Apparent failure of endocarditis prophylaxis caused by penicillin-resistant Streptococcus mitis.
Antibiotic resistance among viridans streptococci has increased with Streptococcus mitis being more resistant than other viridans species. In a case presented in this report, it is possible that antibiotic resistance contributed to an apparent failure of endocarditis prophylaxis. The patient had undergone periodontal surgery on 2 separate occasions and in both instances was administered 2 g of amoxicillin orally 1 hour before each procedure. He subsequently developed a subacute illness and had multiple blood cultures drawn that grew S. mitis with a minimum inhibitory concentration of 1.0 microg/mL for penicillin. Transesophageal echocardiogram provided further evidence of infective endocarditis with vegetations seen on the anterior leaflet of the mitral valve. Combination therapy with high-dose intravenous aqueous crystalline penicillin G and gentamicin sulfate for 4 weeks was curative. Clindamycin, rather than amoxicillin, has since been used as dental prophylaxis for subsequent procedures.
University of Tennessee Medical Center at Knoxville, Graduate School of Medicine, Department of Medicine, 37920-6999, USA.
Glen E
GE
Hall
Larry M
LM
Baddour
D000368:Aged; D000658:Amoxicillin / Q000008:administration & dosage*; D019072:Antibiotic Prophylaxis; D002981:Clindamycin / Q000008:administration & dosage; D024881:Drug Resistance, Bacterial; D004696:Endocarditis / Q000209:etiology / Q000382:microbiology* / Q000517:prevention & control; D006801:Humans; D008297:Male; D019647:Oral Surgical Procedures / Q000009:adverse effects; D010406:Penicillins / Q000008:administration & dosage*; D010510:Periodontal Diseases / Q000601:surgery; D013290:Streptococcal Infections / Q000209:etiology / Q000382:microbiology* / Q000517:prevention & control; D013291:Streptococcus / Q000187:drug effects*; D017211:Treatment Failure
D010406:Penicillins; D002981:Clindamycin; D000658:Amoxicillin