Other Microbiology Commons^™

Mutational Analysis Of Domain Functions In The Yeast Decapping Enzyme Dcp2, Jellisa Ewan, Ambro Van Hoof

Dissertations and Theses (Open Access)

In yeast, the major mRNA decay pathway involves deadenylation of the 3’ poly-A tail, followed by decapping of the 5’ m7Gppp cap and subsequent 5’ to 3’ degradation or 3’ to 5’ degradation. This is carried out by Pan2/Pan3 and Ccr4/Not deadenylases, the decapping enzyme Dcp2, and Xrn1 and  RNA exosome exoribonucleases, respectively. The eukaryotic mRNA decapping enzyme complex, Dcp1/Dcp2, is essential in yeast, and deletion of either gene is lethal. However, the deadenylases that act upstream and the 5’ exoribonuclease that act downstream of the decapping step are not, even though they are all highly conserved with no known …

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 …

Closing The Gaps: Reforming Maryland Controls On Veterinary Antimicrobial Distribution, Samantha Capaldo, Kerry Mcclaughry

Journal of Food Law & Policy

Antimicrobials have been used in livestock and other food animals in the United States (“U.S.”) since the late 1940s. An antimicrobial is “[a]ny natural, synthetic, or semisynthetic substance that can eradicate or prevent the growth of microbes,” including “[a]ntibacterial, antifungal, antiparasitic, and antiviral medications.” Antimicrobial use in food animals is subject to a complex statutory and regulatory framework at both the state and federal levels. Antimicrobial use in food animals has been widely criticized for contributing to antimicrobial-resistant bacterial infections in humans. In response to this criticism, the U.S. Food and Drug Administration (“FDA”) and several states, including Maryland, have …

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 …

The Impact Of Glucose Exposure On Organic Cation Transporters (Oct) Function In A Corneal Epithelial Cell Line, David A. Garza

Theses & Dissertations

Organic cation transporters (OCT) facilitate the movement of neurochemicals and medications, contribute to the removal of cellular waste, and facilitate neuronal communication. Three subtypes of these high-capacity, low-affinity transporters (OCT1, OCT2, and OCT3) are differently expressed in peripheral tissues such as the liver, kidneys, as well as the central nervous system. OCTs are also expressed in ocular tissues. Chronic hyperglycemia is a complication commonly associated with diabetes that can lead to ocular diseases such as diabetic keratopathy, which affects the cornea. In this project, we expose immortalized human corneal epithelial cells (HCE-S) to various glucose concentrations to study their impact …

Donor And Recipient Microbiome Interactions Determine Functional Outcomes Of Fecal Microbiota Transplantation For Clostridioides Difficile Infection, Sophie A. Millard

All Dissertations

Clostridioides difficile is a major cause of healthcare-associated diarrhea. Infection typically occurs after antibiotic treatment disrupts the gut microbiome, allowing C. difficile to colonize and produce toxins leading to disease (CDI). Standard antibiotic treatments can resolve acute infection but frequently lead to recurrence, highlighting the need for alternative strategies that restore the gut ecosystem. Fecal microbiota transplantation (FMT), the transfer of stool from a healthy donor, has emerged as an effective therapy for recurrent C. difficile infection (rCDI). Understanding the mechanisms underlying the success of FMT for treatment of rCDI could lead to safer, more defined microbial mixtures.

This dissertation …

Maintaining And Axenizing Live Cyanobacterial Cultures For Bacterial Genome Sequencing, Yufei Wang, Louisa Acquah

SACAD: Scholarly Activities

Harmful cyanobacterial blooms are an

increasing concern in western Kansas, yet the

bloom-forming species in this region remain

poorly characterized. In this study, we

established and maintained axenic

cyanobacterial cultures to support future

genomic and ecological investigations. By

ensuring low contamination levels and stable

growth conditions, this work provides a

foundation for downstream analyses of bloom-

forming cyanobacteria. It contributes to a better

understanding of freshwater ecosystem health

in western Kansas.

