Microbiology Commons^™

Thymosin Beta-4: A Novel Treatment For Acanthamoeba Keratitis, Victoria A. Murphey

All Theses

Acanthamoeba keratitis (AK) is a severe corneal infection caused by the free-living amoeba, Acanthamoeba. Both stages of its life cycle (trophozoite and cyst) cause infection, primarily in contact lens wearers. It is often misdiagnosed, leading to delayed treatment and poor clinical outcomes. Current treatment options for AK rely on anti-amoebic agents that are toxic to corneal epithelial cells. Further, no single drug can eliminate both forms of the amoeba. Approximately 30% of all AK infections require a corneal transplant.

Thymosin beta-4 (Tβ4) is a G-actin binding protein synthesized in almost all human cells, including corneal epithelial cells. Tβ4 exhibits …

Clinical Characteristics And Outcomes Of Pediatric Staphylococcal Scalded Skin Syndrome (Ssss) At An Inner-City Tertiary Care Center, Nina Kb Gust Md, Ashley Frei Bs, Rebecca M. Adams Bs, Elika Ridelman Phd, Christina Shanti Md, Ronald Thomas Phd, Jocelyn Y. Ang Md

Medical Student Research Symposium

Introduction

Staphylococcal Scalded Skin Syndrome (SSSS) is a blistering skin condition caused by a toxin-producing staphylococcus species. Epidemiologic studies on pediatric SSSS in the United States are limited, with a reported incidence of 7.67 cases per million children and 45.1 per million infants. Immature renal function, lack of protective antibodies, and increased exotoxin target desmoglein-1 are hypothesized to increase incidence in younger children. We aimed to determine clinical and microbiological characteristics of pediatric SSSS and factors that could help predict disease severity.

Methods

A retrospective chart review was performed for admitted patients under 18 years old diagnosed with SSSS from …

The Design, Construction, And Testing Of Mrna Vaccine Against Equine Herpes Virus, Bhawana Devkota

LSU Master's Theses

Equine Herpesvirus-1 (EHV 1) is a worldwide significant pathogen that causes respiratory illness, abortion, and neurological disorders in equine. Current vaccines, including live attenuated, inactivated, and subunit platforms, do not prevent viral latency, mucosal shedding, or cross-strain immunity, requiring alternative approaches. To address these gaps, this project explores the design, synthesis, and in vitro testing of an mRNA vaccine targeting immunogenic EHV 1 glycoprotein (gB, gC, gD, gG, and gM). Epitopes were computationally predicted using the Immune Epitope Database (IEDB), codon-optimized for Bos taurus, and cloned into pUCIDT vectors using SP6/T7 promoters. In vitro transcription (IVT) used nucleotide modifications …

Cardiometabolic Benefits Of A Non-Industrialized-Type Diet Are Linked To Gut Microbiome Modulation, Fuyong Li, Anissa M. Armet, Katri Korpela, Junhong Liu, Rodrigo Margain Quevedo, Francesco Asnicar, Benjamin Seethaler, Tianna B. S. Rusnak, Janis L. Cole, Zhihong Zhang, Shuang Zhao, Adele Gagnon, Edward C. Deehan, Joao F. Mota, Jeffrey A. Bakal, Russell Greiner, Dan Knights, Nicola Segata, Stephan C. Bischoff, Laurie Mereu, Andrea M. Haqq, Catherine J. Field, Liang Li, Carla M. Prado, Jens Walter

Department of Food Science and Technology: Faculty Publications

Industrialization adversely affects the gut microbiome and predisposes individuals to chronic non-communicable diseases. We tested a microbiome restoration strategy comprising a diet that recapitulated key characteristics of non-industrialized dietary patterns (restore diet) and a bacterium rarely found in industrialized microbiomes (Limosilactobacillus reuteri) in a randomized controlled feeding trial in healthy Canadian adults. The restore diet, despite reducing gut microbiome diversity, enhanced the persistence of L. reuteri strain from rural Papua New Guinea (PB-W1) and redressed several microbiome features altered by industrialization. The diet also beneficially altered microbiota-derived plasma metabolites implicated in the etiology of chronic non-communicable diseases. Considerable …

