Genetic variation and phylogenetic relationships of 22 porcine reproductive and respiratory syndrome virus (PRRSV) field strains based on sequence analysis of open reading frame 5

Andreyev, V.G.; Wesley, Ronald D.; Mengeling, W. L.; Vorwald, Ann C.; Lager, Kelly M.

doi:10.1007/s007050050134

Cited by 113 publications

(83 citation statements)

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“…This scenario may be due to the immune pressures to which the external structural proteins are exposed. The relatively low rates of mutation observed in ORFs 1b and 7 are consistent with field observations (4,18,55).…”

Section: Discussionsupporting

confidence: 87%

“…ORF 6 is the most conserved gene among North American isolates, with up to 100% amino acid identity, and is the most conserved gene between North American and European isolates, with 70 to 81% identity (24,33,39). The amino acid sequence homology for ORF 5 varies from 88 to 97% among North American isolates and from 51 to 59% when North American viruses are compared to the Lelystad virus (4,24,31,39). A comparison of the Lelystad virus with isolate ATCC VR-2332, the North American prototype virus, revealed amino acid identities of 63, 58, and 68% for ORFs 2, 3, and 4, respectively (39).…”

mentioning

confidence: 99%

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Evolution of Porcine Reproductive and Respiratory Syndrome Virus during Sequential Passages in Pigs

Chang¹,

Yoon²,

Zimmerman³

et al. 2002

J Virol

117

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Porcine reproductive and respiratory syndrome (PRRS) viruses are recognized as possessing a high degree of genetic and antigenic variability. Viral diversity has led to questions regarding the association of virus mutation and persistent infection in the host and has raised concerns vis-à-vis protective immunity, the ability of diagnostic assays to detect novel variants, and the possible emergence of virulent strains. The purpose of this study was to describe ongoing changes in PRRS virus during replication in pigs under experimental conditions. Animals were inoculated with a plaque-cloned virus derived from VR-2332, the North American PRRS virus prototype. Three independent lines of in vivo replication were maintained for 367 days by pig-to-pig passage of virus at 60-day intervals. A total of 315 plaque-cloned viruses were recovered from 21 pigs over the 367-day observation period and compared to the original plaque-cloned virus by virus neutralization assay, monoclonal antibody analysis, and sequencing of open reading frames (ORFs) 1b (replicase), 5 (major envelope protein), and 7 (nucleocapsid) of the genome. Variants were detected by day 7 postinoculation, and multiple variants were present concurrently in every pig sampled over the observation period. Sequence analysis showed ORFs 1b and 7 to be highly conserved. In contrast, sequencing of ORF 5 disclosed 48 nucleotide variants which corresponded to 22 amino acid variants. Although no epitopic changes were detected under the conditions of this experiment, PRRS virus was shown to evolve continuously in infected pigs, with different genes of the viral genome undergoing various degrees of change.

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Section: Discussionsupporting

confidence: 87%

mentioning

confidence: 99%

Evolution of Porcine Reproductive and Respiratory Syndrome Virus during Sequential Passages in Pigs

Chang¹,

Yoon²,

Zimmerman³

et al. 2002

J Virol

117

View full text Add to dashboard Cite

show abstract

“…27 Furthermore, there are RT-PCR assays for the specific genotype detection available. 1,31 Beside these published RT-PCR assays, several commercial kits for the genome detection and differentiation of PRRSV are available.…”

Section: Introductionmentioning

confidence: 99%

Porcine reproductive and respiratory syndrome virus

et al. 2012

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To compare the real-time reverse transcription quantitative polymerase chain reaction (RT-qPCR) assays used for the diagnosis of Porcine reproductive and respiratory syndrome virus (PRRSV), a Europe-wide interlaboratory ring trial was conducted. A variety of PRRSV strains including North American (NA) and European (EU) genotype isolates were analyzed by the participants. Great differences regarding qualitative diagnostics as well as analytical sensitivity were observed between the individual RT-qPCR systems, especially when investigating strains from the EU genotype. None of the assays or commercial kits used in the ring trial could identify all different PRRSV strains with an optimal analytical and diagnostic sensitivity. The genetic variability of the PRRSV strains, which is supposed to hinder the diagnostic of the RT-PCR because of mutations at the primer binding sites, was also confirmed by sequencing and subsequent phylogenetic analysis. In summary, a major problem in PRRSV diagnostics by RT-qPCR is false-negative results. To achieve maximum safety in the molecular diagnosis of PRRSV, the combined usage of different assays or kits is highly recommended.

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“…PRRSV infection has spread to many countries and causes signifi cant economic losses on swine farms. PRRSV was fi rst isolated in Europe in 1991 and in North America in 1992 [14,15]. To control PRRSV in the fi eld, management strategies, such as herd depopulation, repopulation, herd closure, bio-security, and testing and removal, have been attempted.…”

Section: Introductionmentioning

confidence: 99%

Effects of high molecular weight poly-γ-glutamic acid on PIGS with porcine preproductive and respiratory syndrome virus (PRRSV) infection

Seo

Lee²,

Kang³

et al. 2017

Acta Veterinaria

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Bacillus subtilis sups. chungkookjang produces a higher molecular mass poly-γ-glutamic acid (γ-PGA). Recently, previous studies have demonstrated immune stimulation and an antitumor effect of the high molecular mass γ-PGA using various mouse models although these effects have not been shown in other species of animals. Therefore, the current study was conducted to determine the effect of γ-PGA in pigs with and without PRRSV infection. PRRS-negative pigs were intramuscularly injected with 1, 3, or 5 ml of 20 mg/mll γ-PGA, and one group of pigs served as a non-treatment (NT) group. All groups treated with γ-PGA had signifi cantly higher weight gains, and pigs treated with 5 ml of γ-PGA exhibited higher tumor necrosis factor (TNF)-α, interferon (IFN)-α and IFN-β expression levels compared with the NT group. According to the preliminary results, an animal challenge study was conducted with a highly virulent PRRSV strain, MN184, along with γ-PGA treatment at different time points. Pigs treated with γ-PGA had lower levels of viral loads in the sera and in lungs and gained signifi cantly more weight (p<0.05) compared with the NT group after being challenged with MN184. Moreover, γ-PGA-treatment groups had higher levels of neutralizing antibodies and cytokines related to proinfl ammatory, humoral and cell-mediated responses than the control group after the PRRSV challenge. Therefore, it was concluded that γ-PGA induces higher levels of immune responses and increases resistance to PRRSV infection in pigs.

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Genetic variation and phylogenetic relationships of 22 porcine reproductive and respiratory syndrome virus (PRRSV) field strains based on sequence analysis of open reading frame 5

Cited by 113 publications

References 0 publications

Evolution of Porcine Reproductive and Respiratory Syndrome Virus during Sequential Passages in Pigs

Evolution of Porcine Reproductive and Respiratory Syndrome Virus during Sequential Passages in Pigs

Porcine reproductive and respiratory syndrome virus

Effects of high molecular weight poly-γ-glutamic acid on PIGS with porcine preproductive and respiratory syndrome virus (PRRSV) infection

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