Qu Z H, Boesman-Finkelstein M, Finkelstein R A
Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia 65212.
J Clin Microbiol. 1991 Apr;29(4):773-7. doi: 10.1128/jcm.29.4.773-777.1991.
Urea induces the release of heat-labile enterotoxin (LT) from cells of LT-producing Escherichia coli strains. Optimal conditions were defined by using the checkerboard immunoblotting system. LT release was highest when E. coli cells were incubated in 8 M urea, pH 8.0, at 37 degrees C in a water bath for 30 min. Urea was more effective than polymyxin B in inducing the release of LT antigen from E. coli; the activity of LT from urea-treated cells was seven times that of LT from polymyxin B-treated cells. Urea also increased the antigenic and biological reactivities of purified LT. This procedure is potentially applicable for the detection of LT-producing E. coli strains in the clinical laboratory.
尿素可诱导产热不稳定肠毒素（LT）的大肠杆菌菌株细胞释放LT。通过棋盘式免疫印迹系统确定了最佳条件。当大肠杆菌细胞在8M尿素、pH 8.0、37℃水浴中孵育30分钟时，LT释放量最高。在诱导大肠杆菌释放LT抗原方面，尿素比多粘菌素B更有效；经尿素处理的细胞中LT的活性是经多粘菌素B处理的细胞中LT活性的7倍。尿素还增强了纯化LT的抗原性和生物学活性。该方法有可能应用于临床实验室中检测产LT的大肠杆菌菌株。
