Antigenic degradation in Escherichia coli.

Strains of Escherichia coli isolated in a maternity unit were examined serologically. On primary isolation the strains were shown to be O-antigenically distinguishable, although having the same H antigen, biotype and antibiogram. Subsequent detailed serological studies revealed that the colonial variants derived from them showed similar antigenic diversity, irrespective of the original antigenic structure.