Daijiworld Media Network - New York

New York, Jun 22: In a concerning discovery, US researchers have found that seafood imported into the country could be playing a role in the global spread of resistance to colistin — a last-resort antibiotic used to treat life-threatening infections.

A team led by microbiologist Dr. Issmat Kassem from the University of Georgia has isolated colistin-resistance genes in bacteria found in shrimp and scallops purchased from eight Atlanta food markets. The findings mark the first such detection in seafood sold for public consumption in the US.

Colistin, first introduced in the 1950s and later withdrawn in the 1980s due to severe side effects like nerve and kidney damage, was reintroduced in recent years as a vital treatment against superbugs resistant to most other antibiotics. It is now classified by the World Health Organization as a “high-priority, critically important” medicine.

However, resistance to colistin is rising globally, diminishing its effectiveness and posing serious risks to patients with untreatable infections. The study revealed that some of the bacteria carrying the resistance genes had them encoded on plasmids — small, circular DNA molecules capable of transferring resistance between bacteria, accelerating its spread.

Kassem warned that while imported seafood undergoes standard screening, it typically does not include checks for antimicrobial resistance genes. “About 90% of shrimp consumed in the US is imported,” he said, “but screening doesn’t catch everything — especially these dangerous genes.”

He added that many countries have continued to use colistin in agriculture, which may have contributed to the resistance issue. “We’ve identified one source of colistin resistance, but it’s likely that more exist — and they are spreading.”

With antimicrobial resistance already claiming hundreds of thousands of lives annually, the findings underscore the urgent need for enhanced monitoring and global cooperation to safeguard the efficacy of critical antibiotics.