Detection and identification of fish pathogens: what is the future? A review

Fish diseases pose a universal threat to the ornamental fish industry, aquaculture, and public health. They can be caused by many organisms, including bacteria, fungi, viruses, and protozoa. The lack of rapid, accurate, and reliable means of detecting and identifying fish pathogens is one of the main limitations in fish pathogen diagnosis and disease management and has triggered the search for alternative diagnostic techniques. In this regard, the advent of molecular biology, especially polymerase chain reaction (PCR), provides alternative means for detecting and identifying fish pathogens. Many techniques have been developed, each requiring its own protocol, equipment, and expertise. A major challenge at the moment is the development of multiplex assays that allow accurate detection, identification, and quantification of multiple pathogens in a single assay, even if they belong to different superkingdoms. In this review, recent advances in molecular fish pathogen diagnosis are discussed with an emphasis on nucleic acid-based detection and identification techniques. Major features and applications of current predominant methods and promising methods likely to impact future fish disease control and prevention are outlined