000 02399nam a2200205Ia 4500
005 20150921142343.0
008 150525s2002 xx 000 0 und d
041 _aeng
082 _a0831,T
100 _aAsifa Rasool Bhatti
_97080
110 _cDr.Sameera Akthar
_97081
245 _aFactors Effecting Activity Of Haemagglutinin Of Avian Influenza (H9 Type)Virus
260 _c2002
502 _aAvian influenza virus (AIV) was propagated in 09-day-old chicken embryonated eggs and after 72 hours post incubation the AAF and CAM were harvested and AIV was confirmed by spot agglutination test and agar gel precipitation test. The AIV (H9 type) agglutinated red blood cells from chicken, dog, horse, parrot, pigeon, guinea pig, buffalo and human blood group O but it did not agglutinate the RBC's from sheep and rabbit. The virus gave HA titer of 1:512 when RBC's from chicken, human blood group O÷ve and dog were used. Phosphate buffer saline, haemagglutination, inhibition buffer and 0.5% peptone water when used with chicken RBC's (0.5 and 1%) resulted in similar HA titer 1:512. However HA titer of the virus was low (1:256) when normal saline was used as a diluent. AIV agglutinated 0.5% and 1% chicken RBC's in 35 and 25 minutes respectively and both concentrations of RBC's gave similar HA titer (1:512) in the presence of Phosphate buffer saline, haemagglutination, inhibition buffer and 0.5% peptone water. However AIV with normal saline and 0.5% and 1% chicken RBC's gave a lower HA titer of 1:256 in 35 and 25 minutes. It was also found that RBC's concentration of 0.1% did not result in any agglutination by the virus, even after 60 minutes. Storage of AIV at either 4°C or -20°C did not affect its hemaggitination activity in 6 months. However storage at 37°C resulted in loss of hemagglutination activity after 4 months. Storage at room temperature also resulted in loss of HA but at a lower pace as appended to 37°C temperature. However, vaccines prepared from the alliquotes stored at different temperature did not different in terms of antibody response (HI titer of GMT 137.2) indicating that the loss of hemagglutination activity did not corresponds with loss of immunogencity.
650 _aDepartment of Microbiology
_94609
700 _aDr shakeel
_95505
700 _aDr.Kushi Muhammad
_97082
710 _aFaculty of Veterinary Sciences
_94292
942 _cTH
999 _c2562
_d2562