Food Microbiology Commons^™

Effects Of Fermented Soybean Products On The Human Gut Microbiome, Microbial Metabolism, And Host Physiology, Shannon Moncier

Biology Dissertations

Fermented soybean products (FSPs) contain soybean-derived substrates, fermentation-associated microorganisms, and bioactive compounds that may interact with the human gut microbiome and host physiology. However, despite the growing interest in FSPs, longitudinal human studies specifically evaluating traditional Korean-FSPs (K-FSPs), particularly among United States-based populations, remain limited. The objective of this work was to evaluate the effects of three K-FSPs, including Cheonggukjang, Gochujang, and Doenjang, on host physiological responses, gut microbial community structure, predicted microbial functional potential, and fecal butyrate responses in healthy adults. Three independent dietary intervention cohorts were conducted using FSP formulations produced either by traditional artisan methods (Product A) …

Using Bivalves As An Indicator For Fecal Bacteria, Kamala Chuss

Honors Scholar Theses

This project focuses on the integration of fecal bacteria from warm-blooded animals into bivalve tissue, and the utilization of bivalves as an indicator for fecal bacteria in waterways. Bivalves may give a more representative long-term average of fecal bacteria in water as compared to direct water testing. The primary objective is to create a standard operating procedure to use bacterial testing of bivalves as a proxy for bacteria concentration in the water. This method can be used in places where bivalves do not already exist by adding them to a body of water, or by collecting bivalves that already exist …

Multidrug-Resistant Esbl-Producing Escherichia Coli Coexisting With Colistin-Resistance Genes In Pig Farms, Central Thailand, Wipawee Songsaeng, Nutthee Am-In, Nuvee Prapasarakul, Wandee Sirichokchatchawan

The Thai Journal of Veterinary Medicine

The presence of extended-spectrum beta-lactamase and colistin resistance E. coli in food-producing animals is a public health concern. This study was conducted using a rigorous methodology to survey the prevalence of ESBL-producing and colistin-resistant E. coli from pig farms in the central part of Thailand. A total of 519 samples were collected from fecal, feed, and waste in 53 farms located in central Thailand. All samples were inoculated onto selective agar, and species identification was performed using biochemical assays and MAlDI-TOF MS. Antimicrobial susceptibility was determined by broth microdilution, and ESBL production was confirmed by the combination disc diffusion method. …

Reducing Food Scarcity: The Benefits Of Urban Farming, S.A. Claudell, Emilio Mejia

Journal of Nonprofit Innovation

Urban farming can enhance the lives of communities and help reduce food scarcity. This paper presents a conceptual prototype of an efficient urban farming community that can be scaled for a single apartment building or an entire community across all global geoeconomics regions, including densely populated cities and rural, developing towns and communities. When deployed in coordination with smart crop choices, local farm support, and efficient transportation then the result isn’t just sustainability, but also increasing fresh produce accessibility, optimizing nutritional value, eliminating the use of ‘forever chemicals’, reducing transportation costs, and fostering global environmental benefits.

Imagine Doris, who is …

Developing Disinfection Strategies For Controlling Human Norovirus, Sars-Cov-2, And Clostridioides Difficile Endospores In Long-Term Care Facilities, Jinge Huang

All Dissertations

Long-term care facilities (LTCFs) provide an environment favorable for the transmission of three critical human pathogens: human norovirus (HuNoV), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and Clostridioides difficile. Given residents in LTCFs are susceptible to infections due to their advanced ages and compromised immune systems, effective environmental surface disinfection plays a crucial role in controlling the spread of human pathogens within these settings and, therefore, mitigates the risk of infections caused by these pathogens. This dissertation aimed to assess the efficacy of various types of disinfectants against two HuNoV surrogates [feline calicivirus (FCV) and Tulane virus (TuV)], two …

Effect Of Authentic Kefir And Nigella Sativa On Broilers Challenged By Coccidia And Clostridium Perfringens, Julian E. Nixon

All Dissertations

Black seed oil concentrations of 0%, 0.1%, 1% and 5% were added to milk inoculated with kefir grains and incubated at 25°C for 22 h. The pH and microbial count indicated 1% black seed oil caused low inhibition (P > 0.05) of fermentation, but 5% black seed oil caused significant inhibition of the kefir microorganisms (P < 0.05).

