Anti-Outer Membrane Protein 면역단백질을 이용한 Sandwich ELISA 방법에 의한 우유 내 Salmonella의 검출

The specificity of sandwich enzyme-linked immunosorbent assay (ELISA) to detect Salmonella in milk was determined in this study. The antibodies used in sandwich ELISA were egg yolk immunoglobulin G (IgY) obtained after immunization of hen with outer membrane protein (OMP) fraction from Salmonella typhimurium and rabbit IgG obtained after immunization of rabbit with the purified OMP with the molecular weight of 40,000. The immunoblot assay showed that the IgY reacted strongly with OMP with the molecular weight of 6,000 and the rabbit IgG reacted strongly with OMP with the molecular weights of 40,000, 35,000, and 6,000 from the bacteria including Salmonella which belongs to Enterobacteriaceae. The IgY and rabbit IgG also reacted with other proteins from Salmonella typhimurium in immunoblot assay. Competitive ELISA showed that IgY showed specifity to react with two strains of Salmonella typhimurium and Salmonella cholerasuis but not with Escherichia coli and Yersinia enterocolitica. Two strains of Salmonella typhimurium added to UHT milk showed the highest absorbance of all the bacteria used in the sandwich ELISA. Some strains of Salmonella cholerasuis showed higher absorbances than non-Salmonella bacteria.