Organisms Commons^™

Cryptococcus Neoformans Melanization Incorporates Multiple Catecholamines To Produce Polytypic Melanin, Rosanna P. Baker, Christine Chrissian, Ruth E. Stark, Arturo Casadevall

Publications and Research

Melanin is a major virulence factor in pathogenic fungi that enhances the ability of fungal cells to resist immune clearance. Cryptococcus neoformans is an important human pathogenic fungus that synthesizes melanin from exogenous tissue catecholamine precursors during infection, but the type of melanin made in cryptococcal meningoencephalitis is unknown. We analyzed the efficacy of various catecholamines found in brain tissue in supporting melanization using animal brain tissue and synthetic catecholamine mixtures reflecting brain tissue proportions. Solid-state NMR spectra of the melanin pigment produced from such mixtures yielded more melanin than expected if only the preferred constituent dopamine had been incorporated, …

Genital Chlamydia Infection Is Influenced By The Female Sex Hormones Estrogen And Progesterone In Vivo, Amy Gail Gravitte

Electronic Theses and Dissertations

Chlamydia is the most common bacterial sexually transmitted infection in the United States and worldwide. It often goes unnoticed due to lack of symptoms and left untreated it can ascend the female genital tract to cause sequelae like pelvic inflammatory disease and irreversible tubal infertility. In reproductive-aged women, female sex hormones estrogen (E2) and progesterone (P4) concentrations fluctuate during the menstrual cycle and are influenced by hormonal contraceptives and hormone replacement therapy. E2 and P4 influence genital Chlamydia infection in women and mice, but these multifactorial interactions are not entirely mapped out. The complex interplay of E2 and P4 with …

Arrhythmogenic Hearts In Pkd2 Mutant Mice Are Characterized By Cardiac Fibrosis, Systolic, And Diastolic Dysfunctions, Farideh Amirrad, Rajasekharreddy Pala, Kiumars Shamloo, Brian S. Muntean, Surya M. Nauli

Pharmacy Faculty Articles and Research

Autosomal dominant polycystic kidney disease (PKD) is a hereditary disorder affecting multiple organs, including the heart. PKD has been associated with many cardiac abnormalities including the arrhythmogenic remodeling in clinical evaluations. In our current study, we hypothesized that Pkd2 gene mutation results in structural and functional defects in the myocardium. The structural and functional changes of Pkd2 mutant hearts were analyzed in the myocardial-specific Pkd2 knockout (KO) mouse. We further assessed a potential role of TGF-b₁ signaling in the pathology of Pkd2-KO hearts. Hearts from age-matched 6-month-old MyH6•Pkd2^wt/wt (control or wild-type) and MyH6 …

The Temperature-Dependent Conformational Ensemble Of Sars-Cov-2 Main Protease (Mpro), Ali Ebrahim, Blake T. Riley, Desigan Kumaran, Babak Andi, Martin R. Fuchs, Sean Mcsweeney, Daniel A. Keedy

Publications and Research

The COVID-19 pandemic, instigated by the SARS-CoV-2 coronavirus, continues to plague the globe. The SARS-CoV-2 main protease, or M^pro, is a promising target for development of novel antiviral therapeutics. Previous X-ray crystal structures of M^pro were obtained at cryogenic temperature or room temperature only. Here we report a series of high-resolution crystal structures of unliganded M^pro across multiple temperatures from cryogenic to physiological, and another at high humidity. We interrogate these datasets with parsimonious multiconformer models, multi-copy ensemble models, and isomorphous difference density maps. Our analysis reveals a temperature-dependent conformational landscape for M^pro, including …

Investigating The Developmental Impacts Of 3,3’-Dichlorobiphenyl (Pcb-11) In Zebrafish (Danio Rerio), Monika A. Roy

Doctoral Dissertations

The environmental pollutant 3,3’-dichlorobiphenyl (PCB-11) is a lower-chlorinated polychlorinated biphenyl (PCB) congener present in air and water samples. Both PCB-11 and its metabolite, 4-PCB-11-Sulfate, are detected in humans, including in pregnant women. The work conducted for this dissertation takes a developmental toxicology approach and uses zebrafish (Danio rerio) to investigate PCB-11’s potential impacts to the liver and pancreas. Chapter 1 introduces PCBs and the current knowledge gaps. Chapter 2 investigates PCB-11 interactions in short-term 4-day exposures with the Aryl hydrocarbon receptor (Ahr) pathway in both 0-20 mM individual and mixture exposures with other Ahr agonists. In Chapter 3, …

Editorial: Pathogens, Pathobionts, And Autoimmunity, Linda A. Spatz, Gregg J. Silverman, Judith A. James

Publications and Research

No abstract provided.

