Detection of mip gene by PCR for diagnosis of Legionnaires' disease.

The mip gene of Legionella pneumophila was demonstrated by PCR and probing in paired acute-phase and convalescent-phase sera from five patients with Legionnaires' disease but not in the acute-phase sera of 100 patients with pneumonia that showed no serological evidence of Legionella infection. PCR may help in cases presenting diagnostic difficulty.