Other Microbiology Commons^™

Mobile Genetic Elements Shape Microbial Diversity And Functions In Thawing Permafrost Soils, Jiarong Guo, Samuel T. N. Aroney, Guillermo Domínguez-Huerta, Derek Smith, Dean Vik, Carlos Owusu-Ansah, Akbar Adjie Pratama, Sergei Solonenko, Funing Tian, Cristina Howard-Varona, Zhi-Ping Zhong, Aminata Fofana, Garrett J. Smith, Suzanne B. Hodgkins, Dylan Cronin, Isogenie Field Teams 2010–2017, 2019, Emerge Coordinators, Ben J. Woodcroft, Gene W. Tyson, Virginia I. Rich, Matthew B. Sullivan, Simon Roux, Sarah C. Bagby, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Ecosystems are shaped by communities of microorganisms whose niches and impacts depend on functional profiles influenced by gene gains and losses. Culture-based experiments demonstrate that mobile genetic elements (MGEs) can mediate gene flux, but quantitative understanding of these dynamics in natural systems remains limited. Here we develop and apply a systematic, meta-omic framework to investigate MGEs in a complex natural system using an 8-year soil time series collected at Stordalen Mire, in Sweden’s thawing permafrost margin. In this climate-critical peatland, we identify ~2.1 million MGE recombinases across 89 microbial phyla and assess ecological distributions, affected functions, past mobility and current …

Promiscuous Mutualisms: John Dupré And The Centrality Of Symbiosis In The Living World, Thomas Pradeu

Presidential Fellows Articles and Research

My goal in this chapter is to show that symbiosis, especially symbiotic interactions between ‘macrobes’ (non-microbial organisms) and microbes, is a central topic in John Dupré’s work. This topic is undeniably one of the topics by which Dupré has gained wide recognition among practicing scientists, in addition to his recognition within the philosophical community. I spell out why symbiosis has turned out to be a sort of ideal trope for Dupré, as it encapsulates many of his main personal themes—from promiscuous realism to process ontology. I then show that immunology offers one interesting and complementary entry point into microbial symbiosis …

Enhanced Meropenem Activity And Stability Following Load In Polyvinyl Alcohol Nanofiber Scaffolds With Sitagliptin As Quorum Sensing Inhibitor On Pseudomonas Aeruginosa, Samar A. Salim, Abdelrhman Mohsen, Mohamed Emara, Taghrid Elmahdy

Nanotechnology Research Centre

Background The increasing resistance of bacteria to conventional antibiotics poses a significant health challenge. Innovative strategies, such as combining antibiotics with agents like quorum sensing inhibitors (QSIs), have been developed to combat this issue. QSIs enhance antibiotic efficacy without inhibiting bacterial growth, minimizing the risk of resistance. Aims Evaluate the combined effect of Sitagliptin (STG) as a QSI with Meropenem (MER), fabricate drug-loaded Polyvinyl Alcohol (PVA) nanofibers, and investigate their antimicrobial activity against standard Pseudomonas aeruginosa (PAO1) and carbapenem-resistant P. aeruginosa (CRPA). Methods The combinatorial effect was assessed using a checkerboard assay. PVA/STG, PVA/MER, and PVA/STG/ MER nanofibers were fabricated …

Expression, Characterization, And Comparative Analysis Of Bacillus Bacteriophage Endolysins, Stephen D. Zdgiebloski

Research and Creativity Symposium

Bacteriophages present a promising alternative for combating antibiotic-resistant bacteria without disrupting the normal microbiome or harming human cells. The antibacterial properties of lytic bacteriophages are largely attributed to endolysins, enzymes active in the lytic cycle. Endolysins recognize bacterial cell walls and cleave the peptidoglycan matrix, leading to cell wall disruption. Their specificity and effectiveness against bacterial hosts are determined by two functional domains, including the cell wall binding domain. Our research focuses on characterizing Bacillus phage endolysins. We analyzed the protein sequences of endolysins from six Bacillus phages isolated at the University of Mary Washington. Although these phages were isolated …

