Antigenic analysis of highly pathogenic avian influenza virus H5N1 sublineages co-circulating in Egypt.
Highly pathogenic avian influenza virus H5N1 has spread across Eurasia and Africa, and outbreaks are now endemic in several countries, including Indonesia, Vietnam and Egypt. Continuous circulation of H5N1 virus in Egypt, from a single infected source, has led to significant genetic diversification with phylogenetically separable sublineages, providing an opportunity to study the impact of genetic evolution on viral phenotypic variation. In this study, we analysed the phylogeny of H5 haemagglutinin (HA) genes in influenza viruses isolated in Egypt from 2006 to 2011 and investigated the effect of conserved amino acid mutations in the HA genes in each of the sublineages on their antigenicity. The analysis showed that viruses in at least four sublineages still persisted in poultry in Egypt as of 2011. Using reverse genetics to generate HA-reassortment viruses with specific HA mutations, we found antigenic drift in the HA in two influenza virus sublineages, compared with the other currently co-circulating influenza virus sublineages in Egypt. Moreover, the two sublineages with significant antigenic drift were antigenically distinguishable. Our findings suggested that phylogenetically divergent H5N1 viruses, which were not antigenically cross-reactive, were co-circulating in Egypt, indicating that there was a problem in using a single influenza virus strain as seed virus to produce influenza virus vaccine in Egypt and providing data for designing more efficacious control strategies in H5N1-endemic areas.
Department of Virology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
Yohei
Y
Watanabe
Department of Microbiology and Immunology, Faculty of Veterinary Medicine, Damanhour University, Egypt.
Madiha S
MS
Ibrahim
Department of Poultry Diseases and Hygiene, Faculty of Veterinary Medicine, Damanhour University, Egypt.
Hany F
HF
Ellakany
Genome Information Research Center, Research Institute for Microbial Disease, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan.|Department of Environmental Pharmacometrics, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
Norihito
N
Kawashita
International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan.|Department of Infectious Diseases, Kyoto Prefectural School of Medicine, 465 Kawaramachi-hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan.
Tomo
T
Daidoji
Genome Information Research Center, Research Institute for Microbial Disease, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan.|Department of Environmental Pharmacometrics, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
Tatsuya
T
Takagi
Genome Information Research Center, Research Institute for Microbial Disease, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
Teruo
T
Yasunaga
Department of Infection Metagenomics, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan.|International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan.|Department of Infectious Diseases, Kyoto Prefectural School of Medicine, 465 Kawaramachi-hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan.
Takaaki
T
Nakaya
Department of Virology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
Kazuyoshi
K
Ikuta
D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000276:immunology; D000956:Antigens, Viral / Q000276:immunology*; D001483:Base Sequence; D002460:Cell Line; D002642:Chick Embryo; D002645:Chickens / Q000235:genetics / Q000276:immunology / Q000821:virology; D003429:Cross Reactions / Q000235:genetics / Q000276:immunology; D004196:Disease Outbreaks; D004285:Dogs; D004534:Egypt / Q000453:epidemiology; D019143:Evolution, Molecular; D006031:Glycosylation; D057809:HEK293 Cells; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics / Q000276:immunology*; D006801:Humans; D053124:Influenza A Virus, H5N1 Subtype / Q000235:genetics* / Q000276:immunology*; D007252:Influenza Vaccines / Q000276:immunology; D005585:Influenza in Birds / Q000453:epidemiology / Q000235:genetics / Q000276:immunology / Q000821:virology*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics / Q000276:immunology; D010802:Phylogeny; D015995:Prevalence
D000906:Antibodies; D000956:Antigens, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D007252:Influenza Vaccines; C109963:hemagglutinin, avian influenza A virus