scholarly journals Identification of Two Porcine Reproductive and Respiratory Syndrome Virus Variants Sharing High Genomic Homology but with Distinct Virulence

Viruses ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 875 ◽  
Author(s):  
Nanhua Chen ◽  
Mengxue Ye ◽  
Yucheng Huang ◽  
Shuai Li ◽  
Yanzhao Xiao ◽  
...  
Keyword(s):  
Amino Acid ◽  
Control Strategies ◽  
Economic Loss ◽  
Respiratory Syndrome Virus ◽  
Amino Acid Deletion ◽  
Swine Industry ◽  
Sequence Alignments ◽  
Genetic Feature ◽  
Pathogenic Analysis ◽  
Highly Virulent

Porcine reproductive and respiratory syndrome virus (PRRSV) causes huge economic loss to the global swine industry. Even though several control strategies have been applied, PRRS is still not effectively controlled due to the continuous emergence of new variants and limited cross-protection by current vaccines. During the routine epidemiological investigation in 2017, two PRRSV variants were identified from a severe abortion farm and a clinically healthy farm, respectively. The viruses were isolated and denominated as XJ17-5 and JSTZ1712-12. Genomic sequencing indicated that their genomes are both 14,960 bp in length sharing 99.45% nucleotide identity. Sequence alignments identified a discontinuous 30-amino-acid deletion and a continuous 120-amino-acid deletion in nsp2 of both isolates. Genome-based phylogenetic analysis confirmed that XJ17-5 and JSTZ1712-12 belong to the HP-PRRSV subtype but form a new branch with other isolates containing the same 150-amino-acid deletion in nsp2. Pathogenic analysis showed that XJ17-5 is highly virulent causing 60% mortality, while JSTZ1712-12 is avirulent for piglets. Furthermore, fragment comparisons identified 34-amino-acid differences between XJ17-5 and JSTZ1712-12 that might be associated with the distinct virulence. The identification of highly homologous HP-PRRSV variants with new genetic feature and distinct virulence contributes to further analyze the pathogenesis and evolution of PRRSV in the field.

scholarly journals The 30-Amino-Acid Deletion in the Nsp2 of Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus Emerging in China Is Not Related to Its Virulence

2009 ◽  
Vol 83 (10) ◽  
pp. 5156-5167 ◽  
Author(s):  
Lei Zhou ◽  
Jialong Zhang ◽  
Jingwen Zeng ◽  
Shuoyan Yin ◽  
Yanhua Li ◽  
...  
Keyword(s):  
Amino Acid ◽  
Parental Virus ◽  
Respiratory Syndrome Virus ◽  
Cdna Clones ◽  
Coding Region ◽  
Amino Acid Deletion ◽  
Highly Pathogenic ◽  
Specific Pathogen ◽  
Prrsv Strain ◽  
Highly Pathogenic Prrsv

ABSTRACT During the past 2 years, an atypical clinical outbreak, caused by a highly pathogenic porcine reproductive and respiratory syndrome virus (PRRSV) with a unique 30-amino-acid deletion in its Nsp2-coding region, was pandemic in China. In this study, we generated four full-length infectious cDNA clones: a clone of the highly virulent PRRSV strain JXwn06 (pWSK-JXwn), a clone of the low-virulence PRRSV strain HB-1/3.9 (pWSK-HB-1/3.9), a chimeric clone in which the Nsp2 region containing the 30-amino-acid deletion was replaced by the corresponding region of the low-virulence PRRSV strain HB-1/3.9 (pWSK-JXwn-HB1nsp2), and a mutated HB-1/3.9 clone with the same deletion in Nsp2 as JXwn06 (pWSK-HB1-ND30). We also investigated the pathogenicities of the rescued viruses (designated RvJXwn, RvJXwn-HB1nsp2, RvHB-1/3.9, and RvHB1-ND30, respectively) in specific-pathogen-free piglets in order to determine the role of the 30-amino-acid deletion in the virulence of the highly pathogenic PRRSV. All the rescued viruses could replicate stably in MARC-145 cells. Our findings indicated that RvJXwn-HB1nsp2 retained high virulence for piglets, like RvJXwn and the parental virus JXwn06, although the survival time of piglets infected with RvJXwn-HB1nsp2 was obviously prolonged. RvHB1-ND30 exhibited low virulence for piglets, like RvHB-1/3.9 and the parental virus HB-1/3.9. Therefore, we conclude that the 30-amino-acid deletion is not related to the virulence of the highly pathogenic PRRSV emerging in China.