The Absence Of Cxcl10 Activity Does Not Affect The Capability Of Cd8+ T Cells To Migrate And Eliminate The Tissue Cysts Of Toxoplasma Gondii From The Brains Of Chronically Infected Mice, Rajesh Mani, Yasuhiro Suzuki

Markey Cancer Center Faculty Publications

Toxoplasma gondii forms tissue cysts in neurons and astrocytes in the brain to establish chronic infection, and astrocytes express the CXCL10 chemokine in chronically infected mice. Since chemokines mediate the migration of T cells to attack their targets, and since CXCL10 plays key roles in T cell-mediated control of the proliferation of tachyzoites (the acute stage form) of T. gondii during the acute stage of infection, we examined whether CXCL10 is involved in recruiting anti-cyst CD8+ cytotoxic T cells to eliminate the cysts in their brains. We employed adoptive transfer of CD8+ immune T cells to infected, T cell-deficient SCID …

The Role Of Efflux Pump Inhibitor In Enhancing Antimicrobial Efficiency Of Silver Nanoparticles And Methylene Blue As An Effective Photodynamic Therapy Agent, Yaran Allamyradov

Masters Theses & Specialist Projects

Efflux pumps are critical active transport systems utilized by cells to expel toxic substances, including antibiotics and photosensitizer complexes, thereby contributing to antimicrobial resistance. Efflux pump inhibitors (EPIs), which are compounds that obstruct the transport of molecules through these pumps, play a pivotal role in enhancing the effectiveness of antimicrobial therapies against pathogens. This study investigates the effects of the EPI reserpine on the photodeactivation rate of pathogens when used in conjunction with silver nanoparticles (Ag NPs) and methylene blue (MB), a common photosensitizer.

Our research reveals that the application of reserpine, in combination with Ag NPs and MB, leads …

Staphylococcus Aureus Oleate Hydratase Produces Ligands That Activate Host Ppara, Christopher D. Radka, Matthew W. Frank, Tyler S. Simmons, Cydney N. Johnson, Jason W. Rosch, Charles O. Rock

Markey Cancer Center Faculty Publications

Commensal gut bacteria use oleate hydratase to release a spectrum of hydroxylated fatty acids using host-derived unsaturated fatty acids. These compounds are thought to attenuate the immune response, but the underlying signaling mechanism(s) remain to be established. The pathogen Staphylococcus aureus also expresses an oleate hydratase and 10- hydroxyoctadecanoic acid (h18:0) is the most abundant oleate hydratase metabolite found at Staphylococcal skin infection sites. Here, we show h18:0 stimulates the transcription of a set of lipid metabolism genes associated with the activation of peroxisome proliferator activated receptor (PPAR) in the RAW 264.7 macrophage cell line and mouse primary bone marrow-derived …

The Development And Evaluation Of A Method For Complete Collagenase I Digestion Of Bos Taurus Bone Samples, Reilly Price

Master of Science in Forensic Science Directed Research Projects

Current methods for processing aged forensic bone samples for DNA analysis involve pulverization and organic extraction, which further destroys already degraded DNA and uses large amounts of limited samples. Additionally, the success rates for this type of analysis vary widely as homogenization incorporates PCR inhibitors into the sample. Little research has explored how pulverization results in DNA damage in profiles obtained from skeletal remains. This study proposes an enzymatic digestion method to separate osteocytes from PCR inhibitors in the extracellular bone matrix to improve the quality and quantity of DNA isolated from aged bone samples. The technique described here used …

What Is Microbial Dormancy?, Mark D. Mcdonald, Carlos Owusu-Ansah, Jared B. Ellenbogen, Zachary D. Malone, Michael P. Ricketts, Steve E. Frolking, Jessica Gilman Ernakovich, Michael Ibba, Sarah C. Bagby, J. L. Weissman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Life can be stressful. One way to deal with stress is to simply wait it out. Microbes do this by entering a state of reduced activity and increased resistance commonly called ‘dormancy’. But what is dormancy? Different scientific disciplines emphasize distinct traits and phenotypic ranges in defining dormancy for their microbial species and system-specific questions of interest. Here, we propose a unified definition of microbial dormancy, using a broad framework to place earlier discipline-specific definitions in a new context. We then discuss how this new definition and framework may improve our ability to investigate dormancy using multi-omics tools. Finally, we …

