Serological response in Enterococcus faecalis endocarditis determined by enzyme-linked immunosorbent assay.

Area of Science:

• Microbiology
• Immunology
• Infectious Diseases

Background:

• Enterococcus faecalis causes serious infections, including endocarditis.
• Species-specific surface protein antigens are key targets for diagnosis.
• Current diagnostic methods can be limited, especially in culture-negative scenarios.

Purpose of the Study:

• To develop and evaluate a serodiagnostic test for Enterococcus faecalis endocarditis.
• To detect species-specific surface protein antigens using an enzyme-linked immunosorbent assay (ELISA).

Main Methods:

• Western blotting was used to identify three E. faecalis species-specific surface protein antigens (73,000, 40,000, and 37,000 Da).
• An ELISA system was developed to measure IgG, IgM, and IgA antibody levels against these antigens.
• The ELISA test was evaluated using sera from patients with E. faecalis endocarditis, other streptococcal endocarditis, and other E. faecalis infections.

Main Results:

• The developed ELISA test correctly identified E. faecalis endocarditis in 15 out of 16 cases.
• The test showed high specificity, with negative results in 9 out of 10 cases of other streptococcal endocarditis and 8 out of 10 other E. faecalis infections.
• Antibody responses (IgG) were strongly detected in E. faecalis endocarditis patients.

Conclusions:

• The developed ELISA test demonstrates high sensitivity and specificity for diagnosing E. faecalis endocarditis.
• This serodiagnostic approach is valuable for identifying E. faecalis endocarditis, particularly in culture-negative cases.
• Accurate and timely diagnosis is crucial for effective antibiotic therapy in E. faecalis endocarditis.