Genetic and biological characteristics of recent Korean isolates of avian influenza virus subtype H9N2

  • Acharya, Madhav Prasad (Laboratory of Avian Diseases, College of Veterinary Medicine, Seoul National University) ;
  • Kwon, Hyuk-Joon (Research Institute for Veterinary Science, College of Veterinary Medicine and BK21 for Veterinary Science, Seoul National University) ;
  • Kim, Il-Hwan (Laboratory of Avian Diseases, College of Veterinary Medicine, Seoul National University) ;
  • Lee, Youn-Jeong (Animal, Plant and Fisheries Quarantine and Inspection Agency) ;
  • Kim, Jae-Hong (Laboratory of Avian Diseases, College of Veterinary Medicine, Seoul National University)
  • Received : 2012.10.12
  • Accepted : 2012.10.22
  • Published : 2012.12.31


The worldwide distribution and continuing genetic mutation of avian influenza virus (AIV) has been posed a great threat to human and animal health. A comparison of 3 isolates of AIV H9N2, A/chicken/Korea/KBNP-0028/00 (H9N2) (KBNP-0028), A/chicken/Korea/SNU8011/08 (H9N2) (SNU 8011) and an inactivated oil vaccine strain A/chicken/Korea/01310/01 (H9N2) (01310), was performed. The former 2 AIVs were isolated from field cases before and after the application of an inactivated H9N2 vaccine in 2007, respectively. The antigenic relationship, viral shedding, tissue tropism and genetic analysis were examined. The comparison of virus shedding from the cloaca and the oropharynx revealed that both isolates were more frequently isolated from the upper respiratory tract (90~100%) 1 day post inoculation (DPI) compared with isolation 5 DPI from gastrointestinal tracts (10~60%). Moreover, the isolate KBNP-0028 were recovered from all organs including bone marrow, brain and kidneys, indicating higher ability for broad tissue dissemination than that of SNU 8011. KBNP-0028 replicated earlier than other strains and with a higher titer than SNU 8011. In full-length nucleotide sequences of the NA gene and a partial sequence of the HA gene of SNU 8011, we found that there might be significant changes in tissue tropism, virus replication and genetic mutation in AIV H9N2 isolates.


Supported by : Animal, Plant & Fisheries Quarantine and Inspection Agency (QIA)


  1. Aamir UB, Wernery U, Ilyushina N, Webster RG. Characterization of avian H9N2 influenza viruses from United Arab Emirates 2000 to 2003. Virology 2007, 361, 45-55.
  2. Al-Natour MQ, Abo-Shehada MN. Sero-prevalence of avian influenza among broiler-breeder flocks in Jordan. Prev Vet Med 2005, 70, 45-50.
  3. Alexander DJ. A review of avian influenza in different bird species. Vet Microbiol 2000, 74, 3-13.
  4. Baigent SJ, McCauley JW. Glycosylation of haemagglutinin and stalk-length of neuraminidase combine to regulate the growth of avian influenza viruses in tissue culture. Virus Res 2001, 79, 177-185.
  5. Bano S, Naeem K, Malik SA. Evaluation of pathogenic potential of avian influenza virus serotype H9N2 in chickens. Avian Dis 2003, 47 (3 Suppl), 817-822.
  6. Butt KM, Smith GJ, Chen H, Zhang LJ, Leung YH, Xu KM, Lim W, Webster RG, Yuen KY, Peiris JS, Guan Y. Human infection with an avian H9N2 influenza A virus in Hong Kong in 2003. J Clin Mirobiol 2005, 43, 5760-5767.
  7. Chin PS, Hoffmann E, Webby R, Webster RG, Guan Y, Peiris M, Shortridge KF. Molecular evolution of H6 influenza viruses from poultry in southeastern China: prevalence of H6N1 influenza viruses possessing seven A/ Hong Kong/156/97 (H5N1)-like genes in poultry. J Virol 2002, 76, 507-516.