Protocol For Optimizing Production And Quality Control Of Infective Ecohiv Virions, Hammodah Rawhi Hammodah Alfar, Daphne N. Pariser, Harry Chanzu, Smita Joshi, Daniёlle M. Coenen, Joshua Lykins, Kanakanagavalli Shravani Prakhya, Mary Jane Potash, Wei Chao, Jennifer Kelschenbach, David J. Volsky, Kelly Metcalf-Pate

Saha Cardiovascular Research Center Faculty Publications

EcoHIV is a model of HIV infection that recapitulates aspects of HIV-1 pathology in mice. However, there are limited published protocols to guide EcoHIV virion production. Here, we present a protocol for producing infective EcoHIV virions and essential quality controls. We describe steps for viral purification, titering, and multiple techniques to analyze infection efficacy. This protocol produces high infectivity in C57BL/6 mice which will aid investigators in generating preclinical data.

The Unique Gut Microbiome Of Giant Pandas Involved In Protein Metabolism Contributes To The Host's Dietary Adaption To Bamboo, Feilong Deng, Chengdong Wang, Desheng Li, Yunjuan Peng, Linhua Deng, Yunxiang Zhao, Zhihao Zhang, Ming Wei, Kai Wu, Jiangchao Zhao, Ying Li

Animal Science Faculty Publications and Presentations

Background

The gut microbiota of the giant panda (Ailuropoda melanoleuca), a global symbol of conservation, are believed to be involved in the host’s dietary switch to a fibrous bamboo diet. However, their exact roles are still largely unknown.

Results

In this study, we first comprehensively analyzed a large number of gut metagenomes giant pandas (n = 322), including 98 pandas sequenced in this study with deep sequencing (Illumina) and third-generation sequencing (nanopore). We reconstructed 408 metagenome-assembled genomes (MAGs), and 148 of which (36.27%) were near complete. The most abundant MAG was classified as Streptococcus alactolyticus. A …

Exploring Experimental Design And Multivariate Analysis Techniques For Evaluating Community Structure Of Bacteria In Microbiome Data, Kelsey Karnik

Department of Statistics: Dissertations, Theses, and Student Research

The gut microbiome plays a crucial role in human health, and by working collaboratively with microbiologists, we aim to further our understanding of the human gut and its impact on human health. Promoting a diverse microbiome is emphasized throughout microbiology literature, and involving a statistician in designing experiments to relate gut bacteria and some measured health outcome is crucial for ensuring valid and accurate results. By adopting new experimental design and analysis methods, researchers can begin to gain a deeper understanding of how the genetics of our food affect the composition of taxa within the gut microbiome. This dissertation is …

Development, Optimization, And In Vitro/In Vivo Evaluation Of Azelaic Acid Transethosomal Gel For Antidermatophyte Activity, Ali Nasr, Noha Badawi, Yasmine Tartor, Nader Sobhy, Ali Nasr

Pharmacy

Treatment of dermatophytosis is quite challenging. This work aims to investigate the antidermatophyte action of Azelaic acid (AzA) and evaluate its efficacy upon entrapment into transethosomes (TEs) and incorporation into a gel to enhance its application. Optimization of formulation variables of TEs was carried out after preparation using the thin film hydration technique. The antidermatophyte activity of AzA-TEs was first evaluated in vitro. In addition, two guinea pig infection models with Trichophyton (T.) mentagrophytes and Microsporum (M.) canis were established for the in vivo assessment. The optimized formula showed a mean particle size of 219.8 ± 4.7 nm and a …

Rapid Bacterial And Fungal Successional Dynamics In First Year After Chaparral Wildfire, M. Fabiola Pulido-Chavez, James W. J. Randolph, Cassandra A. Zalman, Loralee Larios, Peter M. Homyak, Sydney I. Glassman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The rise in wildfire frequency and severity across the globe has increased interest in secondary succession. However, despite the role of soil microbial communities in controlling biogeochemical cycling and their role in the regeneration of post-fire vegetation, the lack of measurements immediately post-fire and at high temporal resolution has limited understanding of microbial secondary succession. To fill this knowledge gap, we sampled soils at 17, 25, 34, 67, 95, 131, 187, 286, and 376 days after a southern California wildfire in fire-adapted chaparral shrublands. We assessed bacterial and fungal biomass with qPCR of 16S and 18S and richness and composition …

