Pathogenic Microbiology Commons^™

Enhancing Preparedness: A Genetic Study Of Sar-Cov-2 And Other Microbial Public Health Threats In Wastewater From A College Town, Christian N. Hutchinson

Master's Theses

Problem

The SARS-CoV-2 (COVID-19) pandemic revealed both the systemic vulnerabilities of our healthcare system as well as the importance of timely, localized data for informing public health responses. Traditional testing approaches were essential but often failed to capture the full extent of viral spread, especially in those with mild or asymptomatic conditions that relied on at home testing. This underreporting hindered effective allocation of resources and made developing effective intervention strategies difficult. We also realized the potential for wastewater surveillance to be applied to tracking antimicrobial resistance gene markers. Taken together, this approach should have important implications for improving public …

​ Soilborne Pathogens Of Strawberry In The Central Coast Region Of California: ​ Survey And Cover Cropping With Wheat For Management Of Macrophomina Phaseolina, Mary Steele

Master's Theses

Surveys of the four major soilborne pathogens of strawberry (Fusarium oxysporum f. sp. fragariae, Macrophomina phaseolina, Phytophthora spp., and Verticillium dahliae) to determine their relative prevalence were conducted in Watsonville-Salinas, CA in 2021 and in Santa Maria, CA in 2022. All four major pathogens were detected at relatively similar prevalence in Watsonville-Salinas, between 22% and 31% of sampled fields. In Santa Maria, M. phaseolina was far more prevalent at 52% of sampled fields, the other three falling between 14% and 17%. Additionally replicated greenhouse and field trials were conducted to evaluate the effects of wheat as …

Analysis Of Biofilm Remediation Capacity For Octenyl Succinic Anhydride (Osa), A Bioactive Food Starch Modifier Compound, Matthew R. Borglin

Master's Theses

Matthew R. Borglin

This thesis demonstrates efficacy of Octenyl Succinic Anhydride (OSA), as a biofilm sanitizer. Biofilms allow bacteria to adhere to solid surfaces with the use of excreted polymeric compounds. For example, surfaces found in food production or processing facilities such as the interior of a raw milk holding tank, are some of the most susceptible to biofilm contamination. When present, biofilms can cause a variety of negative effects, which include; reduction of product shelf life, corrosion, and outbreaks of foodborne illnesses. The close association of biofilms with the majority of foodborne illness cases led the US Environmental Protection …

Effectiveness Of Windrow Composting Methodology In Killing A Thermo-Tolerant Species Of Salmonella During Mortality Composting, Spencer Gabriel Myers

Master's Theses

In a large agricultural operation, such as the one at Cal Poly San Luis Obispo, disposal of deceased animals is an immense issue. The cost of transporting and rendering every dead animal is inhibitory to the general function of the agricultural operations and their thin budget. Therefore, we propose that composting mortalities could be an economical alternative. Composting is a recognized method for taking animal waste products along with carbon waste and turning it into a pathogen-free, nutrient-rich topsoil. Carcass composting is in fact performed in other countries and states to varying degrees of success. However, the California EPA limits …

The Effects Of Quorum Sensing And Temperature On The Soluble Proteome Of Vibrio Salmonicida, Christopher L. Massey

Master's Theses

Vibrio salmonicida causes cold-water vibriosis in salmon populations around the world and causes financial damage to fisheries designed to farm these salmon. Very little is known about the physiology of how V. salmonicida causes disease and measures to contain vibriosis are restricted to either vaccinating individual fish against disease or administering antibiotics when an outbreak is detected. These procedures are costly and increase the risk for selection of antibiotic-resistant V. salmonicida strains. A recent reoccurrence of outbreaks in Norwegian fisheries provided incentive to better understand the virulence mechanisms of V. salmonicida. In this thesis, a proteomic approach was used to …

Virulence Gene Expression Of Vibrio Parahaemolyticus In The Viable But Nonculturable State, Tiffany Pui-Yun Tse

Master's Theses

Vibrio parahaemolyticus is a food-borne pathogen commonly associated with the consumption of raw or undercooked seafood resulting in primary infections of the human gastrointestinal tract. It is estimated to cause about 4500 illnesses each year in the United States. However, infection from this food-borne pathogen can be avoided if this organism is detected in the implicated food, prior to consumption. Current standard methods of detecting this organism are dependent on the culturability of the bacteria. Detection based on an organism’s culturability may be problematic as V. parahaemolyticus has been known to exist in a viable but nonculturable (VBNC) state. Bacteria …

Methane Production By A Packed-Bed Anaerobic Digester Fed Dairy Barn Flush Water, Sean Richard Thomson

Master's Theses

Packed-bed digesters are an alternative to covered lagoon digesters for methane production and anaerobic treatment of dilute wastewaters such as dairy barn flush water. The physical media of packed-beds retain biofilms, often allowing increased treatment rates. Previous studies have evaluated several types of media for digestion of dilute wastewaters, but cost and media fouling have setback commercial development. A major operational cost has been effluent recirculation pumping.

In the present effort, a novel approach to anaerobic digestion of flush dairy water was developed at pilot-scale: broken walnut shells were used as a low-cost packed-bed medium and effluent recirculation was replaced …

Characterization Of Corynebacterium Pseudotuberculosis Biovar Equi Isolates Obtained From Cal Poly Horses And Review Of Application Of Transposons To Better Prevent Pigeon Fever In Horses, Irene Hasen

Animal Science

No abstract provided.

Detection Of Viable Microorganisms Using Propidium Monoazide, Erik J. Mcfarland, Adrian Ponce Dr.

STAR Program Research Presentations

Propidium monoazide (PMA) is a molecular tool used to assess viability of microorganisms. Currently, PMA is thought to discern viability through membrane permeability; PMA enters only membrane compromised cells, irreversibly crosslinks to theirDNAand precipitates theDNAout of solution, preventing it from being amplified during polymerase chain reaction (PCR). Using PMA on a sample of live and dead microorganisms results in only theDNAof living organisms being amplified and identified. Therefore, a comparison ofPCRresults with and without PMA allows one to determine the live fraction and total population, respectively.

Current literature provides conflicting evidence as to the effectiveness of the technique. Our research …

Impact Of Collateral Enlargement On Smooth Muscle Phenotype, Alexander Jerome Bynum

Master's Theses

Peripheral Artery Disease is a very serious disease characterized by an arterial occlusion due to atherosclerotic plaques. In response to an arterial occlusion, arteriogenesis occurs, causing smooth muscle cells to transition from a contractile to synthetic state. Also following an arterial occlusion, functional impairment was seen in the collateral circuit. An immunofluorescence protocol was developed in order to assess the impact of collateral enlargement (arteriogenesis) on smooth muscle phenotype at various time points. Smooth muscle α-actin was used to mark all smooth muscle cells, Ki-67 was used to label proliferating smooth muscle cells, and a fluorescent nuclear stain was used …

Synthesis Of An Antimicrobial Textile Coating, William M. Morris

Chemistry and Biochemistry

A titania nanosol was synthesized and coated onto nylon/cotton blended textile substrates. The substrates were characterized via SEM for adhesion and nanoparticle formation, then subjected to antimicrobial efficacy tests. The titania nanosol was successfully coated on to textiles samples. Particles were observed to be around 2 by 3 micrometers and formed between the interstitial space of textile fibers. Although larger than typical nanoparticles, the coatings exhibited what seemed to be antimicrobial activity. Titania nanosol coated textile samples were subjected to Kirby Bauer Assay in the presence of S. aureus. The coated textile sample exhibited an inhibition of growth around its …