Bradley D E
Faculty of Medicine, Memorial University of Newfoundland, St. John's, Canada.
FEMS Microbiol Lett. 1991 Dec 15;69(1):49-52. doi: 10.1016/0378-1097(91)90644-p.
Approximately 24% of a sample of pathogenic Escherichia coli strains from different serogroups were found to synthesize colicins. Serogroup O55 had an unusually large proportion of such strains (33%). In a sample of 27 O55 isolates, one synthesized a class A colicin (identified as ColE9), five produced class B colicins (three ColIa, two, unidentifiable), and three a class A and a class B together.