thus , after challenge with high bacterial inocula , repeated doses of a beta-lactam antibiotic alone were sufficient to prevent viridans streptococcal endocarditis , but multiple doses of a bactericidal combination ( beta-lactam plus aminoglucoside ) , as necessary for the treatment of established endocarditis , were a prerequisite for successful prophylaxis of s. faecalis endocarditis .
C0026458
beta-lactam antibiotic
C0282215
beta-lactam