This work introduces technology for rapid pathogen detection using handheld optical immunoassay and wire-guided droplet PCR systems. There have been a number of cases of foodborne or waterborne illness among humans that are caused by pathogens such as Escherichia coli O157:H7, Salmonella typhimurium, Influenza A H1N1, and the norovirus. The current practices to detect such pathogenic agents are: cell/viral culturing, immunoassays, or polymerase chain reactions (PCRs). These methods are essentially laboratory-based methods that are not at all real-time and thus unavailable for early-monitoring of such pathogens. They are also very difficult to be implemented in field, preventing early detection opportunities. This dissertation is divided into three papers that present methodologies towards the expeditious detections of infectious pathogens and the miniaturization of these detection systems towards field-deployable and point-of-care applications. Specifically, the work presented focuses on two methodologies: (1) light scatter detection using immunoagglutination assays with optimized Mie light scatter parameters in a real biological matrix consisting of plant tissue, and (2) wire-guided droplet manipulations for rapid and improved sample analysis, preparation, and PCR thermocycling. Both of these methods carry a collective objective towards providing high impact technologies for addressing the issues of food-related outbreaks and overall public safety. In the first paper, the direct and sensitive detection of foodborne pathogens from fresh produce samples was accomplished using a handheld lab-on-a-chip device, requiring little to no sample processing and enrichment steps for a near-real-time detection and truly field-deployable device. The detection of Escherichia coli K12 and O157:H7 in iceberg lettuce was achieved utilizing optimized Mie light scatter parameters with a latex particle immunoagglutination assay. The system exhibited good sensitivity, with a limit of detection of 10 CFU mL⁻¹ and an assay time of <6 min. Minimal pretreatment with no detrimental effects on assay sensitivity and reproducibility was accomplished with a simple and cost-effective KimWipes filter and disposable syringe. Mie simulations were used to determine the optimal parameters (particle size d, wavelength λ, and scatter angle θ) for the assay that maximize light scatter intensity of agglutinated latex microparticles and minimize light scatter intensity of the tissue fragments of iceberg lettuce, which were experimentally validated. This introduces a powerful method for detecting foodborne pathogens in fresh produce and other potential sample matrices. The integration of a multi-channel microfluidic chip allowed for differential detection of the agglutinated particles in the presence of the antigen, revealing a true field-deployable detection system with decreased assay time and improved robustness over comparable benchtop systems. In the second paper, we demonstrate a novel method of wire-guided droplet manipulations towards very quick RT-PCR. Because typical RT-PCR assays take about 1–2 h for thermocycling, there is a growing need to further speed up the thermocycling to less than 30 min. Additionally, the PCR assay system should be made portable as a point- of-care detection tool. Rapid movements of droplets (immersed in oil) over three different temperature zones make very quick PCR possible, as heating/cooling will be made by convective heat transfer, whose heat transfer coefficients are much higher than that of conduction, the latter of which is used in most conventional PCR systems. A 30-cycle PCR of a 160 bp gene sequence amplified from 2009 H1N1 influenza A (human origin) was successfully demonstrates in 6 min and 50 sec for a very large 10 μL droplet (with additional 4 min for reverse transcription). The proposed system has a potential to become a rapid, portable, point-of-care tool for detecting influenza A. In the third paper, a wire-guided CNC apparatus was used to perform droplet centrifugation, DNA extraction, and VQ-PCR thermocycling on a single superhydrophobic surface measuring 25 mm by 55 mm and a multi-chambered PCB heater. This methodology exhibited no limitations on the complexity and configuration of procedures that it can perform, making it versatile and far-reaching in its applications. The only modification required for adding or implementing changes for a new protocol is through simple pre-defined programming. The highly adaptive and flexible system was used to execute easily pre-programmed droplet movements and manipulations for the rapid detection of Escherichia coli from PCR detection. Serial dilutions were performed to simulate a diluted field sample with a high level of accuracy. Centrifugation of the diluted sample containing E. coli demonstrated a novel approach to sample pre-treatment. Furthermore, the extraction of DNA from the sample droplet containing E. coli was also performed on the same superhydrophobic surface as the previous 2 steps, requiring less than 10 min. Following extraction, the genetic material was amplified using wire-guided droplet PCR thermocycling, successfully completing 30 cycles of Peptidase D (a long 1500 bp sequence) in 10 min. The droplet centrifugation process was determined to greatly improve the positive band intensity over the non-centrifuged sample. Thus, this work demonstrates the adaptability of the system to replace many common laboratory tasks on a single platform (through re-programmability), in rapid succession (using droplets), and with a high level of accuracy and automation.

