Pathogenic Microbiology Commons^™

Validation Of A Real-Time Pcr Laboratory Developed Test For The Detection Of Pneumocystis Jirovecii In Bronchoalveolar Lavage Samples, Caitlyn Moon

Honors Scholar Theses

Pneumocystis jirovecii is an opportunistic, host-obligate fungal pathogen responsible for causing P. jirovecii pneumonia (PJP) in humans. PJP is treated with trimethoprim-sulfamethoxazole (TMP-SMX), a strong broad-spectrum antibiotic that carries risk of renal and hepatotoxicity. Therefore, rapid diagnosis or exclusion of PJP is crucial to ensure PJP-positive patients receive effective treatment and PJP-negative patients avoid unnecessary antibiotics. Unlike most microorganisms, P. jirovecii cannot be cultured, presenting complications for the typical methods of diagnosing fungal pathogens. Historically, the gold standard for diagnosis was direct microscopic examination with stains such as methenamine silver and calcofluor white, but this diagnostic technique requires highly skilled …

Investigating Corollaries Between Streptococcus Gallolyticus Subsp. Gallolyticus Virulence And Colorectal Cancer, Tyler G. Myers

Pursuit - The Journal of Undergraduate Research at The University of Tennessee

Streptococcus gallolyticus subsp. gallolyticus (Sgg) is a gram-positive, non-beta-hemolytic bacterium that belongs to the Lancefield group D of streptococcal pathogens. For the past several decades, associations between Sgg bacteremia and colorectal cancer (CRC) have been apparent, with gastroenterologists routinely recommending colonoscopies for positive cases of Sgg in either blood or stool samples. However, current research has not wholly established whether Sgg acts as a causative agent of CRC or if pre-existing cancers make the lumen of the colon more hospitable to its colonization. Regardless, Sgg has been implicated in the modulation of host inflammatory pathways and subsequent remodeling …

Surveillance Of A Novel Vesivirus Discovered In An Urban Mephitis Mephitis Population, Amanda E. Diggins

Honors Theses and Capstones

Caliciviridae is a family of non-enveloped, positive-sense, single stranded RNA viruses, including eleven defined genera that contain important pathogens of humans and animals. Within the Caliciviridae family, the genus Vesiviridae includes feline calicivirus, a leading cause of upper respiratory disease in cats, and vesicular exanthema of swine virus, a historical disease of domestic swine that has now been implicated in several marine mammal vesicular diseases, one of which has been confirmed zoonotic. Urban landscapes create a unique environment for rapid intra- and interspecies transmission of viruses. Clustered resources attract high-density populations of synanthropic wildlife species, increasing spatial overlap and heightening …

Synergistic Cefiderocol-Containing Antibiotic Combinations Active Against Highly Drug-Resistant Acinetobacter Baumannii Patient Isolates With Diverse Resistance Mechanisms, Justin Halim, Andrew P. Keane, Jeannete Bouzo, Tope Aderibigbe, Jessica A. Chicola, Katie T. Nolan, Keertana Jonnalagadda, Jason X. Tran, Valerie J. Carabetta

Rowan-Virtua School of Osteopathic Medicine Departmental Research

BACKGROUND: Acinetobacter baumannii is a nosocomial pathogen known for rapidly developing resistance to nearly all antibiotics, including last-line agents. Cefiderocol, a novel siderophore cephalosporin, has shown in vitro activity against A. baumannii and is now used clinically, but resistance is emerging. Data on cefiderocol-based antibiotic combinations are limited.

OBJECTIVES: To evaluate the in vitro activity of cefiderocol alone and in combination with other antibiotics against XDR and PDR A. baumannii clinical isolates, and to explore resistance mechanisms underlying cefiderocol synergy.

