Phagosomal Acidification Is Not a Prerequisite for Intracellular Multiplication of<i>Legionella pneumophila</i>in Human Monocytes

Abstract

Legionella pneumophila is able to multiply in a variety of eukaryotic cells. Contradictory results have been published on the significance of phagosomal acidification in the intracellular multiplication of Legionella species in monocytes. Therefore, we analyzed the phagosomal pH values in 2 different types of human monocytes throughout the intracellular-replication cycles of 2 Legionella species that have different rates of intracellular multiplication. Our results show that phagosomal acidification is not a prerequisite for intracellular replication of Legionella pneumophila in human monocytes.