Investigations into the Pathogenesis of Two Intracellular Bacteria: “Candidatus Berkiella cookevillensis” and Legionella lytica DSB2004

Abstract

Intracellular bacteria have evolved many different mechanisms that allow them to invade and replicate within eukaryotic cells. “Candidatus Berkiella cookevillensis” (CC99) and Legionella lytica strain DSB2004 are two intracellular bacteria originating from human-constructed aquatic environments that primarily infect free-living amoebae. This study reveals the interactions between CC99 and phagocytic immune cells as well as the virulence factors and motility of L. lytica strain DSB2004. Immunofluorescent microscopy revealed that CC99 can infect human neutrophil-like cells but not primary murine macrophages belonging to C57BL/6 strain mice. Due to the lack of infection in murine macrophages, how CC99 affects macrophage polarization remains unresolved. Analysis of the L. lytica strain DSB2004 genome revealed the presence of many virulence genes, including over 50 genes dedicated to motility. This study provides a better understanding of these intracellular bacteria and their intracellular lifestyles.