The activity of imipenem on Legionella pneumophila, with a note on the treatment of two cases.

An in-vitro assessment of the activity of imipenem, a new carbapenem beta-lactam antibiotic, was undertaken on isolates of Legionella pneumophila. The minimum inhibitory concentrations of imipenem were in the range 0.03 to 0.25 mg/l and turbidimetric studies showed that imipenem had a marked bactericidal effect which was more pronounced than that seen with either rifampicin or erythromycin. Two patients with legionella pneumonia were successfully treated with imipenem as part of a clinical trial of the drug.