Decoupling Of Reproduction And Lifespan Trade-Off In Caenorhabditis Elegans Through Microbial Programming, Nora M. Villafuerte

LSU Master's Theses

The microbiome is increasingly recognized as a major regulator of host physiology. Using the Caenorhabditis elegans model, we investigated how natural commensal bacteria modulate host reproduction and lifespan through internal egg hatching, a phenotype in which retained embryos hatch within the maternal body. Screening strains from the CeMbio collection identified four focal strains Ochrobactrum BH3, Lelliottia JUb66, Pantoea BIGb0393, and Enterobacter CEent1 that significantly increased internal egg hatching during the late reproductive period. This contrasts with pathogenic bacteria, which induce early-onset internal egg hatching. Across the focal strains, worms exhibited reduced total brood size but an expanded reproductive window relative …

Exploring Alkaline Protease Activity Of Bacillus Strain Isolated From Sidon Dumpsite Lebanon, Zahra Farroukh, Dalia El-Badan, Jamilah Borjac

BAU Journal - Science and Technology

Proteases are crucial hydrolytic enzymes present in all organisms, performing essential physiological and industrial tasks. This study was conducted to screen and isolate protease-producing bacteria from soil and water samples collected from Sidon dumpsite in Lebanon. Bacterial samples were cultured onto skim milk agar medium to identify the alkaline protease-producing ones. In this study, we report on the partial purification and characterization of one of the isolated alkaline protease-producing bacteria. The bacterium was identified as Bacillus subtilis Z3 based on 16S rRNA sequencing. The molecular weight of the partially purified protease was approximately 55 kDa, estimated by sodium dodecyl sulphate …

Characterization Of The Human Thnatomicrobiome By Decomposition Stage Through Bioinformatic And Meta Data Analysis, Ashton C. Laughlin

Biology Theses

Estimating the postmortem interval (PMI) is one of the most crucial factors in forensic death investigations. Recent advances in forensic microbiology have led to increased interest in using the study of the human postmortem microbiome, or “thanatomicrobiome,” to improve PMI estimates. In addition to current PMI estimation techniques, microbial community succession could serve as a valuable tool in estimating PMI. Further research is needed to develop a comprehensive understanding of the human postmortem microbiome. The purpose of this study is to contribute to the expansion of this tool by reviewing the current literature and analyzing previously published data using the …

Structure And Function Studies On Trna Splicing Endonuclease, Justin G. Underwood

Dissertations and Theses (Open Access)

A subset of eukaryotic pre-tRNAs have introns that must be spliced out to become mature molecules capable of functioning in translation. This essential processing step is performed by tRNA splicing endonuclease (TSEN), a highly conserved heterotetramer with two catalytic and two structural subunits. In addition to this conserved function, archaeal TSEN also processes pre-rRNA and yeast TSEN cleaves some mRNAs that encode mitochondrial proteins to initiate mRNA degradation. Interestingly, single amino acid mutations in TSEN cause the human Mendelian disease pontocerebellar hypoplasia (PCH) by an unknown mechanism. Recently, several groups have determined the structure of human TSEN, revealing similarities and …

Enhancing Cataract Surgery Outcomes: Optimal Use Of Pre- And Post-Operative Eye Drops, Keith Skolnick M.D., Anu Valiaveedu

Mako: NSU Undergraduate Student Journal

Many preoperative and postoperative cataract patients struggle with comprehending the use of prescription medication as directed. Language barriers and low health literacy levels are major factors contributing to improper use of prescriptions. To increase patients comprehension, the Fort Lauderdale Eye Institute employed an educational intervention consisting of a live presentation and an instructional video. Results found that 44% of patients were hesitant to ask questions to clinical staff, 32% felt overwhelmed, and nearly 70% lacked confidence in using their prescribed eye drops. Following the intervention, 91% of patients reported increased confidence in their medications, and most indicated that the video …

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 …

The Astrobiological Figure Of Humboldt As Pioneer In The Rock Varnish Research, Jose Jordan-Soria

