Interaction ofL. pneumophilaand a free living amoeba (Acanthamoeba palestinensis)

Abstract

SUMMARYCo-cultivation ofLegionella pneumophilaserogroup I andAcanthamoeba palestinensis inNeff's medium at 35 °C resulted in the intracellular multiplication of the bacteria as demonstrated by electron microscopy and immunofluorescence. In the closed experimental system used, the number of legionellae rose from 107colony forming units (c. f. u.)/ml initially to a maximum of 1010c. f. u. /ml on day 5. Legionellae were seen in expelled phagosomes, in some amoebae filling the cytoplasm and in others in which the process of encystment appeared to have commenced.