J Vet Sci.  2012 Dec;13(4):377-383.

A survey of porcine reproductive and respiratory syndrome among wild boar populations in Korea

• Choi EJ
• Lee CH
• Hyun BH
• Kim JJ
• Lim SI
• Song JY
• Shin YK

Abstract

No information is currently available on porcine reproductive and respiratory syndrome virus (PRRSV) infection in wild boars (Sus scrofa) in Korea. In this study, the status of PRRS in wild boars was investigated. Blood samples were collected from 267 wild boars from eight provinces in Korea. Four of the samples tested (1.5%) were positive for PRRSV antibodies and eight (3.0%) were positive for antigens. Of the virus-positive samples, three and five samples were typed as containing European (EU, type 1) or North American (NA, type 2) viruses, respectively. Two amplicons (one from type 1 and one from type 2) were used to analyze the PRRSV open reading frame 7 (ORF7) sequence. The nucleotide sequences of type 1 PRRSV ORF7 had identities between 96.1% and 98.4% with PRRSVs from domestic pigs in Korea. The sequences of type 2 PRRSV ORF7 had identities of 100% with the PRRSV strain VR-2332, which was prototypic North American strain. These results show that PRRSVs are present in wild boars in Korea, and effective PRRSV surveillance of the wild boar population might therefore be useful for disease control.

Keyword

ELISA; Korea; porcine reproductive and respiratory syndrome; RT-PCR; wild boar (Sus scrofa)

MeSH Terms

Antibodies
Base Sequence
Enzyme-Linked Immunosorbent Assay
Open Reading Frames
Porcine Reproductive and Respiratory Syndrome
Porcine respiratory and reproductive syndrome virus
Sprains and Strains
Sus scrofa

Figure

• 

  Fig. 1 RT-PCR results for the detection and differentiation of PRRSV in wild boar serum samples. Lane M: 100-bp DNA ladder, Lanes 1, 2, 3, 7, and 8: sample Nos. 49, 77, 167, 193, and 227, respectively (433-bp band), Lanes 4, 5, and 6: sample Nos. 110, 129, and 258, respectively (398-bp band), Lane 9: normal wild boar serum used as a negative control, Lane 10: VR-2332 strain used as a positive control for type 2, Lane 11: Lelystad virus (LV) used as a positive control for type 1.

• 

  Fig. 2 Alignments of the putative amino acid sequences based on ORF7 of wild boar-derived PRRSVs and prototype virus strains. (A) No. 129 and Lelystad virus (LV). (B) No. 49 and VR-2332 strain. Dots indicate identical amino acids.

• 

  Fig. 3 Phylogenetic analysis of ORF7 nucleotide sequences of a wild boar-derived and other various PRRSVs. The phylogenetic tree was constructed with wild boar type 1 (No. 129) PRRSV and PRRSV strains isolated worldwide. PRRSV strains are denoted as follows: PRRSV strain/GenBank accession No./country/collection time, publication year, or vaccine.

Reference

1. Albina E, Mesplède A, Chenut G, Le Potier MF, Bourbao G, Le Gal S, Leforban Y. A serological survey on classical swine fever (CSF), Aujeszky's disease (AD) and porcine reproductive and respiratory syndrome (PRRS) virus infections in French wild boars from 1991 to 1998. Vet Microbiol. 2000. 77:43–57.

2. Allende R, Lewis TL, Lu Z, Rock DL, Kutish GF, Ali A, Doster AR, Osorio FA. North American and European porcine reproductive and respiratory syndrome viruses differ in non-structural protein coding regions. J Gen Virol. 1999. 80:307–315.

3. Baker SR, O'Neil KM, Gramer MR, Dee SA. Estimates of the seroprevalence of production-limiting diseases in wild pigs. Vet Rec. 2011. 168:564.

4. Bartak P, Greiser-Wilke I. Genetic typing of classical swine fever virus isolates from the territory of the Czech Republic. Vet Microbiol. 2000. 77:59–70.

