Over-use of antibiotics in fish-for-food industry encourages bacterial resistance and disease

This practice encourages bacterial resistance and could lead to the evolution of resistant strains of bacteria in animals and humans as well as the fish themselves. A more judicious approach to the use of prophylactic (preventative) antibiotics is necessary.

Dr Felipe Cabello and his colleagues at New York Medical College, reported these findings in the July issue of ‘Environmental Microbiology’. It is common practice in the fish industry, particularly in developing countries, to use large amounts of antibiotics to prevent infection. The antibiotics used are often non-biodegradable and remain in the aquaculture environment for long periods of time. This encourages the growth of bacteria which can survive in the presence of antibiotics – antibiotic resistant bacteria.

Eventually this process could lead to increased antibiotic resistance in the ‘disease-causing’ bacteria (pathogens) of fish. The properties which make bacteria resistant can also be transferred to human and animal pathogens, leading to increased infectious disease in fish, animals and humans alike.

When antibiotics are mixed with fish food, residual antibiotics may be found in fish products and fish meat. People who eat these products will be inadvertently consuming antibiotics, leading to changes in their normal microbial environment, or ‘microflora’ and making them more susceptible to bacterial infection.

“If we don’t curb the heavy use of prophylactic antibiotics in aquaculture, then we will ultimately see more and more antibiotic resistant pathogens emerging, causing increased disease to fish, animals and humans alike” said Dr Cabello.

A global effort to curb the over-use of antibiotics in the rearing of finfish is essential in preventing these detrimental effects to fish, animal and human health.