Assesment Of Antibiotic Resistant Gene Expression In Clinical Isolates Of Pseudomonas Aeruginosa, Dustin Esmond

Biology Theses

Increasing prevalence of nosocomial infections by antimicrobial resistant pathogens resulting in higher mortality rates and financial burden is of great concern. Pseudomonas aeruginosa represents one of six highly virulent “ESKAPE” pathogens that exhibit considerable intrinsic drug resistance as well as mechanisms for acquiring further resistance. As many of these mechanisms are regulated through gene expression, we sought to identify regulatory strategies and patterns at play in 23 clinical isolates collected from Baku, Azerbaijan and Tyler, Texas, USA. Real-time quantitative polymerase chain reaction was performed on six gene targets implicated in resistance and contrasted with antibiotic phenotypes. We found AmpC cephalosporinase …

S-Layer Increases Predation Ability Of Myxococcus Xanthus

Symposium of Student Scholars

Background: Myxococcus xanthus is a gram-negative soil bacterium that exhibits micro-predatory activities. When starved, M. xanthus produces resistant spores within fruiting bodies for survival. The S-layer is a paracrystalline structure intertwined in many different patterns and is composed of proteins or glycoproteins. A species that produces the S-layer is Aeromonas. A. salmonicida is a strain of Aeromonas that infects fish. A. hydrophila is another pathogenic strain that causes a wide range of human diseases. We investigated the ability of the S-layer to protect Aeromonas from predation by Myxobacteria. Methods: Myxococcus and prey Aeromonas cultures were standardized to a concentration …

Effects Of Trans-Acting Factors On The Translational Machinery In Yeast, Brandon M. Trainor

Graduate School of Biomedical Sciences Theses and Dissertations

Synthesis of proteins, or translation, is a complex biological process requiring the coordinated effort of numerous protein and RNA factors. Central to translation is the ribosome, a complex macromolecular complex consisting of both ribosomal RNA (rRNA) and ribosomal protein (r-protein). Ribosomes are essential and are one of the oldest and most abundant biomolecules across all forms of life. In addition to the ribosome, translation requires messenger RNA (mRNA), transfer-RNA conjugated to an amino acid (aa-tRNA), translation factors, and energy in the form of ATP and GTP. Translation universally occurs in four major stages, initiation, elongation, termination, and recycling, with initiation …

From Bloom To Bust: Harmful Algae Blooms And Their Impacts On The Waterfront Economy, Sergio Alvarez

Rosen Research Review

The true costs of harmful algae blooms (HABs) and the mechanics that determine their socio-economic impacts are for the most part unknown. Florida’s 2017–2019 red tide (Karenia brevis) bloom is a historical case study of the ever-growing threats to coastal welfare posed by HABs. A new research project at Rosen College of Hospitality Management has this at its heart. The central objective of the project is the identification of direct, indirect, and induced socioeconomic impacts caused by the 2017–2019 K. brevis bloom in Florida.

Valuing The Negative Impacts Of Harmful Algae Blooms, Sergio Alvarez

Rosen Research Review

Ecological disturbances can impact several ecosystem services, including cultural services such as outdoor recreation opportunities. In Florida, one ecological disturbance that is negatively impacting recreation is the occurrence of harmful algae blooms. In recent work, Dr. Sergio Alvarez at UCF Rosen College of Hospitality Management has assessed the impact that harmful algae blooms have on human wellbeing by using random utility models to estimate changes in the value of recreation in coastal ecosystems resulting from these blooms. The results indicate that harmful algae blooms, which reduced boating access between June and September 2018, may have resulted in losses of up …