Schistosoma Mansoni Infection Causes Consistent Changes To The Fecal Bacterial Microbiota Of Mice Across And Within Sites, Mariam A. Mhanna, David T. Gauthier, Lisa M. Shollenberger

Biological Sciences Faculty Publications

Eggs of Schistosoma mansoni are produced by adult female worms in mesenteries of infected hosts. Eggs can cross the intestinal barrier and form granulomas in the tissue or breach and exit the host through fecal excretion. These interactions may affect the host microbiome assemblages. Given the potential for schistosomal alteration of host gut microbiome and subsequent effects on the fecal bacterial composition, it is important to conduct controlled microbiome studies on model animals. While pursuing these studies, it is important to take into account the different conditions in which microbiome studies are conducted and their consequent impacts on variability and …

The Role Of Horizontal Gene Transfer In Antibiotic Resistance Amidst Prevalent Community And Healthcare-Associated Mrsa Rates, Gabrielle Nascimento

Honors College Theses

In recent decades, cases of community-acquired MRSA (CA-MRSA) and healthcare-associated MRSA (HA-MRSA) have been on the rise. The ability of antibiotic resistance to transfer between microorganisms greatly expands its threat to the effective treatment and containment of bacterial infections. The mecA gene is found on a mobile cassette within the Staphylococcal cell and encodes for PBP2a, an alternate version of penicillin-binding protein (PBP) with less binding affinity for β-lactam antibiotics, increasing resistance to the effects of antibiotics. The goal of this research is to investigate the horizontal transfer of the mecA gene between various Staphylococcus species as well as to …

Development Of A Proposed Selective Medium For The Isolation And Differentiation Of P. Sordellii, Dimyana Bottros

Honors Undergraduate Theses

Clostridium, a genus of anaerobic, spore-forming bacteria, includes clinically and ecologically significant species like Clostridium difficile and Paeniclostridium sordellii. C. difficile causes antibiotic-associated colitis, while P. sordellii is linked to fatal infections and spontaneous abortions. Recent studies found both species in marine sediments, suggesting their role in environmental and wildlife health disturbances, including the 2013 mass mortality of over 300 manatees in the Indian River Lagoon. However, isolating and differentiating P. sordellii is challenging due to the lack of selective media optimized for its growth. This thesis proposes a novel selective medium tailored to P. sordellii’s physiological …

Cultures For Acid-Fast Bacilli: Are We Being Good Stewards?, Jennifer Hanrahan, Julie D. Sill, Patricia Ver Schneider, Jessica F. Copeland, Elsie Frimpongmaa Amoako-Kissi, Ogochukwu O. Ilobi, Angela J. Toepp

Department of Medicine Faculty Publications

Objective: To describe the use of cultures for acid-fast bacilli (AFB) and situations in which AFB cultures are unlikely to be of clinical benefit.

Design: Retrospective descriptive study of AFB cultures submitted to Sentara Health microbiology laboratory from December 1, 2021, to December 1, 2023. Data were collected from the electronic medical record and included patient demographics, the service line that ordered the culture, specimen source, and culture results.

Setting: Sentara Healthcare System.

Patients: All patients who had specimens submitted to the microbiology laboratory during the study period were included.

