Molecular diagnostic and biological methods:an alternative in the prevention and control of bacterial fish diseases

Resumo

The aquaculture sector is limited by numerous bacterial diseases that cause high mortalities of fish and reduce the commercial value of the product. The development of sensitive and rapid diagnostic techniques is essential for the establishment of effective control and prevention measures that reduce the spread of the causative agent of disease. Some of the bacterial diseases that have a high economic impact in the aquaculture sector are: furunculosis, tenacibaculosis, flavobacteriosis and vibriosis. The treatment of these diseases with commercially available antimicrobials during the last decades has led to the appearance of resistant strains. Therefore, alternative strategies based on natural compounds that show antibacterial activity and stimulate the immune system of fish have been proposed to protect fish against infectious diseases. The use of some of these biological methods is very promising for aquaculture because they do not result in the appearance of resistance; and their costs of production and use is much lower than that of specific vaccines. In this PhD work different aspects of the diagnosis, epidemiology and/or control of the fish diseases furunculosis, tenacibaculosis, flavobacteriosis and vibriosis are presented