Telomeric And Sub-Telomeric Structure And Implications In Fungal Opportunistic Pathogens, Raffaella Diotti, Michelle Esposito, Chang Hui Shen

Publications and Research

Telomeres are long non-coding regions found at the ends of eukaryotic linear chromosomes. Although they have traditionally been associated with the protection of linear DNA ends to avoid gene losses during each round of DNA replication, recent studies have demonstrated that the role of these sequences and their adjacent regions go beyond just protecting chromosomal ends. Regions nearby to telomeric sequences have now been identified as having increased variability in the form of duplications and rearrangements that result in new functional abilities and biodiversity. Furthermore, unique fungal telomeric and chromatin structures have now extended clinical capabilities and understanding of pathogenicity …

Intangible Cultural Heritage: A Benefit To Climate-Displaced And Host Communities, Gül Aktürk, Martha B. Lerski

Publications and Research

Climate change is borderless, and its impacts are not shared equally by all communities. It causes an imbalance between people by creating a more desirable living environment for some societies while erasing settlements and shelters of some others. Due to floods, sea level rise, destructive storms, drought, and slow-onset factors such as salinization of water and soil, people lose their lands, homes, and natural resources. Catastrophic events force people to move voluntarily or involuntarily. The relocation of communities is a debatable climate adaptation measure which requires utmost care with human rights, ethics, and psychological well-being of individuals upon the issues …

Neuroactivational And Behavioral Correlates Of Psychosocial Stress-Induced Cocaine Seeking In Rats, Nicole M. Hinds, Ireneusz D. Wojtas, Desta M. Pulley, Stephany J. Mcdonald, Samantha De Guzman, Nicole E. Hubbard, Colin M. Kulick-Soper, Jessica J. Debski, Bianca Patel, Daniel Manvich

Rowan-Virtua Research Day

A prominent feature of cocaine abuse is a high risk of relapse even despite prolonged periods of abstinence. Psychosocial stress is thought to be a major contributor to the onset of cocaine craving and relapse in human substance abusers, yet most preclinical models of stress-induced relapse employ physical stressors (e.g., unpredictable footshock) or pharmacological stressors (e.g., yohimbine to elicit a drug seeking response) and do not rely upon psychosocial stress per se. Importantly, social stressors are well known to activate distinct neural circuits within the brain as compared to other stressors. It is therefore possible that currently available animal models …

Using Citizen Science To Determine The Age Of Alewife Fish, Rodchill-Paul Jules

Honors Scholar Theses

Aging scales of economically important fish like the Alewife (Alosa pseudoharengus) is a critical task in the fisheries industry, which can benefit from the help that citizen science offers. In order for those benefits to take effect, common people should be comfortable and fairly knowledgeable about what is expected of them in the study. Then, results can be generated in a way that gives all types of citizens a good opportunity to participate and produces reliable data that can be used for scientific purposes. This experiment studied the effects of simple word instructions versus diagramed instructions on the …

Identification Of Parasites From Wisconsin And Minnesota Diving Ducks In The Winona Area, Morgan Condon, Kimberly Bates

Ramaley Celebration

Many different diving ducks in the Midwest are hosts to parasites like cestodes, trematodes, and nematodes. These parasites often live in the ducks gastrointestinal tract and use the ducks chyme and intestinal tissues to thrive. For this research, local hunters volunteered to donate diving duck carcasses they harvested. Ducks donated were cut open on the ventral side from esophagus to cloaca. Major organs were separated into bottles containing 0.85% saline, shaken, settled, and then the supernatant removed multiple times to isolate any parasites residing within the duck’s organs and tissues. Any parasites found in dissected diving ducks organ wash were …

Purification And Functional Characterization Of The Iron-Responsive Transcription Factor Aft1 From C. Glabrata, Jade Ikahihifo-Bender

Senior Theses

Due to its unique ability to serve as both an electron donor and acceptor, iron is utilized as a co-factor for many biological processes, including electron transfer, oxygen binding, and vitamin synthesis. Iron is also a key factor during fungal infections as the human host and invading pathogens battle over limited iron pools. The primary iron-responsive transcription factor Aft1 in the opportunistic pathogenic yeast Candida glabrata responds to iron deficiency by activating expression of iron acquisition genes. However, the mechanisms for sensing intracellular iron levels and regulating Aft1 activity in response to iron are unknown. The C. glabrata iron regulation …

