exposed to S. aureus and that the antigens studied were expressed during this exposure.…”

Staphylococcal Septicemia in Children with Atopic Dermatitis

“…An identical strain was isolated from swabs taken from the nose and skin of the patient, as well as from a nasal swab taken from the patient's mother. An ELISA for antibodies against S. aureus capsular polysaccharides (CPs) was performed as described previously (8) and gave the following results: antibody titer against CP5 (CP8) before admission (serum sample collected for determination of IgE 1 year prior to admission), 0.071 (0.031) ELISA units; antibody titer 1 week after admission, 0.828 (0.167) ELISA units [levels in normal age‐related controls: 0.23 ± 0.16 (0.084 ± 0.077)].…”

Comparison of Capsular Typing of Staphylococcus aureus with Bacteriophage Typing: A Study in Gulbarga, India

“…Various researchers have confirmed the reliability, reproducibility, and specificity of capsular typing method [8,[27][28][29][30][31][32][33][34]. Thus we analyzed capsular typing as a tool for screening S. aureus prior to bacteriophage typing.…”