• Chi Nguyen Quynh Ho Biology Department, International University, Ho Chi Minh City
  • Son Nghia Hoang Animal Biotechnology Department, Institute of Tropical Biology, Ho Chi Minh City
  • Thao Thi Phuong Nguyen
  • Chung Chinh Doan Biology and Biotechnology Department, University of Science, Ho Chi Minh City
  • Mai Thi Phuong Nguyen Tay Nguyen Institute of Scientific Research, VAST, Lam Dong Province
  • Trinh Huu Le Animal Biotechnology Department, Institute of Tropical Biology, VAST, Ho Chi Minh City
  • Hoai Thi Thu Nguyen Biology Department, International University, Ho Chi Minh City
  • Long Thanh Le Animal Biotechnology Department, Institute of Tropical Biology, Ho Chi Minh City


Porcine reproductive and respiratory syndrome is a devastating disease that causes heavy losses to the economy and the development of agriculture. In this study, we aimed to assess the genetic variation of the ORF5 gene from 12 Vietnamese porcine reproductive and respiratory syndrome virus (PRRSV) strains. The phylogenetic analysis of the ORF5 sequences of Vietnamese strains and other strains indicated that the Vietnamese strains belong to type II. The Vietnamese strains were also separated into two clusters. Five strains BG/12, TG1/12, TG2/12, TG3/12, and TG4/12 were grouped in cluster 1 with a 98% bootstrap value, while the other seven strains HCM/14, TG5/15, TG6/15, TG7/15, ST1/15, ST2/15, and ST3/15 belonged to cluster 2. The alignment of the deduced amino acid sequences demonstrated that the identity between Vietnamese strains with CH-1a, JXA1, and VR2332 strains were 87–93%, 91–98%, and 83–89%, respectively. The mutation of the N21 glycosylation site (N→S) of the GP5 sequence was observed in five Vietnamese strains from cluster 1. The core sequence of the neutralizing epitopes (including five positions at H25, Q27, I29, Y30, and N31) in GP5 was presented in all Vietnamese strains except strain TG1/12. The hydrophobicity plots of GP5 revealed two different positions of BG/12 strain from CH-1a strain and VR2332 strain. The first difference was the missing of a hydrophilic peak from position amino acid 85 to 95. In this region, the CH-1a and VR2332 strains have 3 hydrophilic peaks. The second difference was the loss of another hydrophilic peak at position amino acid 100.

Key words: genotype; ORF5; phylogenetics; PRRSV; Vietnam



Prašičji respiratorni in reproduktivni sindrom je huda bolezen, ki povzroča velike izgube v gospodarstvu in vpliva na razvoj kmetijstva. V raziskavi smo želeli oceniti gensko raznolikost gena ORF5 v 12 sevih virusa vietnamskega prašičjega respiratornega in reproduktivnega sindroma (PRRSV). Filogenetska analiza baznih zaporedij ORF5 vietnamskih in drugih sevov je pokazala, da vietnamski sevi pripadajo tipu II. Tudi vietnamski sevi so bili ločeni v dve skupini. Pet sevov (BG/12, TG /12, TG2/12, TG3/12 in TG /12) je bilo združenih v skupino 1 z 98-odstotno vrednostjo bootstrap, medtem ko je bilo ostalih sedem sevov (HCM/14, TG5/15, TG6/15, TG7/15, ST1/15, ST2/15 in ST3/15) uvrščenih v drugo skupino. Poravnava zaporedij aminokislin je pokazala, da je podobnost med vietnamskimi sevi in sevi CH-1a 87−93-odstotna, JXA1 91−98-odstotna in VR2332 83−89-odstotna. Pri petih vietnamskih sevih iz skupine 1 smo opazili mutacijo mesta z glikozilacijo N21 (N → S) zaporedja GP5. Glavno zaporedje nevtralizacijskih epitopov (vključno s petimi položaji pri H25, Q27, I29, Y30 in N31) v GP5 je bilo opaženo pri vseh vietnamskih sevih, razen v sevu TG1/12. Grafikoni hidrofobnosti GP5 so pokazali dva različna položaja BG/12 iz CH-1a in VR2332 sevov. Prva razlika je bila odsotnost hidrofilnega vrha pri položaju aminokislin 85 do 95. V tem področju so imeli sevi CH-1a in VR2332 tri hidrofilne vrhove. Druga razlika je bila izguba drugega hidrofilnega vrha na položaju aminokisline 100.

Ključne besede: genotip; ORF5; filogenetika; PRRSV; Vietnam


(1) Thaa B, Sinhadri BC, Tielesch C, Krause E, Veit M. Signal peptide cleavage from GP5 of PRRSV: a minor fraction of molecules retains the decoy epitope, a presumed molecular cause for viral persistence. Plos One 2013; 8(6): e65548 (14 pp.) (April 2016)

(2) Snijder EJ, Meulenberg JJ. The molecular biology of arteriviruses. J Gen Virol 1998; 79(5): 961–79.

(3) Chen Z, Zhou XX, Lunney JK, et al. Immunodominant epitopes in nsp2 of porcine reproductive and respiratory syndrome virus are dispensable for replication, but play an important role in modulation of the host immune response. J Gen Virol 2010; 91: 1047–57.

(4) Allende R, Lewis TL, Lu Z, et al. North American and European porcine reproductive and respiratory syndrome viruses differ in nonstructural protein coding regions. J Gen Virol 1999; 80: 307–15.

