<prompt> Causative organism of late prosthetic valve endocarditis is :Streptococcus viridansProteus mirabilisBeta haemolytic streptococciStaphylococci  <response>: Ans. is a i.e. Streptococcus Viridans Prosthetic valve endocarditis is of two typesEarly onset endocarditis - onset of symptoms within 60 days of surgery.Late onset endocarditis - onset of symptoms after 60 days of surgeryMC Organism causing - Early onset endocarditis - Staph epidermidis Late onset endocarditis - Streptococci Includes viridans streptococci, streptococcus bovis, other non-group A streptococciBut this classification into late and early onset endocarditis is outdated Note, that the question belongs to the time when this classification was in useHarrison 15e divides Prosthetic valve endocarditis into :less than 2 month2-12 monthsMore 12 months after surgeryMC organisms causing prosthetic valve endocarditis according to Harrison 15e -less than 2 month - Coagulase-negative staphylococci Staph, epidermidis is a coagulas negative staphylococci2-12 month - Same as in less than 2 monthmore than 12 months - Streptococci includes viridans streptococci, streptococcus bovis, other non-group A streptococci 