Cobb 500 male chicks (n = 256) were distributed in a randomized block design and received one of four treatments: CTRL1 (Non-medicated, no kefir, no Clostridium perfringens), CTRL2 (Non-medicated, no kefir, C. perfringens inoculated), CTRL3 (BMD medicated, no kefir, C. perfringens inoculated), KTRT (Non-medicated, …

Inhibiting Survival Of Salmonella During Desiccation Through The Use Of Naturally Occurring Signals, Joseph Headrick

Electronic Theses and Dissertations

A rising problem in agriculture is the increase of antibiotic-resistant Salmonella cases associated with chicken eggs, which transmit infection to humans. To counter this, new approaches to combat Salmonella in chickens and desiccated on eggshells are vital in the prevention of human foodborne illness. Disrupting signaling pathways with naturally occurring compounds provides a potential novel avenue for prevention of Salmonella infections, as this would disrupt sensing of these environments and inhibit subsequent optimal gene expression. Starting with signals identified in previous studies, salicylic acid was found to inhibit Salmonella desiccation survival on both eggshells and plastic. To expand upon this, …

Evaluation Of Welded And Polished Stainless-Steel Surfaces In Supporting Sporeformer Biofilms In Dairy Plants, Taghreed Almalki

Electronic Theses and Dissertations

No abstract provided.

Allelopathic Effect Of Cereal Straw Extracts On Growth Of Raphidocelis Subcapitata And Microcystis Aeruginosa, Holly Wren

Graduate Theses and Dissertations

Harmful algal blooms are increasing in size, duration, and intensity around the globe. For several decades, cereal straws have been recognized as a viable algal control method, though the mechanisms by which cereal straws inhibit algae remain a topic of research. The objectives of this study were to evaluate the effectiveness of decomposing cereal straw extract, particularly rice (Oryza sativa) and barley (Hordeum vulgare) straw extract, to inhibit the green alga Raphidocelis subcapitata or cyanobacteria Microcystis aeruginosa in bioassays and to determine if the effectiveness of decomposing rice straw extract is altered by the presence of natural organic matter or …

Effect Of Environmental Factors And Residual Sanitizers On Survival And Attachment Of Indicator Organism And Human Pathogens On Fresh Produce, Vijay Singh Chhetri

LSU Doctoral Dissertations

A comprehensive understanding of the behavior of microbial contaminants on produce surfaces in agricultural farms and during post-harvest activities is essential for the development of produce safety risk management strategies. Our studies investigated the survival and the attachment of E. coli on watermelon surfaces in agricultural settings with different levels of vegetation, and the effect of residual sanitizers on the survival and the attachment of E. coli O157: H7 and L. monocytogenes on spinach leaves. The attachment strength (S_R) of the E. coli cells on watermelon surfaces significantly increased (P<0.05) from 0.04 to 0.99 in the first 24 h, which was primarily due to the decrease in loosely attached population, given that the population of strongly attached cells was constant. The daily die-off rate of E. coli ranged from -0.12 …

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 …

Fungi In The Healthy Human Gastrointestinal Tract, Heather E. Hallen-Adams, Mallory J. Suhr

Department of Food Science and Technology: Faculty Publications

Many species of fungi have been detected in the healthy human gut; however, nearly half of all taxa reported have only been found in one sample or one study. Fungi capable of growing in and colonizing the gut are limited to a small number of species, mostly Candida yeasts and yeasts in the family Dipodascaceae (Galactomyces, Geotrichum, Saprochaete). Malassezia and the filamentous fungus Cladosporium are potential colonizers; more work is needed to clarify their role. Other commonly-detected fungi come from the diet or environment but either cannot or do not colonize (Penicillium and Debaryomyces species, which are …

From Milpas To The Market: A Study On The Use Of Metal Silos For Safer And Better Storage Of Guatemalan Maize, José Rodrigo Mendoza

