Emergence of a novel highly pathogenic porcine reproductive and respiratory syndrome virus in China

Abstract

From 2014 to 2015, four novel highly pathogenic PRRS virus (HP-PRRSV) strains named 14LY01-FJ, 14LY02-FJ 15LY01-FJ, and 15LY02-FJ were isolated from high morbidity (100%) and mortality (40%-80%) in piglets and sows in Fujian Province. To further our knowledge about these novel virus strains, we characterized their complete genomes and determined their pathogenicity in piglets. Full-length genome sequencing analysis showed that these four isolates were closely related to type 2 (North American type, NA-type) isolates, with 88.1%-96.3% nucleotide similarity, but only 60.6%-60.8% homology to the Lelystad virus (LV) (European type, EU-type). The full length of the four isolates was determined to be 15017 or 15018 nucleotides (nt), excluding the poly(A) tail. Furthermore, the four isolates had three discontinuous deletions (aa 322-432, aa 483, and aa 504-522) within hypervariable region II (HV-II) of Nsp2, as compared to the reference strain VR-2332. This deletion pattern in the four isolates is consistent with strain MN184 and strain NADC30 isolated from America. Phylogenetic and molecular evolutionary analyses indicated that these virulent strains originated from a natural recombination event between the JXA1-like HP-PRRSV (JXA-1 is one of the earliest Chinese HP-PRRSV strains; sublineage 8.7) and the NADC30-like (lineage 1) PRRSV. Animal experiments demonstrated that these four strains caused significant weight loss and severe histopathological lung lesions as compared to the negative control group. High mortality rate (40% or 80%) was found in piglets infected with any one of the four strains, similar to that found with other Chinese HP-PRRSV strains. This study showed that the novel variant PRRSV was HP-PRRSV, and it is therefore critical to monitor PRRSV evolution in China and develop a method for controlling PRRS.

Porcine respiratory disease complex after the introduction of H1N1/2009 influenza virus in Brazil

“…The most common pathogens detected in this study were IAV followed by Mhyo, which are also considered pathogens of major relevance in PRDC in other countries (Opriessnig et al., ). PRRS plays an important role in PRDC resulting in significant economic losses in North America, Europe and China (Choi et al., ; Liu et al., ; Sinn et al., ); however, in our study, PRRSV was not detected, consisted with Brazil's PRRS‐free status (Ciacci‐Zanella et al., ). Seventy per cent of the samples were from nursery pigs, the age group considered as at greatest risk for infections due to the waning of maternal antibodies (Van Reeth, Brown, & Olsen, ) and increased stress caused by intermingling of piglets from different farms, as part of the management practices in Brazilian swine production system.…”

The Nucleocapsid Protein and Nonstructural Protein 10 of Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus Enhance CD83 Production via NF-κB and Sp1 Signaling Pathways

“…KEYWORDS CD83, NF-B, PRRSV, Sp1, nonstructural protein 10, nucleocapsid O ver the last 3 decades, porcine reproductive and respiratory syndrome virus (PRRSV) has become a serious threat to the swine industry worldwide (1,2). Current vaccines do not provide complete protection against this disease (3)(4)(5), and it is unclear how PRRSV inhibits the host's immune response and induces persistent infection.…”

A natural recombinant PRRSV between HP-PRRSV JXA1-like and NADC30-like strains

“…reported that HNjz15 inoculated piglets display mild clinical manifestations and that HNjz15 is less pathogenic than the JXA1 and JL580 PRRSV strains (Sun et al., ). Subsequently, the NADC30‐like PRRSV strains, such as 14LY01‐FJ, 14LY02‐FJ, 15LY01‐FJ and 15LY01‐FJ, originating from JXA1‐like PRRSV, induce a similar clinical symptom which is caused by HP‐PRRSV in piglets (Liu et al., ). Collectively, recombination may accelerate evolution and influence the virulence of NADC30‐like PRRSV.…”