Patterns of bacterial colonization of human milk.

Bacterial studies on breast milk collected by an electric suction pump from 44 postpartum mothers were conducted. All samples had bacterial growth, while 84% had organisms identical to those cultured from the mother's nipple. Colony counts varied greatly, with a median of 8700 and mean of nearly 20,000. In 30% of the milk samples, potentially pathogenic organisms were recovered. The significance of these results and collection techniques that might modify these results are discussed.