tetano
Editor, Senior Moderator
J Microbiol Immunol Infect. 2014 Feb 20. pii: S1684-1182(13)00238-7. doi: 10.1016/j.jmii.2013.12.002. [Epub ahead of print]
Cleavage site stability of Egyptian highly pathogenic avian influenza viruses in backyard chickens during 2009-2011.
Elbakrey RM1, El Sisi MA1, Mansour SM2, Ahmed HH3, Rajput M4, Eid AA5.
Author information
Abstract
PURPOSE:
Two distinguishable subclades of H5N1 (classic and variant strains) are cocirculating among the poultry populations in Egypt despite the intensive vaccination programs. A study to investigate the genetic relationship between avian influenza virus (AIV) isolates from backyard chickens in Sharkia (2009-2011), subclades, and commercially available vaccines was carried out.
METHODS:
Forty-eight suspected AIV infected birds were clinically examined and used for virus isolation followed by reverse transcription-polymerase chain reaction. Four H5N1 virus isolates were sequenced and analyzed. The intravenous pathogenicity index (IVPI) of three AIV isolates was determined.
RESULTS:
Thirty-four hemagglutinating viral agents (30 AIV subtype H5N1 and 4 Newcastle disease virus) were detected. Both the nucleotide and amino acid sequence identities of four H5N1 virus isolates (SHZA-0412/2009, SHZA-0801/2010, SHMK-1903/2010, and SHAH-1403/2011) were high-98.4-99.7% and 100%, respectively-indicative of their genetic homogeneity. The hemagglutinin cleavage site characterization revealed the presence of multiple basic amino acids (-PQRERRRKKR/GL-) of the highly pathogenic phenotype. These results were supported by IVPI in chickens of 2.69-2.90. The similarity of our isolates with H5N1 AIV vaccine strains (93.9-95.1%) was higher than that with H5N2 strains (77.8-91.9%). The divergence of four sequences with classic and variant lineages is 2-2.7% and 2.3-3%, respectively, with two amino acid substitutions (A249P and N251Y).
CONCLUSION:
Genetic characterization and IVPI data of backyard H5N1 isolates are indicative of a highly pathogenic avian influenza virus with hemagglutinin cleavage site constancy and two amino acids substitutions with Egyptian classic and variant lineages, suggesting a beginning of antigenic drift.
Copyright ? 2013. Published by Elsevier B.V.
KEYWORDS:
Backyard chicken, Egypt, H5N1, Hemagglutinin gene, Highly pathogenic avian influenza
PMID:
24560697
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/24560697
Cleavage site stability of Egyptian highly pathogenic avian influenza viruses in backyard chickens during 2009-2011.
Elbakrey RM1, El Sisi MA1, Mansour SM2, Ahmed HH3, Rajput M4, Eid AA5.
Author information
Abstract
PURPOSE:
Two distinguishable subclades of H5N1 (classic and variant strains) are cocirculating among the poultry populations in Egypt despite the intensive vaccination programs. A study to investigate the genetic relationship between avian influenza virus (AIV) isolates from backyard chickens in Sharkia (2009-2011), subclades, and commercially available vaccines was carried out.
METHODS:
Forty-eight suspected AIV infected birds were clinically examined and used for virus isolation followed by reverse transcription-polymerase chain reaction. Four H5N1 virus isolates were sequenced and analyzed. The intravenous pathogenicity index (IVPI) of three AIV isolates was determined.
RESULTS:
Thirty-four hemagglutinating viral agents (30 AIV subtype H5N1 and 4 Newcastle disease virus) were detected. Both the nucleotide and amino acid sequence identities of four H5N1 virus isolates (SHZA-0412/2009, SHZA-0801/2010, SHMK-1903/2010, and SHAH-1403/2011) were high-98.4-99.7% and 100%, respectively-indicative of their genetic homogeneity. The hemagglutinin cleavage site characterization revealed the presence of multiple basic amino acids (-PQRERRRKKR/GL-) of the highly pathogenic phenotype. These results were supported by IVPI in chickens of 2.69-2.90. The similarity of our isolates with H5N1 AIV vaccine strains (93.9-95.1%) was higher than that with H5N2 strains (77.8-91.9%). The divergence of four sequences with classic and variant lineages is 2-2.7% and 2.3-3%, respectively, with two amino acid substitutions (A249P and N251Y).
CONCLUSION:
Genetic characterization and IVPI data of backyard H5N1 isolates are indicative of a highly pathogenic avian influenza virus with hemagglutinin cleavage site constancy and two amino acids substitutions with Egyptian classic and variant lineages, suggesting a beginning of antigenic drift.
Copyright ? 2013. Published by Elsevier B.V.
KEYWORDS:
Backyard chicken, Egypt, H5N1, Hemagglutinin gene, Highly pathogenic avian influenza
PMID:
24560697
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/24560697