scholarly journals Immunity against a Japanese local strain of porcine reproductive and respiratory syndrome virus decreases viremia and symptoms of a highly pathogenic strain

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Hiroshi Iseki ◽  
Kenji Kawashima ◽  
Tomoyuki Shibahara ◽  
Masaji Mase
Keyword(s):  
Amino Acid ◽  
Local Strain ◽  
Daily Weight Gain ◽  
Respiratory Syndrome Virus ◽  
Nucleotide Sequence Analysis ◽  
Amino Acid Deletion ◽  
Highly Pathogenic ◽  
Group 3 ◽  
Group 2

Abstract Background The type 2 highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) has spread throughout countries of southeast Asia, where it has caused severe economic losses. Even countries presently free of PRRSV are at high risk for infection and spread of this virus. Some of these countries, including Japan, have broad epidemics of the local type 2 PRRSV, creating chronic pathogenicity in the domestic pig population. The present study aimed to evaluate the protective efficacy of immunity by infection with a Japanese field isolate, EDRD1, against heterologous challenge with a Vietnamese HP-PRRSV field strain. To this end, four groups of PRRSV-negative crossbreed piglets were used for a challenge study. Groups 1 and 2 were inoculated with EDRD1 via the intranasal route. After 26 days, Groups 2 and 3 were inoculated with HP-PRRSV via the same route. Group 4 served as an uninfected control. Blood and oral fluid samples were taken every 3–4 days after HP-PRRSV challenge; on day 16 post-challenge, all pigs were euthanized, and examined pathologically. Results The nucleotide sequence analysis of nonstructural protein 2 gene of EDRD1 and comparison with Vietnamese HP-PRRSV showed that the 39 amino acid deletion sites of EDRD1 was nearly in the same region as the 29 amino acid deletion sites of HP-PRRSV. Immunity conferred by inoculation with EDRD1 dramatically reduced viral load in the sera and tissues besides viral shedding (Group 2) compared with those in pigs infected only with HP-PRRSV (Group 3). The clinical signs and rectal temperature were significantly reduced, and the average daily weight gain was significantly improved in the EDRD1-inoculated pigs (Group 2) compared with the Group 3 pigs. Notably, no viral RNA was detected in various organs of the Group 2 pigs 16 days post-infection with HP-PRRSV, except in one pig. Therefore, the immunity induced by EDRD1 and its genetically close field isolates may play a role in reducing viremia caused by HP-PRRSV. Conclusions The results of the present study demonstrate that pigs are highly protected against heterologous Vietnamese HP-PRRSV challenge by immunity against a Japanese local strain, EDRD1.

scholarly journals WGS- versus ORF5-Based Typing of PRRSV: A Belgian Case Study

Viruses ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2419
Author(s):  
Frank Vandenbussche ◽  
Elisabeth Mathijs ◽  
Marylène Tignon ◽  
Tamara Vandersmissen ◽  
Ann Brigitte Cay
Keyword(s):  
Genetic Diversity ◽  
Large Scale ◽  
Control Strategies ◽  
Added Value ◽  
Respiratory Syndrome Virus ◽  
Serum Samples ◽  
Swine Industry ◽  
High Genetic Diversity ◽  
Rate Analysis ◽  
Phylogenetic Cluster

