These data suggest that either an invasion mechanism is necessary for internalization, or alternatively, a Salmonella specific surface component/structure is triggering Salmonella internalization by 3-D HT-29 cells.
Infection of BMDCs with WT Salmonella reduced surface expression of I-Ak and I-Ek.
As a proof of principle, using Salmonella enterica, surface contamination was established on chicken breasts and inner-matrix contamination was established in pork sausages of soft and hard consistence.
These three genes were present in very low number of surface Salmonella isolates (4%, 4% & 16%, respectively) and environmental Salmonella isolates (18.2%, 18.2% & 13.6% respectively).
We next confirmed that Salmonella down-regulated surface expression of I-A and I-E in BMDCs, similar to what has been observed in human cells [ 15, 22].
The survival of Salmonella on the surface of eggs and subsequent penetration into the egg show a range of variable results as described in previous reviews [ 1, 3, 4] again with a greater focus on SE.
In this study, we attempted to summarize the possible factors that may contribute to the survival of Salmonella in the surface water transmission routes through the produce production and consumption to establish a conceptual model to visualize how Salmonella is transmitted from the environment to irrigation ponds and vice versa, as shown in Fig. 5.
Based on this phylogenic evidence, we established a conceptual model for Salmonella transmission in surface water; i.e., the presence of Salmonella in the ponds on the produce farms likely resulted from numerous reintroduction events from some hosts or reservoirs, such as cattle, horses, swine, husbandry activities, wildlife, etc., associated with the pond environment.
Other studies [ 25, 26] show similar variability in the recovery of Salmonella from egg surfaces and a rapid decline in viable numbers of SE adsorbed to egg surfaces.
Results showed that UV-C doses of 0.60 6.0 kJ/m2 resulted in 2.3 3.5 log CFU per fruit reduction of E. coli O157 H7 compared to 2.15 3.1 log CFU per fruit reduction for Salmonella on the surfaces.
