Clinical and bacteriological studies in four cases of pulmonary infection caused by Protomonas extorquens

Abstract

A novel bacterium, Protomonas extorquens was isolated from sputum, pleural effusion and ascitis in four cases of pulmonary infection by buffered charcoal yeast extract agar (B-CYE) which was generally used for Legionella spp. Three cases were so-called immunocompromised hosts (2 malignant diseases, 1 renal failure), and they died from underlying diseases. Protomonas extorquens was newly named by Komagata in 1984, which was characterized by production of pink pigment, growth in methanol medium and positive production of oxidase and catalase. This organism is ordinarily isolated from soil and dead leaves. This is the first report for isolation of P. extorquens from clinical specimens in Japan and it seems to have a significant role in immunocompromised hosts.