CHINA – Researchers at the Shanghai Academy of Agricultural Sciences have developed an innovative point-of-care detection method for Vibrio parahaemolyticus, a bacterium responsible for numerous foodborne illnesses.

This new platform utilizes recombinant polymerase amplification (RPA) and the CRISPR/Cas12a system, combined with an immunochromatographic test strip (ICS), to offer a low-cost, simple, and visually intuitive solution for the rapid detection of this pathogen in seafood.

Vibrio parahaemolyticus is a Gram-negative, halophilic bacterium commonly found in marine environments. It is the primary cause of acute hepatopancreatic necrosis, also known as early death syndrome, in aquaculture.

The bacterium poses a substantial public health risk, particularly through the consumption of raw or undercooked seafood. Contamination of seafood surfaces can lead to foodborne outbreaks, and current detection methods—relying on microbial isolation, culturing, and biochemical identification—are too slow for effective point-of-care testing.

Published in Food Quality and Safety (DOI: 10.1093/fqsafe/fyae008) in February 2024, the novel detection platform identifies Vibrio parahaemolyticus within 30 minutes.

The new method specifically targets the tlh gene of Vibrio parahaemolyticus, facilitating highly sensitive detection. The procedure begins with the extraction of bacterial DNA from the seafood sample, followed by RPA for amplification.

The CRISPR/Cas12a system then accurately identifies and cleaves the target gene, with the ICS providing a visual confirmation of the bacterium’s presence. This method achieves a detection limit of 2.5×10^2 fg/µL for plasmid DNA and 1.4×10^2 CFU/mL for the bacteria.

Remarkably, it can detect Vibrio parahaemolyticus in salmon sashimi at concentrations as low as 154 CFU/g without sample enrichment.

Overcoming traditional method limitations

The rapid-response system overcomes the drawbacks of traditional culture-based methods, offering a faster and more accessible approach to monitoring seafood safety.

Current detection methods are too slow for effective point-of-care testing, but this new platform offers a swift solution that could significantly reduce the risk of foodborne illness from seafood.

This development comes at a time when food safety is a growing concern worldwide. Vibrio parahaemolyticus represents a considerable public health hazard, and this new detection method could play a crucial role in enhancing food safety measures.

The ability to identify this pathogen quickly and efficiently will aid in preventing foodborne outbreaks and ensuring the safety of seafood products.

Further research and development are expected to refine this detection platform and expand its application across various types of seafood.

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