志贺氏菌的接触性溶血试验

THE CONTACT HEMOLYSIS TEST OF SHIGELLA SPP

本文研究了接触性溶血试验的最适条件,并应用于检测志贺氏菌的毒力.绵羊红细胞(SRBC)和福氏2a志贺氏菌(F2a)的合适浓度分别在2～6×10~9/ml和1～4×10^(10)/ml范围内;细菌在贺氏肉汤内振荡培养8～12h溶血能力最强.比较强毒肠道菌及其无毒突变株的溶血能力与毒力相符;除侵袭性大肠菌以外,志贺氏菌的溶血活性都依赖温度.实验结果表明,接触性溶血试验与志贺氏菌及EIEC大质粒编码的"侵袭相关蛋白"的表达具有相关性.该法具有简便行易、省时、结果较为稳定和客观等特点.可作为检测志贺氏菌毒力的方法之一.

A contact hemolysis test was developed for the identification of the virulence determinants of Shigella spp.Factors affecting this test were determined.The optimal concentration of SRBC was 2-6×10~9/ml and that of Shigella flexneri 2a was 1-4×10^(10)/ml.The value of OD_(570mm) for hemolysis was the highest when the bacteria were grown for 8-12 hjou in meat infusion broth,thereafter,the OD_(570mm) values declined.The positiveness of the contact hemolysis was correlated with the virulence of bacteria when virulent or non-virulent strains of enterobacteria were compared.The contact hemolysis of Shigella spp was temperature dependent,being weakly positive or negative when the bacteria were grown at 30℃ and positive when grown at 37℃.Experimental results showed that contact hemolysis of Shigella spp and EIEC was correlated with the plasmid encoded-invasive protein antigens.As the method is simple,easy to do,time-saving,consistent,it can be used as one of the methods for determining virulence of Shigella spp and EIEC.