METHODS: We tested 21 XDR/PDR clinical isolates and one NDM-1-producing strain using broth microdilution and checkerboard assays with cefiderocol and …

Mechanisms Of Behavioral Change In Hosts Of Toxoplasma Gondii: A Review, Olivia Grimsley

Senior Honors Theses

The parasite Toxoplasma gondii is a highly ubiquitous parasite that latently infects an estimated 33% percent of the global population. Toxoplasmosis is of obvious clinical significance due to the extremely high risks to the unborn who contract it congenitally. Less attention has been given to a more subtle aspect of latent infection, which is the behavioral alterations that are commonly experienced by those who contract the parasite. Infected individuals commonly display a variety of altered behaviors, such as increased aggression and risk-seeking behaviors, depression, higher tendency towards suicide and self-directed violence, a loss of fear response, and a greatly increased …

Development Of A Multi-Epitope Peptide Vaccine Against Monkeypox Virus: Immunoinformatics Analysis For South East Asian Hla Alleles, Nelson Chandra, Mochammad Aqilah Herdiansyah, Viol Dhea Kharisma, Arif Nur Muhammad Ansori, Arli Aditya Parikesit

Makara Journal of Science

The monkeypox virus (MPXV), a DNA virus causing zoonotic disease, poses major global public health challenges, with mortality rates between 3%–6%. Although smallpox vaccines provide partial cross-protection, there is a critical need for a dedicated, effective monkeypox (mpox) vaccine. This study aimed to design a multi-epitope peptide-based vaccine specifically adapted to the HLA allele profiles common in Southeast Asian populations, where MPXV cases are rising. Using immunoinformatics, we screened for and detected B and T cell epitopes from the MPXV cell surface antigen and IFN-alpha/beta receptor proteins. The vaccine design was validated through a rigorous evaluation of its antigenicity, immunogenicity, …

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 …

Nucleotide-Derived Bacterial Alarmones Attenuate The Induction Of Type-I Interferon Responses In A Murine Macrophage Reporter Cell Line, Ryan P. Kilduff, Erin B. Purcell, Lisa M. Shollenberger

Chemistry & Biochemistry Faculty Publications

The stringent response is a well-studied phenomenon in many bacterial systems and regulates resource-consuming activities such as transcription, translation, and replication. The stringent response is a well-conserved signaling framework, as are the nucleotide-derived signaling mediators, collectively referred to as (p)ppGpp or as alarmones. There is a wealth of research evaluating nucleotide-derived alarmone signaling in bacterial models, however, their potential to modulate innate immune signaling has not yet been evaluated. Several common pathogen-synthesized molecules, such as lipopolysaccharide (LPS) and cyclic-di-AMP (c-di-AMP), act as pathogen-associated molecular patterns (PAMPs), which are common patterns that alert the innate immune system of bacterial infection. The …

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 …

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 …

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 …

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 …

Genetic And Biochemical Analysis Of Novel Borrelia Burgdorferi Genes Bb0244 And Bb0246, Christian J. Ruiz-Rodriguez

Honors Undergraduate Theses

As the cause of the most common vector-borne disease in the US, Borrelia burgdorferi continues to affect an estimated hundreds of thousands of patients each year. The spirochete boasts one of the most complex genomes in comparison to all other prokaryotes as it is fragmented across up to 21 different replicons. Moreover, the functions of a majority of the encoded genes remain unknown. Gene of unknown function, bb0244, along with putative co-transcribed genes bb0245, and bb0246 are hypothesized to be involved in the vital functions of cell division and cell wall biogenesis. B. burgdorferi lacking bb0244 demonstrate a significant growth …

Invasion Of Superbugs: Cockroach-Driven Outbreak Of Multidrug-Resistant Enterobacter In An Icu, Jennifer Hanrahan, Nicholas Schouten, Steven H. Fyffe, Annette Jencson, Stephanie Stroever

Department of Medicine Faculty Publications

Objective: To describe factors in an outbreak of multidrug-resistant Enterobacter cloacae (MRE) in an intensive care unit (ICU) over a 20-month period including the likely contribution of cockroaches to the outbreak.

Design: This is a retrospective descriptive study.

Setting: ICU in an urban hospital.

Patients: All patients admitted to the ICU during the 20-month outbreak period were included in the study.

Interventions: Infection prevention interventions included contact isolation, hand hygiene, dedicated patient equipment, environmental cultures, and pest control.

