Endocarditis, Culture Results, Final Diagnosis

The admission blood cultures were reported as positive twenty-four hours later. All three cultures grew Streptococcus viridans, sensitive to penicillin, with a minimum inhibitory concentration, or MIC, of 0.1 micrograms per ml. The precise determination of the level of antibiotic sensitivity is critical in the selection and dose of the most effective drug regimen. Particularly in the presence of antimicrobial resistance.

Since the streptococcal organism was very sensitive to penicillin, daily intravenous penicillin G was continued, and all other antibiotics were discontinued.

The final diagnosis in our patient is acute, severe mitral regurgitation secondary to ruptured mitral chordae as a result of Streptococcus viridans endocarditis.

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