Sequence Stability In Clade 2.3.4.4 In Taiwan

[niman]

Taiwan report on August clade 2.3.4.4 sequences show stabilty when compared to January sequences.

 

http://ai.gov.tw/files/web_structure/1230/file_1.pdf

Edited December 1, 2015 by niman

[niman]

http://ai.gov.tw/files/web_structure/1230/file_1.pdfLivestock Wei - Analysis of the third quarter of avian influenza virus message:
To follow up this year after the occurrence of the new influenza in poultry occurred strain field evolution
The conditions and the recombinant virus or a new invasion, animal health will be a quarterly in accordance with the timing of the regular hair
Green field strain analysis. Separation of the season in August for this (104) in Chiayi County duck
H5N8 bird flu virus and Yunlin County H5N2 avian influenza virus isolates the farm full eight
Analysis of gene sequence segments. By comparison with the two virus strains January isolates (a15 and a5) results
Tables 1 and 2 below. Table 1 shows the H5N2 or H5N8 between January and August of strains, each
Nucleic acid sequence of the gene fragment Jieyou high degree of similarity (similarity are more than 99.2%), two-phase
By comparison, whether H5N8 or H5N2, which in January and August analyze strains are showing high
Degree of homology, not for a new invasion of the virus, nor with domestic local old virus gene rearrangements
group. Its HA gene is still H5 GS / GD series 2.3.4.4 grouping. Each gene conversion
Amino acid sequence similarity and amino acids compared with each variation sites as shown in Table 2; H5N8 8 the month
Compared with January isolates (a15) of the amino acids from plants (h23), NP, NA, M1, M2 and
NEP protein amino acid sequence similarity paragraph 5 was 100%, while the PB2, PB1, PA,
HA and NS1 paragraphs only 1 to 2 sites of amino acid variation, should be a common RNA viruses
Point mutations phenomenon. August H5N2 virus isolates (h24) and January isolates (a5) of the amino acid
Sequence alignment results, in addition to the two proteins NP and M1, other PB2, PB1, PA,
HA, M2, NEP and NS1 protein is a more visible site amino acid variation phenomenon, which
May be associated with the virus by the waterfowl (geese) into terrestrial birds (chicken) is host adaptation, pending further
Assessment.
In livestock Wei October 21 this year, organized by "2015 influenza and poultry
International Symposium on the control "of the report, US researchers isolate the country for analysis,
This wave of the epidemic early viral strains from waterfowl, migratory birds brought in by the (new this year with Taiwan occurred
Highly pathogenic avian influenza virus with the 2.3.4.4 clade A2 group), have not yet adapted to the chicken (test hair
Now, early isolates of mallards just 102 EID50 viral load, to duck just 103 EID50
The amount of virus infection can be established, but the chicken was established in order to infect it needs 105.7 EID50 about ducks
100 to 1,000 times the amount of virus), but later the epidemic (three months later) an isolated place in a commercial chicken disease
Strains of chicken is also only 10 ^ 3.3 EID50 virus infection can be established amount, expressed late isolates
Increase the adaptability of the chickens, so the amount of virus needed also decreases. In the domestic epidemic yet
Before blocking, adaptive evolution similar to going on the same host (as shown in Table 2 amino acid sites changed
Shown oriented), through the evolution of the virus may be a few months, for chickens sensitivity compared outbreak
Early increase. Therefore, we recommend that owners should be vigilant and to strengthen and implement biosecurity measures for poultry farms
Shi is the only way, and work together with the government want to remove the virus.
Isolates the nucleic acid sequence of the season if there are research scholars reference needs, please contact radial carcass Wei
take.
 

[niman]

表 2、胺基酸序列相似度（％） PB2 PB1 PA HA NP NA M1 M2 NEP NS1 H5N8 (a15 與 h23)

99.9 99.9 99.7 99.8 100 100 100 100 100 99.6

變異位 D567N T156A V100A D394N D70N V106M H5N2

(a5 與 h24) 99.5 99.7 99.6 99.5 100 98.7 100 97.9 97.5 97.8

變異位 H13Q V67I V338I A397T E75D G622A N254S I354V D396N M63V S143T S157P K143N S306G R344K E381D T385K N402D L26I V27I I12M M52V H56Y T123I D125G T170A D209G P213L