Microbiology Commons^™

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 …

Gestational Diabetes As A Risk Factor For Gbs Maternal Rectovaginal Colonization: A Systematic Review And Meta-Analysis, Vicki Mercado-Evans, Jacob J Zulk, Zainab A Hameed, Kathryn A Patras

Faculty, Staff and Students Publications

BACKGROUND: Maternal rectovaginal colonization by group B Streptococcus (GBS) increases the risk of perinatal GBS disease that can lead to death or long-term neurological impairment. Factors that increase the risk of rectovaginal GBS carriage are incompletely understood resulting in missed opportunities for detecting GBS in risk-based clinical approaches. There is a lacking consensus on whether gestational diabetes mellitus (GDM) is a risk factor for rectovaginal GBS. This systematic review and meta-analysis aims to address current conflicting findings and determine whether GDM should be clinically considered as a risk factor for maternal GBS colonization.

METHODS: Peer-reviewed studies that provided GDM prevalence …

Host-Microbiome Interactions In The Teleost Brain, Amir Mani Varnoosfaderani

Biology ETDs

This dissertation investigates host-microbial interactions within the teleost brain, previously considered sterile. Reviewing current literature highlights significant gaps in understanding teleost brain immunity, despite prevalent neurotropic diseases. We mapped the immune profiles of rainbow trout brains and meninges, revealing the olfactory bulbs as the immune effector part of the brain and the optic tectum as a nod2 expression hub. High il6 and il10 levels were noted in the telencephalon. A persistent bacterial community within healthy salmonid brains shares diversity with gut and blood microbiota. Brain bacterial isolates exhibit genomic signatures for brain colonization and polyamine biosynthesis. The microbiota shifts across …

Predation Of Appendicularians On Prochlorococcus, Carey Sweeney

Dissertations and Theses

Prochlorococcus is the most abundant photosynthetic cell on Earth. This picocyanobacterium is critical to primary productivity and biogeochemical cycles of the open ocean. While abiotic environmental factors that influence Prochlorococcus are relatively well-understood, biotic controls are less well known. Appendicularians are ubiquitous gelatinous zooplankton that feed on marine microorganisms including Prochlorococcus. However, the details of this feeding interaction are extremely understudied relative to its potential importance. In this study, I characterized the relationship between appendicularians and Prochlorococcus with laboratory experiments. I showed that feeding on Prochlorococcus changes with the life stage of the appendicularians and concentration of prey. I …

Functional And Structural Analysis Of The Neimann-Pick Disease Type C Pathway To Include Caveolin-1, Anthony Michael Seat

Chemistry and Chemical Biology ETDs

Human disease is often thought of as an all or nothing prospect, either one has the disease or one does not. This does not bear out in clinical or personal experiences, instead demonstrating that disease occurs within a spectrum ranging from presumed unaffected to demonstrably and detrimentally affected.Neimann-Pick disease is one example of this spectrum look into diseased states, with multiple named versions of a phenotypically similar disease. We focus on Neimann-Picktype C (NPC), which is the result of a disruption in the efflux of cholesterol and sphingolipids from the endocytic pathway. NPC demonstrates this concept of a spectrum of …

Full-Length Αiibβ3 Cryo-Em Structure Reveals Intact Integrin Initiate-Activation Intrinsic Architecture, Tong Huo, Hongjiang Wu, Zeinab Moussa, Mehmet Sen, Valerie Dalton, Zhao Wang

Faculty, Staff and Students Publications

Integrin αIIbβ3 is the key receptor regulating platelet retraction and accumulation and a proven drug-target for antithrombotic therapies. Here we resolve the cryoEM structures of the full-length αIIbβ3, which covers three distinct states along the activation pathway. Firstly, we obtain the αIIbβ3 structure at 3Å resolution in the inactive state, revealing the overall topology of the heterodimer with the transmembrane (TM) helices and the ligand-binding domain tucked in a specific angle proximity to the TM region. After the addition of a Mn2+ agonist, we resolve two coexisting structures representing two new states between inactive and active state. Our structures show …

