Study of antibiotics in aquaculture

A RECENT research project on the use of antibiotics in aquaculture has looked at the presence of antibiotics in a number of species across 11 countries.

PhD candidate, Hansa Done, and Rolf Halden, PhD, from Arizona State University, studied shrimp, salmon, catfish, trout, tilapia and swai, and found the presence of five antibiotics of 47 evaluated.

Their findings were published in the Journal of Hazardous Material online on 5 October, reports Digital Journal.

The study evaluated the presence of 47 antibiotics in specimens of different fish and shellfish taken from samples purchased from stores in Arizona and California in the US, and all complied with US FDA regulations.

Results showed that five antibiotics were present in detectable amounts: oxytetracycline – the most commonly used antibiotic in aquaculture – in wild shrimp, farmed tilapia, farmed salmon and farmed trout; 4-epioxytetracycline in farmed salmon, sulfadimethoxine in farmed shrimp, ormetoprim in farmed salmon, and virginiamycin in farmed salmon that had been marketed as antibiotic-free.

The finding of oxytetracycline in wild caught shrimp from Mexico may well have been due to mislabelling, coastal pollution from sewage or cross-contamination.

All of the antibiotic levels detected were within FDA guidelines, however the authors point out that even these levels can promote resistance development and the report urges close monitoring of antibiotic use in aquaculture.