Microbiology Commons^™

Detection Of Microbial Growth In Aseptic Food Products Using Non-Invasive Tunable Diode Laser Absorption Spectroscopy (Tdlas), Peter Myintzaw, Nicholas Brian Johnson, Máire Begley, Michael J. Callanan

Department of Biological Sciences Publications

The sensitivity and reliability of Tunable Diode Laser Absorption Spectroscopy (TDLAS) for monitoring the growth of microorganisms in real food matrices was explored. The rapid and non-destructive TDLAS equipment uses laser light to monitor carbon dioxide changes due to microbial growth in the container head space which has the additional advantage of detecting contamination in products and packaging where visual inspection is not possible. TDLAS growth detection of Bacillus fengqiuensis, Candida albicans, Lactococcus lactis, Microbacterium luteolum, Paenibacillus chitinolyticus and Staphylococcus pasteuri was studied in various Ready To Feed (RTF) infant formula products. Detection of growth was correlated with cell numbers …

Psf Sampling In Fluorescence Image Deconvolution, Eric A. Inman

Master's Theses

All microscope imaging is largely affected by inherent resolution limitations because of out-of-focus light and diffraction effects. The traditional approach to restoring the image resolution is to use a deconvolution algorithm to “invert” the effect of convolving the volume with the point spread function. However, these algorithms fall short in several areas such as noise amplification and stopping criterion. In this paper, we try to reconstruct an explicit volumetric representation of the fluorescence density in the sample and fit a neural network to the target z-stack to properly minimize a reconstruction cost function for an optimal result. Additionally, we do …

The Role Of The Novel Diguanylate Cyclase Pg_0686 In Oxidative Stress Resistance In Porphyromonas Gingivalis W83, Alexia Danielle Ximinies

Loma Linda University Electronic Theses, Dissertations & Projects

The survival/ adaptation of Porphyromonas gingivalis to the inflammatory environment of the periodontal pocket requires an ability to overcome oxidative stress. Several functional classes of genes, depending on the severity and duration of the exposure, were induced in P. gingivalis under H2O2-induced oxidative stress, including the PG0686 gene which was upregulated ca. 10-fold. In addition, its upregulation was also observed in the presence of oxygen and nitric oxide. This study is aimed to further characterize the function of this gene in response to H2O2. PG_0686, annotated as a hypothetical protein of unknown function, is a 60 kDa protein with a …

Conformational Rearrangements In The Sensory Rcsf/Omp Complex Mediate Signal Transduction Across The Bacterial Cell Envelope, Sarah Rosemarie Lach Phd

Dissertations and Theses (Open Access)

Timely detection and repair of envelope damage are paramount for bacterial survival. The Regulator of Capsule Synthesis (Rcs) stress response is a complex signaling cascade that monitors gram-negative cell envelope integrity and can transduce the stress signals across the multilayered envelope to regulate gene expression in the cytoplasm. The outer membrane (OM) lipoprotein RcsF is the sensory component, but how RcsF functions remains elusive. RcsF interacts with the β-barrel assembly machinery (Bam) complex, which assembles RcsF in complex with OM proteins (OMPs), resulting in RcsF’s partial cell surface exposure. RcsF can also interact with the periplasmic domain of the negative …

The Kinetics Of Biocontaminant Inactivation: A Comparative Study With Bacillus Globigii And Bacillus Anthracis, Leigh M. Durden

Theses and Dissertations

Bacillus anthracis has been a biological threat for decades and after the 2001 terrorist attack via the U.S. Postal Service where five people died, there was heightened awareness and inquiry on the subject (Goel, 2015; Greenberg et al., 2010; Nicholson & Galeano, 2003; Spotts Whitney et al., 2003). The health risk to humans makes this biological agent, a Tier 1 agent and one of the most likely to be used in an attack (Anthrax as a Bioterrorism Weapon | CDC, n.d.; Driks, 2009; Rose & Rice, 2014). B. anthracis is one of most resistant and potent biological warfare agents as …

Detection And Capture Of Nitrogen Fixing Bacteria From Soil And Roots Using Plant Specific Lectins, Alana Horton