Msl2 Variants Lead To A Neurodevelopmental Syndrome With Lack Of Coordination, Epilepsy, Specific Dysmorphisms, And A Distinct Episignature, Remzi Karayol, Maria Carla Borroto, Sadegheh Haghshenas, Anoja Namasivayam, Jack Reilly, Michael A Levy, Raissa Relator, Jennifer Kerkhof, Haley Mcconkey, Maria Shvedunova, Andrea K Petersen, Kari Magnussen, Christiane Zweier, Georgia Vasileiou, André Reis, Juliann M Savatt, Meghan R Mulligan, Louise S Bicknell, Gemma Poke, Aya Abu-El-Haija, Jessica Duis, Vickie Hannig, Siddharth Srivastava, Elizabeth Barkoudah, Natalie S Hauser, Myrthe Van Den Born, Uri Hamiel, Noa Henig, Hagit Baris Feldman, Shane Mckee, Ingrid P C Krapels, Yunping Lei, Albena Todorova, Ralitsa Yordanova, Slavena Atemin, Mihael Rogac, Vivienne Mcconnell, Anna Chassevent, Kristin W Barañano, Vandana Shashi, Jennifer A Sullivan, Angela Peron, Maria Iascone, Maria P Canevini, Jennifer Friedman, Iris A Reyes, Janell Kierstein, Joseph J Shen, Faria N Ahmed, Xiao Mao, Berta Almoguera, Fiona Blanco-Kelly, Konrad Platzer, Ariana-Berenike Treu, Juliette Quilichini, Alexia Bourgois, Nicolas Chatron, Louis Januel, Christelle Rougeot, Deanna Alexis Carere, Kristin G Monaghan, Justine Rousseau, Kenneth A Myers, Bekim Sadikovic, Asifa Akhtar, Philippe M Campeau

Faculty, Staff and Students Publications

Epigenetic dysregulation has emerged as an important etiological mechanism of neurodevelopmental disorders (NDDs). Pathogenic variation in epigenetic regulators can impair deposition of histone post-translational modifications leading to aberrant spatiotemporal gene expression during neurodevelopment. The male-specific lethal (MSL) complex is a prominent multi-subunit epigenetic regulator of gene expression and is responsible for histone 4 lysine 16 acetylation (H4K16ac). Using exome sequencing, here we identify a cohort of 25 individuals with heterozygous de novo variants in MSL complex member MSL2. MSL2 variants were associated with NDD phenotypes including global developmental delay, intellectual disability, hypotonia, and motor issues such as coordination problems, feeding …

Novel Antivirals Unveiled Against Acute And Persistent Coxsackievirus B3 Infection Via Rapid Screening, Maria Del Mar Villanueva Guzman

Master's Theses

Enteroviruses cause 10 to 15 million infections annually in the United States, and Coxsackievirus B3 is one of the most commonly reported. Coxsackieviruses may become persistent, characterized as a viral infection that is not cleared from host cells and that generates a continuous infection. Patients who develop persistent CVB3 infection may not respond to the same antivirals as an acute infection, which may be detrimental. Therefore, there is a need for broad-range antiviral drugs to combat acute and persistent CVB3 infection, as there is no well-accepted treatment available. We developed a model system to study persistent CVB3 using a pancreatic …

Novel Antivirals Unveiled Against Acute And Persistent Coxsackievirus B3 Infection Via Rapid Screening, Maria Del Mar Villanueva Guzman

Master's Theses

Enteroviruses cause 10 to 15 million infections annually in the United States, and Coxsackievirus B3 is one of the most commonly reported. Coxsackieviruses may become persistent, characterized as a viral infection that is not cleared from host cells and that generates a continuous infection. Patients who develop persistent CVB3 infection may not respond to the same antivirals as an acute infection, which may be detrimental. Therefore, there is a need for broad-range antiviral drugs to combat acute and persistent CVB3 infection, as there is no well-accepted treatment available. We developed a model system to study persistent CVB3 using a pancreatic …

