Chlorine Inactivation of <i>Escherichia coli</i> O157:H7

Abstract

We analyzed isolates of Escherichia coli O157:H7 (which has recently caused waterborne outbreaks) and wild-type E. coli to determine their sensitivity to chlorination. Both pathogenic and nonpathogenic strains were significantly reduced within 1 minute of exposure to free chlorine. Results indicate that chlorine levels typically maintained in water systems are sufficient to inactivate these organisms.