Bacterial Infections and Mycoses Commons^™

Bloodstream To Heart Valve: A Case Of Pseudomonas Endocarditis, Jacob Keesee, Brenden Pearce, Mohammed Faris

South Atlantic Division GME Research Day 2025

No abstract provided.

Analyzing Pseudomonas Aeruginosa With Bacteriophage Tags Using Photoacoustic Flow Cytometry, Jennifer C. Schinke

Electronic Theses and Dissertations

The number of daily bacterial infections is climbing and the CDC explains that this is due to the antibiotic-resistant threat in the United States. Finding a faster way of bacterial identification is necessary as it currently takes 1-4 days for a medical lab to culture and identify bacteria. Photoacoustic flow cytometry (PAFC) can be used as an alternative method resulting in swift identification within an hour (Edgar, 2019). Pseudomonas aeruginosa, cell line PA01, will be coated in up to a few hundred red dyed phages making it detectible by the photoacoustic flow cytometry system. Bacteriophages (phages) are viruses that …

The Effects Of Specialized Pro-Resolving Mediator Lipoxin A4 On Pseudomonas Aeruginosa Biofilms And Interactions With Monocytes, Julianne M. Thornton

Graduate School of Biomedical Sciences Theses and Dissertations

Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen known as a major cause of hospital-acquired secondary infections, commonly causing chronic respiratory infections in immunocompromised individuals, especially those with cystic fibrosis, and often found in wound infections. P. aeruginosa uses the quorum sensing pathway to readily form protective biofilms, which reduce the efficacy of antibiotics and access by host immune cells to eradicate the pathogen. Specialized pro-resolving mediators (SPMs) are lipids endogenously produced by the host immune response to infection to aid in infection resolution. One SPM, Lipoxin A4 (LxA4), has been shown to be a robust quorum sensing inhibitor.

The …

Safety And Efficacy Of Silver-Coated Biomaterials In Vivo, Megan Klem, Darien L. Seidman, Rahyan Mahmoud, Manuella Adu, Lei Yu, Jeffrey Hettinger, Renee M Demarest

Rowan-Virtua Research Day

Overtreatment and overuse of antibiotics in healthcare and agricultural settings have contributed to the selective pressure on bacterial strains to develop resistance. Resistance can develop as a result of mutations and subsequent resistance genes that allow bacteria to survive against antibiotics. Novel silver-oxide coatings were developed and were previously demonstrated to prevent adhesion of gram-negative bacteria (Escherichia Coli and Pseudomonas Aeruginosa) to the disc, but did not prevent gram-positive bacterial adherence (Streptococcus Aureus). In order to determine whether the silver-oxide coatings are bacterial static and may be preventing progression to biofilm formation, in vivo analysis of S. Aureus attached to …

Ecthyma Gangrenosum And Panniculitis Secondary To Acute Pseudomonas Myositis Without Bacteremia, Heather Gosnell, Matthew Burke, Joseph Shnouda

HCA Healthcare Journal of Medicine

Introduction

Ecthyma gangrenosum (EG) is a relatively uncommon cutaneous manifestation of an underlying Pseudomonas aeruginosa infection and is clinically described as necrotic with gangrenous ulcers surrounded by erythematous halos. Cases of EG may occur in the absence of bacteremia and have been increasingly reported in literature. Here we present a patient with features of both EG and panniculitis, despite the lack of underlying bacteremia.

Clinical Findings

A 57-year-old male presented to the emergency department with unrelenting right-sided lower back pain and an “itchy and painful” rash of four to five day duration. The patient had an extensive history of intravenous …

Lipoxin A 4 (Lxa 4 ) Promotes Reduction And Antibiotic Efficacy Against Pseudomonas Aeruginosa Biofilm, Julianne M. Thornton, Jean Walker, Prem Yugandhar Kadiyam Sundarasivarao, Bernd Spur, Ana Rodriguez, Kingsley Yin

Rowan-Virtua Research Day

Pseudomonas aeruginosa (P aeruginosa) is an opportunistic bacterium commonly found in wound infections and airways of cystic fibrosis patients P aeruginosa readily forms biofilms which can reduce the efficacy of antibiotics used to eradicate the pathogen We have previously shown that a Specialized Pro resolving Mediator ( Lipoxin A 4 (LxA 4 is a quorum sensing inhibitor which can reduce P aeruginosa virulence In this study, we examined the direct actions of LxA 4 and RvD 2 on P aeruginosa biofilm formation and virulence gene expression The influence of LxA 4 on antibiotic efficacy and the combined effects on biofilm …

Ecthyma Gangrenosum In An Immunocompromised Patient Without Detectable Bacteremia, Jonathan Miles, Alex Mari, Matthew Crabtree, Vinod Nambudiri, Jilian Sansbury

