Bacterial Infections and Mycoses Commons^™

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 …

Exploring The Physiology Of Clostridioides Difficile: Selenium-Dependent Catabolism Of Host-Derived Nutrients, Michael A. Johnstone

Graduate Thesis and Dissertation 2023-2024

Clostridioides difficile is a bacterial pathogen that causes pseudomembranous colitis and the majority of antibiotic-associated diarrheal cases. Broad-spectrum antibiotic usage disrupts the normal gut microbiota and thereby compromises colonization resistance, the main defense against C. difficile infection. Treatment options are limited to vancomycin, fidaxomicin, and the fecal microbiota transplant. Addressing the scarcity of these therapeutics, we documented two explorations in C. difficile drug discovery: (i) evaluation of antibacterial and toxin-suppressing activity of (+)-puupehenone and similar derivatives, and (ii) clarification of a discrepancy in the hypothesized mechanism of auranofin against C. difficile. A better understanding of how C. difficile colonizes …

Effectiveness Of Doxycycline As Post-Exposure Prophylaxis (Doxy-Pep) For Bacterial Sexually Transmitted Infections (Stis) Among Men Who Have Sex With Men (Msm) In Central Florida, Micah P. Greer

Honors Undergraduate Theses

Bacterial sexually transmitted infections (STIs), notably syphilis, gonorrhea, and chlamydia, have been increasing among men who have sex with men (MSM) in the United States. The rise has been attributed to various factors, including increased condomless sexual acts due to the high uptake of pre-exposure prophylaxis (PrEP) for HIV prevention. To address this concerning trend, post-exposure prophylaxis with doxycycline (Doxy-PEP) has emerged as a potential biomedical intervention. This study aimed to assess the effectiveness of Doxy-PEP in preventing bacterial STIs among MSM in Central Florida, a region with rising STI rates. A de-identified dataset from Pineapple Health Clinic in Orlando, …

Epitope Mapping Novel Monoclonal Antibodies Against Borrelia Burgdorferi Surface Proteins Ospc And Bmpa, Eliza M. Doyle

Honors Undergraduate Theses

In response to the progressive nature of Lyme disease, direct diagnostic testing of Borrelia burgdorferi surface proteins was proposed as a quicker and more sensitive alternative to the current indirect detection methods. To determine the ability of novel monoclonal antibodies to detect the surface lipoproteins BmpA and OspC, recombinant fragments of these proteins were created. These fragments were tested against the putative diagnostic antibodies via western blotting as a means to map the epitope of each of the proteins that the respective antibodies recognize. All BmpA fragments with deletions on the N-terminal end exhibited reactivity, indicating that the epitope is …

Clostridioides Difficile: Identification Of Rival Organisms & Evaluation Of Non-Antibiotic Treatment Implementation, Justin Davis

Honors Undergraduate Theses

Clostrioides difficile is a common cause of nosocomial (hospital-acquired) infections. Patients receiving antibiotic treatment experience dysbiosis of gut microbiota, and C. difficile, normally held in check by the various other organisms, takes this opportunity to propagate. Symptoms of infection generally include diarrhea, colitis, dehydration, and fever. Understanding that C. difficile generally only causes illness when it is the dominant bacterium (i.e. when growth is relatively unchecked by other microbes), it is appropriate to investigate potential competitive organisms that may be introduced after antibiotic courses or during active C. difficile infection to effectively displace it. Fecal samples from the University …

Analysis Of Multi-Drug Resistant Mycobacterium Tuberculosis Using Split Deoxyribozymes, Abryana Fergus

Electronic Theses and Dissertations, 2020-2023

Globally, tuberculosis, a disease caused by the species of Mycobacterium tuberculosis (Mtb) complex, stands as a leading cause of death from a single infectious agent. Even though antituberculous drugs are available, treatment is challenging due to antibiotic resistance associated with point mutations in the bacterial genome. Resistance to the first-line antibiotics – rifampin and isoniazid – results in multidrug-resistant tuberculosis (MDR) requiring a more complicated treatment regimen. Timely and accurate identification of drug-resistant TB cases can help prescribe the most effective treatment and prevent the spread of infection. This research aims to develop an assay to discern multi-drug resistant forms …

Trends In Antibiotic Susceptibility Of Staphylococcus Aureus Isolates In A Pediatric Hospital: An Analysis Of The Impact Of The Sars-Cov-2 Pandemic, Juan Miguel S. Gonzalez Rivero

