The effect of iron and transferrin on the killing of Escherichia coli in fresh serum.

Abstract

Iron in excess of the binding capacity of transferrin allows Escherichia coli to grow in fresh serum. This appears to be due to two mechanisms. Firstly iron stimulates growth as it is an essential metabolite which is not available to E. coli in serum. Secondly, it interferes with bacterial killing, a process normally mediated by natural antibody and complement.