Molecular assays
Portions of cutaneous samples stored at -20°C were macerated in liquid nitrogen, and genomic DNA was extracted from each sample using a Universal Genomic DNA Extraction Kit (D2100, Solarbio, China) and subjected to PCR analysis. Fragments of S. scabiei cytochrome oxidase 1 (cox-1) (374 bp) and the second internal transcribed spacer gene (ITS2) (361 bp) were amplified (S2)(Fraser et al., 2018; Naz et al., 2020). The amplification products were sequenced by Sangon Biotech (Shanghai) Co., Ltd and identified by BLAST (NCBI).
The sequences of cox 1 and ITS2 were aligned and analyzed using MegAlign (7.1). Phylogenetic trees were constructed based on thecox 1 gene with MEGA-7 software (7.0) using the neighbor-joining method(Peltier et al., 2017a).