Viability of Vibrio cholerae biotype El Tor and of cholera phage on vegetables.

Different vegetables were contaminated with sewage water containing large amounts of El Tor vibrios, and the viability of these vibrios was studied under defined conditions of storage. During the dry season (summer) in Jerusalem, the El Tor vibrios survived for up to 24 hr on parsley, 24 to 30 hr on tomatoes and carrots, 24 to 48 hr on cucumbers, peppers and okra and two to three days on lettuce, when the vegetables were stored at room temperature. The survival time was longer during the rainy season or during storage of the vegetables in a refrigerator. It was also prolonged on damaged vegetables. The El Tor vibrios survived for only a few hours on vegetables exposed to sunlight. The El Tor vibrios survived for 12 to 24 days in experimentally contaminated sewage water, and for up to 10 days in sewage-contaminated soil. The El Tor bacteriophage persisted for up to 36 days on phage-contaminated vegetables.