Primers and probes
Primers and TaqMan MGB probes (Table 2 ) were designed using Primer Express (Thermo Fisher Scientific, Waltham, MA, USA) and synthesized by General Biosystems (Chuzhou, China). A ROX or Cy5 reporter was incorporated at the 5’ end of the probes, and a nonfluorescent quencher at the 3’ end. The sensitivity and specificity were evaluated using the sequence alignments in GenBank and the Basic Local Alignment Search Tool on NCBI, respectively.