Escherichia coli serotypes in the faeces of healthy adults over a period of several months.

The faeces of nine subjects eating mainly at home were collected at regular intervals over periods ranging from 2--5 months. Although a large number of serotypes of E. coli were isolated, the variety per subject was lower than is usually found. In most subjects only a limited number of serotypes persisted over most of the periods of study while many serotypes were only isolated on single occasions.