|Authors: ||G. Gu , S.L. Rideout, A.H.C. van Bruggen, J.M. Cevallos-Cevallos|
|Keywords: ||foodborne illness, Salmonella enterica, tomato, rain dispersal, internal contamination|
Human food-borne pathogens associated with fresh produce, like Salmonella enterica on tomatoes, have been related to recent outbreaks of enteric diseases.
Estimation of the probability of contamination and internalization of tomato fruits with Salmonella would be needed for food safety risk assessment and minimization.
With respect to surface contamination, our greenhouse studies showed that rain splash could contribute to the dispersal of Salmonella on tomato plants, which was affected by rain intensity and duration, bacterial rdar (red, dry and rough) morphotype and plant leaf trichome density.
In other greenhouse studies, we found that GFP-labeled Salmonella could enter tomato plants through leaves, move through the vascular system and internally contaminate fruits and seeds.
After inoculation with 109 CFU/ml, the internal contamination rate was about 1.5% for fruits, and 5% for seeds in contaminated fruits.
Hydathodes and stomata were shown to be entrance sites for Salmonella. Phloem might be the main route for the internal movement of Salmonella in plants.
Surfactant application, conventional instead of organic management, bacterial rdar morphotype and guttation were positively correlated with the internalization and/or internal persistence of Salmonella in tomato plants.
These results contribute to our knowledge about the interaction between Salmonella and tomato plants and future risk assessment.
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