Researchers at the Chinese Academy of Sciences have developed an assay using PCR (polymerase chain reaction) to detect bacterial infections that cause economically devastating losses in fish farming.


Aquaculture of fish is a major source of food, as well as being a way to rebuild wild stocks. However, infections caused by fish pathogens, including Aeromonas, Vibrio, Edwardsiella and Streptococcus, has a major impact. In research published in Letters in Applied Biology, researchers created a multiplex polymerase chain reaction (mPCR) assay, for the simultaneous detection and differentiation of fish pathogenic bacteria in these four genera.

The assay used genus-specific primers rather than species-specific primers, which means that it could target a wider range of bacteria. These were validated alone (uniplex PCR) and in combination (mPCR) against DNA from target and non-target bacteria, and the results showed that the assay could differentiate between the two groups.

According to the researchers, PCR can be used as a powerful alternative to the conventional culture-based method, with rapid, specific, sensitive and reliable detection of target pathogens.

While the xxpress PCR technology was not used in this work, the size, accuracy, cost and speed of the system mean that it has potential in small labs and on-site at fish farms.