The Rise and Fall of Antibiotics in Aquaculture

It is well known that antibiotics are playing leading roles in several areas such as human and animal health and farm production. Unfortunately, the use of antimicrobial compounds as a panacea is coming to an end. More and more antibiotic-resistant bacterial strains are listed in all spheres of activity where they were used. Aquaculture, which is a key industry in providing animal protein needs to an exponentially growing human population, is undergoing the attack of pathogens that are increasingly difficult to control due to antibiotic resistance. In this chapter, we will explore, from an aquaculture perspective, the discovery and use of antibiotics, explain the major mechanisms of antibiotic resistance and the adverse consequences of using broad-spectrum antibiotics, and finally discuss briefly on alternatives to traditional antimicrobial agents. We will also give a concrete example with the bacterium Aeromonas salmonicida subsp. salmonicida, which is a worrisome pathogen for the aquaculture industry and for which crucial discoveries have been recently made thanks to the advances in sequencing technologies.