Outbreaks of salmonella illness associated with raw tomatoes have been reported [140,141]. Tomatoes inoculated with high doses of S. Montevideo (SeM) and stored for 3 days retained viable cells on skin and stem scars . However, SeM survived at 2 to 4 log10 higher concentrations in scars and cracks compared to skin, both after washes in water and 100 mg/ml aqueous chlorine. Tomato plants inoculated at stems or flowers with a combination of five different S. eraierzca serovars including SeM were analyzed to determine the incidence and length of time salmonella survived in fruit . SeM was isolated from stem scar tissue up to 49 days after inoculation, but S. Poona, S. Michigan, and S. Enteritidis also were isolated at 22 to 39 days from pulp and stem scar tissue. Further studies with the five strain combination with hydroponically grown tomato plants reported the uptake and survival of salmonella for at least nine days on hypocotyls, cotyledons, stems, and leaves of plants inoculated at intact or cut roots . These studies confirmed the capability of Se to survive and grow on and in tomato plants and fruit, and indicated the possibilities of strain differences in attachment, and multiple types of attachment involved in the interaction of Se with a variety of plant tissues.
Apple fruit provides a surface and environment for human pathogens similar to that of tomato fruit. The intact skin is composed of a waxy cuticle less conducive to attachment by human pathogens than other regions of the fruit . Apple fruit immersed in 108 CFU/ml of a strain of S. Chester and dried for 10 minutes retained human pathogen on broken skin, and the calyx and stem, at 20°C better than at lower temperatures; also, more human pathogen cells in these regions survived chemical sanitization than those on intact skin.
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