Colistin-Resistance Genes Found in Imported Seafood Raise Concerns

Recent research has raised alarms about the discovery of colistin-resistance genes in bacteria associated with imported seafood, particularly shrimp and scallops. A team from the University of Georgia found these genes in samples sourced from markets in Atlanta, USA. As colistin is a last-resort antibiotic, this development poses significant risks to public health.

Colistin is administered in two forms: colistimethate sodium, which can be injected into veins or muscles, and colistin sulfate, primarily used topically or orally. The emergence of bacterial resistance to this antibiotic is alarming, as it could transform previously treatable infections into life-threatening conditions. The research team highlighted that the genes responsible for this resistance can transfer between bacteria through mobile elements known as plasmids.

The journey to understanding colistin resistance began in 2016 when researchers first isolated these genes from imported seafood. Since then, the presence of colistin-resistant bacteria has raised concerns about the implications for food safety and public health, particularly given that approximately 90% of shrimp consumed in the U.S. is imported.

The predominant bacteria found in imported shrimp belong to the Gram-negative genera Serratia and Aeromonas. The specific genes identified, referred to as mcr, are classified as mobile due to their ability to spread among different bacterial populations. To date, ten distinct mcr genes have been identified, alongside several variants known as alleles.

The researchers pointed out that aquaculture practices may serve as a source for the spread of these resistance genes. They emphasized the interconnectedness of our world, stating, “We move a lot, we travel a lot, our food travels, and we are going to spread whatever emerges, even across national borders.” This underscores the urgent need for robust monitoring systems and international collaboration to combat antimicrobial resistance.

The findings of this research were published in the journal mSphere under the title “Introduction of the transmissible mobile colistin resistance genes mcr-3 and mcr-9 to the USA via imported seafood.” This highlights the necessity of vigilance in tracking the origins of food products and their potential health impacts.

In related developments, researchers have recently unveiled a new class of antibiotics that specifically targets Neisseria gonorrhoeae, the bacteria responsible for gonorrhea. These innovative substances trigger a self-destruction program within the bacteria, including multi-resistant strains, showcasing the ongoing efforts to address antibiotic resistance globally.

The findings regarding colistin resistance in seafood are a significant wake-up call for consumers, health officials, and regulatory bodies alike. As the battle against antibiotic resistance continues, the implications of these discoveries will likely shape policies surrounding food safety and public health initiatives.