Susceptibility and Interleukins-6 Serum Level of Broilers Chickens Vaccinated with Baculovirus Expressed H5N1-ND after Experimental Infection with Virulent E. coli

Avian pathogenic Escherichia coli cause severe respiratory and systemic disease in poultry yet the nature and consequences of host immune responses to infection are poorly understood. Here, an experimental study was conducted on broiler chickens for evaluating the effect of BEST, Baculovirus Expressed H5N1-ND inactivated vaccine on controlling non-specifically of virulent E. coli infection with special reference to serum IL6 as indicator for potent immune response. Two groups from broilers chickens each one consisted of 250 birds, 1st group was vaccinated with BEST, at 10 day of age, while 2nd group was vaccinated with inactivated ND vaccine at 6 day of age and also inactivated H5N3 vaccine at 10 day of age. E. coli suspension 1.5x108 cfu ml from selected virulent and multidrug resistant E. coli isolate was used in experimental infection. Results revealed that 1st group showed slight respiratory signs and slight diarrhea with 8 % mortalities begin at 3rd day post experimental infection and ended in 6th day with slight air sacculitis and slight pericarditis, in the other hand 2nd group recorded severe respiratory signs with nasal discharge, eye lid inflammation and diarrhea accompanied by 12 % mortalities with perihepatitis, pericarditis and air sacculitis. IL6 serum level also was recorded for each experimentally infected groups as follow, 1st group IL6 conc. was 55, 62, 35, 40 and 55pg/ml while for 2nd group IL6 conc. was 32, 40, 30, 35and 40 pg/ml. Such data inform the rational design of strategies to control of endemic Collibacillosis disease of poultry.