A bacterial pathogen that typically multiplies outside of host cells can enter and induce the destruction of cells called macrophages, according to a study published June 20 in the open-access journal PLOS Pathogens by Anne-Béatrice Blanc-Potard of the Université de Montpellier in France, and colleagues.
Pathogenic bacteria are commonly classified as intracellular or extracellular pathogens. Pathogenic bacteria are commonly classified as intracellular or extracellular pathogens. Intracellular bacterial pathogens can replicate within host cells, including macrophages, which ingest and kill microorganisms in a process called phagocytosis. By contrast, extracellular pathogens such as Pseudomonas aeruginosamultiply outside of cells. However, recent data have shown that several extracellular pathogens can enter host cells. For example, P. aeruginosa has been reported to be engulfed by macrophages in animal models.