Microbiological Study In A Gneissic Cave From Sri Lanka, With Special Focus On Potential Antimicrobial Activities, Ethige Isuru P. Silva, Pathmakumara Jayasingha, Saman Senanayake, Anura Dandeniya, Dona Helani Munasinghe

International Journal of Speleology

The emergence of antibiotic resistance is a global health crisis, thus the search for novel antimicrobial compounds has become a continuous necessity. Underexplored and extreme environments, such as cave ecosystems, have been identified as a promising potential source for the discovery of novel microorganisms with novel antimicrobial compounds (AMC). This study presents the first cave microbiological investigation in Sri Lanka, with a special preference for bioprospecting of novel AMC. The cave sediment characterization demonstrated the presence of close to strong acidic conditions (pH 3.1 – 3.3) and thus indicates the possibility of isolating acidophilic microorganisms. Eight cave wall/ceiling fungal strains …

When The Pandemic Opts For The Lockdown: Secretion System Evolution In The Cholera Bacterium, Francis J. Santoriello, Stefan Pukatzki

Publications and Research

Vibrio cholerae, the causative agent of the diarrheal disease cholera, is a microbe capable of inhabiting two different ecosystems: chitinous surfaces in brackish, estuarine waters and the epithelial lining of the human gastrointestinal tract. V. cholerae defends against competitive microorganisms with a contact-dependent, contractile killing machine called the type VI secretion system (T6SS) in each of these niches. The T6SS resembles an inverted T4 bacteriophage tail and is used to deliver toxic effector proteins into neighboring cells. Pandemic strains of V. cholerae encode a unique set of T6SS effector proteins, which may play a role in pathogenesis or pandemic …

Functional Influence Of 14-3-3 (Ywha) Proteins In Mammals, Elizabeth Barley, Santanu De

Mako: NSU Undergraduate Student Journal

The 14-3-3 (YWHA) proteins are homologous, ubiquitous, and conserved in most organisms ranging from plants to animals and play important roles in regulating key cellular events such as cell signaling, development, apoptosis, etc. These proteins consist of seven isoforms in mammals, termed under Greek alphabetization: beta (β), gamma (γ), epsilon (ε), eta (η), tau/theta (τ), sigma (σ), and zeta (ζ). Each of these isoforms can interact with a plethora of binding partners and has been shown to serve a distinct role in molecular crosstalk, biological processes, and disease susceptibility. Protein 14-3-3 isoforms are scaffolding proteins capable of forming homodimers and …

Characterizing The Physiology And Genetics Of Contact Dependent Growth Inhibiton Systems In Burkholderia Species, Alice Elizabeth Oates

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

Contact-dependent growth inhibition (CDI) systems mediate interbacterial competition. The genes encoding these systems are widespread among Gram-negative bacteria, including Burkholderia pathogens. CDI systems of Burkholderia species are composed of two-partner secretion pathway proteins and function to deliver the toxic C-terminus of a polymorphic surface-exposed exoprotein BcpA (Burkholderia CDI protein A) to the cytoplasm of neighboring recipient bacteria upon cell-cell contact. Specific outer and inner membrane proteins facilitate BcpA translocation both out of the donor bacterium and into the recipient cell cytoplasm. Most Burkholderia species-specific CDI translocation factors in recipient cells are unknown. BcpA intoxication functions as a mechanism by …

Covid19 Disease Map, A Computational Knowledge Repository Of Virus–Host Interaction Mechanisms, Marek Ostaszewski, Tomáš Helikar, Bhanwar Lal Puniya, A Host Of Co-Authors, Covid-19 Disease Map Community

Department of Biochemistry: Faculty Publications

We need to effectively combine the knowledge from surging literature with complex datasets to propose mechanistic models of SARS-CoV-2 infection, improving data interpretation and predicting key targets of intervention. Here, we describe a large-scale community effort to build an open access, interoperable and computable repository of COVID-19 molecular mechanisms. The COVID-19 Disease Map (C19DMap) is a graphical, interactive representation of disease-relevant molecular mechanisms linking many knowledge sources. Notably, it is a computational resource for graph-based analyses and disease modelling. To this end, we established a framework of tools, platforms and guidelines necessary for a multifaceted community of biocurators, domain experts, …