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

This project aimed to implement the use of metal silos to improve quality and safety of maize consumed by inhabitants of the highlands of Guatemala. This manuscript includes a literature review of the maize production chain in Guatemala, a survey about agricultural practices used in the region of study, as well as a characterization of the analyzed maize regarding its mycoflora, nutritional composition, and insect infestation. To better understand the current situation regarding agricultural practices and maize consumption, a survey was carried out. Sample consisted of 280 families representing 14 rural communities distributed in the townships of Todos Santos and …

An Analysis Of Bacterial Contamination Of Chicken Eggs And Antimicrobial Resistance, Holly Spitzer

All College Thesis Program, 2016-2019

Chicken eggs are a major component of American diets, with an average yearly consumption of approximately 250 eggs per person (American Humane Society). While highly nutritious, eggs are also one of the leading causes of food poisoning and food borne illness in the United States. Eggs may become contaminated by a number of different types of bacteria during production, including Salmonella, a group of bacteria that, according to the CDC, causes more than 1.2 million cases of food borne illness in the United States every year. In an effort to decrease the frequency of bacterial contamination, many food producers …

A Tail Of Two Phages: Genomic And Functional Analysis Of Listeria Monocytogenes Phages Vb_Lmos_188 And Vb_Lmos_293 Reveal The Receptor-Binding Proteins Involved In Host Specificity, Aidan Casey, Kieran Jordan, Horst Neve, Aidan Coffey, Olivia Mcauliffe

Department of Biological Sciences Publications

The physical characteristics of bacteriophages establish them as viable candidates for downstream development of pathogen detection assays and biocontrol measures. To utilize phages for such purposes, a detailed knowledge of their host interaction mechanisms is a prerequisite. There is currently a wealth of knowledge available concerning Gram-negative phage-host interaction, but little by comparison for Gram-positive phages and Listeria phages in particular. In this research, the lytic spectrum of two recently isolated Listeria monocytogenes phages (vB_LmoS_188 and vB_LmoS_293) was determined, and the genomic basis for their observed serotype 4b/4e host-specificity was investigated using comparative genomics. The late tail genes of these …

Prokaryotic Diversity In The Rhizosphere Of Organic, Intensive, And Transitional Coffee Farms In Brazil, Adam Caldwell, Livia Silva, Cynthia Da Silva, Cleber Ouverney

Faculty Publications, Biological Sciences

Despite a continuous rise in consumption of coffee over the past 60 years and recent studies showing positive benefits linked to human health, intensive coffee farming practices have been associated with environmental damage, risks to human health, and reductions in biodiversity. In contrast, organic farming has become an increasingly popular alternative, with both environmental and health benefits. This study aimed to characterize and determine the differences in the prokaryotic soil microbiology of three Brazilian coffee farms: one practicing intensive farming, one practicing organic farming, and one undergoing a transition from intensive to organic practices. Soil samples were collected from 20 …

Concomitant Uptake Of Antimicrobials And Salmonella In Soil And Into Lettuce Following Wastewater Irrigation, J. Brett Sallach, Yuping Zhang, Laurie Hodges, Daniel D. Snow, Xu Li, Shannon L. Bartelt-Hunt

Department of Civil and Environmental Engineering: Faculty Publications

The use of wastewater for irrigation may introduce antimicrobials and human pathogens into the food supply through vegetative uptake. The objective of this study was to investigate the uptake of three antimicrobials and Salmonella in two lettuce cultivars. After repeated subirrigation with synthetic wastewater, lettuce leaves and soil were collected at three sequential harvests. The internalization frequency of Salmonella in lettuce was low. A soil horizon-influenced Salmonella concentration gradient was determined with concentrations in bottom soil 2 log CFU/g higher than in top soil. Lincomycin and sulfamethoxazole were recovered from lettuce leaves at concentrations as high as 822 ng/g and …

Understanding The Factors Affecting Microbiological Quality Of Wheat Milled Products: From Wheat Fields To Milling Operations, Luis E. Sabillón Galeas

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

Although regarded as a low-risk commodity, wheat flour-based mixes have been implicated in several food safety incidents. The present thesis is a compilation of five scientific manuscripts on the effect of weather variation, milling steps and implementation of pre-milling interventions on the microbiological quality and safety of wheat and milled products. The first manuscript is a review of the microbiological quality and safety of wheat-based products. Despite the low water activity, wheat flour may harbor dormant but viable microorganisms, which could lead to safety concerns when flour is used to produce refrigerated dough products. The second manuscript illustrates the effect …