  8. Choi JG, Lee YJ, Kim YJ, Lee EK, Jeong OM, Sung HW, Kim JH, Kwon JH. An inactivated vaccine to control the current H9N2 low pathogenic avian influenza in Korea. J Vet Sci 2008, 9, 67-74.
  9. Choi YK, Seo SH, Kim JA, Webby RJ, Webster RG. Avian influenza viruses in Korean live poultry markets and their pathogenic potential. Virology 2005, 332, 529-537.
  10. Ejaz R, Ahmed Z, Siddique N, Naeem K. Chicken meat as a source of avian influenza virus persistence and dissemination. Int J Poult Sci 2007, 6, 871-874.
  11. Fereidouni SR, Starick E, Grund C, Globig A, Mettenleiter TC, Beer M, Harder T. Rapid molecular subtyping by reverse transcription polymerase chain reaction of the neuraminidase gene of avian influenza A viruses. Vet Microbiol 2009, 135, 253-260.
  12. Fouchier RAM, Munster V, Wallensten A, Bestebroer TM, Herfst S, Smith D, Rimmelzwaan GF, Olse B, Osterhaus ADME. Characterization of a novel influenza A virus hemagglutinin subtype (H16) obtained from blackheaded gulls. J Virol 2005, 79, 2814-2822.
  13. Gharaibeh S. Pathogenicity of an avian influenza virus serotype H9N2 in chickens. Avian Dis 2008, 52, 106-110.
  14. Guan Y, Shortridge KF, Krauss S, Webster RG. Molecular characterization of H9N2 influenza viruses: were they the donors of the "internal" genes of H5N1 viruses in Hong Kong? Proc Natl Acad Sci USA 1999, 96, 9363-9367.
  15. Guo YJ, Krauss S, Senne DA, Mo IP, Lo KS, Xiong XP, Norwood M, Shortridge KF, Webster RG, Guan Y. Characterization of the pathogenicity of members of the newly established H9N2 influenza virus lineages in Asia. Virology 2000, 267, 279-288.
  16. Haghighat-Jahromi M, Asasi K, Nili H, Dadras H, Shooshtari AH. Coinfection of avian influenza virus (H9N2 subtype) with infectious bronchitis live vaccine. Arch Virol 2008, 153, 651-655.
  17. Hoffmann E, Stech J, Guan Y, Webster RG, Perez DR. Universal primer set for the full-length amplification of all influenza A viruses. Arch Virol 2001, 146, 2275-2289.
  18. Homme PJ, Easterday BC, Anderson DP. Avian influenza virus infections. II. Experimental epizootiology of influenza A/Turkey/Wisconsin/1966 virus in turkeys. Avian Dis 1970, 14, 240-247.
  19. Kim JA, Cho SH, Kim HS, Seo SH. H9N2 influenza viruses isolated from poultry in Korean live bird markets continuously evolve and cause the severe clinical signs in layers. Vet Microbiol 2006, 118, 169-176.
  20. Kim HR, Lee YJ, Lee KK, Oem JK, Kim SH, Lee MH, Lee OS, Park CK. Genetic relatedness of H6 subtype avian influenza viruses isolated from wild birds and domestic ducks in Korea and their pathogenicity in animals. J Gen Virol 2010, 91 (Pt 1), 208-219.
  21. Kwon HJ, Cho SH, Ahn YJ, Kim JH, Yoo HS, Kim SJ. Characterization of a chicken embryo-adapted H9N2 subtype avian influenza virus. Open Vet Sci J 2009, 3, 9-16.
  22. Lee CW, Song CS, Lee YJ, Mo IP, Garcia M, Suarez DL, Kim SJ. Sequence analysis of the hemagglutinin gene of H9N2 Korean avian influenza viruses and assessment of the pathogenic potential of isolate MS96. Avian Dis 2000, 44, 527-535.
