Detection on integron carried gene cassettes from pathogens by loop mediated isothermal amplification assays

- Six valid and rapid LAMP assays targeting on integron genes were developed.
- Gene dfrA12, orfF, aadA2, dfrA17, aadA5 and blaVIM2 were used as target genes.
- 272 positive and 685 negative isolates were applied on LAMP with 100% detection rate and specificity.

In this study, a number of frequently detected gene cassettes from bacterial integrons have been detected and characterized by rapid and simple loop-mediated isothermal amplification (LAMP) assays. Six gene cassettes commonly found in class 1 integrons were studied, including dfrA12, dfrA17, aadA2, aadA5, orfF, and blaVIM2. Primers design, sensitivity, specificity, optimization of each LAMP assay, as well as application of the developed 6 individual LAMP assays on a large scale of bacteria, had been conducted. The optimal amplification was obtained with temperature as 65 °C, reaction time span as 45 min and volume as 25 μl. For application, 272 isolates with various gene cassettes yielded expectable positive amplicons and other 685 integron-negative bacteria showed negative results for the LAMP assays, totaling 100% detection rate and specificity.