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Phylogenetic analysis of neuraminidase gene of H9N2 avian influenza viruses isolated from chicken in Iran during 2010-2011.

Norouzian H, Bashashati M, Vasfimarandi M - Iran J Microbiol (2014)

Bottom Line: The Iranian isolates can be divided into 2 main subgroups; 11-T like subgroup viruses isolated mainly during 1998-2004 and second subgroup viruses isolated during 2004-2009.The nucleotide sequences of the three studied isolates showed high identity to recent Pakistani H9N2 isolates (94.5-97%) compared to former Iranian AIV isolates (89-94%).High frequency of substitutions in the NA gene of studied isolates in recent years and effects of those substitutions on the pathogenicity of AI virus highlight the need to continue surveillance of genetic characteristics of AIV H9N2 in Iran.

View Article: PubMed Central - PubMed

Affiliation: Department of Clinical Sciences, Faculty of Veterinary Medicine, Lorestan University, Khorram-Abad,Iran.

ABSTRACT

Backgrounds and objectives: Classified as low pathogenic avian influenza (LPAI) viruses, the H9N2 subtype causes severe respiratory disease in poultry farms and occasional respiratory disease in humans. In this study, the neuraminidase (NA) gene of three Avian Influenza (AI) H9N2 strains isolated from poultry farms in Iran during 2010-11, as well as other reported Iranian H9N2 isolates, were genetically analyzed and their nucleotide changes were evaluated.

Materials and methods: The NA gene of three AIVs were sequenced and evaluated for genetic characteristics and phylogenetic relationship.

Results: One new potential glycosylation site (PGS) at amino acid position 306 was observed in one of the studied isolates (A/Chicken/Iran/N102/2011). Antigenic sites of NA in Iranian H9N2 isolates have varied in a yearly manner. The Iranian isolates can be divided into 2 main subgroups; 11-T like subgroup viruses isolated mainly during 1998-2004 and second subgroup viruses isolated during 2004-2009. Interestingly, the three studied isolates fell into a third subgroup. The nucleotide sequences of the three studied isolates showed high identity to recent Pakistani H9N2 isolates (94.5-97%) compared to former Iranian AIV isolates (89-94%).

Conclusion: High frequency of substitutions in the NA gene of studied isolates in recent years and effects of those substitutions on the pathogenicity of AI virus highlight the need to continue surveillance of genetic characteristics of AIV H9N2 in Iran.

No MeSH data available.


Related in: MedlinePlus

Phylogenetic relationships of NA gene of some influenza A viruses isolated in Iran and Pakistan. The lengths of horizontal lines are proportional to the minimum number of nucleotide differences required to join nodes. Vertical lines are for spacing branches and labels. ck, chicken; pk, pakistan; Ir, Iran.
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Figure 1: Phylogenetic relationships of NA gene of some influenza A viruses isolated in Iran and Pakistan. The lengths of horizontal lines are proportional to the minimum number of nucleotide differences required to join nodes. Vertical lines are for spacing branches and labels. ck, chicken; pk, pakistan; Ir, Iran.

Mentions: All studied Iranian H9N2 isolates fell into the same main group (G1 sub-lineage) as the viruses isolated in Pakistan. The Iranian isolates can be divided into 2 main subgroups (Fig. 1). The first subgroup (11-T like sub-lineage) included viruses that were isolated between 1998, first AI outbreak reported in Iran, and 2004. The former Pakistani isolates (A/chicken/Pakistan/4/99) were placed in a close relationship with this subgroup of Iranian isolates. The second subgroup comprised the strains isolated from 2004 to 2008. However, some exceptions were seen in both subgroups. Interestingly, 3 viruses isolated in this study on 2010-2011 didn′t place with other Iranian isolates in the second subgroup, but placed in a new subgroup in a close relationship with some recent Pakistani H9N2 isolates (A/chicken/Pakistan/UDL-01/2006) (Fig. 1).


