Abstract
Infective endocarditis (IE) has been believed to be induced by bacteremia after tooth extraction in susceptible patients such as damaged heart valves. To prevent IE, antibiotics prophylaxis has been recommended by American Heart Association (AHA) . In the present study, according to the AHA recommendation, antimicrobial susceptibilities of antibiotics, ampicillin (ABPC), amoxicillin (AMPC), clindamycin (CLDM), vancomycin (VCM), erythromycin (EM), and cefaclor (CCL), to 31 Streptococci isolated from tooth extraction bacteremia were examined. No highly resistant strain to ABPC, AMPC, VCM could be found. However two Streptococci were sensitive to CLDM. MIC80 of EM and CCL were 50 and 100μg/ml, respectively. It was concluded that ABPC and AMPC were the most suitable antibiotics for prevention of IE by the present results of MICs, which was identical to the AHA recommendation. However, the dosage of the AHA recommendation was too large for Japanese individuals, so it was suggested to use an ABPC prodrug such as bacampicillin (BAPC) for substitution. BAPC could obtain higher antibiotic concentration level in the blood than ABPC and AMPC with the same dose, and its susceptibility to oral Streptococci was comparable.