30 pp. / The Favorite Food Show Guide provides basic information for 4-H youth and adults to better prepare for this event. Multiple illustrations make this guide very user friendly and information could be used as lessons for 4-H meetings.

2 pp. / Revision of 1997 title by Meer and Misner / From 1988 to 1992, 66% of all food-borne illnesses caused by salmonella enteritidis involved eggs or foods containing eggs. Contamination of eggs may occur on the inside as well as the outside of the shell. This article outlines the proper refrigeration, cooking and handling methods to prevent most egg safety problems.

In South Africa there is a need within the milling industry for controlling food safety especially due to customer's demands and government's regulations. The best way to ensure food safety is with the implementation of a HACCP based food safety system. Therefore, the principal aim of this study was to develop a generic HACCP model for the flour milling industry. Afterwards this generic model can then be adapted for each specific mill and its needs.

There is a growing demand for safe and convenient meat products. The effect of natural spice extracts incorporated with other hurdles for controlling pathogenic bacteria and extending the shelf life of RTE doner kebab were investigated. A comprehensive literature review was undertaken to establish the status of microbial risk, use of additives, knowledge on oxidative deterioration and HACCP associated with meat products. The in vitro antioxidant and antibacterial activities of spice extracts were screened and compared. Cinnamon, clove, and sumac alcoholic extracts demonstrated strong antimicrobial effect, however, rosemary proved effective as antioxidant in a lamb fat model. An accelerated shelf life study on a model system indicated that storage temperature was the most critical factor affecting lipid oxidation, which was effectively delayed by vacuum packaging and rosemary extracts. The effects of spice extracts, packaging and storage time on physiochemical, microbiological, and sensory attributes of doner kebab were evaluated. Application of rosemary and cinnamon extracts significantly reduced TVC, inhibited LAB, and retarded lipid oxidation rate. Sensory evaluation by a consumer panel indicated that only taste and spiciness perception was significantly different between treatments. A challenge test against Listeria monocytogenes showed significant differences between control and spice treatments at day 28. Strong inhibitory effects were associated to high levels of cinnamon particularly when applied after cooking. The effect of heat treatment and sumac (Rhus coriaria) on Bacillus cereus and Clostridium perfringens inactivation was evaluated on a doner kebab prototype. Addition of sumac significantly reduced D-values and z-values for both organisms in comparison to the control. The investigation of the effect of spice extracts, and environmental conditions on changes in growth kinetic parameters for L. monocytogenes and Salmonella Typhimurium showed that spice extracts are highly significant. For both microorganisms, Mumax was reduced as salt and spice concentrations increased, and pH levels decreased. This study shows that spice extracts incorporated with other hurdles can help to maintain safe and good quality RTE doner kebab.

