Evaluation of loop-mediated isothermal amplification based kits for rapid detection of Escherichia coli O157:H7

Abstract:

[Objective] To evaluate the efficacy of loop-mediated isothermal amplification (LAMP) based kits for rapid detection of Escherichia coli O157:H7. [Methods] Specificity, sensitivity, repeatability and stability of the kits were evaluated, and the result detected by LAMP kits was compared with the detection result by traditional microbiological detection method in practical samples. [Results] All E. coli O157:H7 standard strain samples were detected positive, while all non-E. coli O157:H7 samples were detected negative, showing that the detection had no cross reaction. The minimum test limit of the kit was 29 CFU. Detection specificity, accuracy and sensitivity of the kit were preeminent, and the detection result was highly consistent with that obtained by traditional microbiological detection method. The detecting repetition rate for high concentration of target bacteria and negative bacteria samples detected by the kits was 100%, and the inter-batch testing repetition rate for low concentration of target bacteria samples was 94%. This kit could be preserved for more than 9 months at 4 °C, and it remained its efficacy after a variable temperature storage for more than 72 h. [Conclusion] The kit has high specificity, sensitivity, repeatability and easy storage characteristics, which make it applicable for rapid detection of E. coli O157:H7.