The Phagosome-Lysosome Fusion Is the Target of a Purified Extract (PQSE) in Reducing Infection of Fish Macrophages by the Bacterial Pathogen .

, the etiological agent of Piscirickettsiosis, is a Gram-negative and facultative intracellular pathogen that has affected the Chilean salmon industry since 1989. The bacterium is highly aggressive and can survive and replicate within fish macrophages using the Dot/Icm secretion system to evade the host's immune response and spread systemically. To date, no efficient control measures have been developed for this disease; therefore, the producers use large amounts of antibiotics to control this pathogen.