5. Bøtner A, Strandbygaard B, Sørensen KJ, Have P, Madsen KG, Madsen ES, Alexandersen S. Appearance of acute PRRS-like symptoms in sow herds after vaccination with a modified live PRRS vaccine. Vet Rec. 1997. 141:497–499.

6. Cha SH, Choi EJ, Park JH, Yoon SR, Song JY, Kwon JH, Song HJ, Yoon KJ. Molecular characterization of recent Korean porcine reproductive and respiratory syndrome (PRRS) viruses and comparison to other Asian PRRS viruses. Vet Microbiol. 2006. 117:248–257.

7. Cheon DS, Chae C, Lee YS. Seroprevalence of antibody to porcine reproductive and respiratory syndrome virus using enzyme-linked immunosorbent assay in selected herds in Korea. J Vet Diagn Invest. 1997. 9:434–436.

8. Cságola A, Kecskeméti S, Kardos G, Kiss I, Tuboly T. Genetic characterization of type 2 porcine circoviruses detected in Hungarian wild boars. Arch Virol. 2006. 151:495–507.

9. de Deus N, Casas M, Peralta B, Nofrarías M, Pina S, Martín M, Segalés J. Hepatitis E virus infection dynamics and organic distribution in naturally infected pigs in a farrow-to-finish farm. Vet Microbiol. 2008. 132:19–28.

10. 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. 145:659–688.

11. Felsenstein J. An alternating least squares approach to inferring phylogenies from pairwise distances. Syst Biol. 1997. 46:101–111.

12. Felsenstein J. Confidence limits on phylogenies: an approach using the bootstrap. Evolution. 1985. 39:783–791.

13. Han SH. Survey and Resource Management of Wildlife. 2011. Seoul: National Institute of Biological Resources;14.

14. Inoue R, Tsukahara T, Sunaba C, Itoh M, Ushida K. Simple and rapid detection of the porcine reproductive and respiratory syndrome virus from pig whole blood using filter paper. J Virol Methods. 2007. 141:102–106.

15. Kim SH, Roh IS, Choi EJ, Lee C, Lee CH, Lee KH, Lee KK, Song YK, Lee OS, Park CK. A molecular analysis of European porcine reproductive and respiratory syndrome virus isolated in South Korea. Vet Microbiol. 2010. 143:394–400.

16. Kimura M. A simple method for estimating evolutionary rates of base substitutions through comparative studies of nucleotide sequences. J Mol Evol. 1980. 16:111–120.

17. Kweon CH, Kwon BJ, Lee HJ, Cho JJ, Hwang EK, Shin JH, Yoon YD, Kang YB, An SH, Kim YH, Huh W, Jun MH, Wensvoort G. Isolation of porcine reproductive and respiratory syndrome virus (PRRSV) in Korea. Korean J Vet Res. 1994. 34:77–83.

18. Lee C, Kim H, Kang B, Yeom M, Han S, Moon H, Park S, Kim H, Song D, Park B. Prevalence and phylogenetic analysis of the isolated type I porcine reproductive and respiratory syndrome virus from 2007 to 2008 in Korea. Virus Genes. 2010. 40:225–230.

19. Leifer I, Hoffmann B, Höper D, Rasmussen TB, Blome S, Strebelow G, Höreth-Böntgen D, Staubach C, Beer M. Molecular epidemiology of current classical swine fever virus isolates of wild boar in Germany. J Gen Virol. 2010. 91(Pt 11):2687–2697.

20. Mardassi H, Wilson L, Mounir S, Dea S. Detection of porcine reproductive and respiratory syndrome virus and efficient differentiation between Canadian and European strains by reverse transcription and PCR amplification. J Clin Microbiol. 1994. 32:2197–2203.

21. Mateu E, Diaz I. The challenge of PRRS immunology. Vet J. 2008. 177:345–351.

22. Meng XJ, Paul PS, Halbur PG, Lum MA. Phylogenetic analyses of the putative M (ORF 6) and N (ORF 7) genes of porcine reproductive and respiratory syndrome virus (PRRSV): implication for the existence of two genotypes of PRRSV in the U.S.A. and Europe. Arch Virol. 1995. 140:745–755.