  23. Lee YJ, Shin JY, Song MS, Lee YM, Choi JG, Lee EK, Jeong OM, Sung HW, Kim JH, Kwon YK, Kwon JH, Kim CJ, Webby RJ, Webster RG, Choi YK. Continuing evolution of H9 influenza viruses in Korean poultry. Virology 2007, 359, 313-323.
  24. Luo G, Chung J, Palese P. Alterations of the stalk of the influenza virus neuraminidase: deletions and insertions. Virus Res 1993, 29, 141-153.
  25. Matrosovich MN, Krauss S, Webster RG. H9N2 influenza A viruses from poultry in Asia have human virus-like receptor specificity. Virology 2001, 281, 156-162.
  26. Mo IP, Song CS, Kim KS, Rhee JC. An occurrence of non-highly pathogenic avian influenza in Korea. Avian Dis 2003, 47, 379-383.
  27. Naeem K, Ullah A, Manvell RJ, Alexander DJ. Avian influenza A subtype H9N2 in poultry in Pakistan. Vet Rec 1999, 145, 560.
  28. Nagarajan S, Rajukumar K, Tosh C, Ramaswamy V, Purohit K, Saxena G, Behera P, Pattnaik B, Pradhan HK, Dubey SC. Isolation and Pathotyping of H9N2 Avian Influenza viruses in Indian poultry. Vet Microbiol 2009, 133, 154-163.
  29. Nili H, Asasi K. Natural cases and an experimental study of H9N2 avian influenza in commercial broiler chickens of Iran. Avian Pathol 2002, 31, 247-252.
  30. Ninomiya A, Takada A, Okazaki K, Shortridge KF, Kida H. Seroepidemiological evidence of avian H4, H5, and H9 influenza A virus transmission to pigs in southeastern China. Vet Microbiol 2002, 8, 107-114.
  31. Ohuchi M, Ohuchi R, Feldmann A, Klenk HD. Regulation of receptor binding affinity of influenza virus hemagglutinin by its carbohydrate moiety. J Virol 1997, 71, 8377-8384.
  32. Office international des epizooties (OIE). Manual of diagnostic tests and vaccines for terrestrial animals. OIE, Paris, 2008.
  33. Pant GR, Selleck PW. Surveillance for Avian influenza in Nepal 2004-2005. Avian Dis 2007, 51 (1 Suppl), 352-354.
  34. Peiris M, Yuen KY, Leung CW, Chan KH, Ip PLS, Lai RWM, Orr WK, Shortridge KF. Human infection with influenza H9N2. Lancet 1999, 354, 916-917.
  35. Perdue ML, Swayne DE. Public health risk from avian influenza viruses. Avian Dis 2005, 49, 317-327.
  36. Reed LJ, Muench H. A simple method for estimating fifty percent endpoints. Am J Hyg 1938, 27, 493-497.
  37. Shortridge KF, Zhou NN, Guan Y, Gao P, Ito T, Kawaoka Y, Kodihalli S, Krauss S, Markwell D, Murti KG, Norwood M, Senne D, Sims L, Takada A, Webster RG. Characterization of avian H5N1 influenza viruses from poultry in Hong Kong. Virology 1998, 252, 331-342.
  38. Swayne DE, Halvorson DA. Influenza. In: Saif YM, Fadly AM, Glisson JR, McDougald LR, Nolan LK, Swayne DE (eds.). Diseases of Poultry. 12th ed. pp. 153-184, Blackwell, Ames, 2008.
  39. Webster RG, Bean WJ, Gorman OT, Chambers TM, Kawaoka Y. Evolution and ecology of influenza A viruses. Microbiol Rev 1992, 56, 152-179.
  40. Zhang P, Tang Y, Liu X, Liu W, Zhang X, Liu H, Peng D, Gao S, Wu Y, Zhang L, Lu S, Liu X. A novel genotype H9N2 influenza virus possessing human H5N1 internal genomes has been circulating in poultry in eastern China since 1998. J Virol 2009, 83, 8428-8438.