IN PROCESS QUALITY CONTROL FACTORS AFFECTING THE QUALITY OF LOCALLY PREPARED SALMONELLA GALLINARUM ANTIGEN

Seroserveillance of fowl typhoid using imported antigen is not cost effective, more over import of meager quantity of antigen is always not possible. Therefore, Fowl typhoid antigen was locally prepared and evaluated for sensitivity and specificity. Effect of preservatives and temperature on sensitivity of local antigen was also studied. Of three test antigens (6, 8 & 10 million cells/ml), one with 10 million cells showed visible agglutination with known antisera upto log 10^-3 dilution (3000 cells/0.3 ml) as compared to other two antigens (8, 6 million cells/ml) that showed agglutination upto 10^-2 dilution (24000cells/0.3ml, 18000cells/0.3ml respectively). Antigens stored at -20°C and 25°C showed visible agglutination up to 90 and 30 days post preservation respectively in presence of both preservatives thimerosal sodium and sodium azide, separately, while no change in agglutination reaction was observed for antigen stored at 4°C throughout the whole storage period of 6 months. No cross reactivity of local antigen with antisera against Mycoplasma gallisepticum, Mycoplasma synoviae and negative control serum was observed. On comparison, local antigen proved equally efficient as imported antigen with known positive and negative control sera and may be used for screening of Salmonella gallinarum infection in poultry.