## 1 Introduction
The vaccination of poultry with attenuated _Salmonella_-expressing _Campylobacter_ outer-membrane proteins or epitopes resulted in multiple log reductions during a homologous _Campylobacter_ challenge [24; 26]. However, vaccines tend to be narrow in their efficacy, inhibiting only a few strains of a particular pathogen but not providing broader coverage for the entire spectrum of strains. In the case of _Campylobacter_, this may result from the known genetic heterogeneity of surface structures through the action of phase variation, and the consequent evasion of host immunity [27; 28]. In addition, these vaccines are administered to poultry by oral gavage, which can be impractical for large-scale producers. Many of the experimental vaccines express a subunit of _Campylobacter_ in live enteric bacteria through genetic modification, causing GMO regulatory difficulties. Breeding for genetic resistance to _Campylobacter_ is confounded by the differences between individual poultry of the same breed, and essentially nothing is known at present about allelic variation that would be pertinent to _Campylobacter_ resistance [22]. In competitive exclusion, defined or undefined mixtures of beneficial bacteria or prebiotics are orally administered to compete with _Campylobacter_ for binding and/or resources in the poultry GI tract. The results following competitive exclusion have tended to be inconsistent, which may reflect the undefined nature of the agents or inadequate selective agents in the agar plate counting of _Campylobacter_[29]. Other potential treatments for _Campylobacter_ are the application of short- and medium-chain fatty acids [30; 31] or bacteriocins [32; 33] to animal feeds. Human _Listeria monocytogenes_ infection (listeriosis) accounted for an estimated 14,169 illnesses and 3175 deaths globally in 2010 [34]. According to the FDA, there are about 1600 human cases of listeriosis and about 260 deaths from listeriosis each year in the US alone [35]. Although the global incidence of listeriosis is relatively low, it is nonetheless ranked as one of the most important foodborne illnesses due to its high fatality rate [36; 37]. Human infection with _Listeria monocytogenes_ can range from subclinical gastroenteritis to severe invasive disease, with three main clinical forms: (1) pregnancy-associated neonatal listeriosis; (2) septicemia; (3) central nervous system infection (meningitis). The majority of these clinical forms are of the septicemia type [38]. The treatment of human invasive _L. monocytogenes_ is most effective with aminopenicillin or benzopenicillin. Treatment with meropenem has been associated with a higher mortality compared to treatment with these penicillins [39]. Listeriosis is frequently associated with refrigerated ready-to-eat (RTE) foods [15; 16; 17; 18; 40]. Common food associations for _L. monocytogenes_ are RTE meats such as deli-sliced meats and those in prepacked sandwic, cold-smoked fish, and prepared salads and fruits [38]. Recent US outbreaks include a 2020 outbreak across seventeen US states attributed to enoki mushrooms, and a 2023 outbreak across six states involving deli meat and cheese [41]. [Insert paragraph about _Listeria monocytogenes_, illness statistics, common food associations, etc.] The US Department of Agriculture (USDA) Food Safety and Inspection Service (FSIS) has ruled _L. monocytogenes_ as an adulterant in ready-to-eat (RTE) products. The FSIS requires that producers of RTE products either test for _Listeria_ species on food contact surfaces in the post-lethality processing environment or treat the product itself with a post-lethality antimicrobial treatment. Such a treatment must achieve at least a 1 log reduction in _L. monocytogenes_ before the product leaves the plant; otherwise, the producer must establish the freezing of the product to suppress the growth of _L. monocytogenes_ throughout the shelf life of the product [42].