The prevalent status and genetic diversity of porcine reproductive and respiratory syndrome virus in China: a molecular epidemiological perspective

Abstract

Porcine reproductive and respiratory syndrome virus (PRRSV) has been epidemic more than 30 years in America and 20 years in China. It is still one of the most important causative agents to the worldwide swine industry. Here, we systematically analyzed the prevalence status of PRRSV in China by a molecular epidemiological perspective. Now both PRRSV-1 and PRRSV-2 are circulating and approximately more than 80% of pig farms are seropositive for PRRSV. For PRRSV-2, there are four lineages (lineage 1, lineage 3, lineage 5, lineage 8) circulating in the fields. Lineage 8 (CH-1a-like) and lineage 5 (BJ-4-like) appeared almost at the same time during 1995-1996. Notably, BJ-4 shares 99.6% and 99.8% identity with VR2332 and RespPRRS MLV, respectively. It means that lineage 5 is likely to be imported from America. Now highly pathogenic PRRSV (HP-PRRSV) which was considered to be evolved from local diversity of lineage 8 strains is predominant with different variants. Lineage 3 appeared in 2010 which is mainly sporadic in south of China. Lineage 1, also known as NADC30-like strains in China, has been prevalent since 2013 and leads to PRRS pandemic again. For PRRSV-1, although sporadic at present, more than 9 provinces/regions have been reported. All the circulating strains belong to subtype I. It should be paid more attention since there are no vaccines available. Our analysis would help to deeply understand the prevalent status of PRRSV in China and provide useful information for prevention and control of porcine reproductive and respiratory syndrome (PRRS).

Two novel recombinant porcine reproductive and respiratory syndrome viruses belong to sublineage 3.5 originating from sublineage 3.2

“…Overall, type 2 PRRSVs were split into nine monophyletic lineages based on the ORF5 gene (Shi et al, ). Currently, five lineages (lineages 1, 3, 5, 8 and 9) represent the prevalent type 2 PRRSV strains in China (Gao et al, ; Guo et al, ). With lineage 3 PRRSV spreading in southern China (Gao et al, ; Sun et al, ), we further divided lineage 3 into five sublineages according to the locations of PRRSV isolation and the shape on the phylogenetic tree (Figure ).…”

“…PRRSV is categorized into two different genotypes, type 1 and type 2, which are represented by European prototypical isolate Lelystad virus (LV) and the North American prototypical isolate ATCC VR‐2332, respectively (Collins et al, ; Wensvoort et al, ), which share 60% nucleotide identity (Allende et al, ). Type 2 PRRSVs are divided into 9 lineages, and lineages 1, 3, 5, 8 and 9 have been detected in China (Gao et al, ; Guo, Chen, Li, Qiao, & Zhang, ).…”

Emergence of a novel highly pathogenic recombinant virus from three lineages of porcine reproductive and respiratory syndrome virus 2 in China 2017

“…PRRSV2 isolates have existed in China for more than 20 years and are predominant in Chinese swine herds even though PRRSV1 has also been sporadically isolated (Chen et al., ; Guo, Chen, Li, Qiao, & Zhang, ). Chinese PRRSV2 isolates are clustered into four lineages (Guo et al., ).…”

“…PRRSV2 isolates have existed in China for more than 20 years and are predominant in Chinese swine herds even though PRRSV1 has also been sporadically isolated (Chen et al., ; Guo, Chen, Li, Qiao, & Zhang, ). Chinese PRRSV2 isolates are clustered into four lineages (Guo et al., ). Lineage 1 contains NADC30‐like PRRSV2 isolates (e.g., JL580 and CHsx1401) sharing the highest similarity with American NADC30 strain isolated in 2008 (Zhou et al., ; Zhao et al., ).…”

Insight into the evolution of nidovirus endoribonuclease based on the finding that nsp15 from porcine Deltacoronavirus functions as a dimer

“…Among the coronaviruses, Deltacoronavirus has the smallest genome, ranging in size from ϳ25.4 to 26.6 kb (4). In contrast to coronaviruses, arteriviruses possess the smallest genomes of all nidoviruses; their genomes are ϳ12.7 to 15.7 kb in size (9,10).…”