Article by: Nur Hidayahanum Hamid

Source: American Society for Microbiology

A recent study published in mBio, the journal of the American Society for Microbiology, reveals that a deadly bacterial outbreak affecting catfish farms in the southeastern United States likely originated from Asia. Researchers from Auburn University and collaborating institutions have identified that the strain of Aeromonas hydrophila causing widespread losses in catfish farms across Alabama, Mississippi, and Arkansas since 2009 is closely related to strains previously found in diseased grass carp in China.

The infection, known as Aeromonas septicemia, is highly virulent and can kill affected fish within 12 hours. Infected catfish exhibit severe clinical symptoms, including hemorrhagic skin lesions and significant blood loss. This emerging strain has significantly disrupted the U.S. catfish industry, posing a serious threat to aquaculture productivity and sustainability.

The genetic similarities between the U.S. and Chinese strains suggest a transboundary movement of the pathogen, highlighting the potential global biosecurity risks in aquaculture. The study emphasizes the importance of monitoring international fish trade, implementing stricter biosecurity protocols, and conducting routine surveillance to prevent future outbreaks.

This research not only underscores the need for rapid pathogen identification and response strategies but also calls attention to the ecological and economic impacts of introduced aquatic pathogens. Proactive measures, such as improved diagnostics, cross-border data sharing, and responsible fish importation practices, are essential to safeguarding the health of aquaculture industries worldwide.

Picture 1: Fish infected with Aeromonas hydrophila commonly show reddening of the skin, fins and eyes. Credit Photo: © Anita M Kelly

Date of Input: 30/04/2025 | Updated: 11/11/2025 | m_fakhrulddin