Qu Z H, Boesman-Finkelstein M, Kazemi M, Finkelstein R A
Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia 65212.
J Infect Dis. 1991 Oct;164(4):796-9. doi: 10.1093/infdis/164.4.796.
A new technique, checkerboard immunoblotting (CBIB), has been applied to detect and to differentiate heat-labile enterotoxins, (LTs), from enterotoxigenic strains of Escherichia coli of human origin using polyclonal and monoclonal antibodies. Optimal conditions of production and release of LTs were defined using CBIB. LT release was enhanced when E. coli cells were treated with 8 M urea. LT production was highest when E. coli strains were incubated with shaking (200 rpm) at 37 degrees C for 12 h in CAYE-2 medium. Two hundred and five strains of E. coli, isolated from patients with diarrhea in Japan, Thailand, the United States, Mexico, and Brazil, were examined for LT. Of 133 LT-positive strains, 4 (3%) produced an LT that reacted like H-LT-1 (originally isolated from E. coli strain H-74-114) while 126 strains (94.7%) produced LT that reacted like H-LT-2 (originally isolated from strain H-10407) or H-LT-3 (from strain H-240-3). Three strains of human origin (2.3%) produced an LT that reacted like P-LT (produced by E. coli strains of porcine origin). This study shows that CBIB, a simple, efficient, and practical assay, might be useful for epidemiologic surveys and for evaluation of serologic responses to LTs and antitoxic vaccines.
一种新技术，棋盘免疫印迹法（CBIB），已被应用于使用多克隆抗体和单克隆抗体来检测和区分人源产肠毒素大肠杆菌的不耐热肠毒素（LTs）。使用CBIB确定了LTs产生和释放的最佳条件。当大肠杆菌细胞用8M尿素处理时，LT释放增强。当大肠杆菌菌株在CAYE-2培养基中于37℃振荡培养（200rpm）12小时时，LT产量最高。对从日本、泰国、美国、墨西哥和巴西腹泻患者中分离出的205株大肠杆菌进行了LT检测。在133株LT阳性菌株中，4株（3%）产生的LT与H-LT-1（最初从大肠杆菌菌株H-74-114中分离）反应相似，而126株（94.7%）产生的LT与H-LT-2（最初从菌株H-10407中分离）或H-LT-3（从菌株H-240-3中分离）反应相似。三株人源菌株（2.3%）产生的LT与P-LT（由猪源大肠杆菌菌株产生）反应相似。这项研究表明，CBIB作为一种简单、高效且实用的检测方法，可能对流行病学调查以及评估对LTs的血清学反应和抗毒素疫苗有用。
