Serological diagnosis of experimental Enterococcus faecalis endocarditis

Area of Science:

• Infectious Diseases
• Immunology
• Animal Models

Background:

• Endocarditis is a serious infection of the heart lining.
• Enterococcus faecalis is a common cause of infective endocarditis.
• Accurate models are needed to study host immune responses.

Purpose of the Study:

• To establish a modified rat model of endocarditis using Enterococcus faecalis.
• To measure IgG antibody responses during the course of infection.
• To characterize the kinetics of antibody production in response to infection.

Main Methods:

• A modified rat model of endocarditis was established using catheterization and Enterococcus faecalis.
• Different bacterial inocula were used to determine infectious dose (ID50, ID90).
• Enzyme-linked immunosorbent assays (ELISA) were used to quantify IgG antibodies in rat serum.

Main Results:

• Increasing inocula of Enterococcus faecalis correlated with bacterial load in vegetations and spleen.
• Bacterial load peaked around day 7 and then decreased.
• IgG antibody responses were detected early (day 2) and increased significantly throughout the infection, plateauing around days 14-21.

Conclusions:

• A reliable rat model for studying endocarditis and immune responses was successfully established.
• The model demonstrated a clear increase in IgG antibodies against Enterococcus faecalis during infection.
• This model can be used for further research into endocarditis pathogenesis and treatment.