Characterization Of The Glyoxal Response In Pseudomonas Aeruginosa, Christopher James Corcoran

Dissertations

The toxic dialdehyde glyoxal is found in all domains of life and results as a by-product from a variety of metabolic activities such as DNA oxidation, lipid peroxidation, and autoxidation of sugars such as glucose. If allowed to accumulate, the reactive aldehyde groups of glyoxal have the ability to react with a plethora of molecules including, DNA, lipids, and protein side chains. Most notably, glyoxal can react with arginine, lysine, and cysteine residues, forming irreversible covalent modifications known as advanced glycation end products (AGEs). These glyoxal-derived AGEs can impair protein function, leading to cellular toxicity and eventual cell death. Due …

Disambiguation Of Aerococcus Urinae Species Diversity, Brian Ian Choi

Dissertations

Aerococcus urinae is an uncommon inhabitant of the human urogenital tract. The Gram-positive bacterium has been implicated in a wide range of urinary tract diseases that, if left untreated or undiagnosed, can progress to severe disease such as infective endocarditis. Comparative analysis of 115 A. urinae isolates from infection episodes of urinary tract infection, bacteremia, infective endocarditis, urgency urinary incontinence, stress urinary incontinence, interstitial cystitis / painful bladder syndrome, and asymptomatic individuals reveal substantial diversity with respect to predicted virulence factors, metabolism, and observed biofilm behavior. Through whole genome sequencing analysis, these strains can be reorganized into six new taxonomic …

Investigating The Antimicrobial Potential Of Bovine Lactoferrin Against The Neonatal Pathogen, Staphylococcus Capitis, Anna Desmond, Lesley Cotter, Des Field, Fiona O'Halloran

Department of Biological Sciences Publications

Lactoferrin is an antimicrobial glycoprotein that demonstrates a broad-spectrum of activity against a wide variety of clinical pathogens. This study investigated the potential of bovine lactoferrin (bLf) against multidrug resistant Staphylococcus capitis (S. capitis) strains. Growth curve analysis and time-kill curves demonstrated that at 750 µg ml−1 lactoferrin significantly inhibited (50.6%, P < 0.05) the growth of most isolates tested (90%), and this effect was based on a bacteriostatic mechanism. At the same concentration, bLf also significantly inhibited (30%, P < 0.05) biofilm formation in 40% of strains tested. Combinations of bLf with selected antibiotics were assessed for enhanced antimicrobial activity using growth curves. BLf combined with β-lactam antibiotics reduced the growth of S. capitis strains, however, the effects were not significant. BLf displays antimicrobial effects against multidrug resistant S. capitis isolates, but with strain-specific effects.

Effects Of Vitis Vinifera L. Seed Extract On Short-Term Memory Of Amyloid-Beta-Mediated Neurodegeneration In Transgenic Caenorhabditis Elegans, Elise Patrick

Theses

Alzheimer's disease (AD) is a neurodegenerative condition that is a common cause of dementia and a growing concern worldwide with no effective treatment or cure. Two pathological AD hallmarks include buildup of amyloid beta (Aβ) plaques and neurofibrillary tangles in the brain. Recent attention has turned to exploring natural products and compounds for AD symptom relief and treatment. Vitis vinifera grape seed extract (GSE) contains many beneficial substances. GSE has been tested in several animal models and has shown to improve memory and is even being examined in an AD treatment human clinical trial. In this study, the aim was …

Effects Of Spatial And Temporal Variability On Bacterial Diversity And Community Composition In Roof-Harvested Rainwater Across Central Virginia, Jade Riddle

Longwood Senior Thesis Proposal

No abstract provided.

