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Validation Of Thermal Destruction Of Pathogenic Bacteria In Rendered Animal Products, Mary Hayes

All Dissertations

This study tested enumeration techniques for high fat food matrices and determined thermal death times in rendering animal products. Standard Class O phosphate/magnesium chloride dilution buffer series (Dilution Series A) and a modified (pre-warmed to 32oC) lecithin phosphate dilution buffer series (Dilution Series B) were used to enumerate a Salmonella cocktail from both poultry and beef rendering materials. Results of this study indicate use of a modified lecithin buffer did not improve Salmonella enumeration accuracy from rendering materials. Instead, the results suggested use of xylose lysine deoxycholate agar (XLD) with either buffer system accurately enumerated Salmonella from rendering materials. The …

Phenotypic, Physiological And Growth Interactions Among Salmonella Serovars, Juliany Rivera Calo

Graduate Theses and Dissertations

This thesis consists of four research parts: a literature review that covers Salmonella spp., one of the more prominent foodborne pathogens that represents a major risk to humans (chapter 1). Understanding the growth of Salmonella serovars and strains is an important basis for more in depth research. In this case we studied a) the aerobic and anaerobic growth responses of multiple strains from six different serovars, b) how the spent media from different serovars, more importantly S. Heidelberg, affect the growth of S. Typhimurium, and c) determined whether or not two different serovars undergo competitive interactions when they were …

Electrostatic Spray Application Of Food-Grade Organic Acids And Plant Extracts To Decrease Escherichia Coli O157:H7 And Salmonella Typhimurium On Select Produce, Leighanna Maeree Massey

Graduate Theses and Dissertations

Both consumers and suppliers have been negatively affected by an increase in foodborne pathogens contaminating fruits. Consequently, there is a need for the development of more efficient antimicrobials and application techniques to decrease contamination. Natural preservatives such as organic acids and plant extracts have demonstrated promising results in decontaminating produce. In addition, the effectiveness of such preservatives may be enhanced by the use of an electrostatic sprayer. The objective of this research was to determine the combinations and concentrations of organic acids and plant extract that were able to reduce Salmonella Typhimurium (ST) and Escherichia coli O157:H7 (EC) inoculated fruits …

A Case Study Of The Crisis Communications Used In The 2009 Salmonella Outbreak In Peanut Products, Erica Irlbeck, Jessica Fry Jennings, Courtney Meyers, Courtney Gibson, Todd Chambers

Journal of Applied Communications

The 2009 Salmonella outbreak in peanut products caused by contaminated peanut butter created a period of negative publicity for the peanut industry in the United States. It was one of many large food outbreaks the United States has seen in the past few years. Although one company was the cause of the outbreak, the peanut industry worked together to maintain its reputation. Crisis communications plans were put into effect, and crisis management teams worked together throughout. The purpose of this study was to examine the crisis communications efforts taken by peanut industry public relations practitioners during the 2009 Salmonella outbreak …

A Comparison Of Salmonella Enterica Serovars: Are Prevalence, Virulence And Responses To Environmental Conditions Serovar Or Strain Dependent?, Nan Zhang

Masters Theses

Salmonella are considered the leading cause of foodborne illnesses with frequent outbreaks in United States. While more than 2500 serovars have been identified, Salmonella Typhimurium and Salmonella Enteritidis are primarily responsible for most human infections while Salmonella Kentucky and Salmonella Heidelburg are currently the most prevalent serovars associated with poultry contamination. The relationship between virulence and prevalence is not fully understood, but may be a result of environmental stress exposure such as acid stress. In this research, organic acid (acetate) and inorganic acid (hydrogen chloride) were applied to 15 different serovars isolated from human infections or poultry. The growth curves …

Comparison Of Potential Salmonella Portals Of Entry And Tissue Distribution Following Challenge Of Poultry, Gopala Krishna Kallapura Sheshagiri