Investigating Antibiotic Resistance Levels Of Salmonella Internalized In Lettuce Leaves, Jason B. Thomas

McNair Scholars Research Journal

Contamination of food crops by the human pathogen Salmonella is a food safety threat worldwide. Though using treated wastewater for irrigation is a sustainable practice, it may introduce trace levels of Salmonella that may contaminate food crops. Salmonella could develop resistance to antibiotics present in wastewater. The overall goal of the project is to increase the understanding of the public health risk associated with the use of treated wastewater to irrigate food crops. The objective of this particular study is to determine the antibiotic resistance level of Salmonella internalized in lettuce leaves. In this experiment, thirty-six plants of the lettuce …

Transcriptome Analysis Of Listeria Monocytogenes Exposed To Biocide Stress Reveals A Multi-System Response Involving Cell Wall Synthesis, Sugar Uptake, And Motility, Aidan Casey, Edward M. Fox, Stephan Schmitz-Esser, Aidan Coffey, Olivia Mcauliffe, Kieran Jordan

Department of Biological Sciences Publications

Listeria monocytogenes is a virulent food-borne pathogen most often associated with the consumption of “ready-to-eat” foods. The organism is a common contaminant of food processing plants where it may persist for extended periods of time. A commonly used approach for the control of Listeria monocytogenes in the processing environment is the application of biocides such as quaternary ammonium compounds. In this study, the transcriptomic response of a persistent strain of L. monocytogenes (strain 6179) on exposure to a sub-lethal concentration of the quaternary ammonium compound benzethonium chloride (BZT) was assessed. Using RNA-Seq, gene expression levels were quantified by sequencing …

Phages Of Non-Diary Lactococci: Isolation And Characterization Of Phi L47, A Phage Infecting The Grass Isolate Lactococcus Lactis Ssp Cremoris Dpc6860, Daniel Cavanagh, Caitríona M. Guinane, Horst Neve, Aidan Coffey, R. Paul Ross, Gerald F. Fitzgerald, Olivia Mcauliffe

Department of Biological Sciences Publications

Lactococci isolated from non-dairy sources have been found to possess enhanced metabolic activity when compared to dairy strains. These capabilities may be harnessed through the use of these strains as starter or adjunct cultures to produce more diverse flavor profiles in cheese and other dairy products. To understand the interactions between these organisms and the phages that infect them, a number of phages were isolated against lactococcal strains of non-dairy origin. One such phage, ΦL47, was isolated from a sewage sample using the grass isolate L. lactis ssp. cremoris DPC6860 as a host. Visualization of phage virions by transmission electron …

Analysis Of Microbial Diversity By Amplicon Pyrosequencing, Ryan Legge

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

Microorganisms numerically dominate terrestrial biodiversity, and play important biochemical and geochemical roles in the environments they inhabit. To understand structure and function of complex ecosystems, it is essential to identify primary drivers of microbial diversity and community structure. Historically, the study of microbial ecology was reductive, limited to microbes able to be cultured and enumerated. Microbes meeting this criterion were thought to comprise the dominating members of the environments they were isolated from, however, estimates suggesting up to 99% of the endogenous species are uncultivable with existing methodologies; a concept that reflects experimental failure, rather than a verifiable conclusion. Therefore …

Letter From The Dean, Lalit Verma

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

Integronlike Structures In Campylobacter Spp. Of Human And Animal Origin, Brigid Lucey, D. Crowley, P. Moloney, B. Cryan, M. Daly, F. O'Halloran, E. J. Threlfall, S. Fanning

Department of Biological Sciences Publications

Resistance to antimicrobial agents used to treat severe Campylobacter spp. gastroenteritis is increasing worldwide. We assessed the antimicrobial resistance patterns of Campylobacter spp. isolates of human and animal origin. More than half (n = 32) were resistant to sulphonamide, a feature known to be associated with the presence of integrons. Analysis of these integrons will further our understanding of Campylobacter spp. epidemiology.