Can fish scales be a potential source of pathogenic microorganisms for human health

Abstract

Abstract: Resistance of fish to diseases in natural conditions is much higher than in artificial breeding conditions. The appearance of pathogenic bacterial flora in fish in combination with dangerous parasites is the result of a biocenotic imbalance. One of the factors causing fish diseases are abiotic factors. Human interference in fish farming (e.g. feeding, fertilizing, aeration) sometimes also disturbs this balance. Decaying food and plant debris promote putrefactive processes and the creation of favorable conditions for pathogenic microorganisms including bacteria, viruses, fungi and also specific protozoa that threaten fish health and often lead to their sleep. Being in the natural environment, fish carry diseases between themselves and other organisms living in the aquatic environment, such as snails, crayfish, etc. Catching from natural conditions to artificial conditions for culinary and demonstration purposes (domestic aquariums or in zoos) can cause many dangerous zoonoses for humans. The review of the work discusses the main fish diseases induced by bacterial, fungal and viral pathogens found on fish scales that can cause zoonotic diseases in humans. Therefore, their knowledge of the scales, their color, shape and stiffness may indicate specific fish diseases caused by the pathogenic microorganisms described in this paper. The most frequently mentioned pathogenic and potentially pathogenic bacterial agents isolated from fish include: mycobacteria (Mycobacterium spp.), streptococci (Streptococcus iniae), vibrio vulnificus (Vibrio spp.), Aeromonas spp., Salmonella spp., Listeria monocytogenes, Clostridium botulinum and many more. Careless aquarists who do not follow certain hygiene rules may become victims of opportunistic bacteria. The aim of the article is to present the current state of knowledge regarding fish diseases and their health implications for humans. Typically, ichthyosis infections are most common among aquarists and swimming pool users. Knowledge about human infections caused by fish scales is insufficient, diagnostic procedures are late and often ineffective, and therapy is long and difficult. Tropical fish placed on the market in an aquarium should have a certificate that they are free from mycobacteria and other potential diseases that threaten human health and life. Therefore, this study clarifies these issues