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Diazotrophs increase plant productivity by providing ammonia directly to plants in the rhizosphere or through association with the roots (Sun et al., 2021). Leveraging diazotrophs can aid in the reduction or application of harmful synthetic nitrogen fertilizers. This thesis aims to use plant root proteins, or lectins, to more rapidly recover viable diazotrophs that are likely to associate with crops. In this study, lectins, are used to recover bacteria from bulk soil by taking advantage of the binding relationship between lectins and bacterial cell surface polysaccharides. When commercially-available lectins were used with a magnetic pulldown to separate the lectin, bacterial …

The Immunomodulating Effects Of Delta-9 Tetrahydrocannabinol (Thc) And Cannabidiol (Cbd) In The Context Of Infection, Rose D. Goodman, Kate Rouse, Victor Jimenez

Annual Research Symposium

No abstract provided.

A Systematic Review: Toxoplasma Gondii Infection And Drugs Of Abuse, Amani Sastry

Annual Research Symposium

No abstract provided.

Comparison Of Two Diagnostic Assays For The Detection Of Serum Neutralizing Antibody To Porcine Epidemic Diarrhea Virus, Justin Brown, Korakrit Poonsuk, Ting-Yu Cheng, Chris Rademacher, Erin Kalkwarf, Liying Tian, Lauren A. Mckeen, Chong Wang, Luis Gimenez-Lirola, Gimenez-Lirola Baum, Locke A. Karriker

Nebraska Center for Virology: Faculty Publications

Lactogenic immunity is important for the protection of piglets against many pathogens including porcine epidemic diarrhea virus. Circulating neutralizing antibodies levels in sow sera may help determine if a detectable immune response could confer protection to piglets. Neutralizing antibodies can be detected through various diagnostic assays. This study evaluated the diagnostic characteristics of two neutralizing antibody assays for porcine epidemic diarrhea virus neutralizing antibodies in serum of challenged gilts. Four treatment groups, control, non-vaccinated, vaccinated prior to challenge, and vaccinated following challenge, were comprised of 20 gilts. Serum sample were collected from each gilt prior to and following challenge with …

Was Kaposi’S Sarcoma-Associated Herpesvirus Introduced Into China Via The Ancient Silk Road? An Evolutionary Perspective, Zhenqiu Liu, Qiwen Fang, Jialu Zuo, Veenu Minhas, Charles Wood, Na He, Tiejun Zhang

Nebraska Center for Virology: Faculty Publications

Kaposi’s sarcoma-associated herpesvirus (KSHV) has become widely dispersed worldwide since it was first reported in 1994, but the seroprevalence of KSHV varies geographically. KSHV is relatively ubiquitous in Mediterranean areas and the Xinjiang Uygur Autonomous Region, China. The origin of KSHV has long been puzzling. In the present study, we collected and analysed 154 KSHV ORF-K1 sequences obtained from samples originating from Xinjiang, Italy, Greece, Iran and southern Siberia using Bayesian evolutionary analysis in BEAST to test the hypothesis that KSHV was introduced into Xinjiang via the ancient Silk Road. According to the phylogenetic analysis, 72 sequences were subtype A …

Directed Carbapenemase Testing Is No Longer Just For Enterobacterales: Cost, Labor, And Workflow Assessment Of Expanding Carbapenemase Testing To Carbapenem-Resistant P. Aeruginosa, Fred C. Tenover, Christian M. Gill, Poonam Rajkotia, Amity L. Roberts, David P. Nicolau

Biology Faculty Publications

Molecular carbapenem-resistance testing, such as for the presence of carbapenemases genes, is commonly implemented for the detection of carbapenemase-producing Enterobacterales. Carbapenemase-producing P. aeruginosa is also associated with significant morbidity and mortality, although; prevalence may be underappreciated in the United States due to a lack of carbapenemase testing. The present study sought to compare hands-on time, cost and workflow implementation of carbapenemase gene testing in Enterobacterales and P. aeruginosa isolates versus sending out isolates to a public health laboratory (PHL) for testing to assess if in-house can provide actionable results. The time to carbapenemase gene results were compared. Differences in cost …

