TY - BOOK AU - M. Furqan Shahid (2014-VA-322) AU - Prof. Dr. Asim Aslam AU - Prof. Dr. Tahir Yaqub ED - TI - Pathological Investigations Of Different Isolates Of H9n2 Prevalent In Broiler Chicken U1 - 2459-T PY - 2016/// KW - Department of Pathology N1 - In recent years, H9N2 virus has attained a great importance as its infection has reached panzootic proportions. AIV H9 has different antigenic variants that has made it problematic to diagnose and thus to understand the pathogenicity of this virus is also very difficult. Detection of AI H9 antibodies can be used as a complementary method for sero-epidemiological studies as an indicator of AI H9 infection. The haemagglutination inhibition (HI) assay is used routinely for subtyping and detecting an increase of antibodies to AI viruses. Surveillance and early diagnosis of AI virus is essential for poultry. It demands rapid, sensitive and inexpensive diagnostic tests. Thus, it is important to identify different antigenic variants of H9. In this study a total of seven H9 virus samples were isolated out of total 100 collected sample from field outbreaks. These isolates were confirmed by molecular methods like PCR. Then four isolates from these seven isolates were used to infect the experimental broiler chicken. Clinical signs were recorded after the inoculation of H9N2 virus to the broiler. The results of this study showed that clinical signs were more sever upto 5 DPI. The severity of signs was proved by observing the gross pathology and histopathology of organs (Lung, Kidney, Trachea and Liver) of infected birds which were collected on 5 and 9 DPI. Serum of infected birds was also collected on 7 and 14 DPI to analyze the antibody level of infected birds against experimentally used isolate of H9N2. Then cross reactivity of different isolates of H9N2 was also checked against pannel of hyperimmune sera raised against different isolates of H9N2 and their results showed different antibody level against different isolates of H9N2. The sero-biochemical study of serum of infected birds revealed that H9N2 virus has pathogenic potential on kidney and liver ER -