Mouse lung oedema caused by a toxic substance of Escherichia coli strains.

Some Escherichia coli strains isolated from patients and instilled into the nostrils of mice cause a rapidly developing fatal, haemorrhagic lung oedema. Lung toxic strains were found in different serogroups, with the predominance of 04, 06, and 018. The toxic material seems to be bound to the cells; the toxin yield is poor by different methods of extraction. The toxic principle causes toxic, haemorrhagic oedema in mouse foot pad test and shows cytotoxicity for AV-3 cells. The "lung toxin" is heat labile and after Sephadex fractionation has a molecular weight of about 100 000 dalton. There is a possible identity with a toxic haemolysin.