Bakgrund: Stamcellstransplantation är en behandlingsmetod mot flera olika typer av leukemi. Efter transplantationen blir patienten infektionskänslig. Vid detta tillstånd skyddsisoleras patienten och får en livsmedelsbegränsad kost.Syfte: Sammanställa och jämföra isoleringsrutiner gällande livsmedelsbegränsningar för patienter vid Sveriges hematoloigavdelningar där allogen transplantation sker och jämföra med aktuell forskning bakom livsmedelsbegränsningar.Metod: Tvärsnittsstudie vid jämförelsen av livsmedelsbegränsningarna vid Sveriges hematologiavdelningar samt en litteraturstudie vid undersökningen av aktuell forskning i databaserna Pubmed och Cinahl.Resultat: I tvärsnittsstudien använde alla sjukhusen olika rutiner. Ingen signifikant skillnad gällande infektionsincidensen mellan patienter som hade livsmedelsbegränsningar jämfört med de som inte hade det fanns i litteratursökningen.Slutsats: Livsmedelsbegränsningar minskar troligtvis inte infektionsrisken för infektionskänsliga patienter. Det behövs högkvalitativ forskning för att utforma tydliga riktlinjer kring vilka livsmedelsbegränsningar som bör användas. / Background: Stem cell transplantation is a treatment for patients with leukemia. After the transplantation, the patients are at a higher risk of getting an infection and are therefore kept in protective isolation and get a food restricted diet.Purpose: To compile and compare the differences in food restricted diet for neutropenic patients at the hematology departments in Sweden where stem cell transplantation is performed and compare food restricted diet to current research.Method: A cross-sectional study to compare the food restrictions and a literature study to find out what the current research says using Pubmed and Cinahl.Result: The cross-sectional study showed that all the hospitals used different diets. In the literature review, no significant difference regarding infections rates when comparing patients who ate a food restricted diet with those who did not.Conclusion: Food restrictions are unlikely to reduce the infection rate of neutropenic patients. More high quality research is needed to formulate clear guidelines about what food restricted diet should be used.

HOPE VI, instituted in 1993 and subsequent related policies, resulted in the demolition of traditional public housing and the relocation of former residents. For former residents living on low incomes, combining housing subsidy and other social services is important to survival. One crucial type of social services support provides food supplements. Research indicates that among low-income families, many do not receive necessary food social services. For example, among eligibles, food stamp utilization is at 50 to 60%, and for Special Supplemental Nutrition Program for Women Infants and Children (WIC) rates vary from 38 to 73%. Research indicates that 35% of food insecure older adults are ineligible for the Elder Nutrition Program, and approximately 60% of eligibles are wait-listed upon application. Social services utilization patterns among eligibles are affected by neighborhood contexts. Relocation due to public housing transformation policies has been shown to change neighborhood context. This in turn has affected former public housing resident’s cultural capital and social capital. But how this affects food social services utilization has not been studied. I use Klinenberg’s (2002) activist client thesis as a framework to investigate the effect of cultural capital and social capital for housing subsidy recipients (relocated public housing residents) in Atlanta on their utilization of food social services using secondary longitudinal data from the Georgia State University Urban Health Initiative analyzed using ordered logistic regression. Most specifically, my research investigated how varying neighborhood contexts affect food social services utilization for former public housing residents in Atlanta. This research informs public policy on the provision of housing subsidy and the provision of food social services.

