Reaction Mechanisms of Nascent C567 (Reactive Lysis). II. Killing of a Rough Form of Escherichia coli by C567, C8, and C9

A rough strain of Escherichia coli, which is highly sensitive to killing by whole serum, was killed by exposure to the activated trimolecular complex C̅567 with C8 and C9 in the absence of antibody and the early complement components. The killing was enhanced by prior treatment of the bacteria with EDTA and was greatly augmented by an extra factor that is found in the gamma and beta regions of DE-52 cellulose chromatography of the pseudoglobulin fraction of human serum. The extra factor exerted its action only after the bacteria were brought to the state BC̅56789. This work extends the relevance of the nascent C̅567 system to include bacterial killing.