Lactobacillus endocarditis.

Two cases of endocarditis due to Lactobacillus plantarum and Lactobacillus casei var. rhamnosus are described. Both patients were successfully treated medically. The response of the two isolates to a range of concentrations of penicillin in an apparatus which continuously monitored growth is reported. The strain of L. casei var. rhamnosus was found to be penicillin tolerant. The use of a combination of a penicillin with gentamicin to treat endocarditis due to penicillin tolerant strains of lactobacillus is discussed. The criteria for selecting oral agents to follow intravenous therapy are assessed also.