Homage to Alexander von Humboldt: Travels to and from Spain Throughout the Centuries / Homenaje a Alexander von Humboldt: Viajes hacia y desde España de todos los siglos

From Humboldt is particularly interesting -and little know- his description of mineral coatings on rocks 200 years ago, reported in his book Personal Narrative of Travels to the Equinoctial Regions of the New Continent during the years 1799-1804, co-written with Aimé Bonpland, for which is considerate the father of rock coating research. On June 5th 1799 set sail from A Coruña -Spain- to Cumaná -Venezuela- beginning five years of expedition. While they explored the Orinoco River system, in th eriver basin waterfalls, Humboldt observed the presence of dark coating depositions. He ascertained a manganese-rich accretion, reporting similar structures in other …

Phytochemical Analysis And Antimicrobial Activity Of Micromeria Barbata Leaf And Stem Extracts Against Pseudomonas Aeruginosa: Insights From Molecular Docking And In Vitro Assays, Shiraz Rawas, Dalia El-Badan, Nawal Al Hakawati

BAU Journal - Science and Technology

The present study provides the characterization of the phytochemical content and the antibacterial activity of ethanolic extracts from the leaves (LM) and stems (SM) of Micromeria barbata (M.barbata) against Pseudomonas aeruginosa . Important functional groups were determined by analyzing the FTIR spectra of LM and SM. The phytochemical profiles were analyzed by GC-MS, and these characterized the chemicals according to retention periods and peak regions. The binding affinities of discovered compounds with the P. aeruginosa LasR and PqsD proteins were evaluated using molecular docking approach. Assays for biofilm formation, MIC, MBC, and agar well diffusion were used to assess the …

Detection Of Quorum-Sensing Molecules In The Mutualistic Bacteria Vibrio Fischeri Exposed To Simulated Microgravity Using Cell-Based Biosensors., Paulina Slick, Maria C. Tobarra, Alba A. Chavez, Hugo Castillo

Beyond: Undergraduate Research Journal

Bacteria flourish in multiple environments when communicating with each other in a process known as Quorum Sensing. This process is accomplished by the production of small signaling molecules referred to as Autoinducers (AI). This communication allows the bacteria to alter their gene expression in an effort to regulate their cell number, behavior, community formation and virulence. The space environment provides stressful conditions for bacteria as they are exposed to radiation and Microgravity (µG or MG) altering synthesis and concentration of Autoinducers. The purpose of this research was to expose the model system Vibrio fischeri to simulated microgravity using the recently …

Decoding Bacterial Resilience: Srnas And Sigma Factors In Stress Adaptation And Persistence Of Salmonella, Anita Nguyen

Honors Theses

Small RNAs (sRNAs) are noncoding RNA molecules in bacteria that function primarily to regulate gene expression, including those associated with stress. The Borchert Lab has identified 173 sRNAs and > 500 sRNAs that are responsive to desiccation and carbon starvation (c-starvation), respectively. Prokaryotic transcription involves an RNA Polymerase (RNAP) that transcribes DNA into RNA. RNAP involves sigma factors, which recognize promoters for the initial steps of RNA synthesis. The Borchert Lab has determined that there are significant overlaps between sRNAs expressed in cells subjected to both short-term durations and long-term durations of carbon starvation. Salmonella enterica serovars can have outbreaks associated …

Integration Of Multi-Omics Datasets Evaluating Structural And Functional Features Of The Gut Microbiome In People With Hiv (Pwh)., Aakarsha Vijayakumar Rao

Electronic Theses and Dissertations

Gut dysbiosis characterized by reduced abundance of beneficial butyrate-producing bacteria has been independently linked to HIV-1 infection and heavy alcohol drinking. Further, gut dysbiosis results in loss of gut barrier integrity, microbial translocation and host-specific systemic inflammation. Therefore, to evaluate the functional consequences of structural changes in the gut microbiome, integrated data analysis is imperative. In this dissertation, we perform integrated analyses using data from multi-omics platforms to examine the structural and functional features of the gut microbiome of PWH. Gut microbiome composition was evaluated by sequencing V4 region of 16S rDNA, concentrations of metabolites and host-specific immune markers were …