Escherichia coli (E. coli) are common and typically innocuous copiotrophic bacteria found in the mammalian gut microbiome. However, over the past 30 years, pathogenic E. coli have been responsible for several outbreaks of foodborne illness linked to contaminated produce. The introduction of Escherichia coli to an agricultural soil, via contaminated water, compost, or raw manure, exposes the bacterium to a medley of ecological forces not found in a mammalian gut environment. This study assesses a variety of abiotic and biotic soil factors that influence the ability of an "invasive" copiotrophic coliform bacterium to survive in compost-amended agricultural soil. The study included both field and laboratory components. In the lab experiment, a cocktail of rifampicin-resistant generic E.coli strains was added to sterile and non-sterile extracts of eight different composts and one soil sample from the field sites. E. coli abundance was monitored over a one-week period and composts were analyzed for their nutrient profile. In the field experiment, the same E. coli cocktail was sprayed on plots with the following treatments: 1) dairy windrow compost, 2) dairy vermicompost, 3) poultry windrow compost, or 4) no compost. E. coli abundance, soil water potential, soil temperature, extracellular enzyme activity, microbial respiration, phospholipid fatty acid biomarker abundance, and genetic sequencing of the microbial community were measured over a six-month field season. The lab experiment showed that E. coli were able to grow well in sterile compost extracts, without microbial competition for nutrients. Conversely, E. coli populations were only able to survive in non-sterile soil extracts. These results suggest that copiotrophic organisms adapted for high-nutrient environments may depend on the extracellular enzyme activity of native oligotrophic organisms to acquire sufficient nutrients to survive in soils. Results of the field experiment showed clear and interdependent effects of soil moisture and nutrient availability on microbial community dynamics and E. coli survival. Data suggest that saturated soils cause a decrease in microbial extracellular enzyme activity, and drying-rewetting cycles can cause respiration bursts, nutrient mineralization, and shifts in community composition. The saturation of soils, which mobilizes nutrients and may result in a decrease in competition from aerobic organisms, correlated directly with increased survival of E. coli. Additionally, amendment with ammonium-rich poultry compost resulted in the maintenance of high levels of E. coli throughout the field season. Despite an increase in microbial biomass from dairy vermicompost amendment, poultry compost was the only compost that had a significant effect on E. coli survival. The results suggest that nitrogen availability and water potential are strong drivers of E. coli's survival in soils. Correlations among abiotic factors, community composition, and E. coli survival reveal insights into the complex relationships that occur in disturbed agricultural soil environments. Further research on E. coli's response to targeted organisms, abiotic soil properties, and nutrient inputs could have implications for agricultural considerations in food safety and microbial ecology.

Thesis: Food law in the Czech Republic before and after joining the European Union This thesis deals with the comparison of food legislation in the Czech Republic before and after joining the European Union, while it predominantly focuses on the area of food safety and food hygiene, as well as on the institutional backup. The aim of this thesis is to provide an introduction to food legislation, its concepts, legal sources and basic principles and subsequently to perform a comparison of the most important changes in the respective areas in the Czech Republic before and after joining the European Union. In its conclusion, the thesis evaluates the overall impact of the identified changes, especially with regards to the level and quality of the system securing food safety and food hygiene in the Czech Republic after joining the European Union.

The aim of this thesis was to explore food safety as part of Home and consumer studies (HCS) education in Swedish compulsory school. Firstly, a nationwide web-based questionnaire was performed among HCS teachers to obtain an overall picture of their knowledge, behaviour and attitudes regarding food safety.  The second study was a questionnaire among school Year 9 students, where the data were collected using a student response system. The questions were related to the students’ food safety knowledge and behaviour, as well as cooking habits and sources of food safety knowledge and trust. Finally, qualitative interviews were performed among HCS teachers regarding their didactic choices of teaching content. The results indicated a routine behaviour connected to cleaning practices and teaching regarding different perishable food to differ between teachers. The students’ food safety knowledge and behaviour were reported to be inadequate, especially among boys, and that students might leave school without having learnt even basic food safety principles. Mothers and thereby the home were reported to be an important as well as a trusted source of food safety knowledge, especially among the girls. Boys reported HCS to also be an important as well as trusted source, especially students that rarely or never reported to cook at home. For those students HCS must be seen as particularly valuable. To increase the students’ learning, the teaching needs to be related to the students’ everyday practices and to be more reflective in order for it to be practiced outside the HCS classroom. The teachers’ didactic choices could imply consequences for the students’ food safety learning and a need for more education and updated information for the teachers was noticed. In summary, the results indicate that risk areas related to all the Four Cs in Food safety (Cooking, Cleaning, Chilling and avoidance of Cross-contamination) need to be highlighted in HCS teaching and for food safety to become a conscious didactic choice for the teachers.  As teaching regarding food safety in HCS seem to differ it needs to be highlighted in HCS policy documents to ensure equivalent food safety learning for all students in compulsory school.