Sequence analysis of the spike gene of Porcine epidemic diarrhea virus isolated from South China during 2011–2015

Zhao, Xiaoya; Li, Zhili; Zeng, Xiduo; Zhang, Guanqun; Niu, Jianqiang; Sun, Baoli; Ma, Jingyun

Between February 2011 and March 2015 in Guangdong province, China, porcine intestinal and fecal samples were collected from piglets with watery diarrhea and dehydration. The intestinal and fecal samples were placed in phosphate buffer saline supplemented with penicillin G (10,000 IU/mL) and streptomycin (2 mg/mL) and centrifuged at 1,500 × g for 15 min. Viral presence in the supernatant was determined by using RT-PCR with viral gene-specific primers: (5′ to 3′) GCAACTCAAGTGTTCTCAG and GAGTCATAAAAGAAACGTCCG. RNA extraction and reverse transcription were carried out as previously described [27] . PCR products were purified by using an AxyPrep DNA gel extraction kit (Axygen, USA) according to the manufacturer's instructions, and the product was cloned into the pMD-19T vector (Takara Bio, China). The purified recombinant plasmids were sequenced by Invitrogen Trading (Invitrogen, China). Sequences of all samples detected to be positive for the complete S gene of PEDV were submitted to GenBank (National Center for Biotechnology Information, USA) under accession Nos. KP399601-KP399634 and accession Nos. KR296663-KR296683.