Differential Progression Of Pancreatic Premalignancy In Geographically Distant Murine Transgenic Cohorts Uncovers Key Role Of Microbial Metabolites, Rian M. Howell

Dissertations and Theses (Open Access)

Cancer is a leading cause of death worldwide. Despite recent advances in diagnostic and therapeutic modalities, pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer that remains highly lethal. Efforts have been made to increase the understanding of the underlying mechanisms driving early stages of tumor development, when the cancer is most susceptible to intervention. To this end, genetically engineered mouse models (GEMMs) have been developed with the mutations most commonly seen in the patient population. Expression of these mutations in select cellular compartments has resulted in the ability to recapitulate characteristics of human pancreatic cancer such as the development of …

Antibiotic Resistance Profile Of Enterobacteriaceae Isolated From Healthy Pigs In The Republic Of Armenia, Yura Shirvanyan, Irma Artushyan, Lilit Hovsepyan, Ashkhen Shirvanyan, Elmira Ghazaryan, Tigran Markosyan

The Thai Journal of Veterinary Medicine

The rising prevalence of antimicrobial resistance (AMR) among Enterobacteriaceae in livestock presents a significant threat to both animal and human health. This study investigates the antibiotic resistance profiles of Enterobacteriaceae isolated from 160 samples collected from the lymph nodes of healthy pigs in Armenia. Fifty isolates were identified, including Escherichia coli (24), Klebsiella spp. (10), Salmonella spp. (6), Raoultella ornithinolytica (4), Pseudomonas aeruginosa (4), and Proteus mirabilis (2). Resistance was evaluated using the disk diffusion method against 22 antibiotics from nine classes. Alarmingly, 94.5% of isolates were resistant to clarithromycin and 90.3% to erythromycin, while resistance to cephalothin and amoxicillin …

Cyanobacteria And Algae From Chýnov And Koněprusy Caves (Czech Republic), Michaela Wipplingerová, Jan Pokorný, Jan Kaštovský

International Journal of Speleology

Algae and cyanobacteria have been studied in two so far phycologically unexplored show caves (Chýnov and Koněprusy) in the Czech Republic. Taxa were identified morphologically using cultivation and subsequent light microscopy, while problematic cyanobacterial species were verified by sequencing the genes for 16S rRNA and 16S–23S internal transcribed spacer. A total of 13 cyanobacterial taxa were found, two Bacillariophyceae, three Xanthophyceae, four Chlorophyceae, six Trebouxiophyceae, 11 Streptophyta, and three Euglenida; many of these species were found for the first time in the caves. The darker parts of the caves were dominated by cyanobacteria, and green algae were found predominantly right …

Culturable Microbial Communities In Root Nodules Of Red Alder (Alnus Rubra Bong.) And Scotch Broom (Cytisus Scoparius L.): Patterns Of Diversity And Composition, Felisha (Fay) Rene Pooler

Dissertations and Theses

Endophytes are a hyper diverse group of bacterial or fungal organisms residing within plant tissues without causing visible symptoms of disease. While their overall diversity and ecological functions are not well-understood, some endophytes can provide a range of important benefits to their host such as enhanced growth and increased tolerance to environmental stress. Nitrogen-fixing bacteria residing within nodules--specialized structures on the roots of legumes and actinorhizal plants--play an integral role in the plant microbiome by facilitating nitrogen availability in nutrient-poor environments. Remarkably, the patterns of diversity including both bacterial and fungal endophytes in root nodules are virtually known, except in …

Spermidine And Polyamine Blockade As Key Mediators Of Intestinal Epithelial Cell Functions, Madison Lynn Flory

Theses and Dissertations--Microbiology, Immunology, and Molecular Genetics

Frequently, alterations in the composition of the gut microbiota and its metabolites are linked with intestinal diseases, including inflammatory bowel disease and colorectal cancer. However, the direct connections between alterations in the microbiome and disease states often remain elusive. Prior research has identified increases in both polyamines, which are a class of microbial metabolite, and in the abundance of bacteria that can produce polyamines, in a murine colorectal cancer model. Understanding the significance of the interaction between these microbial metabolites and intestinal epithelial cells (IECs) will provide new and expanded evidence of the importance of the gut microbiome in colorectal …

