Rapid detection of Aeromonas hydrophila with a DNAzyme-based sensor

Aeromonas hydrophila is a highly pathogenic bacteria that is naturally present in foods and the environment. A. hydrophila contamination can lead to economic losses to food industries and pose a critical threat to human's health. In this study, an unmodified DNA library was used for eight rounds of in vitro selection to obtain a DNAzyme (named DAh1) targeting A. hydrophila. DAh1T1, which had the highest activity among the truncated sequences of DAh1, was immobilized in circles of a polystyrene board using trehalose and pullulan. A fluorescent biosensor was designed for the detection of A. hydrophilic, and the fluorescent signal was observed within 10 min, with the detection limit of 36 CFU/mL when the crude extracellular mixture of A. hydrophilic (CEM-AH) as the target was added. Moreover, the sensor was stored at room temperature for more than 6 months with the performance not changed. The biosensor was validated by detecting A. hydrophila in food, with expected results. The simple, convenient, and efficient characteristics make the proposed biosensor useful for preventing and detecting foodborne pathogens in the food industry.

Automated summary

A DNAzyme targeting Aeromonas hydrophila was developed through in vitro selection, and a fluorescent biosensor was designed for detecting the bacteria efficiently. The biosensor showed stable performance for more than 6 months and was validated for detecting the pathogen in food samples, demonstrating its potential for use in preventing and detecting foodborne pathogens in the food industry.