[The microbiology of infectious endocarditis].

If streptococci and staphylococci remain the main bacteria responsible for infective endocarditis (80%), the emergence of Streptococcus bovis associated with intestinal lesions, the confirmation of the role of Coxiella burnetii, and the discovery of the responsibility of Bartonella sp in case of negative blood culture endocarditis have been the principal microbiological modifications during the last few years. Blood cultures performed under the best technical conditions and the examination and culture of the valve after surgery remain the better means for diagnosing infective endocarditis. In case of negative blood culture (11% of the infective endocarditis), the serologic tests against C. burnetii and Bartonella should decrease the rate of diagnostic uncertainty. The development of bacteriological techniques, particularly molecular methods, should improve the microbiology of infective endocarditis lead to the discovery new aetiological agents.