Reevaluation of the cellular fatty acid composition of Legionella micdadei Bari 2/158.

The cellular fatty acid composition of Legionella micdadei Bari 2/158 was reevaluated because of its purported differences from other L. micdadei strains and its similarity to L. bozemanii. We found the fatty acid content of this strain to be consistent with that of 11 other strains of L. micdadei, including the presence of an anteiso branched-chain, monounsaturated, 17-carbon acid (Ca17:1) which is characteristic of this species. The double-bond position of Ca17:1 was established at the omega 7 (or delta 9) position by combined gas chromatographic-mass spectrometric analysis of dimethyl disulfide derivatives. The Ca17:1 omega 7 acid was absent in each of 14 strains of L. bozemanii.