Blomström Anne-Lie, Fossum Caroline, Wallgren Per, Berg Mikael
Department of Biomedical Sciences and Veterinary Public Health, Section of Virology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
Department of Biomedical Sciences and Veterinary Public Health, Section of Immunology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
PLoS One. 2016 Dec 1;11(12):e0166863. doi: 10.1371/journal.pone.0166863. eCollection 2016.
The development of high-throughput sequencing technologies have allowed the possibility to investigate and characterise the entire microbiome of individuals, providing better insight to the complex interaction between different microorganisms. This will help to understand how the microbiome influence the susceptibility of secondary agents and development of disease. We have applied viral metagenomics to investigate the virome of lymph nodes from Swedish pigs suffering from the multifactorial disease postweaning multisystemic wasting syndrome (PMWS) as well as from healthy pigs. The aim is to increase knowledge of potential viruses, apart from porcine circovirus type 2 (PCV2), involved in PMWS development as well as to increase knowledge on the virome of healthy individuals. In healthy individuals, a diverse viral flora was seen with several different viruses present simultaneously. The majority of the identified viruses were small linear and circular DNA viruses, such as different circoviruses, anelloviruses and bocaviruses. In the pigs suffering from PMWS, PCV2 sequences were, as expected, detected to a high extent but other viruses were also identified in the background of PCV2. Apart from DNA viruses also RNA viruses were identified, among them were a porcine pestivirus showing high similarity to a recently (in 2015) discovered atypical porcine pestivirus in the US. Majority of the viruses identified in the background of PCV2 in PMWS pigs could also be identified in the healthy pigs. PCV2 sequences were also identified in the healthy pigs but to a much lower extent than in PMWS affected pigs. Although the method used here is not quantitative the very clear difference in amount of PCV2 sequences in PMWS affected pigs and healthy pigs most likely reflect the very strong replication of PCV2 known to be a hallmark of PMWS. Taken together, these findings illustrate that pigs appear to have a considerable viral flora consisting to a large extent of small single-stranded and circular DNA viruses. Future research on these types of viruses will help to better understand the role that these ubiquitous viruses may have on health and disease of pigs. We also demonstrate for the first time, in Europe, the presence of a novel porcine pestivirus.
高通量测序技术的发展使得研究和表征个体的整个微生物组成为可能，从而更好地洞察不同微生物之间的复杂相互作用。这将有助于理解微生物组如何影响继发病原体的易感性和疾病的发展。我们应用病毒宏基因组学来研究患有多因素疾病断奶后多系统消耗综合征（PMWS）的瑞典猪以及健康猪的淋巴结病毒组。目的是增加对除2型猪圆环病毒（PCV2）之外可能参与PMWS发展的病毒的了解，并增加对健康个体病毒组的了解。在健康个体中，观察到多种不同病毒同时存在的多样化病毒群落。鉴定出的大多数病毒是小型线性和环状DNA病毒，如不同的圆环病毒、环病毒和博卡病毒。在患有PMWS的猪中，正如预期的那样，PCV2序列被大量检测到，但在PCV2背景中也鉴定出了其他病毒。除了DNA病毒，还鉴定出了RNA病毒，其中一种猪瘟病毒与美国最近（2015年）发现的一种非典型猪瘟病毒高度相似。在PMWS猪的PCV2背景中鉴定出的大多数病毒也能在健康猪中鉴定出来。在健康猪中也鉴定出了PCV2序列，但程度远低于受PMWS影响的猪。尽管这里使用的方法不是定量的，但PMWS患病猪和健康猪中PCV2序列数量的明显差异很可能反映了已知是PMWS标志的PCV2的强烈复制。综上所述，这些发现表明猪似乎有相当多的病毒群落，在很大程度上由小型单链和环状DNA病毒组成。对这类病毒的未来研究将有助于更好地理解这些普遍存在的病毒可能对猪的健康和疾病所起的作用。我们还首次在欧洲证明了一种新型猪瘟病毒的存在。