Characterization And Evaluation Of Bacteriophages Φpa-C And Φpa-Tc Infecting Pseudomonas Aeruginosa, Joanne Harrison

Master's Theses

Pseudomonas aeruginosa are prevalent opportunistic bacterial pathogens that cause nosocomial infections in at-risk individuals. The rise of multidrug-resistant P. aeruginosa poses an immense threat to hospitals. Additionally, P. aeruginosa are common food spoilage organisms that contribute to food waste. Alternative effective treatment methods are needed to improve public health and reduce food waste. Recent studies have shown that bacteriophages, viruses that only kill host-specific bacteria, are promising alternatives. This study characterizes two lytic P. aeruginosa phages, ΦPa-C and ΦPa-Tc, and evaluates their efficacy against P. aeruginosa in two model food systems. The morphology, genome, structural proteins, host range, growth kinetics, …

Characterization And Evaluation Of Bacteriophages Φpa-C And Φpa-Tc Infecting Pseudomonas Aeruginosa, Joanne Harrison

Master's Theses

Pseudomonas aeruginosa are prevalent opportunistic bacterial pathogens that cause nosocomial infections in at-risk individuals. The rise of multidrug-resistant P. aeruginosa poses an immense threat to hospitals. Additionally, P. aeruginosa are common food spoilage organisms that contribute to food waste. Alternative effective treatment methods are needed to improve public health and reduce food waste. Recent studies have shown that bacteriophages, viruses that only kill host-specific bacteria, are promising alternatives. This study characterizes two lytic P. aeruginosa phages, ΦPa-C and ΦPa-Tc, and evaluates their efficacy against P. aeruginosa in two model food systems. The morphology, genome, structural proteins, host range, growth kinetics, …

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 …

Elucidation Of Potential Antimicrobial Properties Of Chalcones, Caleb Howell

Theses

The rise of antibiotic-resistant bacteria is a growing concern for the medical and biological community. Increased use of antibiotics has led to increased development of bacterial tolerances. This phenomenon, driven by the principles of evolution, has been exacerbated by the improper antibiotic use of these antibiotics. Often, individuals stop taking antibiotics once symptoms subside, mistakenly believing the infection is cured. This practice allows bacteria or fungi to develop resistance.

These antibiotics have been developed from secondary metabolites. While we have many effective antibiotics we are facing new threats. Chalcones are being looked at for their potential in addressing this issue. …

Exome Sequencing Identifies Novel Genes Underlying Primary Congenital Glaucoma In The National Birth Defects Prevention Study, Elizabeth E Blue, Kristin J Moore, Kari E North, Tania A Desrosiers, Suzan L Carmichael, Janson J White, Jessica X Chong, Michael J Bamshad, Mary M Jenkins, Lynn M Almli, Lawrence C Brody, Sharon F Freedman, Jennita Reefhuis, Paul A Romitti, Gary M Shaw, Martha Werler, Denise M Kay, Marilyn L Browne, Marcia L Feldkamp, Richard H Finnell, Wendy N Nembhard, Faith Pangilinan, Andrew F Olshan, National Institutes Of Health Intramural Sequencing Center, University Of Washington Center For Mendelian Genomics, National Birth Defects Prevention Study

Faculty, Staff and Students Publications

Background: Primary congenital glaucoma (PCG) affects approximately 1 in 10,000 live born infants in the United States (U.S.). PCG has a autosomal recessive inheritance pattern, and variable expressivity and reduced penetrance have been reported. Likely causal variants in the most commonly mutated gene, CYP1B1, are less prevalent in the U.S., suggesting that alternative genes may contribute to the condition. This study utilized exome sequencing to investigate the genetic architecture of PCG in the U.S. and to identify novel genes and variants.

Methods: We studied 37 family trios where infants had PCG and were part of the National Birth Defects Prevention …

Author Reply To Letter By Topkan Et Al Regarding Delays In Starting Postoperative Radiotherapy, Kelsey A Duckett, Byung Joo Lee, Bhisham S Chera, Sidharth V Puram, Vlad C Sandulache, Russel Kahmke, Shaun A Nguyen, Brian Nussenbaum, Anthony J Alberg, Chanita Hughes Halbert, Katherine R Sterba, Evan M Graboyes

Faculty, Staff and Students Publications

No abstract provided.