EXPERIMENTS ON FEEDING ADULT VOLUNTEERS WITH ESCHERICHIA COLI 111, B4, A COLIFORM ORGANISM ASSOCIATED WITH INFANT DIARRHEA

Abstract

1. Adult human volunteers who were fed a mixture of 3 strains of Escherichia coli, 111, B₄ in milk experienced symptoms similar to acute bacterial food poisoning when the dosage of organisms was large. Feeding 530,500,000 organisms or less produced a very mild illness or no effect. There was no evidence that a bacteremia developed or that the organisms were excreted in the urine. 2. A large percentage of volunteers who ingested E. coli 111, B₄ strains developed serum agglutinins for the organism. Some who showed no symptoms developed agglutinins to some degree. 3. Volunteers who ingested a strain of E. coli isolated from a normal infant experienced no ill effects attributable to the feeding, although the number of organisms ingested was equal to the largest dose of E. coli 111, B₄. No volunteer developed a rise in agglutinins for the normal coliform organism. 4. Although a carrier state can result from ingestion of E. coli 111, B₄, the evidence of this study suggests that normal adults are resistant to infection under normal conditions. However, the view is advanced that E. coli 111, B₄ may cause diarrhea in a debilitated adult.