Inhibition of membrane functions in intact HeLa cells byClostridium difficile cytotoxic culture filtrates

Abstract

The basis for cytotoxicity to intact HeLa cells by culture filtrates ofClostridium difficile has been investigated. Decrease in intracellular K+ levels and inhibition of α-aminoisobutyric acid uptake were detected first after exposure to filtrates, followed by inhibition of macromolecular synthesis. Twenty-five percent of the K+ remained associated with the cell monolayer, and amino acid uptake and macromolecular synthesis were not totally abolished. These results indicate thatC. difficile culture filtrates preferentially inhibited membrane functions, either by exhausting ATP supplies or by disrupting the permeability barrier of the cell.