Patricia A. Curtis

Salmonella Enteritidis (SE) is a major foodborne pathogen responsible for causing gastrointestinal infections in humans, predominantly due to the consumption of contaminated eggs. In layer hens, SE colonizes the intestine and migrates to various organs, including the oviduct, thereby leading to egg yolk and shell contamination. This study investigated the efficacy of caprylic acid (CA), a medium-chain fatty acid, in reducing SE colonization and egg contamination in layers. Caprylic acid was supplemented in the feed at 0%, 0.7%, or 1% (vol/wt) from day 1 of the experiment. Birds were challenged with 10¹⁰ log colony-forming units (CFU)/mL of SE by crop gavage on day 10, and re-inoculated (10¹⁰ log CFU/mL) on day 35. After 7 days post first inoculation, eggs were collected daily and tested for SE on the shell and in the yolk separately. The birds were sacrificed on day 66 to determine SE colonization in the ceca, liver, and oviduct. The consumer acceptability of eggs was also determined by triangle test. The experiment was replicated twice. In-feed supplementation of CA (0.7% and 1%) to birds consistently decreased SE on eggshell and in the yolk (pp0.05). The results suggest that CA could potentially be used as a feed additive to reduce eggborne transmission of SE.

Electrical safety has rapidly risen in prominence in industrial applications due to increased awareness of hazards and risks. There are numerous occupational health and safety organizations around the world that now mandate practices and procedures to maximize electrical safety in the workplace. Training workers to meet these requirements typically follows the standard methods based on seminars and short courses which have been widely used for many years. Maximizing electrical safety, however, cannot be achieved by simply memorizing facts or procedures taught in this environment. The critical aspect of electrical safety lies in the actions of the worker in the workplace-what people do in certain situations when given particular information is based on their higher-level thought process and their sequential decisions and actions. It is not possible to fully train workers in this skillset in advance, and the needs in this area are normally addressed on the job by direct observation and personal interaction. In this paper, a simulation-based electrical safety training module is described that allows the participant to move through a simulated environment while making observations and decisions and taking actions. The ability of the participant to recognize key facts and take appropriate actions when faced with simulated electrical safety scenarios can be scored and evaluated in the same manner as a typical computer game with the total score based on the accumulated choices of the participant. A score threshold can then be used to indicate the level to which the participant has mastered the training scenarios. Determining such a total score is exemplary of the necessary changes in assessment required when using virtual learning environments for training purposes.

Salmonella enterica serovar Enteritidis is a major foodborne pathogen in the United States, causing gastroenteritis in humans, primarily through consumption of contaminated eggs. Chickens are the reservoir host of S . Enteritidis. In layer hens, S . Enteritidis colonizes the intestine and migrates to various organs, including the oviduct, leading to egg contamination. This study investigated the efficacy of in-feed supplementation with trans -cinnamaldehyde (TC), a generally recognized as safe (GRAS) plant compound obtained from cinnamon, in reducing S . Enteritidis cecal colonization and systemic spread in layers. Additionally, the effect of TC on S . Enteritidis virulence factors critical for macrophage survival and oviduct colonization was investigated in vitro . The consumer acceptability of eggs was also determined by a triangle test. Supplementation of TC in feed for 66 days at 1 or 1.5% (vol/wt) for 40- or 25-week-old layer chickens decreased the amounts of S . Enteritidis on eggshell and in yolk ( P < 0.001). Additionally, S . Enteritidis persistence in the cecum, liver, and oviduct in TC-supplemented birds was decreased compared to that in controls ( P < 0.001). No significant differences in feed intake, body weight, or egg production in birds or in consumer acceptability of eggs were observed ( P > 0.05). In vitro cell culture assays revealed that TC reduced S . Enteritidis adhesion to and invasion of primary chicken oviduct epithelial cells and reduced S . Enteritidis survival in chicken macrophages ( P < 0.001). Follow-up gene expression analysis using real-time quantitative PCR (qPCR) showed that TC downregulated the expression of S . Enteritidis virulence genes critical for chicken oviduct colonization ( P < 0.001). The results suggest that TC may potentially be used as a feed additive to reduce egg-borne transmission of S . Enteritidis.