Results: A total of 13,944 AFB cultures from 8,243 …

Oral Microbiome And Inflammatory Bowel Disease: New Understanding And Call To Action, Michael Saadeh, Sydney Donohue, Shaina Ailawadi, Gordon Hong, David A. Johnson

Department of Medicine Faculty Publications

The oral microbiome is the second largest microbial community in the human body after the gut microbiome. It includes an array of fungi, bacteria, amoebae, flagellates, archaea, and viruses, all of which are potential pathogens. This microbiome can act as a facilitator not only for protection but also for aggravation when dysbiosis occurs. Although conventional thought is this is primarily in terms of oral health issues, such as dental caries and gingival disease. The systemic effects of the oral microbiome however, are relevant to both gastrointestinal (GI) disease and non-GI disease. These systemic risks occur for several reasons, including upregulation …

Specialized Contact Sites Regulate The Fusion Of Chlamydial Inclusion Membranes, Christine Linton, Jordan Wesolowski, Anna Lobley, Toshiyuki Yamaji, Kentaro Hanada, Fabienne Paumet

Department of Microbiology and Immunology Faculty Papers

The intracellular bacterial pathogen Chlamydia trachomatis replicates within a membrane-bound compartment called the inclusion. Upon infection with several chlamydiae, each bacterium creates its own inclusion, resulting in multiple inclusions within each host cell. Ultimately, these inclusions fuse together in a process that requires the chlamydial protein IncA. Here, we show that inclusions form unique contact sites (inclusion contact sites, ICSs) prior to fusion, that serve as fusogenic platforms in which specific lipids and chlamydial proteins concentrate. Fusion depends on IncA clustering within ICSs and is regulated by PI(3,4)P₂ and sphingolipids. As IncA concentrates within ICSs, its C-terminus likely interacts …

Ophidiomyces Ophidiicola And Texas Snakes: A Field To Bench Study Of Ophidiomycosis, Kenlynn L. Volz

Biology Theses

Ophidiomyces ophidiicola (Oo), the primary cause of Ophidiomycosis, is a fungal pathogen recently detected in Texas snakes. Prior to this study, there were major knowledge gaps regarding Oo growth, spread, and suitable environmental conditions. This study filled those gaps using a field to bench approach involving sampling snakes across Texas, in vitro fungal growth, and ecological niche modeling. 103 snakes were sampled across Texas in 2023 and 2024 and six cases of Oo infection were detected. Results of the growth experiment suggest that Oo prefers more stable temperatures and high humidity to a point and that there is a …

Bean Yellow Mosaic Virus And Its Management In Lupins, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Bean yellow mosaic virus (BYMV) is an aphid-transmitted virus that commonly causes necrotic symptoms that kills lupin plants when infected early before pod set. When plants are infected after pod set, black pods develop (known as black pod syndrome).

BYMV is found predominantly in high rainfall areas of the Western Australian (WA) grainbelt. This page outlines the symptoms, diagnosis, factors favouring disease risk and spread, yield and quality impacts, and management for BYMV in lupin crops in WA

Cucumber Mosaic Virus And Its Management In Narrow Leafed Lupins, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Cucumber mosaic virus (CMV) is a seed- and aphid-borne virus that infects narrow-leafed lupins. Western Australian (WA) grainbelt regions most at risk are the high rainfall zones of the northern and central agricultural region and the south coastal region.

The principal infection source for lupin crops is sowing infected lupin seed.

Wheat Streak Mosaic Virus And Wheat Curl Mite And Their Management, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Wheat streak mosaic virus (WSMV) is a seed and mite-borne virus that infects wheat, causing severe leaf symptoms and reduced yields. The symptoms and damage are more severe in wheat than other hosts, in which infection is symptomless.

Wheat streak mosaic virus can cause crop failure when widespread infection occurs in seedling wheat, particularly when a heavily WSMV-infected green bridge is not controlled before sowing an early crop, and warm temperatures favour mites.

Wheat curl mite (Aceria tosichella) is the only known vector of WSMV. It can transmit the virus in its nymph and adult stages.

Leaf Diseases And Their Management In Oats, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Leaf diseases of oats impact on grain yield and quality and reduce hay quality characteristics, such as colour and digestibility. This page outlines the symptoms, factors favouring disease risk and spread, and management.

Major leaf diseases of oats are septoria avenae blotch, stem rust, leaf rust, and barley yellow dwarf virus. Their severity changes with seasons.