Graduate Theses and Dissertations

The following studies evaluated our hypothesis that transmission by the fecal-respiratory route may be a viable portal of entry for Salmonella and could explain some clinical impressions of relatively low-dose infectivity under field conditions in relation to the requisite high oral challenge dose that is typically required for infection of poultry through the oral route in laboratory studies. Initial field reports indicating tracheal sampling to be a sensitive tool for monitoring Salmonella infection in commercial flocks, suggested that tracheal contamination could be a good indicator of Salmonella infection under commercial conditions. Further, a usual assumption regarding airborne Salmonella reaching the …

Development Of Rapid Detection Methods And Novel Control Measures For Salmonella In Poultry, Si Hong Park

Graduate Theses and Dissertations

This dissertation consists of three research parts: 1) development of rapid detection methods for foodborne pathogens; 2) immune response of chicken cells against Salmonella and bacteriophage P22; 3) evaluation of novel control measures for poultry productions. In order to develop rapid and accurate detection methods for foodborne pathogens, two types of PCR assays were utilized. Three foodborne pathogens included Campylobacter, Escherichia coli and Salmonella in watershed were qualitatively and quantitatively detected by multiplex PCR and qPCR (chapter 2). Since Salmonella species are commonly present in poultry and poultry products as well as most popular foodborne pathogen in …

Isolation, Antibiotic Resistance And Clonal Similarities Of Salmonella Spp. In Catfish And Processing Facilities, Norman N. Arroyo Llantin

Theses and Dissertations

Salmonella spp. is a human pathogen that has been reported in catfish, but with conflicting results. Salmonella spp. was isolated from live catfish, catfish products and the processing environment during catfish production, followed by evaluation of their antibiotic resistance and clonal similarities. Distinction of Salmonella spp. was increased by lowering background microflora with the addition of the antimicrobial novobiocin to the agar media. More than ten Salmonella serotypes were isolated from catfish and catfish products, such as live, chilled fillets, frozen fillets, and conveyor belts in catfish processing facilities. The isolates that were recovered include Salmonella ser. Typhimurium, Barranquilla, Mbadaka, …

Spatial And Temporal Distribution Of Microbial Pathogens In Poultry Litter And The Development Of Microbial Inactivation Constants In Waste Application, Brandy Nicole Roberts

Theses and Dissertations

The increase in production farming, also known as concentrated animal feeding operations (CAFOs), garners more investigations on the implications to public health regarding the disposal of the wastes of food production animals. In addition to the vast amount of animal manure produced, human biosolids is another waste residual that must be managed. The research focus was the sustainability of foodborne pathogens in waste products and the variables that manipulate these environments such as moisture, temperature, organic matter and time. The first study was designed to analyze spatial differences in microbial populations in broiler litter by investigating the relationship of intra-house …

Efficacy Of Selected Disinfectants Against Salmonella Isolates From Broiler Breeders, Arslan Aslam

Graduate Theses and Dissertations

Salmonella have been causing huge losses in the poultry industry and have been a major cause food borne illness for many years. Salmonella infections in humans from poultry have been increasing. Good hygiene and biosecurity measures can reduce the incidence of Salmonella infections at poultry farms. Disinfection is a most important measure taken to prevent Salmonellosis in poultry. This research was conducted to determine the efficacy of 12 disinfectants against seven Salmonella isolates in the presence and absence of organic matter. A bacterial solution of a specific optical density value was prepared and .05x, .1x and .2x concentrations of disinfectants …

Influence Of Compost Particle Size On Pathogen Survival Under Greenhouse Condition, Junshu Diao

All Theses

The number of foodborne pathogen outbreaks related to fresh produce has increased significantly in recent decades. Animal waste directly applied to agricultural field is one of the possible contamination sources for fresh produce. Composting is one of the recommended means for waste treatments to eliminate or reduce pathogens in manure on farms. Although pathogens can be eliminated by proper composting process, pathogens are able to survive, recolonize and regrow on compost heap surfaces under certain conditions. Due to the outdoor nature of composting process, bioaerosols with different particle sizes can be generated on compost surfaces which can carry pathogens, travel …

