Mechanism of formation of the orange-colored sputum, in pneumonia caused by Legionella pneumophila

Abstract

It has been said that the color of sputum from patients with Legionella pneumophila pneumonia is orange. However, why the color is orange has not been clarified. First, orange-colored sputum obtained from a patient with L. pneumophila pneumonia is presented. Then, the formation of an orange-colored pigment in a culture medium (without charcoal) after the growth of L. pneumophila is demonstrated. © 2007 The Japanese Society of Internal Medicine.