A successful treatment of an infective endocarditis caused by methicillin-resistant staphylococcus aureus with a combination of cefmetazole with fosfomycin

A case of infective endocarditis caused by methicillin-resistant Staphylococcus aureus (MRSA) was successfully treated with a combination therapy with cefmetazole (CMZ) and fosfomycin (FOM). A 55 year old man was admitted to the Keio Hospital because of fever of unknown origin. Physical examination revealed blood pressure of 132/62 mmHg, heart rate of 118/min and body temperature of 39.8°C. Diastolic regurgitant murmur (Levine II/VI) was heard at the left sternal border on the third intercostal space. Chest X-ray showed mild cardiomegaly. Two dimensional echocardiography and color flow mapping demonstrated mildly dilated and hyperkinetic left ventricle, redundant aortic valve, giant vegetation from the aortic valve and severe aortic regurgitation. MRSA was isolated from the blood of this patient. Bacteriostatic synergism between CMZ and FOM against S. aureus isolated from the blood of this patient was detected both by the KIRBY-BAUER method and by the checker-board method. The combination therapy with CMZ and FOM cleared the clinical symptoms and normalized the inflammatory reactions. No relapse was observed for at least 10 months. We concluded that the combination therapy with CMZ and FOM was invaluable for the treatment of infections endocarditis by MRSA.