Multicenter comparison of molecular methods for detection of Legionella spp. in sputum samples.

Legionellosis can be diagnosed by PCR using sputum samples. In this report, the methods of nine laboratories for 12 sputum samples with Legionella pneumophila and Legionella longbeachae are compared. We conclude that (i) liquefaction prevents PCR inhibition, (ii) the employed mip gene PCRs detected L. pneumophila only, and (iii) the 16S rRNA gene PCR detected both Legionella species and is preferred for the diagnosis of legionellosis.