Life Sciences Commons^™

Synthesizing Inactivation Efficacy Of Treatments Against Bacillus Cereus Through Systematic Review And Meta-Analysis And Evaluating Inactivation Efficacy Of Commercial Cleaning Products Against B. Cereus Biofilms And Spores Using Standardized Methods, Minho Kim

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Bacillus cereus is ubiquitous and can be easily carried in food processing facilities. It is problematic because it can survive various treatments such as heat, radiation, and chemical cleaning by forming spores and biofilms. Some review papers have discussed inactivation efficacies of different treatments against B. cereus, but they are narrative without quantitative summaries. This study first aimed to find effective and food industry-applicable treatment candidates against B. cereus spores and biofilms by synthesizing and comparing the efficacy of treatments using systematic review and meta-analysis. After screening, 17 studies were included, but only nine studies were used for meta-analysis …

A Systematic Literature Review Of Sanitizer Efficacy To Remove Listeria Monocytogenes, Salmonella Spp., And Shiga Toxin-Producing Escherichia Coli Biofilms From Food Processing Surfaces, Ashlynn Robinson

Food Science Undergraduate Honors Theses

Sanitizing in food production environments is essential to prevent, reduce, and/or eliminate foodborne pathogens. Biofilms consist of one or more different types of microorganisms and can grow on numerous types of surfaces (Costerton,1999). SLRs provide transparency about what steps were taken to acquire the sources included in the analysis (Liberati et al.,2009; Moher et al., 2009). The references obtained from the databases were based on specific eligibility criteria to ensure reproducible results. The inclusion criteria included six surface types (stainless steel, glass, plastic, polyurethane, PVC, rubber), seven sanitizer types (anionic acid, benzalkonium chloride, iodine, iodophor, peracetic acid, quaternary ammonium, and …

Effect Of Long Pasteurization Run Times On Bacterial Numbers In Milk, Brynli Tattersall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This project was funded by the Western Dairy Center to understand how long a milk pasteurizer can be operated before increases in bacterial numbers are observed in the pasteurized milk. While pasteurization kills pathogenic bacteria there are some non-pathogenic bacteria that can survive and have the ability to become attached to the surfaces in the cooling sections of the pasteurizer. Some bacteria can also produce spores that survive pasteurization even if the bacterial cells are killed. Temperatures in the cooling section remain in a range suitable for growth of these heat-tolerant bacteria and can allow germination of bacterial spores. While …

Assessment Of Salmonella Enterica Biofilms And Expression Differences Among Serovars, Zhaohao Shi

Graduate Theses and Dissertations

Biofilms are communities of microorganisms associated by a matrix of extracellular polymers. In this state, microorganisms occupy an ecological niche distinct from their free-floating, planktonic counterparts. Also, biofilm bacteria become biologically unique as they form communities and lose motility. The acquisition of these physiological attributes enables the biofilm to persist through harsh environmental conditions, including antimicrobial induced stress and to resist sanitization efforts. Because of these features, biofilms can rapidly disseminate across numerous surfaces and as they establish, become challenging to remove. This is a particular issue for the food industry as processing plants offer favorable conditions for biofilm formation …

Relationships Between Factors Influencing Biofilm Formation And Pathogen Retention In Complex Rhizosphere Microbial Communities, Aaron Coristine

Theses and Dissertations (Comprehensive)

Riparian wetlands are unique habitats facilitating all forms of life. The riverbanks of these environments provide ideal conditions for bacteria, plants, and higher organisms. Of particular interest to this research was the variation in microbial community structure at high, intermediate and poor water quality impacted areas. Assessing the capabilities of plants to retain microbial pathogens was identified. Root systems and corresponding soil are ideal locations for bacterial deposition, resulting in attachment at these areas. Biofilm production in these regions is important for long-term establishment, leading to persistence and potential naturalization. Opportunistic pathogens originating from mammalian fecal matter are introduced into …

Investigating Natural And Induced Biofilm Dispersion In Listeria Monocytogenes, Brett Boulden

