Zhengzhou Major Pig Disease Prevention and Control Laboratory, College of Veterinary Medicine, Henan Agricultural University, Zhengdong New District Longzi Lake 15#, Zhengzhou 450046, People's Republic of China.
Department of Life Science, Zhengzhou Normal University, Zhengzhou 450044, Henan Province, People's Republic of China.
Infect Genet Evol. 2021 Oct;94:105016. doi: 10.1016/j.meegid.2021.105016. Epub 2021 Jul 27.
Porcine circovirus type 2 (PCV2) is the causative agent of porcine circovirus-associated diseases (PCVAD), causing substantial economic losses to the swine industry worldwide. PCV3, as a recently discovered virus, is associated with porcine dermatitis, nephropathy syndrome, reproductive failure, congenital tremors, and other clinical symptoms. To further investigate the epidemic profile and genetic diversity of the two viruses, a total of 198 samples from swine at various growth stages suspected for PCVAD on 55 different pig farms between 2018 and 2020 were analyzed for presence of PCV2 and PCV3 by using a multiplex real-time PCR assay. Among the 198 samples, 113 (57.07%) and 72 (36.36%) were positive for PCV2 and PCV3 respectively, and 39 (19.7%) were positive for PCV2 and PCV3 co-infection. Subsequently, whole genome sequences of 34 PCV2 and 19 PCV3 strains were obtained from 30 and 19 clinical samples, respectively. Of these, 8 PCV2 strains belonged to PCV2a, 10 belonged to PCV2b and 16 belonged to PCV2d, indicating PCV2d was the predominant PCV2 genotype circulating in central China. Furthermore, co-infection of different PCV2 genotype strains was identified in three samples (JZ-4, KF-2 and JY-1), and a cross-recombination was found in the ORF2 region of the sequenced 13 PCV2d strains whose putative parental strains were LN6/1999 (MF278777) and MEX/41238/2014 (KT795287) strains. The phylogenetic analysis of PCV3 showed high nucleotide identity (>98%) among sequences obtained in this study and reference sequences. These data will aid our understanding of the molecular epidemiology and evolution of PCV2 and PCV3.
猪圆环病毒 2 型(PCV2)是猪圆环病毒相关疾病(PCVAD)的病原体,给全球养猪业造成了巨大的经济损失。PCV3 是一种新发现的病毒,与猪皮炎肾病综合征、繁殖障碍、先天性震颤等临床症状有关。为了进一步研究这两种病毒的流行情况和遗传多样性,我们使用多重实时 PCR 检测方法,对 2018 年至 2020 年期间来自 55 个不同猪场的不同生长阶段的疑似 PCVAD 猪的 198 个样本进行了 PCV2 和 PCV3 的检测。在 198 个样本中,PCV2 和 PCV3 的阳性率分别为 57.07%(113/198)和 36.36%(72/198),39 个样本(19.7%)同时感染了 PCV2 和 PCV3。随后,从 30 个临床样本中获得了 34 株 PCV2 全基因组序列,从 19 个临床样本中获得了 19 株 PCV3 全基因组序列。其中,8 株 PCV2 属于 PCV2a,10 株属于 PCV2b,16 株属于 PCV2d,表明 PCV2d 是中国中部地区主要流行的 PCV2 基因型。此外,在三个样本(JZ-4、KF-2 和 JY-1)中发现了不同 PCV2 基因型菌株的混合感染,在测序的 13 株 PCV2d 菌株的 ORF2 区发现了交叉重组,这些菌株的假定亲代菌株分别为 LN6/1999(MF278777)和 MEX/41238/2014(KT795287)。PCV3 的系统进化分析显示,本研究获得的序列与参考序列之间的核苷酸同源性较高(>98%)。这些数据将有助于我们了解 PCV2 和 PCV3 的分子流行病学和进化。