GOLDFISH, CARASSIUS-AURATUS, A NOVEL ANIMAL-MODEL FOR THE STUDY OF MYCOBACTERIUM-MARINUM PATHOGENESIS

We have developed an animal model for studying mycobacterial pathogene sis using Mycobacterium marinum and the goldfish, Carassius auratus. G oldfish are injected intraperitoneally with doses between 10(2) and 10 (9) CFU of M. marinum organisms. Depending on the dose of M. marinum o rganisms administered, an acute or chronic disease is produced. The ac ute disease is characterized by systemic mycobacterial infection, seve re peritonitis, tissue necrosis, and a short median survival time. The chronic disease is characterized by granuloma formation in all organs and survival of animals to the end point of the experiment (56 days). Colony counts in organ homogenates showed recovery of mycobacteria fr om a high percentage of inoculated animals. We believe this well-chara cterized animal model will be useful for studying mycobacterial pathog enesis.