Results: 25 patients were identified as being colonized or infected with MRE. Relatedness of the outbreak strain and strains found in cockroaches …

Elucidating The Impact Of Sos-Response Timing In On Escherichia Coli Survival Following Treatment With Fluoroquinolone Topoisomerase Inhibitors, Stephanie Schofield

Honors Scholar Theses

Antibiotic treatment failure is a public health crisis, with a 2019 report stating that roughly 35,000 deaths occur in the United States yearly due to bacterial infections that are unresponsive to antibiotics (1). One complication in the treatment of bacterial infection is antibiotic persistence which further compromises our battle to effectively treat infection. Bacterial persisters can exist in clonal bacterial cultures and can tolerate antibiotic treatment by undergoing reversible phenotypic changes. They can survive drug concentrations that their genetically identical kin cannot. Some persisters remain in a slow growing state and are difficult to target with current antibiotics. A specific …

Diagnosis Of Urinary Tract Infections And Rapid Molecular Characterization Of Antibiotic Resistance, Mohammed Harris

All Dissertations

Urinary tract infections (UTIs) are one of the most common infectious clinical entities in both community and hospital settings. They have a broad range of clinical severity yet inflict large epidemiological burden of morbidity and mortality on patients and the healthcare system with billions of dollars in cost of treatment. Understanding what methods are optimal for diagnosing UTIs are critical to mitigate the marked impact and cost of these infections.

Chapter 1 and 2 in this work surveys the broad array of diagnostic modalities for UTIs and highlights their advantages and limitations in the context of the current standard of …

Investigating The Antibacterial And Immunomodulatory Properties Of Lactobacillus Acidophilus Postbiotics, Rachael M. Wilson

Graduate School of Biomedical Sciences Theses and Dissertations

Probiotics are nonpathogenic microorganisms that have been extensively studied for their ability to prevent various infectious, gastrointestinal, and autoimmune diseases. The mechanisms underlying these probiotic effects have not been elucidated. However, we and other researchers have evidence suggesting that probiotic bacteria secrete metabolites that are antimicrobial and anti-inflammatory. As such, we developed a methodology to collect the secreted metabolites from a probiotic bacterium, Lactobacillus acidophilus, and tested this cell free filtrate (CFF) both in vitro and in vivo. Using this CFF, we have demonstrated that L. acidophilus secretes a molecule(s) that has specific bactericidal activity against the opportunistic pathogen, Pseudomonas …

Using Nspefs To Sensitize Mrsa To Vancomycin Treatment, Areej Malik, Alexandra E. Chittams-Miles, Claudia Muratori, Erin B. Purcell

The Graduate School Posters

Staphylococcus aureus (S. aureus) is a biofilm-forming pathogen. S. aureus treatment is marked by the development of antibiotic resistance. The public health impact has increased since the emergence of methicillin-resistant S. aureus (MRSA), which has started to show intermediate resistance to vancomycin in MRSA. Nano-second pulse electric fields (nsPEFs) are low-energy and high-power electric pulses, which have been suggested to sensitize pathogens to antibiotics by creating transient pores in the cell membrane. Our combinatorial treatment includes nsPEF pre-treatment and vancomycin post-treatment of MRSA cells. Our results show that MRSA log phase cells had the highest susceptibility to vancomycin. …

Characterizing The Cutaneous Microbiome Of Eurycea Lucifuga As A Potential Defense Against Chytridiomycosis, Madeline Key

Senior Honors Theses

Chytridiomycosis is an emerging infectious disease that is significantly reducing global amphibian populations. The disease is caused by Batrachochytrium dendrobatidis (Bd), a fungus that lethally modifies amphibian skin. Recent research has suggested that the cutaneous microbiome of individual amphibians may play a role in susceptibility to the pathogen. In this study, twelve cave salamanders (Eurycea lucifuga) were collected. Cutaneous bacteria from each salamander were isolated and identified using Sanger Sequencing. Additionally, a Bd-challenge assay was performed to determine each isolate’s antifungal activity. Results indicated many microbial isolates possessed inhibitory capabilities against Bd, which may …

Resolving The Repression Pathway Of Virulence Gene Hila In Salmonella, Alexandra King, Lon Chubiz Phd, Brenda Pratte, Lauren Daugherty

Undergraduate Research Symposium

Salmonella is a relatively abundant, virulent species of bacteria that is most known for spreading gastrointestinal diseases through food. These illnesses result in approximately 1.35 million infections, including over 25,000 hospitalizations each year, in the U.S. alone (CDC.gov). As antibiotic resistance becomes an increasingly urgent public health problem, the importance of developing alternative treatment methods is only becoming more crucial. One of the genes responsible for this virulence is known as hilA. HilA is the main transcriptional regulator of Salmonella Pathogenicity Island-1 gene (UniProt). SPI-1 plays an important role in the invasion of Salmonella into epithelial cells. The proteins encoded …

