Abstract: | A fragment of the gene for cytolysin has been cloned. The product of the gene has been earlier identified as an immunoserological marker of Legionella pneumophila. Clones were selected by immunodetection of cytolysin gene product expression. An EcoRI 3.8 kb fragment of the genomic DNA from Legionella pneumophila strain Philadelphia-1 was used as a DNA probe that hybridized with the bacterial colonies of 20 Legionella pneumophila strains but not with the colonies of 10 other Legionella species or 8 other bacterial genera. The cloned fragment has been shown to be unique for Legionella pneumophila. The region of homology is suggested to be longer than a possible dimension of the cytolysin gene. |