Studies on the chick-lethal toxin of Eecherichia coli

Abstract

A toxin which is lethal for two week old chicks has been recovered from strains of Escherichia coli O78:K80 of bovine and avian origin and from avian isolates of serogroups O2, O45 and O109. The toxin is heat-labile, antigenic, high in protein, inactivated by pronase, trypsin, amylase, and pancreatic lipase. The toxin may be precipitated by ammonium sulfate or TCA treatment from the supernatant obtained by repeated centrifugation of sonicated cells. Considerable purification has been obtained by column chromatography using Sepharose 6B.