title: Evolution of an avian H5N1 influenza A virus escape mutant.
abstract: OBJECTIVE
  To investigate the genetic constitution of an escape mutant H5N1 strain and to screen the presence of possible amino acid signatures that could differentiate it from other Egyptian H5N1 strains.
  
  
  METHODS
  Phylogenetic, evolutionary patterns and amino acid signatures of the genes of an escape mutant H5N1 influenza A virus isolated in Egypt on 2009 were analyzed using direct sequencing and multisequence alignments.
  
  
  RESULTS
  All the genes of the escape mutant H5N1 strain showed a genetic pattern potentially related to Eurasian lineages. Evolution of phylogenetic trees of different viral genes revealed the absence of reassortment in the escape mutant strain while confirming close relatedness to other H5N1 Egyptian strains from human and avian species. A variety of amino acid substitutions were recorded in different proteins compared to the available Egyptian H5N1 strains. The strain displayed amino acid substitutions in different viral alleles similar to other Egyptian H5N1 strains without showing amino acid signatures that could differentiate the escape mutant from other Egyptian H5N1.
  
  
  CONCLUSIONS
  The genetic characteristics of avian H5N1 in Egypt revealed evidence of a high possibility of inter-species transmission. No amino acid signatures were found to differentiate the escape mutant H5N1 strain from other Egyptian H5N1 strains.
authors.affiliation: Kamel M A Hassanin, Biochemistry Department, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef 62511, Egypt.
authors.forename: Kamel M A
authors.initials: KM
authors.lastname: Hassanin
authors.forename: Ahmed S
authors.initials: AS
authors.lastname: Abdel-Moneim
keywords: Chicken; Genotyping; H5N1; Influenza; Virus evolution