(5) Kroese MV, Zevenhoven-Dobbe JC, Bos-de Ruijter JN, et al. The nsp1alpha and nsp1 papain-like autoproteinases are essential for porcine reproductive and respiratory syndrome virus RNA synthesis. J Gen Virol 2008; 89: 494-9.

(6) Lee C, Yoo D. The small envelope protein of porcine reproductive and respiratory syndrome virus possesses ion channel protein-like properties. Virology 2006; 355: 30–43.

(7) Hai NN, Vi VTH, Hung VT. PRRS in Vietnam and its diagnosis. J Life Sci 2015; 9: 272–6.

(8) Wang C, Wu B, Amer S, et al. Phylogenetic analysis and molecular characteristics of seven variant Chinese field isolates of RRSV. BMC Microbiol 2010; 10: e146 (11 pp.) (April 2016)

(9) Fan B, Wang H, Bai J, Zhang L, Jiang PA. Novel isolate with deletion in GP3 gene of porcine reproductive and respiratory syndrome virus from Mid-Eastern China. Biomed Res Int 2014; 2014: e306130 (11 pp.) journals/bmri/2014/306130/ (April 2016)

(10) Shi M, Lam TT, Hon CC, et al. Phylogeny-based evolutionary, demographical, and geographical dissection of North American type 2 porcine reproductive and respiratory syndrome viruses. J Virol 2010; 84: 8700–11.

(11) Wei Z, Lin T, Sun L, et al. N-linked glycosylation of GP5 of porcine reproductive and respiratory syndrome virus is critically important for virus replication in vivo. J Virol 2012; 86(18): 9941–51.

(12) Plagemann PGW, Rowland RRR, Faaberg KS. The primary neutralization epitope of porcine respiratory and reproductive syndrome virus strain VR-2332 is located in the middle of the GP5 ectodomain. Arch Virol 2002; 147: 2337–47.

(13) Li J, Yin Y, Guo B, et al. Sequence analysis of the NSP2, ORF5, and ORF7 genes of 11 PRRS virus isolates from China. Virus Genes 2012; 45: 256–64.

(14) Tamura K, Peterson D, Peterson N, Stecher G, Nei M, Kumar S. MEGA5: molecular evolutionary genetics analysis using maximum likelihood, evolutionary distance, and maximum parsimony methods. Mol Biol Evol 2011; 28: 2731–9.

(15) Saitou N, Nei M. The Neighbor-Joining method: a new method for reconstructing phylogenetic trees. Mol Biol Evol 1987; 4: 406–25.

(16) Kyte J, Doolittle RA. Simple method for displaying the hydropathic character of a protein. J Mol Biol 1982; 157: 105–32.

(17) Zhou YJ, Yu H, Tian ZJ, et al. Monoclonal antibodies and conserved antigenic epitopes in the C terminus of GP5 protein of the North American type porcine reproductive and respiratory syndrome virus. Vet Microbiol 2009; 138: 1–10.

(18) Van NT, Mai NC, Thanh LT, et al. Sequence and phylogenetic analysis of five PRRSV isolates in Vietnam. In: ISBENS 2013. International Symposium on Biological Engineering and Natural Sciences: special issue. Bangkok, 2013: 1-11.

(19) Thuy NTD, Thu NT, Son NG, et al. Genetic analysis of ORF5 porcine reproductive and respiratory syndrome virus isolated in Vietnam. Microbiol Immunol 2013; 57(7): 518– 26.

(20) Swenson SL, Hill HT, Zimmerman JJ, et al. Preliminary assessment of an inactivated PRRS virus vaccine on the excretion of virus in semen. Swine Health Prod 1995; 3: 244–7.

(21) Zimmerman JJ, Yoon KJ, Pirtle E C, Wills RW, Sanderson TJ, McGinley MJ. Studies of porcine reproductive and respiratory syndrome (PRRS) virus infection in avian species. Vet Microbiol 1997; 55: 329–36.

(22) Zimmerman JJ, Yoon KY, Pirtle EC, et al. Susceptibility of four avian species to PRRS virus. In: Proceedings of the Annual Meeting of the Livestock Conservation Institute. St Louis, USA, 1993: 107–8.

(23) De Jong MF, Cromwijk W, Van’t Veld P. The new pig disease: epidemiology and production losses in the Netherlands. In: Report of a Seminar on the New Pig Disease (PRRS). Brussels, Belgium, 1991: 9–19.

(24) Tisdell CA. Trends in Vietnam's pork supply and structural features of its Pig Sector. The Open Area Studies Journal 2009; 2: 52-71.

(25) Dea S, Gagnon CA, Mardassi H, Pirzadeh B, Rogan D. Current knowledge on the structural proteins of porcine reproductive and respiratory syndrome (PRRS) virus: comparison of the North American and European isolates. Arch Virol 2000; 145: 659–88.




How to Cite

Ho, C. N. Q., Hoang, S. N., Nguyen, T. T. P., Doan, C. C., Nguyen, M. T. P., Le, T. H., Nguyen, H. T. T., & Le, L. T. (2017). THE ORF5 VARIATION OF VIETNAMESE PORCINE REPRODUCTIVE AND RESPIRATORY SYNDROME VIRUS STRAINS. SLOVENIAN VETERINARY RESEARCH, 54(3). Retrieved from



Original Research Article