Endocarditis due to Streptococcus morbillorum

Two cases of endocarditis due to Streptococcus morbillorum are described. Neither patient had any known history of valvular disease. These are believed to be the first such reported cases in the U.K. In the first case, previous anal surgery and, in the second, drainage of a dental abscess and extraction of a tooth are the likely procedures which initiated endocarditis. The first case is of further interest in that the incriminated strain showed marked tolerance to beta-lactam antibiotics. A combination of penicillin with gentamicin was shown to be required in order to give satisfactory bactericidal activity in vitro.