Functional Characterization Of Mycobacterium Smegmatis Phage Moomoo Gene Products: Identification Of Toxic Genes, Whitney Heard

Masters Theses & Specialist Projects

Mycobacteriophages are a group of phages that infect members of the genus Mycobacteria. Previous studies have conducted extensive comparisons of the mycobacteriophage genomes and amino acid sequences to establish different phage families. MooMoo is a singleton mycobacteriophage that has been characterized due to its lack of appreciable homology to other phages. Some of its unique properties include its structure and the isolation of a mutant that causes clear plaque phenotypes. The experiments described in this thesis identified three MooMoo phage (gp87, gp90, and gp91) encoded proteins that are toxic to the bacterial host, Mycobacterium smegmatis.Through the use of a …

The Coxsackievirus And Adenovirus Receptor Has A Short Half-Life In Epithelial Cells, Poornima Kotha Lakshmi Narayan, James M. Readler, Mahmoud S. Alghamri, Trisha L. Brockman, Ray Yan, Priyanka Sharma, Vladislav Snitsarev, Katherine J.D.A Excoffon, Abimbola O. Kolawole

Department of Biology Faculty Scholarship and Creative Works

The coxsackievirus and adenovirus receptor (CAR) is an essential cellular protein that is involved in cell adhesion, cell signaling, and viral infection. The 8-exon encoded isoform (CAREx8) resides at the apical surface of polarized epithelia, where it is accessible as a receptor for adenovirus entering the airway lumen. Given its pivotal role in viral infection, it is a target for antiviral strategies. To understand the regulation of CAREx8 and determine the feasibility of receptor down regulation, the half-life of total and apical localized CAREx8 was determined and correlated with adenovirus transduction. Total and apical CAREx8 has a relatively short half-life …

Characterizing The Amino Acid Activation Center Of The Naturally Editing-Deficient Aminoacyl-Trna Synthetase Phers In Mycoplasma Mobile, Nien-Ching Han, Arundhati Kavoor, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

To ensure correct amino acids are incorporated during protein synthesis, aminoacyl-tRNA synthetases (aaRSs) employ proofreading mechanisms collectively referred to as editing. Although editing is important for viability, editing-deficient aaRSs have been identified in host-dependent organisms. In Mycoplasma mobile, editing-deficient PheRS and LeuRS have been identified. We characterized the amino acid activation site of MmPheRS and identified a previously unknown hyperaccurate mutation, L287F. Additionally, we report that m-Tyr, an oxidation byproduct of Phe which is toxic to editing-deficient cells, is poorly discriminated by MmPheRS activation and is not subjected to editing. Furthermore, expressing MmPheRS and the hyperaccurate variants renders …

Oxidation Alters The Architecture Of The Phenylalanyl-Trna Synthetase Editing Domain To Confer Hyperaccuracy, Pooja Srinivas, Rebecca E. Steiner, Ian J. Pavelich, Ricardo Guerrera-Ferreira, Puneet Juneja, Michael Ibba, Christine M. Dunham

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

High fidelity during protein synthesis is accomplished by aminoacyl-tRNA synthetases (aaRSs). These enzymes ligate an amino acid to a cognate tRNA and have proofreading and editing capabilities that ensure high fidelity. Phenylalanyl-tRNA synthetase (PheRS) preferentially ligates a phenylalanine to a tRNA^Phe over the chemically similar tyrosine, which differs from phenylalanine by a single hydroxyl group. In bacteria that undergo exposure to oxidative stress such as Salmonella enterica serovar Typhimurium, tyrosine isomer levels increase due to phenylalanine oxidation. Several residues are oxidized in PheRS and contribute to hyperactive editing, including against mischarged Tyr-tRNA^Phe, despite these oxidized residues not …

