Ampicillin resistant Haemophilus parainfluenzae endocarditis.

A case of Haemophilus parainfluenzae bacterial endocarditis is described. This is the first reported case of endocarditis caused by ampicillin resistant H parainfluenzae. Resistance was not mediated by a beta lactamase. Ampicillin therapy had not controlled the infection, but a four-week course of chloramphenicol was curative. Several general therapeutic points are discussed.