Salmonella contamination of vegetables irrigated with untreated wastewater

The irrigation of vegetables with raw wastewater has been practised in El Azzouzia, the wastewater-spreading field of Marrakesh city (Morocco), for many years. This water was found to be contaminated with different serogroups of Salmonella. B and C were the most frequently isolated groups. These same serogroups were detected on vegetables irrigated with these wastewater effluents. The crops whose edible product develops on the ground surface, such as lettuce and parsley, were more contaminated than those which grow, above the soil surface, like tomatoes and pimento. Except on lettuce, Salmonella on crops did not persist beyond 3 days after irrigation.