COMPARISON OF CLASSICAL AND ALTERNATIVE PATHWAYS OF SERUM COMPLEMENT OF KHAZAK AGAINST AVIAN PATHOGENIC ESCHERICHIA COLI

Background and Aim:Khazak chicken, as backyard and native poultry, is distributed in Sistan, border of Iran. There has been no investigation about the mechanism of serum of Khazak against Avian Pathogenic Escherichia coli (APEC).The present study was aimed to differentiate the potency of classical and alternative pathways of serum complement of Khazak against APEC.Methods:Serum was collected, aseptically, from Khazak chickens. Based on pervious references, respectively, EGTA/MgCl2, and 50’ C for 20 min was applied to inactive the classical and alternative pathways of serum complement. Into flat-bottomed 96-well microtiter plates, 104 CFU of APEC was mixed with inactivated alternative or classical pathway of Khazak complement serum, individually, with same volume. The controls were considered. The growth was screened every 30 min for 6 hr, triplicates, at 37’C. The statistical differences of slope value of growth curve was considered at p<0.05.Results:As an interesting finding, there was no statistical significance difference between inhibitory effect of alternative and classical pathways of complement system of Khazak serum against growth rate tested bacterium (p> 0.05).Conclusion:As a first report from Iran, about complement system of a native backyard chicken, the knowledge about APEC serum resistance was increased and it could play as a preliminary study to conduct vast investigation, regarding immune system of Khazak, as a potent poultry for investment. The findings could be explained by species-specific or other complement factors found in khazak immune system.

کلیدواژه ها:

khazak ، apec ، immune system