Comprehensive assessment of pathogenic bacterial diseases and their control in Nile tilapia (Oreochromis niloticus): implications for the sustainable aquaculture and human health

Aquaculture is one of the fastest-growing food production sectors and plays a crucial role in meeting the demand for nutritious and affordable food for billions of people worldwide. Nile tilapia is an economically important fish species that is widely farmed in over 140 countries. However, diseases affecting Nile tilapia significantly hinder the expansion and development of sustainable aquaculture. Recently, the industry has faced serious bacterial infections that have resulted in substantial losses for Nile tilapia farmers. These bacterial infections—including Aeromonas hydrophila, Yersinia ruckeri, Escherichia coli, Streptococcus aureus, Flavobacterium columnare, Pseudomonas aeruginosa, Streptococcus agalactiae, Streptococcus iniae, and Edwardsiella tarda affect various parts of the fish such as the skin, eyes, kidneys, gills, and liver. The absence of effective disease prevention and appropriate biosecurity measures makes these infections a major threat to global Nile tilapia farming. Moreover, factors such as high nutrient levels, elevated water temperatures, and high fish density can promote bacterial growth, including that of potentially pathogenic bacteria. Strategies employed to combat diseases in tilapia include the use of feed supplements, herbal extracts, and vaccines. This review aims to provide an updated overview of the disease risks affecting Nile tilapia production, emphasizing the challenges related to these diseases and their treatment approaches. Moreover, it seeks to enhance understanding of country-specific bacterial diseases and addresses a critical gap in knowledge regarding health and disease pathways for sustainable aquaculture and the control strategies implemented thus far.