To the Editor.
—We read with interest the report by Backes et al in the April Archives1 concerning group B streptococcal (GBS) infective endocarditis. Recently, we have had the opportunity to attend two patients with GBS infective endocarditis who developed complications and died.
Report of Cases.
—Both were women, aged 71 and 63 years. They had not undergone manipulations prior to admission. The diagnosis was made on the basis of three blood cultures that yielded two strains of group B β-hemolytic streptococci (Streptococcus agalactiae), fever, petechiae, heart murmurs, splenomegaly, and echocardiographic findings compatible with valvular vegetations affecting the mitral valve in both cases. Both strains had a minimal inhibitory concentration of 0.06 mg/L of penicillin G sodium and the peak serum acid level was 1:1,028 in both cases. On admission, treatment was started with 24 million units of penicillin G sodium and 240 mg of gentamicin sulfate (daily) for