Incidence Of Salmonella On Reptiles In The Pet Trade, Casey R. Cain, Drew Tyre, Dennis Ferraro

Andrew J Tyre

Reptiles are very common carriers of Salmonella and can be infected without showing any symptoms. Humans can contract reptile-associated Salmonellosis (RAS) by handling a Salmonella-infected reptile or any object contaminated by a Salmonella-infected reptile then failing to properly wash their hands, or by allowing reptiles to contaminate areas of food preparation.

This study tested reptiles for Salmonella in four Nebraska pet shops in March of 2007 to estimate the prevalence of Salmonella in captive reptiles in Nebraska. Of 80 pet reptiles tested, 53.8% (43) yielded Salmonella, which is much higher than the 6.6% (12 of 182) prevalence of Salmonella in …

Using Behavior-Analytic Techniques To Benefit An African Non-Governmental Organization: Improving And Expanding Services, Amy L. Durgin

Dissertations

The combination of a slowly recovering global economy, increased corporate competition, and higher standards from donors with respect to governance and accountably have posed significant challenges for nonprofit organizations around the world. In order to survive, these organizations must adapt their operational models and find new strategies for delivering on strategic goals, improving operational efficiency, and differentiating their services. The purpose of the present project was to employ behavioral techniques to improve operational efficiency and to develop opportunities for organizational growth by expanding the range of services provided by a nongovernmental organization (NGO) in East Africa that uses scent-detection rats …

Lung Dendritic Cells Induce Migration Of Protective T Cells To The Gastrointestinal Tract, Darren Ruane, Lucas Brane, Bernardo S. Reis

Publications

Developing efficacious vaccines against enteric diseases is a global challenge that requires a better understanding of cellular recruitment dynamics at the mucosal surfaces. The current paradigm of T cell homing to the gastrointestinal (GI) tract involves the induction of α4β7 and CCR9 by Peyer's patch and mesenteric lymph node (MLN) dendritic cells (DCs) in a retinoic acid-dependent manner. This paradigm, however, cannot be reconciled with reports of GI T cell responses after intranasal (i.n.) delivery of antigens that do not directly target the GI lymphoid tissue. To explore alternative pathways of cellular migration, we have investigated the ability of DCs …

Development And Evaluation Of Molecular-Based Assays For Detecting Salmonella Serovars In Various Food Commodities, Qianru Yang

LSU Doctoral Dissertations

As a leading cause of foodborne illnesses and outbreaks, Salmonella poses a major public health risk in the United States and worldwide. Various food commodities including meat and poultry, eggs, and fresh produce can serve as the transmission vehicles for Salmonella infections. To better ensure the safety of these products and protect public health, rapid, accurate, and reliable detection methods for Salmonella are needed. Molecular-based methods like loop-mediated isothermal amplification (LAMP), have gained wide applications in Salmonella detection, owning to their rapidity, specificity, and sensitivity. However, there is a paucity of data on the robustness of these assays. And very …

A Case Study Of The Risk And Crisis Communications Used In The 2008 Salmonella Outbreak, Ashley Palmer, Erica Irlbeck, Courtney Meyers, Todd Chambers

Journal of Applied Communications

The Salmonella outbreak of 2008 was one of the largest foodborne illness outbreaks in the last 20 years. Tomatoes were initially pinpointed as the source of the outbreak, and the tomato industry suffered losses of $100 million in 2008. Eventually the FDA was able to trace the outbreak to imported jalapeño peppers, but this discovery was too late to recover losses for the tomato industry. The purpose of this study was to examine the risk and crisis communication efforts taken by public relations practitioners in the produce industry during the 2008 Salmonella outbreak to determine which efforts were successful and …