Investigating The Dna-Binding Role Of Tbp1 In Toxoplasma Gondii: Expression And Characterization Of A Recombinant Protein, Madison T. Jeckell

Honors Theses and Capstones

Toxoplasma gondii is an obligate intracellular parasite with a complex life cycle and an unusual transcriptional machinery compared to other eukaryotes. Unlike most organisms, Toxoplasma lacks multiple well-conserved promoter motifs and has multiple TATA-binding proteins (TBPs), including TBP1, whose function in DNA binding and transcription regulation is poorly understood. This study aimed to generate and express a recombinant TBP1 protein from Toxoplasma to enable future DNA-binding assays and motif identification. Using RT-PCR, the TgTBP1 gene was amplified and cloned into a pGEX vector to produce a GST-tagged protein. The recombinant plasmid was transformed into E. coli BL21 cells, and protein …

Analysis Of The Microbiome Of Amblyomma Americanum In The Statesboro Region, Ella Zierdt, Lorenza Beati, Mary Humphrey, Saviour Dralabu

Honors College Theses

The lone star tick, Amblyomma americanum, is the most common tick in Georgia. It is mainly known as an Ehrlichia spp. vector, but its microbiome can be diverse, depending on geography, developmental stage, and season. Little is known about bacterial diversity in ticks from the southeastern U.S. A Nanopore MinION sequencer was used for a preliminary analysis of the bacterial microbiome in A. americanum from the Statesboro region. DNA was extracted from 39 nymphs, 35 males, and 39 females. DNA samples were pooled by month of collection and life stage/sex, amplified with barcoded 16SrDNA primers, and sequenced. Approx. 77% …

Bioindicators Of Mercury In Riverine Systems, Kathryn Mudica

All-Inclusive List of Electronic Theses and Dissertations

This study focuses on the bioaccumulation and biomagnification of mercury in freshwater food webs, with emphasis on bioindicators, such as macroinvertebrates, crayfish, and river otters. Despite regulatory efforts and advancements in monitoring, significant gaps remain in understanding mercury dynamics in freshwater systems—especially regarding its transport, methylation, and bioavailability across different ecosystems. To address these knowledge gaps, this study adopts a biocentric approach, emphasizing the role of living organisms in their environment. By utilizing macroinvertebrates, crayfish, and river otters as bioindicators, we aim to assess mercury bioavailability and distribution. These organisms provide varying temporal and spatial scales of mercury accumulation, offering …

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 …

Antimicrobials Produced By Ants: Chemical Properties And Microbe Specificity, Katy Chon

Master's Theses

Antibiotic resistance is a growing public health concern worldwide, and for over a decade, we have been witnessing the growth of difficult to treat infectious diseases caused by bacteria that are becoming resistant to antibiotics. This resistance can be mostly related to the misusing and improper use of antibiotics in both humans and animals. To restore this problem, humans have turned to new sources for the production of antibiotics. In this study, we focused on using ants. Social insects, including ants and bees, have faced strong disease pressures during their evolution and have developed a range of methods to fight …

Characterizing The Quorum Sensing (Qs) System In The Model Eukaryote Chlamydomonas Reinhardtii, Kirstin Donnette Cutshaw

Theses and Dissertations

Group behaviors in microorganisms are often regulated by low-molecular weight molecules that enable them to sense population density, a signaling system known as quorum sensing (QS). QS in prokaryotes has provided insight into the role ‘social’ behaviors play in the bacterial world and refined our models of virulence, bacterial motility, and more. While less common, similar behaviors are observed in certain fungi, primarily yeasts, in which QS controls cell morphology, biofilm production, and other phenotypes. We have recently pursued the potential for QS to be more broadly distributed among unicellular eukaryotes, which could significantly alter our understanding of social behaviors …