Granulomatous bacterial diseases in fish: An overview of the host's immune response

• Published in: Comparative biochemistry and physiology. Part A, Molecular & integrative physiology Vol. 261; p. 111058
• Main Authors: Rajme-Manzur, David, Gollas-Galván, Teresa, Vargas-Albores, Francisco, Martínez-Porchas, Marcel, Hernández-Oñate, Miguel Ángel, Hernández-López, Jorge
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.11.2021
• Subjects: Animals; Bacterial diseases; Bacterial Infections - complications; Bacterial Infections - microbiology; Fish Diseases - immunology; Fish Diseases - microbiology; Fishes - immunology; Fishes - microbiology; Granuloma - complications; Granuloma - microbiology; Granuloma formation; Granulomatous processes; Immune response; Immunity, Innate; Immune response; Granuloma formation; Bacterial diseases; Granulomatous processes
• ISSN: 1095-6433; 1531-4332
• DOI: 10.1016/j.cbpa.2021.111058

Bacterial diseases represent the main impediment to the development of fish aquaculture. Granulomatous diseases caused by bacteria lead to fish culture losses by high mortality rates and slow growth. Bacteria belonging to genera Streptococcus spp., Mycobacterium sp., Nocardia sp., Francisella sp., and Staphylococcus sp. have been implicated in the development of granulomatous processes. The granuloma formation and the fish's immune response continue to be the subject of scientific research. In fish, the first defense line is constituted by non-specific humoral factors through growth-inhibiting substances such as transferrin and antiproteases, or lytic effectors as lysozyme and antimicrobial peptides, and linking with non-specific phagocyte responses. If the first line is breached, fish produce antibody constituents for a specific humoral defense inhibiting bacterial adherence, as well as the mobilization of non-phagocytic host cells and counteracting toxins from bacteria. However, bacteria causing granulomatous diseases can be persistent microorganisms, difficult to eliminate that can cause chronic diseases, even using some immune system components to survive. Understanding the infectious process leading to granulomatosis and how the host's immune system responds against granulomatous diseases is crucial to know more about fish immunology and develop strategies to overcome granulomatous diseases. [Display omitted] •Granulomatous diseases caused by bacteria cause high mortality rates and slow growth in fish.•Streptococcus, Mycobacterium, Nocardia, Francisella, and Staphylococcus genera are associated with granulomatous processes.•Granuloma formation is a complex process involving the host's immune responses and the pathogen resistance.•The immune response includes inflammation process accompanied by humoral- and cell-mediated defense.