Honors Undergraduate Theses

Infections caused by the organism Staphylococcus aureus are one of the most common causes for community-associated and healthcare-acquired infections (HAI). Isolates of this bacterium found within the healthcare setting often demonstrate a higher prevalence of antibiotic resistance making these infections difficult to treat. Historically, considerable focus has been placed on methicillin-resistant S. aureus (MRSA), which are strains resistant to β-lactam antibiotics like penicillin, oxacillin and cephalosporins; however, methicillin-sensitive (MSSA) strains may also possess resistance to several first-line antibiotics. Resistance to antibiotics can be acquired through horizontal gene transfer (HGT) by means of mobile genetic elements or by random DNA mutations …

Cholera Transmission Dynamic Model With Environmental Impacts Of Plankton Reservoirs, Sweety Sarker

Electronic Theses and Dissertations, 2020-2023

Cholera is an acute disease that is a global threat to the world and can kill people within a few hours if left untreated. In the last 200 years, seven pandemics occurred, and, in some countries, it remains endemic. The World Health Organization (WHO) declared a global initiative to prevent cholera by 2030. Cholera dynamics are contributed by several environmental factors such as salinity level of water, water temperature, presence of plankton especially zooplankton such as cladocerans, rotifers, copepods, etc. Vibrio cholerae (V. cholerae) bacterium is the main reason behind the cholera disease and the growth of V. cholerae depends …

Reexamining Cytolethal Distending Toxin's Host Cell Entry And Trafficking: The First Steps Down A Long Road, George Huhn

Electronic Theses and Dissertations, 2020-2023

Cytolethal distending toxin (CDT) is a virulence factor produced by many Gram-negative bacteria, including Haemophilus ducreyi, the causative agent of genital chancroid. CDT is a heterotrimeric toxin consisting of a cell-binding domain (CdtA + CdtC) and a catalytic domain (CdtB) that has DNase activity. After binding to the host plasma membrane, CDT undergoes endocytosis and travels through the endosomes en route to the endoplasmic reticulum (ER). Only CdtB and CdtC arrive in the Golgi before moving to the ER. Only then does CdtB move into the nucleus, causing DNA damage that induces cell-cycle arrest and apoptosis. The previous CDT trafficking …

Role Of Rela In Dormancy And Toxr Proteolysis In Vibrio Cholerae, Zachary J. Malaussena

Honors Undergraduate Theses

Vibrio cholerae, the etiological agent of the severe diarrheal disease cholera, is an enteric pathogen that can be found in aquatic ecosystems when not colonizing the human gastrointestinal tract. Under adverse environmental conditions, V. cholerae is capable of entering dormant states that increase its survival during these ecological fluctuations. In these states, V. cholerae slows its metabolic activity and exhibits drastically altered gene expression and morphology. Stressors that lead to entry into these states vary from nutrient limitation, suboptimal pH, or antimicrobials. Cells in these dormant states are highly resistant to antimicrobials and cannot be detected using standard microbiological techniques …

Chitosan-Gallium Nanocomposite: Synthesis, Characterization And Antibacterial Activity, Samjhana Bhandari

Electronic Theses and Dissertations, 2020-2023

The emergence of multidrug-resistant (MDR) strains of bacteria and the lack of a novel class of antibiotics has become a global health concern. Pseudomonas aeruginosa is one common MDR bacteria responsible for nosocomial infections and related mortality worldwide. It has developed resistance against commonly available antibiotics and is in the WHO's priority list of bacteria for which new antibiotics are desperately needed. Currently there is a growing interest in developing metal and non-metal-based nanoparticles to target multidrug-resistant bacteria. The objective of this study is to evaluate the efficacy of a novel nanocomposite of two non-traditional antimicrobials: a metal (Ga-III) and …

Cerium Oxide Nanoparticles And Beneficial Bacteria: Two Novel Treatments For Eradicating Bacteria Associated With Prosthetic Infection?, Etta Conteh

Honors Undergraduate Theses

The purpose of this thesis was to investigate new possible compounds that can be used to treat orthopedic implant infections caused by bacterial pathogens. Current treatment includes the use of antibiotics and the DAIR procedure, which stands for debridement, antibiotic therapy, irrigation, and retention. However, antibiotics are becoming less effective as a treatment due to bacteria gaining antibiotic resistance. Two bacterial species involved in orthopedic implant infections are P. aeruginosa and S. aureus. This thesis investigated cerium oxide nanoparticles and L. fermentum, a beneficial bacterium, as possible treatments to stop bacterial growth and the formation of biofilm. This …

