Bacterial endocarditis is most commonly caused by?

Ans. is 'c' i.e., Staphylococcus aureusEndocarditis is an inflammation of the inner layer of the hea, i.e. endocardium.o It usually involve the hea valves (native or prosthetic).o Other structures which may be involved are interventricular septum, chordae tendinae, the mural endocardium, and intracardiac devices.Endocarditis can be classified into -1.Infective endocarditis In this, infection is the source of inflammation.Most common causes of infective end ocarditisIn native wall --> Staphylococcus aureus.In early prosthetic valve (up to 12 months after valve surgery) Staphylococcus epidermidis (coagulase negative staphylococcus).In late prosthetic valve (more than 12 months after valve surgery) --> streptococcus viridans.In IV drug abusers --> Staphylococcus aureus.In patients with intravenous catheter --> coagulase negative staphylococci.o After dental procedure (tooth extraction) --> streptococcus mutans.Infective endocarditis can be fuher divided intoA. Acute infective endocarditiso Occurs on a previously normal hea valve.o Caused by an organism with high virulence, e.g. staphylococcus aureus.o Involvement and progression is more severe.B. Subacute infective endocarditiso Occurs on previously damaged or abnormal valve.o Caused by organism with low virulence, e.g. streptococci.o Disease is insidious in onset with less severe involvement and slow progression.2.Non-infective endocarditis o Source is other than infection, eg. non-infective thrombotic endocarditis, rheumatic carditis, Libmansack's endocarditis.