EFFECT OF MONENSIN ON THE INVASIVENESS AND MULTIPLICATION OF LEGIONELLA-PNEUMOPHILA

The polyether antibiotic monensin exhibited bacteriostatic activity ag ainst a clinical isolate of Legionella pneumophila in vitro. Experimen ts designed to test the effect of the compound on the invasiveness and multiplication of L. pneumophila in HeLa cells showed that, in the pr esence of the antibiotic, legionellas that penetrated the cells did no t multiply. However, monensin did not alter the characteristics of pha gosomes that contained ingested legionellas. In the presence of monens in, infected cells exhibited extensive vacuolation and a noticeable re duction in the number of intracellular micro-organisms was evident a f ew hours after infection.