Role Of A Cryptic Trna Gene Operon In Survival Under Translational Stress, Javier Santamaría-Gómez, Miguel Ángel Rubio, Rocío López-Igual, Ana B. Romero-Losada, Fernando M. Delgado-Chaves, Roque Bru-Martínez, Francisco J. Romero-Campero, Antonio Herrero, Michael Ibba, Jesús A. G. Ochoa De Alda, Ignacio Luque

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

As compared to eukaryotes, bacteria have a reduced tRNA gene set encoding between 30 and 220 tRNAs. Although in most bacterial phyla tRNA genes are dispersed in the genome, many species from distinct phyla also show genes forming arrays. Here, we show that two types of arrays with distinct evolutionary origins exist. This work focuses on long tRNA gene arrays (L-arrays) that encompass up to 43 genes, which disseminate by horizontal gene transfer and contribute supernumerary tRNA genes to the host. Although in the few cases previously studied these arrays were reported to be poorly transcribed, here we show that …

Deacylated Trna Accumulation Is A Trigger For Bacterial Antibiotic Persistence Independent Of The Stringent Response, Whitney N. Wood, Kyle Mohler, Jesse Rinehart, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Bacterial antibiotic persistence occurs when bacteria are treated with an antibiotic and the majority of the population rapidly dies off, but a small subpopulation enters into a dormant, persistent state and evades death. Diverse pathways leading to nucleoside triphosphate (NTP) depletion and restricted translation have been implicated in persistence, suggesting alternative redundant routes may exist to initiate persister formation. To investigate the molecular mechanism of one such pathway, functional variants of an essential component of translation (phenylalanyltRNA synthetase [PheRS]) were used to study the effects of quality control on antibiotic persistence. Upon amino acid limitation, elevated PheRS quality control led …

Contaminated Mycoscapes: Designing With Living Organisms, Maria Gutierrez, Elise Zilius

Architecture Senior Theses

The Anthropocene has stripped the planet of its resources, leaving behind an abundance of contamination. The built environment no longer meets the standards set by our turbulent planet. Humankind has lost the privilege of agency in design and construction. Construction methods have failed to evolve concurrently to the intense accumulation of waste; remaining firmly rooted in the materiality of the past, they have upheld architectural notions of stagnancy, cleanliness, and hygiene and ignore the rapidly changing conditions of the environment. This investigation uses contamination to fuel mycelial growth and construct emergent forms whilst executing remediation strategies for polluted sites of …

Inhibition Of Biofilm Formation By The Synergistic Action Of Egcg-S And Antibiotics, Shrameeta Shinde, Lee Lee, Tinchun Chu

Department of Biology Faculty Scholarship and Creative Works

Biofilm, a stress-induced physiological state, is an established means of antimicrobial tolerance. A perpetual increase in multidrug resistant (MDR) infections associated with high mortality and morbidity have been observed in healthcare settings. Multiple studies have indicated that the use of natural products can prevent bacterial growth. Recent studies in the field have identified that epigallocatechin gallate (EGCG), a green tea polyphenol, could disrupt bacterial biofilms. A modified lipid-soluble EGCG, epigallocatechin-3-gallate-stearate (EGCG-S), has enhanced the beneficial properties of green tea. This study focuses on utilizing EGCG-S as a novel synergistic agent with antibiotics to prevent or control biofilm. Different formulations of …

Survival, Growth, And Characterization Of Microbes In E-Liquids, Jessica Bunn

Master of Science in Forensic Science Directed Research Projects

Health risks associated with the use of e-cigarettes have become a concern in the last ten years, including the inhalation of volatile organic compounds, trace heavy metals, and cancer-causing agents. An additional, but poorly characterized health threat for e-liquids is the potential for bacterial contamination since the presence of pathogenic organisms can potentially cause disease from the inhalation of the microbes into the lungs. This work aims to investigate microbial growth and survival within the e-liquid matrix. Bacillus cereus T. strain and Escherichia coli were the chosen organisms for analysis of growth by absorbance, survival by viable plate counts, and …

Inaction On Lead Despite The Relevant Knowledge: Predictors, Covariates, And Outreach Implications, Alessandra Rossi, Bernabas Wolde, Pankaj Lal, Melissa Harclerode

