Survival of Pathogenic Escherichia Coli on Basil,Lettuce, and Spinach |
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| Authors: | S M Markland K L Shortlidge D G Hoover S Yaron J Patel A Singh M Sharma K E Kniel |
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| Institution: | 1. Department of Animal and Food Sciences, University of Delaware, , Newark, DE, USA;2. Faculty of Biotechnology and Food Engineering, Technion‐Israel Institute of Technology, , Haifa, Israel;3. Environmental Microbial and Food Safety Laboratory, USDA‐Agricultural Research Service, , Beltsville, MD, USA |
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| Abstract: | The contamination of lettuce, spinach and basil with pathogenic E. coli has caused numerous illnesses over the past decade. E. coli O157:H7, E. coli O104:H4 and avian pathogenic E. coli (APECstx‐ and APECstx+) were inoculated on basil plants and in promix substrate using drip and overhead irrigation. When overhead inoculated with 7 log CFU/ml of each strain, E. coli populations were significantly (P = 0.03) higher on overhead‐irrigated plants than on drip‐irrigated plants. APECstx‐, E. coli O104:H4 and APECstx+ populations were recovered on plants at 3.6, 2.3 and 3.1 log CFU/g at 10 dpi (days post‐inoculation), respectively. E. coli O157:H7 was not detected on basil after 4 dpi. The persistence of E. coli O157:H7 and APECstx‐ were similar when co‐inoculated on lettuce and spinach plants. On spinach and lettuce, E. coli O157:H7 and APEC populations declined from 5.7 to 6.1 log CFU/g and 4.5 log CFU/g, to undetectable at 3 dpi and 0.6–1.6 log CFU/g at 7 dpi, respectively. The detection of low populations of APEC and E. coli O104:H4 strains 10 dpi indicates these strains may be more adapted to environmental conditions than E. coli O157:H7. This is the first reported study of E. coli O104:H4 on a produce commodity. |
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| Keywords: | E coli persistence irrigation basil survival lettuce spinach promix avian pathogenic E coli |
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