Use of a hemadsorption technique to evaluate the stability of the hemagglutination reaction of Escherichia coli cultures possessing human colonization factor antigens.

摘要: Two strains of Escherichia coli, producing different colonization factor antigens (CFA), were monitored for the population density CFA-producing bacteria after repeated subculture. The production CFA was estimated by flooding agar plates containing isolated colonies with suspensions human or bovine erythrocytes. erythrocytes suspended in a low-ionic-strength buffer and fixed to CFA-positive 1.0% tannic acid solution. Strain H-10407, possessing CFA/I fimbriae, showed rapid loss hemagglutinin when subcultured, whereas strain CL-9699, CFA/II, very stable. By using hemadsorption assay, we could rapidly easily distinguish CFA- positive from CFA-negative variants. A survey additional E. coli demonstrated utility specificity technique used. Images