Pilz Domain-Containing Proteins Regulate Motility In Acinetobacter Baumannii, Gabriel Smith

Electronic Theses and Dissertations

Acinetobacter baumannii is an increasingly multidrug-resistant pathogen contributing to hospital-acquired infections, necessitating a greater understanding of how it interacts with its surroundings. Many bacteria utilize different methods of bacterial motility to move about and interact with these surroundings. A bacterial second messenger, cyclic diguanosine monophosphate (c-di-GMP), can regulate various motility factors that are potentially advantageous for survival in and adaptation to their environment. Concentrations of c-di-GMP are regulated by specific synthesizing and degrading enzymes. Controlled levels of c-di-GMP allow interaction between the c-di-GMP and its binding effectors that induce changes in bacterial phenotypes such as biofilm formation and motility. A …

Candida Albicans Farnesol Synthesis And Secretion, Daniel J. Gutzmann

School of Biological Sciences: Dissertations, Theses, and Student Research

Candida albicans is a polymorphic fungus and opportunistic commensal found primarily in the gastrointestinal and skin of healthy individuals. Several barriers prevent C. albicans from causing disease including a healthy immune system and microbiome. When these barriers become comprised, C. albicans can transition to a pathogen and disseminate through the intestinal mucosa leading to life-threatening bloodstream and invasive infections with mortality rates of up to 64%. Morphogenic plasticity is key to this transition and impacts virulence, adaptation to different host environments, and evasion of host immune responses. One regulator of morphogenesis is farnesol. Farnesol is a secondary metabolite of …

The Physiological Significance Of Nitric Oxide Synthase In Staphylococci, Ryan M. Singh

Theses & Dissertations

Staphylococci, particularly Staphylococcus epidermidis, are common causes of implant-associated infections that may result in notable morbidity and mortality. One of the ways the innate immune system attempts to combat these invading pathogens is via the respiratory burst, in which free radical species such as nitric oxide (NO^•), toxic to bacterial respiration, are released in large quantities. Despite the toxicity of NO^•, some bacteria, including staphylococci, encode an endogenous bacterial nitric oxide synthase (bNOS), whose physiological role has been unclear until now. In this dissertation, we demonstrate that S. epidermidis is able to overcome the toxicity …

Efficacy Of Mcl-1 Inhibitors In Multiple Myeloma Cells Resistant To Bortezomib, Emily Nelson, Omar S. Al-Odat, Sabrina M. Paparo, Daniel A. Guirguis, Gabriella Yao, Manoj Pandey, Subash Jonnalagadda, Tulin Budak-Alpdogan

Rowan-Virtua Research Day

Multiple myeloma (MM) is a type of cancer that affects plasma B cells. Patients with MM often experience frequent relapses and can develop resistance to drugs. As a medical researcher, it is important to understand the role of Mcl-1 in preventing intrinsic apoptosis and drug resistance. Mcl-1 belongs to the anti-apoptotic subgroup of Bcl-2 family proteins and plays a crucial role in these processes. Mcl-1 plays a crucial role in driving disease progression and contributing to drug resistance in MM. It has been observed that there is an increased expression of Mcl-1 in 52% of patients with MM during diagnosis, …

Analysis Of Antibiotic Sensitivity Patterns In Pasteurellaceae Family Isolates: A Microbial And Molecular Investigation, Jillian Barron

Honors Scholar Theses

Bacteria in the Pasteurellaceae family are known to cause disease in both human and animal species. Like all species of bacteria, the pathogens in the Pasteurellaceae family evolve and acquire antimicrobial-resistant traits. Antimicrobial resistance of bacteria is a significant public health concern, as treatment of resistant pathogens becomes more difficult, if not impossible, with current medical capabilities. In this project, phenotypic and genotypic analyses were performed on Pasteurellaceae family isolates sourced from the Connecticut Veterinary Medical Diagnostic Laboratory. Phenotypic antibiotic sensitivity patterns of each isolate were assessed against a panel of antibiotics through a Kirby-Bauer disk diffusion test. Disk diffusion …