Phylogenetic analysis of neuraminidase gene of H9N2 avian influenza viruses isolated from chicken in Iran during 2010-2011.

Norouzian H, Bashashati M, Vasfimarandi M - Iran J Microbiol (2014)

Phylogenetic relationships of NA gene of some influenza A viruses isolated in Iran and Pakistan. The lengths of horizontal lines are proportional to the minimum number of nucleotide differences required to join nodes. Vertical lines are for spacing branches and labels. ck, chicken; pk, pakistan; Ir, Iran.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4281667&req=5

Figure 1: Phylogenetic relationships of NA gene of some influenza A viruses isolated in Iran and Pakistan. The lengths of horizontal lines are proportional to the minimum number of nucleotide differences required to join nodes. Vertical lines are for spacing branches and labels. ck, chicken; pk, pakistan; Ir, Iran.
Mentions: All studied Iranian H9N2 isolates fell into the same main group (G1 sub-lineage) as the viruses isolated in Pakistan. The Iranian isolates can be divided into 2 main subgroups (Fig. 1). The first subgroup (11-T like sub-lineage) included viruses that were isolated between 1998, first AI outbreak reported in Iran, and 2004. The former Pakistani isolates (A/chicken/Pakistan/4/99) were placed in a close relationship with this subgroup of Iranian isolates. The second subgroup comprised the strains isolated from 2004 to 2008. However, some exceptions were seen in both subgroups. Interestingly, 3 viruses isolated in this study on 2010-2011 didn′t place with other Iranian isolates in the second subgroup, but placed in a new subgroup in a close relationship with some recent Pakistani H9N2 isolates (A/chicken/Pakistan/UDL-01/2006) (Fig. 1).

Bottom Line: The Iranian isolates can be divided into 2 main subgroups; 11-T like subgroup viruses isolated mainly during 1998-2004 and second subgroup viruses isolated during 2004-2009.The nucleotide sequences of the three studied isolates showed high identity to recent Pakistani H9N2 isolates (94.5-97%) compared to former Iranian AIV isolates (89-94%).High frequency of substitutions in the NA gene of studied isolates in recent years and effects of those substitutions on the pathogenicity of AI virus highlight the need to continue surveillance of genetic characteristics of AIV H9N2 in Iran.

View Article: PubMed Central - PubMed

Affiliation: Department of Clinical Sciences, Faculty of Veterinary Medicine, Lorestan University, Khorram-Abad,Iran.

ABSTRACT

Backgrounds and objectives: Classified as low pathogenic avian influenza (LPAI) viruses, the H9N2 subtype causes severe respiratory disease in poultry farms and occasional respiratory disease in humans. In this study, the neuraminidase (NA) gene of three Avian Influenza (AI) H9N2 strains isolated from poultry farms in Iran during 2010-11, as well as other reported Iranian H9N2 isolates, were genetically analyzed and their nucleotide changes were evaluated.

Materials and methods: The NA gene of three AIVs were sequenced and evaluated for genetic characteristics and phylogenetic relationship.

Results: One new potential glycosylation site (PGS) at amino acid position 306 was observed in one of the studied isolates (A/Chicken/Iran/N102/2011). Antigenic sites of NA in Iranian H9N2 isolates have varied in a yearly manner. The Iranian isolates can be divided into 2 main subgroups; 11-T like subgroup viruses isolated mainly during 1998-2004 and second subgroup viruses isolated during 2004-2009. Interestingly, the three studied isolates fell into a third subgroup. The nucleotide sequences of the three studied isolates showed high identity to recent Pakistani H9N2 isolates (94.5-97%) compared to former Iranian AIV isolates (89-94%).

Conclusion: High frequency of substitutions in the NA gene of studied isolates in recent years and effects of those substitutions on the pathogenicity of AI virus highlight the need to continue surveillance of genetic characteristics of AIV H9N2 in Iran.

No MeSH data available.


Related in: MedlinePlus