Food poisoning under the ‘LAMP’

Scientists in Thailand have developed a DNA-based method for the efficient detection of a bacterium causing food poisoning in many parts of the world¹. The research was led by Parin Chaivisuthangkura of Srinakharinwirot University, Bangkok. The bacterium, Vibrio parahaemolyticus, causes disease in farmed fish, shellfish and shrimps and food poisoning in humans, often resulting in severe gastroenteritis.

Current biochemical methods for identifying and diagnosing V. parahaemolyticus are time consuming. An added problem is that Vibrio species are difficult to distinguish biochemically. The new method developed by Chaivisuthangkura and his collaborators specifically detects the V. parahaemolyticus gene encoding thermolabile haemolysin, a protein found in all strains of this bacterial species.

The researchers first amplified the target DNA using a technique called loop-mediated isothermal amplification (LAMP). The amplified DNA was then labelled and detected using a craftily designed dipstick. They showed that the method is considerably more sensitive than conventional PCR-based methods. As a proof of principle, they showed that it efficiently detected V. parahaemolyticus in spiked shellfish but correctly gave negative results for closely related Vibrio species as well as unrelated bacteria.

Chaivisuthangkura and colleagues believe that the method will be a useful tool for the rapid and accurate detection of V. parahaemolyticus.