title: Effect of irrigation method on transmission to and persistence of Escherichia coli O157:H7 on lettuce.
abstract: In this study, the transmission of Escherichia coli O157:H7 to lettuce plants through spray and surface irrigation was demonstrated. For all treatments combined, the number of plants testing positive following a single exposure to E. coli O157: H7 through spray irrigation (29 of 32 plants) was larger than the number testing positive following surface irrigation (6 of 32 plants). E. coli O157:H7 persisted on 9 of 11 plants for 20 days following spray irrigation with contaminated water. Immersion of harvested lettuce heads for 1 min in a 200 ppm chlorine solution did not eliminate all E. coli O157:H7 cells. The results of this study suggest that regardless of the irrigation method used, crops can become contaminated; therefore, the irrigation of food crops with water of unknown microbial quality should be avoided.
authors.affiliation: Department of Food Science, Cook College, Rutgers, The State University of New Jersey, New Brunswick 08901-8520, USA.
authors.forename: Ethan B
authors.initials: EB
authors.lastname: Solomon
authors.forename: Catherine J
authors.initials: CJ
authors.lastname: Potenski
authors.forename: Karl R
authors.initials: KR
authors.lastname: Matthews
mesh_terms: D000383:Agriculture / Q000379:methods; D002713:Chlorine / Q000494:pharmacology*; D019453:Escherichia coli O157 / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D005506:Food Contamination / Q000032:analysis; D005516:Food Microbiology; D018545:Lactuca / Q000382:microbiology*; D014871:Water Microbiology
chemical_list: D002713:Chlorine