A simple and rapid identification method for newly emerged porcine Deltacoronavirus with loop-mediated isothermal amplification

Zhang, Fanfan; Ye, Yu; Song, Deping; Guo, Nannan; Peng, Qi; Li, Anqi; Zhou, Xingrong; Chen, Yanjun; Zhang, Min; Huang, Dongyan; Tang, Yuxin

It is obvious that the RT-LAMP has some advantages over the conventional PCR-based tests and serological tests. The selected set of four primes specific to the N gene of PDCoV dramatically enhanced the specificity of RT-LAMP assay in contrast of the traditional diagnostic methods [4-7, 18, 19] . The fact that the RT-LAMP assay could not detect several reference swine viruses (PEDV, TGEV, PKoV, PAsTV, PRRSV, CSFV, and PCV2) demonstrated that this method established was highly specific. In addition, the results of sensitivity/detection limit comparisons indicated that the assay was the most sensitive among the tests employed for the evaluation of the assay in this study. Moreover, the RT-LAMP was a one-step assay in which the reverse transcription and LAMP reaction were combined, which further simplified the procedure and shortened the time of the reaction of the assay. The RT-LAMP was simple and user-friendly, and only required a water bath with a constant temperature feature or a traditional heat block to perform. To evaluate the practicability of RT-LAMP in the field, 192 clinical diarrhea samples of piglets were examined. The results showed that the RT-LAMP had a similar sensitivity with nested RT-PCR and was much sensitive than conventional RT-PCR in detection of PDCoV. These data further suggested that PDCoV was a leaved out pathogen related to swine diarrhea in China, and might cause the high mortality in diarrheal piglets.