23. Nielsen J, Bøtner A, Bille-Hansen V, Oleksiewicz MB, Storgaard T. Experimental inoculation of late term pregnant sows with a field isolate of porcine reproductive and respiratory syndrome vaccine-derived virus. Vet Microbiol. 2002. 84:1–13.

24. Reiner G, Fresen C, Bronnert S, Willems H. Porcine reproductive and respiratory syndrome virus (PRRSV) infection in wild boars. Vet Microbiol. 2009. 136:250–258.

25. Ruiz-Fons F, Segalés J, Gortázar C. A review of viral diseases of the European wild boar: effects of population dynamics and reservoir rôle. Vet J. 2008. 176:158–169.

26. Seo SW, Sunwoo SY, Hyun BH, Lyoo YS. Detection of antibodies against classical swine fever virus in fecal samples from wild boar. Vet Microbiol. 2012. 161:218–221.

27. Stadejek T, Oleksiewicz MB, Scherbakov AV, Timina AM, Krabbe JS, Chabros K, Potapchuk D. Definition of subtypes in the European genotype of porcine reproductive and respiratory syndrome virus: nucleocapsid characteristics and geographical distribution in Europe. Arch Virol. 2008. 153:1479–1488.

28. Storgaard T, Oleksiewicz M, Bøtner A. Examination of the selective pressures on a live PRRS vaccine virus. Arch Virol. 1999. 144:2389–2401.

29. 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. 28:2731–2739.

30. Vengust G, Grom J, Bidovec A, Kramer M. Monitoring of classical swine fever in wild boar (Sus scrofa) in Slovenia. J Vet Med B Infect Dis Vet Public Health. 2006. 53:247–249.

31. Vengust G, Valencak Z, Bidovec A. A serological survey of selected pathogens in wild boar in Slovenia. J Vet Med B Infect Dis Vet Public Health. 2006. 53:24–27.

32. Vicente J, Ruiz-Fons F, Vidal D, Höfle U, Acevedo P, Villanúa D, Fernández-de-Mera IG, Martín MP, Gortázar C. Serosurvey of Aujeszky's disease virus infection in European wild boar in Spain. Vet Rec. 2005. 156:408–412.

33. Won CM, Yoo BH, Yang BG, Kim WM, Moon JS, Oh H, Lee H. Wildlife Survey. 2005. Incheon: National Institute of Environmental Research;18.

34. Wu WH, Fang Y, Farwell R, Steffen-Bien M, Rowland RRR, Christopher-Hennings J, Nelson EA. A 10-kDa structural protein of porcine reproductive and respiratory syndrome virus encoded by ORF2b. Virology. 2001. 287:183–191.

35. Yoon SH, Song JY, Lee CH, Choi EJ, Cho IS, Kim B. Genetic characterization of the Korean porcine reproductive and respiratory syndrome viruses based on the nucleocapsid protein gene (ORF7) sequences. Arch Virol. 2008. 153:627–635.

36. Zhang W, Sun Z. Random local neighbor joining: a new method for reconstructing phylogenetic trees. Mol Phylogenet Evol. 2008. 47:117–128.

37. Zimmerman JJ, Benfield DA, Murtaugh MP, Osorio F, Stevenson GW, Torremorell M. Straw BE, Zimmerman JJ, D'Allaire S, Taylor DJ, editors. Porcine reproductive and respiratory syndrome virus (porcine arterivirus). Diseases of Swine. 2006. 9th ed. Ames: Blackwell Publishing;387–417.

38. Župančić Ž, Jukić B, Lojkić M, Čač Ž, Jemeršić L, Starešina V. Prevalence of antibodies to classical swine fever, Aujeszky's disease, porcine reproductive and respiratory syndrome, and bovine viral diarrhoea viruses in wild boars in Croatia. J Vet Med B Infect Dis Vet Public Health. 2002. 49:253–256.