Porcine reproductive and respiratory syndrome virus (PRRSV) is the causative agent of one of the most widespread and economically devastating diseases in the swine industry. Typing circulating PRRSV strains by means of sequencing is crucial for developing adequate control strategies. Most genetic studies only target the highly variable open reading frame (ORF) 5, for which an extensive database is available. In this study, we performed whole-genome sequencing (WGS) on a collection of 124 PRRSV-1 positive serum samples that were collected over a 5-year period (2015–2019) in Belgium. Our results show that (nearly) complete PRRSV genomes can be obtained directly from serum samples with a high success rate. Analysis of the coding regions confirmed the exceptionally high genetic diversity, even among Belgian PRRSV-1 strains. To gain more insight into the added value of WGS, we performed phylogenetic cluster analyses on separate ORF datasets as well as on a single, concatenated dataset (CDS) containing all ORFs. A comparison between the CDS and ORF clustering schemes revealed numerous discrepancies. To explain these differences, we performed a large-scale recombination analysis, which allowed us to identify a large number of potential recombination events that were scattered across the genome. As PRRSV does not contain typical recombination hot-spots, typing PRRSV strains based on a single ORF is not recommended. Although the typing accuracy can be improved by including multiple regions, our results show that the full genetic diversity among PRRSV strains can only be captured by analysing (nearly) complete genomes. Finally, we also identified several vaccine-derived recombinant strains, which once more raises the question of the safety of these vaccines.

scholarly journals A Single Amino Acid Deletion in the Matrix Protein of Porcine Reproductive and Respiratory Syndrome Virus Confers Resistance to a Polyclonal Swine Antibody with Broadly Neutralizing Activity

2015 ◽  
Vol 89 (12) ◽  
pp. 6515-6520 ◽  
Author(s):  
Benjamin R. Trible ◽  
Luca N. Popescu ◽  
Nicholas Monday ◽  
Jay G. Calvert ◽  
Raymond R. R. Rowland
Keyword(s):  
Amino Acid ◽  
Matrix Protein ◽  
Infectious Clone ◽  
Virus Neutralization ◽  
Single Amino Acid ◽  
Respiratory Syndrome Virus ◽  
Amino Acid Deletion ◽  
Neutralizing Activity ◽  
The Matrix

Assessment of virus neutralization (VN) activity in 176 pigs infected with porcine reproductive and respiratory syndrome virus (PRRSV) identified one pig with broadly neutralizing activity. A Tyr-10 deletion in the matrix protein provided escape from broad neutralization without affecting homologous neutralizing activity. The role of the Tyr-10 deletion was confirmed through an infectious clone with a Tyr-10 deletion. The results demonstrate differences in the properties and specificities of VN responses elicited during PRRSV infection.

scholarly journals Attenuation and Immunogenicity of a Live High Pathogenic PRRSV Vaccine Candidate with a 32-Amino Acid Deletion in the nsp2 Protein

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Wenhui Lu ◽  
Baoli Sun ◽  
Jianyue Mo ◽  
Xiduo Zeng ◽  
Guanqun Zhang ◽  
...  
Keyword(s):  
Amino Acid ◽  
Vaccine Candidate ◽  
Clinical Signs ◽  
Respiratory Syndrome Virus ◽  
Amino Acid Deletion ◽  
Lethal Challenge ◽  
Nsp2 Gene ◽  
Amino Acid Mutations

A porcine reproductive and respiratory syndrome virus (PRRSV) QY1 was serially passed on Marc-145 cells. Virulence of different intermediate derivatives of QY1 (P5, P60, P80, and P100) were determined. The study found that QY1 had been gradually attenuated during the in vitro process. Pathogenicity study showed that pigs inoculated with QY1 P100 and P80 did not develop any significant PRRS clinic symptoms. However, mild-to-moderate clinical signs and acute HP-PRRSV symptoms of infection were observed in pigs inoculated with QY1 P60 and P5, respectively. Furthermore, we determined the whole genome sequences of these four intermediate viruses. The results showed that after 100 passages, compared to QY1 P5, a total of 32 amino acid mutations were found. Moreover, there were one nucleotide deletion and a unique 34-amino acid deletion found at 5′UTR and in nsp2 gene during the attenuation process, respectively. Such deletions were genetically stable in vivo. Following PRRSV experimental challenge, pigs inoculated with a single dose of QY1 P100 developed no significant clinic symptoms and well tolerated lethal challenge, while QY1 P80 group still developed mild fever in the clinic trial after challenge. Thus, we concluded that QY1 P100 was a promising and highly attenuated PRRSV vaccine candidate.

scholarly journals Glyceraldehyde 3 phosphate dehydrogenase restricted in cytoplasmic location by viral GP5 facilitates PRRSV replication via its glycolytic activity

