Host determination role of some amino acid sequences in the
receptor-binding site and phylogenetic analysis of a high pathogenic
Avian Influenza (H5N1) viruses isolated from Northern Turkey
Abstract
Avian influenza (AI) H5N1 viruses are zoonotic agents that cause high
mortality rates in humans and poultry. In this study, some molecular
characterizations and phylogenetic analysis of Hemagglutinin gene of
H5N1 isolates seen in our country in 2006 were performed. Thus, it is
aimed to determine the pathogenicity levels of those available isolates
and whether they have the ability to transmit from person to person and
establish the evolutionary relationships to some other viruses
circulated in Europe, Asia and Africa. In the scope of the study,
seventeen H5N1 isolates that were isolated from various Avian species
were used. After the isolates were regenerated and produced in specific
pathogen-free (SPF) embryonated chicken eggs, chorioallantoic fluids of
the eggs were collected and RNA extraction was made, and the enzyme
cleavage and receptor binding site of the hemagglutinin gene was
replicated using RT-PCR. After this process, the enzyme cleavage site of
the Hemagglutinin genes and the amino acid sequence of the
receptor-binding site were determined by the BioEdit program. As a
result, it was determined that all the seventeen isolates are High
Pathogenic AI viruses. In addition, the sequence analysis of the
receptor-binding site indicated that seventeen isolates did not have any
mutations in the relevant amino acid positions. Also, our isolates were
classified as clade 2.2 and clade 2.2.1 and were closely related to
European and Asian isolates. Moreover, it is found that our isolates are
not capable of transmitting from person to person; However, due to the
virus traits, it has been concluded that the molecular and antigenic
characteristics of the virus should be determined in places where the
disease occurs since it is still circulating in some parts of the world
and can be transported with migratory birds.