Mansour Mayahi
Shahid Chamran University of Ahvaz, Iran
Title: Effect of experimental infectious bursal disease virus on clinical signs and pathogenesis of avian influenza virus H9N2 in turkey poult by real time PCR
Biography
Biography: Mansour Mayahi
Abstract
The purpose of study was to examine the effects of IBDV on clinical signs, pathogenesis, virus shedding, cellular and humoral response of poults to avian influenza virus (AIV) H9N2. A total of 100 day-old commercial poults were divided into 4 equal groups. Groups 1 and 2 were infected with 104CID50 of IBDV by intra-bursal route at a day-old; Groups 1 and 3 were each infected with 106EID50 of AIV (H9N2) by the oculo-nasal routes on the 30th day. Poults of the 4th Group served as negative control. All groups were vaccinated against Newcastle disease vaccine (NDV). Clinical signs were observed twice daily while trachea and cloacal swabs from 3 live birds of each group, and tissue samples from lung, pancreas and kidneys from 3 euthanized birds from each group at 3, 7, 11 and 15 days post avian influenza virus H9N2 inoculation, were collected randomly. Avian influenza virus H9N2 in trachea and cloaca swabs and in the tissues, was confirmed by Real-time polymerase chain reaction (PCR). Spleen on mentioned days were collected and cell mediated immunity was assessed by means of lymphocytes proliferation repose to phytohaemagglutinin. Ten blood samples from each group were randomly collected and were measured by HI and Elisa tests. The study showed that the clinical signs of avian influenza virus(AIV) H9N2 were prolonged and more intensive in the IBD infected group and the mean HI titers to avian influenza virus in the IBD infected group were significantly lower compare to the uninfected IBD group from days 14 post infection (P≤0.05). In the IBD infected group, shedding of avian influenza virus from the trachea, on days 3 and 7, and from the cloaca on days 7 and 11, were significantly higher than uninfected IBD group (P≤0.05). The proliferation of avian influenza virus in the lung on days 7, 11 and 15 was significantly higher in the IBD infected birds (P≤0.05). It was concluded that IBD changed the pathogenesis of (AIV) H9N2 and influenza virus replication, while shedding in infected birds increased which resulted in prolonged severity and duration of clinical signs.