2021 ◽  
Author(s):  
Xuewei Liu ◽  
Xing Liu ◽  
Juan Bai ◽  
Yanni Gao ◽  
Zhongbao Song ◽  
...  
Keyword(s):  
Amino Acid ◽  
Viral Infection ◽  
Treatment Strategies ◽  
Viral Envelope ◽  
Respiratory Syndrome Virus ◽  
Viral Envelope Protein ◽  
Host Proteins ◽  
Swine Industry ◽  
Amino Acid Region ◽  
Glycolytic Activity

Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most important endemic swine pathogens, causing enormous losses in the global swine industry. Commercially available vaccines only partially prevent or counteract the virus infection and correlated losses. PRRSV replication mechanism has not been well understood. In this study, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was screened to bind with the viral major envelope glycoprotein 5 (GP5) after PRRSV infection. The interacting sites are located within a 13 amino acid region (93 105 aa) of GP5 and at Lys227 of GAPDH. Interestingly, viral GP5 restricts the translocation of GAPDH from the cytoplasm to the nucleus. Moreover, cytoplasmic GAPDH facilitates PRRSV replication by virtue of its glycolytic activity. The results suggest that PRRSV GP5 restricts GAPDH into the nucleus and exploits its glycolytic activity to stimulate virus replication. The data provide insight into the role of GAPDH in PRRSV replication and reveal a potential target for controlling viral infection. Importance PRRSV poses a severe economic threat to the pig industry. PRRSV GP5, the major viral envelope protein, plays an important role in viral infection, pathogenicity, and immunity. However, interactions between GP5 and host proteins have not yet been well studied. Here, we show that GAPDH interacts with GP5 through binding a 13-amino-acid sequence (93–105 aa) in GP5, while GP5 interacts with GAPDH at the K277 amino acid residue of GAPDH. We demonstrate that GP5 interacts with GAPDH in the cytoplasm during PPRSV infection, inhibiting GAPDH entry into the nucleus. PRRSV exploits the glycolytic activity of GAPDH to promote viral replication. These results enrich our understanding of PRRSV infection and pathogenesis, and open a new avenue for antiviral prevention and PRRSV treatment strategies.

scholarly journals Immunity Against a Japanese Local Strain of Porcine Reproductive and Respiratory Syndrome Virus Decreases Viremia and Symptoms of a Highly Pathogenic Strain

2021 ◽  
Author(s):  
HIROSHI ISEKI ◽  
Kenji Kawashima ◽  
Tomoyuki Shibahara ◽  
Masaji Mase
Keyword(s):  
Amino Acid ◽  
Local Strain ◽  
Daily Weight Gain ◽  
Respiratory Syndrome Virus ◽  
Nucleotide Sequence Analysis ◽  
Amino Acid Deletion ◽  
Highly Pathogenic ◽  
Group 3 ◽  
Group 2

Abstract Background: The type 2 highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) has spread throughout countries of southeast Asia, where it has caused severe economic losses. Even countries presently free of PRRSV are at high risk for infection and spread of this virus. Some of these countries, including Japan, have broad epidemics of the local type 2 PRRSV, creating chronic pathogenicity in the domestic pig population. The present study aimed to evaluate the protective efficacy of immunity by infection with a Japanese field isolate, EDRD1, against heterologous challenge with a Vietnamese HP-PRRSV field strain. To this end, four groups of PRRSV-negative crossbreed piglets were used for a challenge study. Groups 1 and 2 were inoculated with EDRD1 via the intranasal route. After 26 days, Groups 2 and 3 were inoculated with HP-PRRSV via the same route. Group 4 served as an uninfected control. Blood and oral fluid samples were taken every 3–4 days after HP-PRRSV challenge; on day 16 post-challenge, all pigs were euthanized, and examined pathologically.Results: The nucleotide sequence analysis of nonstructural protein 2 gene of EDRD1 and comparison with Vietnamese HP-PRRSV showed that the 39 amino acid deletion sites of EDRD1 was nearly in the same region as the 29 amino acid deletion sites of HP-PRRSV. Immunity conferred by inoculation with EDRD1 dramatically reduced viral load in the sera and tissues besides viral shedding (Group 2) compared with those in pigs infected only with HP-PRRSV (Group 3). The clinical signs and rectal temperature were significantly reduced, and the average daily weight gain was significantly improved in the EDRD1-inoculated pigs (Group 2) compared with the Group 3 pigs. Notably, no viral RNA was detected in various organs of the Group 2 pigs 16 days post-infection with HP-PRRSV, except in one pig. Therefore, the immunity induced by EDRD1 and its genetically close field isolates may play a role in reducing viremia caused by HP-PRRSV.Conclusions: The results of the present study demonstrate that pigs are highly protected against heterologous Vietnamese HP-PRRSV challenge by immunity against a Japanese local strain, EDRD1.