A Meta-Analysis For Laboratory Diagnostics For Coccidioidomycosis, Mary C. Cowen

Biological Sciences Undergraduate Honors Theses

Coccidioidomycosis, commonly referred to as Valley Fever, is a fungal infection found in arid regions of the southwestern United States and Mexico. Infection occurs through inhalation of airborne spores from Coccidioides species, Coccidioides immitis and/or Coccidioides posadasii, and proceeds in both pulmonary and disseminated fashions. Approximately 60% of patients with coccidioidomycosis remain asymptomatic, while 40% will experience symptoms. Within the literature, there are no papers that summarize sensitivity and specificity values between different tests; therefore, this paper presents sensitivity and specificity results across different tests and companies (Meridian, IMMY, and MiraVista).

Investigating Vital Neutrophil Extracellular Trap Pathogen Response In Neutropenic Individuals, Ryan Illig

Thinking Matters Symposium

Neutrophils, also called polymorphonuclear leukocytes (PMNs), constitute the majority of innate immune cells. These cells possess a complex arsenal of functions that allow them to detect and eliminate a broad spectrum of pathogens. Neutropenia is characterized by decreased levels of neutrophils in the bloodstream, typically falling below the normal range. Moderate to severe neutropenia can increase the risk of pathogenic infections and without treatment can be life-threatening. Although the concentration of neutrophils in neutropenic individuals is decreased, upon activation, neutrophils still release neutrophil extracellular traps (NETs). NETs are pivotal in combating a spectrum of pathogens through their non-selective nature. Overreactive …

Exploration Of Enterococcus Faecalis Bacteriophages Diversity: Comprehensive Phylogenetic Analysis And Discovery Isolation Of Enterococcus Faecalis Phage From A Soil Sample In South Florida, Hailey N. Jauernick

All HCAS Student Capstones, Theses, and Dissertations

Enterococcus faecalis is a commensal bacterium found in the gastrointestinal tract, oral cavity, and vagina of humans, which can transition to pathogenic states, leading to diverse infections. Many E. faecalis infections are becoming progressively challenging to treat, stemming from the lack of effective antibiotic therapies against its virulence factors, including biofilm formation and antibiotic resistance. Phage therapy emerges as a promising alternative, targeting bacteria with minimal impact on host flora. However, despite phages' ubiquitous presence and potential applications in medicine and biotechnology, their diversity and ecological niches are vastly understudied. Here, we investigated the diversity of sequenced E. faecalis phages …

Interplay Of Periodontal Bacterial Metabolites In The Progression Of Coronary Artery Disease: A System Biological Approach, Janakiraman V

Annual Research Symposium

Purpose:

The purpose of this study is to investigate the intricate relationship between periodontal disease (PD) and coronary artery disease (CAD), as evidenced by epidemiological associations. Metalloproteinase inhibitor (TIMP1) plays a pivotal role in cellular signaling, differentiation, cell death, and migration by binding to target metalloproteinases, forming complexes with other molecules (collagenases) to inactivate them. However, the expression of TIMP1 is reduced in both PD and CAD, leading to an upregulation of other metalloproteinases. This research explores the hypothesis that metabolites released from (Porphyromonas gingivalis), a prevalent bacterium in atherosclerotic patients, may inhibit TIMP1, thereby influencing CAD progression. …

Managing Stress: A Study Of Stress Response Mechanisms In Mycobacteria, Augusto C. Hunt Serracin

Biology Dissertations - Archive

Mycobacteria encompass many pathogenic species known to cause severe disease in humans. A well-known example is Mycobacterium tuberculosis (Mtb), the causative agent of the lung disease tuberculosis, which kills millions of humans worldwide yearly. Pathogenic mycobacteria like Mtb are challenging to treat because of their innate ability to adapt to environmental stress. Their unique cell physiology and conserved stress responses allow them to combat biological insults, regulate growth, and regulate genes involved in stress; all these responses increase tolerance to antibiotics. The current therapies to treat mycobacterial infections are lengthy and, at times, unsuccessful, partly due to antibiotic tolerance. A …