College Of Natural Sciences Newsletter, November 2022 - January 2023, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Volme 3, Issue 7

Page 1 Dean's Message
Page 2 Awards & Recognition
Page 3 Sioux Falls Middle School Visit
Page 4 Bio-Micro Day of Scholars
Page 5 GIS Day at USGS EROS
Page 6 Indigenous People's Festival, & Visiting Jack's Imagination Lab
Page 7 Media Coverage of CNS, & Research Highlights from Geography & Geospatial Sciences
Page 8 Media Coverage of CNS. cont.
Page 9 Open PRAIRIE Data
Page 10 Recent Publications from CNS
Page 11 Recent Publications from CNS. cont.
Page 12 CNS Holiday Snapshots
Page 13 & 14 Fall 2022 Dean's List
Page 12-14 Fall 2022 Outreach …

Evaluation Of Qpcr To Detect Shifts In Population Composition Of The Rhizobial Symbiont Mesorhizobium Japonicum During Serial In Planta Transfers, Kenjiro W. Quides, Yoobeen Lee, Teresa Hur, Hagop S. Atamian

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Microbial symbionts range from mutualistic to commensal to antagonistic. While these roles are distinct in their outcome, they are also fluid in a changing environment. Here, we used the Lotus japonicus–Mesorhizobium japonicum symbiosis to investigate short-term and long-term shifts in population abundance using an effective, fast, and low-cost tracking methodology for M. japonicum. We use quantitative polymerase chain reaction (qPCR) to track previously generated signature-tagged M. japonicum mutants targeting the Tn5 transposon insertion and the flanking gene. We used a highly beneficial wild type and moderately beneficial and non-beneficial mutants of M. japonicum sp. nov. to demonstrate the specificity …

From The Organismal To Biosphere Levels: Environmental Impacts On The Amphibian Microbiota, Obed Hernandez-Gomez, Jessica Hua

Natural Sciences and Mathematics | Faculty Scholarship

This review summarizes the role of environmental factors on amphibian microbiotas at the organismal, population, community, ecosystem, and biosphere levels. At the organismal-level, tissue source, disease status, and experimental manipulations were the strongest predictors of variation in amphibian microbiotas. At the population-level, habitat quality, disease status, and ancestry were commonly documented as drivers of microbiota turnover. At the community-level, studies focused on how species’ niche influence microbiota structure and function. At the ecosystem-level, abiotic and biotic reservoirs were important contributors to microbiota structure. At the biosphere-level, databases, sample banks, and semi-natural experiments were commonly used to describe microbiota assembly mechanisms …

Long‑Term Adaptation To Galactose As A Sole Carbon Source Selects For Mutations Outside The Canonical Gal Pathway, Artemiza A. Martínez, Andrew Conboy, Sean Buskirk, Daniel A. Marad, Gregory I. Lang

Biology Faculty Publications

Galactose is a secondary fermentable sugar that requires specific regulatory and structural genes for its assimilation, which are under catabolite repression by glucose. When glucose is absent, the catabolic repression is attenuated, and the structural GAL genes are fully activated. In Saccharomyces cerevisiae, the GAL pathway is under selection in environments where galactose is present. However, it is unclear the adaptive strategies in response to long-term propagation in galactose as a sole carbon source in laboratory evolution experiments. Here, we performed a 4,000-generation evolution experiment using 48 diploid Saccharomyces cerevisiae populations to study adaptation in galactose. We show that fitness …

Ifn-Γ Production By Brain-Resident Cells Activates Cerebral Mrna Expression Of A Wide Spectrum Of Molecules Critical For Both Innate And T Cell-Mediated Protective Immunity To Control Reactivation Of Chronic Infection With Toxoplasma Gondii, Yasuhiro Suzuki, Jenny Lutshumba, Kuey Chu Chen, Mohamed H. Abdelaziz, Qila Sa, Eri Ochiai

