Comparison of the virulence of three H3N2 canine influenza virus isolates from Korea and China in mouse and Guinea pig models

• Published in: BMC veterinary research 2018-05, Vol.14 (1), p.149-149, Article 149
• Main Authors: Xie, Xing, Na, Woonsung, Kang, Aram, Yeom, Minjoo, Yuk, Heejun, Moon, Hyoungjoon, Kim, Sung-Jae, Kim, Hyun-Woo, Kim, Jeong-Ki, Pang, Maoda, Wang, Yongshan, Liu, Yongjie, Song, Daesub
• Format: Article
• Language: English
• Subjects: Analysis; Animals; BALB/c mice; China - epidemiology; Disease Models, Animal; Dog Diseases - virology; Dogs; Female; Genetic aspects; Guinea Pigs; H3N2 canine influenza virus; Health aspects; Influenza A Virus, H3N2 Subtype - pathogenicity; Influenza viruses; Mice; Mice, Inbred BALB C; Orthomyxoviridae Infections - veterinary; Orthomyxoviridae Infections - virology; Pathogenicity; Patient outcomes; Real-Time Polymerase Chain Reaction - veterinary; Republic of Korea - epidemiology; Swine; Transmissibility; Viral Load; Virulence; Virulence (Microbiology)
• ISSN: 1746-6148; 1746-6148
• DOI: 10.1186/s12917-018-1469-1

Avian-origin H3N2 canine influenza virus (CIV) has been the most common subtype in Korea and China since 2007. Here, we compared the pathogenicity and transmissibility of three H3N2 CIV strains [Chinese CIV (JS/10), Korean CIV (KR/07), and Korean recombinant CIV between the classic H3N2 CIV and the pandemic H1N1 virus (MV/12)] in BALB/c mouse and guinea pig models. The pandemic H1N1 (CA/09) strain served as the control. BALB/c mice infected with H1N1 had high mortality and obvious body weight loss, whereas no overt disease symptoms were observed in mice inoculated with H3N2 CIV strains. The viral titers were higher in the group MV/12 than those in groups JS/10 and KR/07, while the mice infected with JS/10 showed higher viral titers in all tissues (except for the lung) than the mice infected with KR/07. The data obtained in guinea pigs also demonstrated that group MV/12 presented the highest loads in most of the tissues, followed by group JS/10 and KR/07. Also, direct contact transmissions of all the three CIV strains could be observed in guinea pigs, and for the inoculated and the contact groups, the viral titer of group MV/12 and KR/07 was higher than that of group JS/10 in nasal swabs. These findings indicated that the matrix (M) gene obtained from the pandemic H1N1 may enhance viral replication of classic H3N2 CIV; JS/10 has stronger viral replication ability in tissues as compared to KR/07, whereas KR/07 infected guinea pigs have more viral shedding than JS/10 infected guinea pigs. There exists a discrepancy in pathobiology among CIV isolates. Reverse genetics regarding the genomes of CIV isolates will be helpful to further explain the virus characteristics.