scholarly journals Pathogenic Characterization of European Genotype Porcine Reproductive and Respiratory Syndrome Virus Recently Isolated in Mainland China

2017 ◽  
Vol 11 (1) ◽  
pp. 83-89 ◽  
Author(s):  
Sun Ming ◽  
Ma Yongying ◽  
Liu Bohua ◽  
Lu Huiying ◽  
Deng Xiaoyu ◽  
...  
Keyword(s):  
Mainland China ◽  
Economic Loss ◽  
Respiratory Syndrome Virus ◽  
Type I ◽  
Swine Industry ◽  
Virulent Type ◽  
Prrsv Strain ◽  
European Genotype ◽  
And Control

Background:Porcine reproductive and respiratory syndrome virus (PRRSV) is an important pathogen in pig that causes tremendous economic loss in the global swine industry. PRRSV is divided into the European and North American genotypes, with virulence ranging from apathogenic-moderately virulent to highly pathogenic. The emergence of new highly virulent type 1 strains and coexistence of the two genotypes complicate the differential diagnosis, disease prevention, and control of PRRSV. Although the emergence of a novel type 1 PRRSV strain in mainland China was first confirmed in 2011, there is no information available concerning the pathogenesis of this strain.Objectives:We sought to determine the pathogenesis of a newly emerged Chinese type 1 PRRSV strain HLJB1.Methods:Pigs were infected with HLJB1 and characterized using serological and histopathological tests.Results:HLJB1 infection induced transient chemosis, reddened conjunctiva, skin cyanosis, mild transient pyrexia, dyspnea, and tachypnea between 7 and 13 days post-infection. Gross pneumonic lesions were characterized by multifocal, tan-mottled areas. Lymph nodes and spleen were enlarged. Characteristic microscopic lesions consisted of pulmonary consolidation and alveolar septal thickening with red blood cell infiltration, depletion of splenic lymphocytes, and hyperplasia and activation of macrophage. No pigs infected with HLJB1 died during the experiment.Conclusion:Our findings indicate that Chinese type I PRRSV strain HLJB1 caused classic PRRSV-specific lesions. As it caused lower viremia in pigs compared with other classic type 1 isolates, HLJB1 is less virulent than other type I strains.

Hubsm: A Novel Amino Acid Substitution Matrix for Comparing Hub Proteins

2017 ◽  
Vol 7 (8) ◽  
pp. 212
Author(s):  
Renganayaki G. ◽  
Achuthsankar S. Nair
Keyword(s):  
Amino Acid ◽  
Amino Acid Substitution ◽  
Low Complexity ◽  
Database Search ◽  
Substitution Matrix ◽  
Compositional Bias ◽  
Sequence Alignments ◽  
Amino Acid Substitution Matrix ◽  
Alignment Algorithms ◽  
Hub Proteins

Sequence alignment algorithms and  database search methods use BLOSUM and PAM substitution matrices constructed from general proteins. These de facto matrices are not optimal to align sequences accurately, for the proteins with markedly different compositional bias in the amino acid.   In this work, a new amino acid substitution matrix is calculated for the disorder and low complexity rich region of Hub proteins, based on residue characteristics. Insights into the amino acid background frequencies and the substitution scores obtained from the Hubsm unveils the  residue substitution patterns which differs from commonly used scoring matrices .When comparing the Hub protein sequences for detecting homologs,  the use of this Hubsm matrix yields better results than PAM and BLOSUM matrices. Usage of Hubsm matrix can be optimal in database search and for the construction of more accurate sequence alignments of Hub proteins.

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