Two Highly Pathogenic Avian Influenza H5N1 Viruses of Clade 2.3.2.1 with Similar Genetic Background but with Different Pathogenicity in Mice and Ducks. Issue 2 (12th April 2012)

• Record Type: Journal Article
• Authors: Hu, J.; Zhao, K.; Liu, X.; Wang, X.; Chen, Z.; Liu, X.
• Is Part Of: Transboundary and emerging diseases. Volume 60:Issue 2(2013)
• Page Start: 127
• Page End: 139
• Publication Date: 2012-04-12
• Subjects: Veterinary medicine -- Periodicals; 636.089
• DOI: 10.1111/j.1865-1682.2012.01325.x
• Languages: English
• ISSNs: 1865-1674

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Summary</title> <p>A number of genetic markers for virulence of avian influenza viruses (AIVs) in different hosts have been identified. However, we isolated two H5N1 AIVs, A/Chicken/Jiangsu/k0402/2010(CK/10) and A/Goose/Jiangsu/k0403/2010(GS/10) with similar genetic background, but most well‐defined molecular markers for virulence in mammals and avian species were not found in both viral genomes. In addition, pathogenicity of this pair of viruses in different hosts remains unclear. Therefore, we evaluated their pathogenicity in chickens, mice, ducks and guinea pigs. Infection of CK/10 and GS/10 in chickens caused 100% mortality within 24 h. Mouse experiment showed that CK/10 was highly pathogenic (MLD<sub>50</sub> = 0.33 log<sub>10</sub> EID<sub>50</sub>), whereas GS/10 was avirulent (MLD<sub>50</sub> > 6.32 log<sub>10</sub> EID<sub>50</sub>). Interestingly, the virulence of CK/10 in ducks (DLD<sub>50</sub> = 3.83 log<sub>10</sub> EID<sub>50</sub>) was higher than that of GS/10 (DLD<sub>50</sub> = 7.7 log<sub>10</sub> EID<sub>50</sub>), which correlated with viral pathogenicity in mice. Although CK/10 and GS/10 showed distinct pathogenicity in mice, they both were lethal to guinea pigs, with CK/10 replicating to higher titres in airways than GS/10. Collectively, these findings suggest that AIVs with similar genetic backgrounds may exhibit distinct pathogenicity in specific hosts and that some unknown molecular markers for virulence may exist and need to be identified.</p> </abstract>