Markey Cancer Center Faculty Publications

We previously demonstrated that brain-resident cells produce IFN-g in response to reactivation of cerebral infection with Toxoplasma gondii. To obtain an overall landscape view of the effects of IFN-g from brain-resident cells on the cerebral protective immunity, in the present study we employed NanoString nCounter assay and quantified mRNA levels for 734 genes in myeloid immunity in the brains of T and B cell-deficient, bone marrow chimeric mice with and without IFN-g production by brain-resident cells in response to reactivation of cerebral T. gondii infection. Our study revealed that IFN-g produced by brain-resident cells amplified mRNA expression for the molecules …

Recombinant Protein Vaccines Formulated With Enantio-Specific Cationic Lipid R-Dotap Induce Protective Cellular And Antibody-Mediated Immune Responses In Mice, Siva Gandhapudi, Hua Shi, Martin Ward, John Peyton Bush, Margarita G. Avdiushko, Karuna Sundarapandiyan, Lauren V. Wood, Mania Dorrani, Afsheen Fatima, Joe Dervan, Frank Bedu-Addo, Greg Conn, Ted M. Ross, Jerold Woodward

Markey Cancer Center Faculty Publications

Adjuvants are essential components of subunit vaccines added to enhance immune responses to antigens through immunomodulation. Very few adjuvants have been approved for human use by regulatory agencies due to safety concerns. Current subunit vaccine adjuvants approved for human use are very effective in promoting humoral immune responses but are less effective at promoting T-cell immunity. In this study, we evaluated a novel pure enantio-specific cationic lipid 1,2-dioleoyl-3-trimethylammonium-propane (R-DOTAP) as an immunomodulator for subunit vaccines capable of inducing both humoral- and cellular-mediated immunity. Using recombinant protein antigens derived from SARS-CoV2 spike or novel computationally optimized broadly reactive influenza antigen (COBRA) …

Genetic Determinants Involved In Acquisition Of Iron In The Opportunistic Pathogen Mycobacterium Abscessus, Manal F. Farhat

Dissertations, Theses, and Capstone Projects

The opportunistic pathogen Mycobacterium abscessus subsp. abscessus (Mab) has become an emerging public health threat due to the increasing number of Mab-associated chronic pulmonary disease cases. Infection cure rates are only 50% due to the complex resistance of Mab to most antimicrobial drugs and chemotherapy.

Deeper knowledge of Mab biology is needed to illuminate potential candidates for development of improved therapeutics against Mab infections. The ESX-3 type VII protein secretion system of Mab plays an important role in host inflammatory and pathological responses during infection.

In this study, we demonstrate a functional link between the ESX-3 secretion …

The Immune Modulation On Innate Immunity, From Pathogen Recognition To Fungal Clearance., Ko-Wei Liu

Dartmouth College Ph.D Dissertations

The human lung is not sterile but a complex environment with various microorganisms. Besides commensals in the lung, hundreds to thousands of individual microbiomes enter the lung every day but without causing the symptom. Host innate immunity plays an important role in maintaining homeostasis of the lung environment and as the first defense line against pathogens. Aspergillus fumigatus (A. fumigatus) is a saprophytic filamentous fungus that can cause human disease in immune compromised patients. However, with functional innate immunity, immune cells can quickly recognize pathogen associated molecular patterns (PAMPs) from A. fumigatus through pattern recognition receptors (PRRs). The activation of …

Displaying And Delivering Viral Membrane Antigens Via Ww Domain–Activated Extracellular Vesicles, Sengjin Choi, Zhiping Yang, Qiyu Wang, Zhi Qiao, Maoyun Sun, Joshua Wiggins, Shi-Hua Xiang, Quan Lu

Nebraska Center for Virology: Faculty Publications

Membrane proteins expressed on the surface of enveloped viruses are conformational antigens readily recognized by B cells of the immune system. An effective vaccine would require the synthesis and delivery of these native conformational antigens in lipid membranes that preserve specific epitope structures. We have created an extracellular vesicle–based technology that allows viral membrane antigens to be selectively recruited onto the surface of WW domain–activated extracellular vesicles (WAEVs). Budding of WAEVs requires secretory carrier-associated membrane protein 3, which through its proline-proline-alanine-tyrosine motif interacts with WW domains to recruit fused viral membrane antigens onto WAEVs. Immunization with influenza and HIV viral …