Two-step scheme for rapid identification and differentiation of Legionella pneumophila and non-Legionella pneumophila species.

A rapid two-step scheme based on PCR amplification and enzymatic digestion analysis of a 226-bp fragment of the 16S rRNA gene was developed to identify the Legionella genus by PCR amplification and to differentiate the Legionella pneumophila and non-Legionella pneumophila species by enzymatic digestion analysis. Among 42 ATCC strains (16 strains of L. pneumophila and 26 strains of non-L. pneumophila) and 200 Legionella isolates from environmental water samples, including pools, rivers, lakes, and cooling towers in Guangdong province, 99.59% of L. pneumophila and non-L. pneumophila strains were correctly identified and differentiated by this scheme. The procedure of this two-step identification and differentiation scheme is simple and takes only about 4 h. These results suggest that this two-step scheme provides a simple and convenient method for the rapid identification and differentiation of L. pneumophila and non-L. pneumophila species.