A semi-automated system for detecting changes in the staining properties of cell monolayers applied to the characterization of bacterial enterotoxins

The authors have established a semi-automated microtitre-based system for the quantitation of dye binding to cultured eukaryotic cells. The system makes possible the characterization of biological activities by detecting the changes they elicit in the staining properties of cell monolayers. The objective of this work is the establishment of a cell culture system that will both detect and discriminate between enterotoxins in clinical and environmental samples on a large scale. The activities of bacterial toxins in cell culture have been divided into cytotoxic and cytotonic effects. With the former, cells remain intact but changes shape while with the latter, cells are actually destroyed. They have examined the ability of our system to detect and discriminate between two cytotoxic activities, Clostridium perfringens enterotoxin and Escherichia coli "Vero toxin", and three cytotonic activities, cholera toxin, dibutyryl cyclic adenosine monophosphate (dbcAMP) and theophylline.