Investigating The Development Of Alcohol Tolerance In The Eskape Pathogens, Hannah Durkee

West Chester University Master’s Theses

Antiseptics and disinfectants are used globally to kill or inhibit the growth of bacteria to prevent infection. Considering the well-documented development of antibiotic resistance, the potential for evolved tolerance to alcohol-based antimicrobial agents raises concern. The ESKAPE bacterial pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) are a major cause of healthcare-associated mortality and present a threat to public health due to the progression of multi-drug resistance. We conducted an experiment to determine if the ESKAPE pathogens develop an increased tolerance to ethanol upon repeated exposure by selecting for survivors after a …

Reiq-Mediated Alarmone Signalling Regulates Growth, Stress-Induced Biofilm Formation And Spore Accumulation In Clostridioides Difficile, Areej Malik, Adenrele Oludiran, Asia Poudel, Orlando Berumen Alvarez, Charles Woodward, Erin B. Purcell

Chemistry & Biochemistry Faculty Publications

The bacterial stringent response (SR) is a conserved transcriptional reprogramming pathway mediated by the nucleotide signalling alarmones, (pp)pGpp. The SR has been implicated in antibiotic survival in Clostridioides difficile, a biofilm- and spore-forming pathogen that causes resilient, highly recurrent C. difficile infections. The role of the SR in other processes and the effectors by which it regulates C. difficile physiology are unknown. C. difficile RelQ is a clostridial alarmone synthetase. Deletion of relQ dysregulates C. difficile growth in unstressed conditions, affects susceptibility to antibiotic and oxidative stressors and drastically reduces biofilm formation. While wild-type C. difficile displays increased biofilm …

Gut Dysbiosis Correlates With Covid-19 Severity, Ednita Escobar

CMC Senior Theses

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) impacts not only respiratory but also gut and oral microbiomes, influencing the manifestations of COVID-19. Each person’s unique microbiome consists of microorganisms such as bacteria, fungi, and viruses, some of which are symbiotic and others potentially harmful. Alterations in the gut microbiome, specifically, can affect the severity and symptoms of COVID-19. A review of studies indicate a pattern of gut dysbiosis in COVID-19 patients characterized by a decrease in beneficial microbiota and/or an increase in opportunistic pathogens. This gut imbalance correlates with disease severity, suggesting that the gut microbiome plays a significant role …

Harnessing Antagonistic Pleiotropy: Tolc-Dependent Coliphages Can Drive Reduced Antibiotic Resistance In E. Coli, Cooper Mckenna

CMC Senior Theses

The rise of multidrug-resistant (MDR) bacterial pathogens has been a growing concern in healthcare around the world, and bacteriophage (phage) therapy is a promising method to combat MDR infections. One defense mechanism of E. coli against antibiotics is the TolC-AcrAB efflux pump. At the same time, some phages use TolC as a surface receptor to infect the cell. This puts TolC at a crossroads in which it is beneficial to the bacteria to protect against antibiotics but harmful by allowing phage infection, creating the potential for evolutionary trade-offs. Previous research has identified only three TolC-dependent phages and shown phage-resistant E. …

Contributions Of The Replication Initiator Protein Dnaa To Physiology And Virulence Of The Lyme Disease Spirochete, Andrew Krusenstjerna

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

Borrelia burgdorferi, the etiological agent of Lyme disease, is the most prevalent vector-borne disease in the United States. The spirochetal population is naturally maintained by consistently cycling between Ixodid ticks and small vertebrates. To survive within these diverse niches, B. burgdorferi has evolved a unique physiology and regulatory network to sense and respond to environmental fluxes. Replication is a hallmark of the Lyme spirochete’s enzootic life cycle, specifically at the nymphal tick-to-vertebrate interface. The mechanisms and regulatory schema for the basic cellular processes in B. burgdorferi, or indeed any member of the phylum spirochaetota, are largely unknown. The central hypothesis …