Dendrimer-Based Antibiotics For The Treatment Of Bacterial Biofilm In Cystic Fibrosis (Cf), Younan Ma

Theses and Dissertations

Pseudomonas aeruginosa (PA) is the predominant pathogen in chronic lung infections of cystic fibrosis (CF) patients. The most important mechanism of adaptation of PA to host defense and antibiotic treatment is the formation of biofilms within the mucus layer covering the lung bronchi. The effectiveness of antibiotics such as aminoglycosides is significantly attenuated by their limited penetration through thick mucus and embedded biofilm matrix in patients’ lung. Inhaled tobramycin (Tobra), which is the most commonly used antibiotics in the treatment of PA infections for CF patients, is usually found to be in very high concentration in patients’ lung, and yet …

Bacterial Association Networks From Healthy And Cancer-Associated Gut Microbiomes, Mark Loftus

Electronic Theses and Dissertations, 2020-

The human gastrointestinal tract is colonized by a diverse community of symbiotic microorganisms, mainly bacteria, that are known to play essential roles in maintaining the health of their human host. Disruption of this bacterial community has been associated with numerous diseases, including Colorectal Cancer (CRC). CRC is one of the leading causes of cancer-related deaths worldwide. As such, focus has been placed on the modulation of the bacterial community within the cancer-associated gut microbiome as the next step in possible CRC treatment and prevention strategies. To use the bacterial community for these purposes, a better understanding of the associations that …

Novel Mammalian Models For Understanding And Treating Spinal Cord Injury, Michael B. Orr

Theses and Dissertations--Physiology

Spinal cord injury (SCI) is devastating and often leaves the injured individual with persistent dysfunction. The injury persists because humans have poor wound repair and there are no pharmacologic treatments to induce wound repair after SCI. The continued efforts to discover therapeutic targets and develop treatments heavily relies on animal models. The purpose of this project is to develop and study novel mammalian models of SCI to provide insights for the development and effective implementation of SCI therapies.

Lab mice (Mus musculus) are a powerful tool for recapitulating the progression and persistent damage evident in human SCI, but …

Cellular Bioenergetics Regulates Cell Proliferation During Mammalian Regeneration, Sandeep Saxena

Theses and Dissertations--Biology

Mammalian system consists of stress-sensing molecules that regulates their cellular response against damage, injury and oncogenic stress. During vertebrate regeneration, cells responding to injury re-enter the cell cycle and proliferate to form new tissue. Cell cycle re-entry or arrest is at least partly regulated by cellular senescence which negatively impacts the proliferative pool of cells during regeneration. What remains unclear is whether cells in regenerating systems possess an increased propensity to proliferate and are refractory to signals that induce senescence. My thesis work has focused on how fibroblasts from the ear pinna differentially regulate healing in highly regenerative mammals (e.g., …

Advancing Cyanobacteria Biomass Estimation From Hyperspectral Observations: Demonstrations With Hico And Prisma Imagery, Ryan E. O'Shea, Nima Pahlevan, Brandon Smith, Mariano Bresciani, Todd Egerton, Claudia Giardino, Lin Li, Tim Moore, Antonio Ruiz-Verdu, Steve Ruberg, Stefan G.H. Simis, Richard Stumpf, Diana Vaičiūtė

Biological Sciences Faculty Publications

Retrieval of the phycocyanin concentration (PC), a characteristic pigment of, and proxy for, cyanobacteria biomass, from hyperspectral satellite remote sensing measurements is challenging due to uncertainties in the remote sensing reflectance (∆R_rs) resulting from atmospheric correction and instrument radiometric noise. Although several individual algorithms have been proven to capture local variations in cyanobacteria biomass in specific regions, their performance has not been assessed on hyperspectral images from satellite sensors. Our work leverages a machine-learning model, Mixture Density Networks (MDNs), trained on a large (N = 939) dataset of collocated in situ chlorophyll-a concentrations (Chla), …