Clinical, Bacteriological, and Serological Observations of two Human Volunteers Following Ingestion of Escherichia coli

Two healthy, adult white, male volunteers ingested, respectively, 4 and 8 million organisms of E. colt serotype 0127: B8. 2. Symptoms of mild to moderate gastroenteritis appeared in both subjects 7 to 17 hours after ingestion of the organisms and persisted for 32 to 46 hours. 3. By daily rectal swab cultures, E. colt 0127:B8 organisms were recovered within 24 hours after ingestion and were found during 5 days in one and 12 days in the second volunteer. 4. Hemagglutinins were detected 3 days and bacterial agglutinins 5 days following ingestion. Antibody titers in both subjects rose rapidly, reaching peaks by the eighth to ninth day. Hemagglutination titers were consistently higher than bacterial agglutination titers. 5. Challenge ingestion of 8,000.000 organisms by one volunteer was followed by bacterial and serological response without appearance of clinical symptoms.