By Robert Preidt
FRIDAY, Oct. 24, 2014 (HealthDay News) -- Researchers who discovered antibiotics in farmed and wild fish say their findings are cause for concern.
The use of antibiotics in animals, including fish, that are raised for human consumption contribute to the development of antibiotic-resistant bacteria that threaten people's health, according to background information from the study.
Each year in the United States, antibiotic-resistant germs sicken about 2 million people and kill about 23,000, according to the Infectious Diseases Society of America.
Arizona State University researchers analyzed 27 samples of seafood that originated in 11 countries and were bought from stores in Arizona and California. The species included five of the top 10 most consumed types of seafood in the United States: shrimp, tilapia, catfish, swai and Atlantic salmon.
Detectable amounts of five antibiotics were found in the seafood samples: oxytetracycline 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 most common antibiotic in the samples was oxytetracycline, which is also the most widely used antibiotic in farmed fish.
While antibiotic levels in the seafood samples were below U.S. Food and Drug Administration limits, those levels can still promote the development of antibiotic resistance, the researchers said.
The study was published recently in the Journal of Hazardous Materials.