Department of Biology Faculty Scholarship and Creative Works

Testing residential soil and paint for lead provides actionable information. By showing where and how much lead exists on the residence, it allows one to quantify risk and determine the best ways to reduce exposure along with the corresponding health and financial costs. For these reasons, several federal and state programs offer outreach to audiences on the benefits of testing residential soil and paint for lead. Not all individuals who know about lead’s adverse health effects, however, test their residence for lead, potentially limiting the actionable information that could have helped to reduce their exposure. Such individuals represent a challenge …

Assessment Of Grain Safety In Developing Nations, Jose R. Mendoza

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

Grains are the most widely consumed foods worldwide, with maize (Zea mays) being frequently consumed in developing countries where it feeds approximately 900 million people under the poverty line of 2 USD per day. While grain handling practices are acceptable in most developed nations, many developing nations still face challenges such as inadequate field management, drying, and storage. Faulty grain handling along with unavoidably humid climates result in recurrent fungal growth and spoilage, which compromises both the end-quality and safety of the harvest. This becomes particularly problematic where there is little awareness about health risks associated with poor …

Biomethane Production From Distillery Wastewater, Zachary Christman

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Distillery wastewater treatment is a great ecological problem, for example, India produces 2.7 billion liters of alcohol that results in 40 billion liters of wastewater. However, this material can be seen as a resource since 11 million cubic meters of biogas at 60% methane could be produced in addition to cleaning the water. The distillery has two options of what to do with the biogas. The first is to use the biogas to fuel the distillery making the production plant more energy efficient and removing some of the need to buy natural gas. The other is to upgrade the biogas …

Developing A Modern Microbiology Laboratory Manual To Enhance Student Learning, Alexander Yonchak

Senior Honors Projects

My project has been addressing the issue of incorporating recent developments in biosafety and pedagogical approaches for lab-courses into our existing educational curriculum by developing a new, modern lab manual aimed at improving experiential learning for introductory microbiology teaching labs. Through researching the most recent safety regulations, industry standards, & guidelines for such teaching labs, my manual clearly delineates learning outcomes to match the skills expected of undergraduates completing degrees within the life sciences. In addition, the lab manual that I have designed has been modernized to incorporate the most recent recommended safety precautions and is written in a user-friendly …

Genetic Diversity In The Leucoagaricus Cultivar Fungus Of Trachymyrmex Septentrionalis Fungus-Growing Ants, Lee Deininger

MCB Articles

No abstract provided.

Properties Of A Genetically Unique Mycobacteriophage, Amanda K. Staples

Masters Theses & Specialist Projects

Bacteriophage MooMoo is a temperate phage that was isolated and propagated on Mycobacterium smegmatis (M. smeg). It typically produces turbid plaques, however spontaneous clear plaque mutants can be readily isolated. Both turbid (MooMoo-T) and clear plaque (MooMoo-C) formers can establish stable lysogens, but the parental turbid plaque forming phage has a higher lysogenic frequency. The phage repressor protein typically plays the central role in regulating the lysis/lysogeny decision. Therefore, we expected that the mutation responsible for the clear plaque phenotype would be located in the repressor gene. Remarkably, whole genome sequencing detected a single base pair mutation in the minor …

Enhancement Of Immune Response Against Bordetella Spp. By Disrupting Immunomodulation, Monica C. Gestal, Laura K. Howard, Kalyan Dewan, Hannah M. Johnson, Mariette Barbier, Clare Bryant, Illiassou Hamidou Soumana, Israel Rivera, Bodo Lina, Uriel Blas-Machado, Eric T. Harvill

Faculty & Staff Scholarship

Well-adapted pathogens must evade clearance by the host immune system and the study of how they do this has revealed myriad complex strategies and mechanisms. Classical bordetellae are very closely related subspecies that are known to modulate adaptive immunity in a variety of ways, permitting them to either persist for life or repeatedly infect the same host. Exploring the hypothesis that exposure to immune cells would cause bordetellae to induce expression of important immunomodulatory mechanisms, we identified a putative regulator of an immunomodulatory pathway. The deletion of btrS in B. bronchiseptica did not affect colonization or initial growth in the …