A patient with a prosthetic hea valve develops endocarditis eight months after valve replacement. Most likely organism responsible is:
Answer is B (Staphylococcus Epidermidis) The most common causative organisms of infective endocarditic within the first 12 months after valve surgery are Coagulase Negative Staphylococci. Staphylococcus Epidermidis is a coagulase negative staphylococcus and the single best answer of choice. Organism Prothetic Valve endocarditis (% of cases) Time of onset after valve surgery < 2 months 2-12 months > 12 months Coagulase Negative Staphylococcus 33 32 1 I Staphylococcus Aureus 22 12 18 Enterococcii 08 12 11 Streptococcii (Viridans) 01 09 31 Gram Negative Bacilli 05 06 08 Gram Negative Coccohacilii (HACEK) - - 06 Paravalvular abscesses in patients with acute infective endocarditis is especially seen in association with virulent organisms like staphylococci and enterococcii. Such abscesses may also be seen in association with some virulent strains of streptococcal endocarditis. Staphylococcus however are the most common organisms associated with such abscesses.
Staphylococcus Aureus
Staphylococcus Epidermidis
Streptococcus Viridans
HACEK group