The origin of O serotypes of <i>Escherichia coli</i> in babies after normal delivery

Abstract

A total of 2525 strains of Escherichia coli were isolated from the faeces of 33 mothers, the faeces of their babies and the mucus extracted from the babies' mouths after delivery. Of these strains 1832 could be O-serotyped with 150 O antisera. E. coli were isolated from 28 babies and the same serotypes as were found in their mothers were found in 22 of them. E. coli was isolated from only 14 of the mucus specimens but in 12 of these at least one of the serotypes present was subsequently found in the babies' stools.