AN OXALOACETATE DECARBOXYLASE HOMOLOG PROTEIN INFLUENCES THE INTRACELLULAR SURVIVAL OF LEGIONELLA-PNEUMOPHILA

Legionella pneumophila is a facultative intracellular parasite which i s able to survive in various eukaryotic cells. We characterised a Tn5- mutant of the L. pneumophila Corby strain and were able to identify th e insertion site of the transposon. It is localised within an open rea ding frame which shows high homology to the alpha-subunit of the oxalo acetate decarboxylase (OadA) of Klebsiella pneumoniae. The OadA homolo gous protein of L. pneumophila was detected in the wild-type strain by Western blotting. Since the intracellular multiplication of the oadA( -) mutant strain is reduced in guinea pig alveolar macrophages and hum an monocytes, it is concluded that the oadA gene product has an effect on the intracellular survival of L. pneumophila.