Water is vital to agriculture. It is essential that the water used for the production of fresh produce commodities be safe. Microbial pathogens are able to survive for extended periods of time in water. It is critical to understand their biology and ecology in this ecosystem in order to develop better mitigation strategies for farmers who grow these food crops. In this review the prevalence, persistence and ecology of four major foodborne pathogens, Shiga toxin-producing Escherichia coli (STEC), Salmonella, Campylobacter and closely related Arcobacter, and Listeria monocytogenes, in water are discussed. These pathogens have been linked to fresh produce outbreaks, some with devastating consequences, where, in a few cases, the contamination event has been traced to water used for crop production or post-harvest activities. In addition, antimicrobial resistance, methods improvements, including the role of genomics in aiding in the understanding of these pathogens, are discussed. Finally, global initiatives to improve our knowledge base of these pathogens around the world are touched upon.

Functional innate and acquired immune responses are required to protect the host from pathogenic bacterial infections. Modulation of host immune functions may have beneficial or deleterious effects on disease outcome. Different types of dietary fatty acids have been shown to have variable effects on bacterial clearance and disease outcome through suppression or activation of immune responses. Therefore, we have chosen to review research across experimental models and food sources on the effects of commonly consumed fatty acids on the most common food-borne pathogens, including Salmonella sp., Campylobacter sp., Shiga toxin-producing Escherichia coli, Shigella sp., Listeria monocytogenes, and Staphylococcus aureus. Altogether, the compilation of literature suggests that no single fatty acid is an answer for protection from all food-borne pathogens, and further research is necessary to determine the best approach to improve disease outcomes.

Poultry products such as meat and eggs are known reservoirs for Salmonella serovars. Macrophages play an important role by limiting bacterial replication using several defense mechanisms including immune and inflammatory mediators, antibacterial proteins, reactive nitrogen and oxygen species. In this study, we evaluate transcriptional changes in Toll-like receptors, immune/inflammatory cytokines, chemokines, antibacterial factors, and nitric oxide (NO) production in HD11 chicken macrophages in response to intracellular persistence of poultry-derived Salmonella enterica Enteritidis (SE), Typhimurium (ST), and Heidelberg (SH) that were associated with human salmonellosis. Invasion of ST was higher than SE or SH; however, SH persistence in HD11 cells at 18 h post infection (hpi) was more pronounced than the other 2 serovars. In comparison to the uninfected control HD11 cells, expression of TLR5 was >2 fold higher for SE and SH which was followed by up-regulation of downstream signal transduction molecules. Significant up-regulation of antibacterial peptides, proinflammatory chemokines, cytokines, and NO production were observed in response to SE, SH, and ST at 18 hpi. These results indicate that although antibacterial factors contribute to the clearance of invading Salmonella, some of the differences in response could also be due to the different virulence properties of these serovars.

In the United States, Salmonella enterica ser. Enteritidis (SE) is among the leading bacterial cause of foodborne illness via consumption of raw or undercooked eggs. The top Salmonella serovars implicated in U.S. foodborne outbreaks associated with chicken consumption include SE, Typhimurium (ST), Heidelberg (SH), Montevideo, Mbandka, Braenderup, and Newport. While enforcement actions target the eradication of SE from layer hens, there is a growing concern that other serovars could occupy this niche and be a cause of egg-transmitted human salmonellosis. Therefore, we tested the invasion and survival of SE, SH, ST, and Salmonella enterica ser. Hadar (S. Hadar) at 4 and 20 h post infection (hpi) in chicken ovarian granulosa cells (cGC); a cellular layer which surrounds the previtelline layer and central yolk in egg-forming follicles. We also evaluated cGC transcriptional changes, using an antibacterial response PCR array, to assess host response to intracellular Salmonella.

Salmonella enterica serovar Oranienburg (SO) was linked to a human salmonellosis outbreak in the Midwest in 2015 and 2016 from consumption of eggs. H