Masters Theses

Dispersion is a natural part of a biofilm life cycle in many bacterial species. Dispersion occurs when bacteria revert from a stationary, sessile state to a free-swimming, planktonic state and are freed from a biofilm. Bacterial biofilms consist of proteins, polysaccharides, and extracellular DNA that together make up the extracellular polymeric substances. Surrounded by this mucus-like substance, sessile cells can be extremely difficult to eradicate as compared to the planktonic form of Listeria monocytogenes. Biofilms are robust due to increased surface adherence, inhibition of diffusion of harmful compounds, and increased genetic diversity that exists within a biofilm. As a …

Controlling Brochothrix Thermosphacta As A Spoilage Risk Using In Package Atmospheric Cold Plasma, Apurva Patange, Daniela Boehm, Carmen Bueno-Ferrer, Patrick Cullen, Paula Bourke

Articles

Brochothrix thermosphacta is a predominant spoilage microorganism in meat and its control in processing environments is important to maintain meat product quality. Atmospheric cold plasma is of interest for control of pathogenic and spoilage microorganisms in foods. This study ascertained the potential of dielectric barrier discharge atmospheric cold plasma (DBD-ACP) for control of B. thermosphacta in response to key parameters such as treatment time, voltage level, interactions with media composition and post treatment storage conditions. Challenge populations were evaluated as suspensions in PBS, as biofilms in meat model medium and surface attached on raw lamb chops under MAP.

ACP treatment …

Echerichia Coli Biofilm Formation In Musca Domestica Crops, Lufan Wang

Masters Theses

The house fly, Musca domestica can transmit human pathogens including Escherichia coli O157:H7 through regurgitation of ingested bacteria from the crop which is a foregut organ of house fly and stores the excess ingested nutrients. Interactions between the ingested bacteria and the crop have a direct influence on bacteria persistence, survival and ultimately fly vector competence. In this research, in situ crop vessel assay was developed to investigate bacterial growth within fly crops up to 48 hours post-ingestion. Flies were fasted for 12 h prior to feeding E. coli O₁₅₇:H₇ pEGFP and then fed bacteria with red …

Controlling Microbial Safety Challenges Of Meat Using High Voltage Atmospheric Cold Plasma, Lu Han, Dana Ziuzina, Caitlin Marie Heslin, Daniela Boehm, Apurva Patange, David Millan-Sango, Vasilis Valdramidis, Patrick Cullen, Paula Bourke

Articles

Atmospheric cold plasma (ACP) is a non-thermal technology, effective against a wide range of pathogenic microorganisms. Inactivation efficacy results from plasma generated reactive species. These may interact with any organic components in a test matrix including the target microorganism, thus food components may exert a protective effect against the antimicrobial mode of action. The effect of an in-package high voltage ACP process applied in conjunction with common meat processing MAP gas compositions as well as bacteria type and meat model media composition have been investigated to determine the applicability of this technology for decontamination of safety challenges associated with meat …

Transfer Of Listeria Monocytogenes From Stainless Steel And High Density Polethylyene To Cold Smoked Salmon And Listeria Monocytogenes Biofilm Cohesive Energy Investigation, Fujia Zhang

Masters Theses 1911 - February 2014

Listeria monocytogenes is a major concern for the food industry. It is one of the major agents causing listeriosis. The objective of the first part of this study is to evaluate the effect of hydration level on attached listeria monocytogenes on stainless steel/High density polyethylene transferred to food products. Attached cells were prepared on stainless steel/High density polyethylene. Transfer experiments were conducted from inoculated surface material slides to cold smoked salmon fillets. This experiment was repeated 6 times. The results were analyzed with an analysis of variance by SAS. The differences between the different RH% and surface conditions were not …

Attachment Of Salmonella Typhimurium And Listeria Monocytogenes To Glass As Affected By Surface Film Thickness, Cell Density, And Bacterial Motility, James S. Dickson, E. K. Daniels

James S. Dickson

With equal cell densities, surface film thickness did not influence the numbers &Salmonella typhimurium and Listeria monocytogenes cells which attached to glass. Motile L. monocytogenes cells had a greater cell surface charge and generally attached in higher numbers than non-motile cells.