Flippase Inhibitors As Antimicrobial Agents, Robert Tancer

Seton Hall University Dissertations and Theses (ETDs)

Drug resistant microbes are a considerable challenge for modern medicine to overcome. The research described in this dissertation involved development of lipid flippase inhibitors and investigating their potential as antimicrobial agents against various drug resistant microbes. The microbes primarily investigated were methicillin resistant Staphylococcus aureus (MRSA) & Cryptococcus neoformans. Chapter 1 reviews the historical perspective and summarizes the current state of the field of research. In Chapter 2, the design space of an antimicrobial peptide known as humimycin was explored and the effects of modifications on its structure were observed against MRSA. Several key observations resulted. Most notably, the …

Diversity Of Bacteriophage In Burkholderia Species, Abigail Price

Honors Projects

Bacteriophages are viruses that infect and replicate within bacteria and offer the potential of a therapeutic alternative to chronic infections that do not respond to antibiotic-based therapies. B. vietnamiensis is one of a number of Burkholderia species involved with chronic drug resistant infections in the lungs of individuals with compromised respiratory systems, as found in those with chronic obstructive pulmonary disease and, most especially, are of particular significance in patients with cystic fibrosis. The diversity of the Burkholderia species is explored by using online databases and looking at bacteriophage or phage-encoding viruses found in B. vietnamiensis. The open reading frames …

Investigating Alternative Induction Of The S. Aureus 80a Prophage, Jody Caretti

Student Scholar Showcase

Widespread antibiotic resistance has quickly become one of the most concerning crises affecting modern medicine, especially in cases of Staphylococcal infections, which have become resistant to all ��-lactam antibiotics. As a result, research into alternative forms of treatment for bacterial infections is a top priority. Bacteriophage therapy is a popular candidate for replacing antibiotics, due to the way the viruses interact with the bacteria. The 80�� prophage integrates its DNA into Staphylococcus aureus strain 10616 via the lysogenic cycle, and replicates with the bacterial cell. When stressed, the bacteria stop replicating and the prophage stimulates the lytic cycle, activating transcription …

A Quantitative Analysis Of The Efficacy Of Various Essential Oils Against The Sars Cov-2 Virus, Elizabeth Wagstaff, Chandrelyn Kraczek, Jack Brandon Lopez

Annual Research Symposium

A poster presentation and abstract for the Roseman Symposium. The project focuses on testing 3 essential oil blends and two disinfectants containing an essential oil blend against SARS CoV-2 in response to the COVID-19 pandemic. The project procedure involves plaque assays, disinfection, and neutralization techniques.

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 …

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 …

Host Cell Responses To Zika Virus Infection, Bikash Ranjan Sahoo

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

The re-emergence of Zika virus (ZIKV) in 2015 as a significant human pathogen causing neurological diseases in infants as well as adults is a serious global health concern. A clear understanding of the mechanisms involved in ZIKV replication in infected host cells as well as the host responses to virus infection are keys to the development of therapeutic strategies against ZIKV. Studies conducted in this dissertation demonstrate that ZIKV infection induces the activation of mTOR signaling cascade that promotes viral protein accumulation and infectious progeny production. While both mTORC1 and mTORC2 are essential for ZIKV replication, the observation that depletion …

Development Of Vaccines And Antivirals Against Zika Virus, Aryamav Pattnaik

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

The re-emergence of Zika virus (ZIKV), an arbovirus, poses a major global human health concern because of its ability to cause congenital abnormalities and neurological diseases. While many candidate vaccines and antiviral drugs are in the developmental pipeline, none have been approved for use against ZIKV infection. This dissertation describes the characterization of one vaccine and two antiviral drug candidates against ZIKV infection. A bacterial ferritin-based nanoparticle vaccine, termed zDIII-F, is designed to display multiple copies of ZIKV E protein domain III on its surface. These stable nanoparticles are shown to induce robust antibody-mediated protection against lethal ZIKV infection in …

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 …