Intraleukocytic Bacteria in Endocarditis Patients

Leukocyte monolayers from the peripheral blood of 16 patients suspected of having infective endocarditis and six normal control subjects were examined microscopically. No intraleukocytic bacteria were observed in preparations from the six normal controls. Six of the 16 endocarditis suspects had sterile blood cultures and the diagnosis was discarded. All six patients had negative monolayer preparations. Intraleukocytic bacteria were found in six of the ten patients with a final clinical diagnosis of endocarditis. Nine of these patients also had positive blood cultures. A leukocyte monolayer preparation from the one endocarditis patient with negative blood cultures contained intracellular cocci, and the patient responded to antibiotic therapy.