Detection Of Point Mutations Conferring Gentamicin Resistance In Escherichia Coli Using A Split-G4 Probe, Michael J. Greenberg

Honors Undergraduate Theses

The objective of this project was to develop a DNA hybridization sensor that can detect the presence of E. coli and reveal its resistance to the drug gentamicin. This probe will enable rapid and user-friendly diagnostics of E. coli infections and analysis of bacterial gentamicin-susceptibility profile by interrogation of a fragment of E. coli 16S rRNA bearing a substitution in the gentamicin-resistant cells. The sensor is promising for the point-of-care use to provide a timely UTI diagnostic solution. A quick diagnosis of E. coli infection and antibiotic resistance is crucial for treatment. To design a hybridization probe, we proposed a …

The Envelope Stress Response In Sedimentation-Resistant Escherichia Coli, Neel K. Shah

Honors Undergraduate Theses

Previous research discovered the existence of sedimentation-resistant mutants of E. coli. Genomic studies revealed that these mutants resisted sedimentation due to independent modifications to genes that influenced the Rcs signal transduction pathway, causing increased secretion of an exopolysaccharide capsule comprised primarily of colanic acid. The Rcs system is responsible for detecting envelope stressors; consequently, ampicillin and osmotic stress were used to perturb the cellular envelope and study the response of the mutants compared to wild-type cells. It was found that the overproduction of colanic acid in the mutants confers some resistance to envelope stress; however, the mutants still behaved …

Modeling Disease Impact Of Vibrio-Phage Interactions, Christopher Botelho

Electronic Theses and Dissertations

Since the work of John Snow, scientists and medical professionals have understood that individuals develop cholera by means of consuming contaminated water. Despite the knowledge of cholera's route of infection, many countries have experienced and still experience endemic cholera. Cholera is caused by the Vibrio cholerae (V. cholerae) bacterium and presents with acute diarrhea and vomiting. If untreated, infected individuals may die due to dehydration. Cholera is a disease that most commonly affects countries with poor infrastructure and water sanitation. Despite efforts to control cholera in such countries, the disease persists. One such example is Haiti which has been experiencing …

Etiology Of Community Acquired Clostridium Difficile-Associated Disease, Shannan Sherman, Dr. Pamela Ark

The Pegasus Review: UCF Undergraduate Research Journal

A review of literature related to community acquired Clostridium difficile -associated disease (CA-CDAD) was conducted. Nine relevant studies were identified using the Cumulative Index to Nursing and Allied Health (CINAHL) and MEDLINE-EBSCOhost databases. Clinical practice recommendations were obtained from the Centers for Disease Control and Prevention. The studies provided information about epidemiology of infection due to C. difficile in the community and interventions to reduce transmission. Multiple studies found underlying gastrointestinal disorders and use of cephalosporin antibiotics to be a risk factor. Another risk factor was administration of gastric acid suppressive drugs. No particular C. difficile strain was more likely …

Aeromonas Hydrophila In Amphibians: Harmless Bystander Or Opportunistic Pathogen, Zachary P. Rivas

Honors Undergraduate Theses

For several decades amphibian populations have been declining. Historically, the bacterium A. hydrophila (Ah) was hypothesized to be the causal factor in amphibian disease and population declines. However, with the discovery of a chytrid fungus, Batrachochytrium dendrobatidis (Bd) in 1998, which was identified on the skin of amphibians during documented mortality events, Ah research became of minor interest as focus shifted to Bd. Recent studies into the immunocompromising abilities of Bd, however, have opened new questions about its relationship with Ah and their combined effects on a host.

In this study, I explore the …

Evaluation Of Immunogenicity Of Transgenic Chloroplast Derived Protect, Vijay Koya

Electronic Theses and Dissertations

Anthrax, a fatal bacterial infection is caused by Bacillus anthracis, a gram-positive, spore forming, capsulated, rod shaped organism. Centers for Disease Control (CDC) lists anthrax as Category A biological agent due to its severity of impact on human health, high mortality rate, acuteness of the disease and potential for delivery as a biological weapon. The currently available human vaccine in the United States (AVA anthrax vaccine adsorbed) is prepared from Alum adsorbed formalin treated supernatant culture of toxigenic, non-encapsulated strain of Bacillus anthracis with the principle component being protective antigen (PA83). Evaluation of anthrax vaccine given to nearly 400,000 US …