Dermatology

Ecthyma gangrenosum (EG) is typically pathognomonic of Pseudomonas aeruginosa bacteremia among immunocompromised patients, particularly with underlying malignancy. Recently, other pathogens and clinical histories have been implicated, challenging the classic picture of patients with EG. The cutaneous findings in patients follow a pattern of lesion progression from indurated pustules and hemorrhagic vesicles evolving to necrotic ulcers with central black eschar and surrounding erythema. While lesions typically occur on the perineum or lower extremities, their presence has also been described elsewhere. Herein, we describe a case of an immunocompromised man with chronic lymphocytic leukemia and multiple myeloma actively undergoing chemotherapy presenting with …

Azithromycin For Early Pseudomonas Infection In Cystic Fibrosis. The Optimize Randomized Trial., Nicole Mayer-Hamblett, George Retsch-Bogart, Margaret Kloster, Frank Accurso, Margaret Rosenfeld, Gary Albers, Philip Black, Perry Brown, Annemarie Cairns, Stephanie D. Davis, Gavin R. Graff, Gwendolyn S. Kerby, David Orenstein, Rachael Buckingham, Bonnie W. Ramsey, Optimize Study Group

Manuscripts, Articles, Book Chapters and Other Papers

RATIONALE: New isolation of Pseudomonas aeruginosa (Pa) is generally treated with inhaled antipseudomonal antibiotics such as tobramycin inhalation solution (TIS). A therapeutic approach that complements traditional antimicrobial therapy by reducing the risk of pulmonary exacerbation and inflammation may ultimately prolong the time to Pa recurrence.

OBJECTIVES: To test the hypothesis that the addition of azithromycin to TIS in children with cystic fibrosis and early Pa decreases the risk of pulmonary exacerbation and prolongs the time to Pa recurrence.

METHODS: The OPTIMIZE (Optimizing Treatment for Early Pseudomonas aeruginosa Infection in Cystic Fibrosis) trial was a multicenter, double-blind, randomized, placebo-controlled, 18-month trial …

The Impact Of Exos On Pseudomonas Aeruginosa Internalization By Epithelial Cells Is Independent Of Fleq And Correlates With Bistability Of Type Three Secretion System Gene Expression, Abby R. Kroken, Camille K. Chen, David J. Evans, Timothy L. Yahr, Suzanne M. J. Fleiszig

Faculty Publications & Research of the TUC College of Pharmacy

Pseudomonas aeruginosa is internalized into multiple types of epithelial cell in vitro and in vivo and yet is often regarded as an exclusively extracellular pathogen. Paradoxically, ExoS, a type three secretion system (T3SS) effector, has antiphagocytic activities but is required for intracellular survival of P. aeruginosaand its occupation of bleb niches in epithelial cells. Here, we addressed mechanisms for this dichotomy using invasive (ExoS-expressing) P. aeruginosaand corresponding effector-null isogenic T3SS mutants, effector-null mutants of cytotoxic P. aeruginosa with and without ExoS transformation, antibiotic exclusion assays, and imaging using a T3SS-GFP reporter. Except for effector-null PA103, all strains were internalized while …

Human Tear Fluid Reduces Culturability Of Contact Lens-Associated Pseudomonas Aeruginosa Biofilms But Induces Expression Of The Virulence-Associated Type Iii Secretion System, Yvonne T. Wu, Connie Tam, Lucia S. Zhu, David J. Evans, Suzanne M. J. Fleiszig

Faculty Publications & Research of the TUC College of Pharmacy

Purpose

The type III secretion system (T3SS) is a significant virulence determinant for Pseudomonas aeruginosa. Using a rodent model, we found that contact lens(CL)-related corneal infections were associated with lens surface biofilms. Here, we studied the impact of human tear fluid on CL-associated biofilm growth and T3SS expression.

Methods

P. aeruginosa biofilms were formed on contact lenses for up to 7 days with or without human tear fluid, then exposed to tear fluid for 5 or 24 h. Biofilms were imaged using confocal microscopy. Bacterial culturability was quantified by viable counts, and T3SS gene expression measured …

Mucosal Fluid Glycoprotein Dmbt1 Suppresses Twitching Motility And Virulence Of The Opportunistic Pathogen Pseudomonas Aeruginosa, Jianfang Li, Matteo E. O. Metruccio, David J. Evans, Suzanne M. J. Fleiszig

Faculty Publications & Research of the TUC College of Pharmacy

It is generally thought that mucosal fluids protect underlying epithelial surfaces against opportunistic infection via their antimicrobial activity. However, our published data show that human tear fluid can protect against the major opportunistic pathogen Pseudomonas aeruginosa independently of bacteriostatic activity. Here, we explored the mechanisms for tear protection, focusing on impacts of tear fluid on bacterial virulence factor expression. Results showed that tear fluid suppressed twitching motility, a type of surface-associated movement conferred by pili. Previously, we showed that twitching is critical for P. aeruginosa traversal of corneal epithelia, exit from epithelial cells after internalization, and corneal virulence. Inhibition …

Path To Resistance: Risk Factors Associated With Carbapenem-Resistant Pseudomonas Aeruginosa, Kushal Patel, Jessica J.F. Kram, Dennis J. Baumgardner

Journal of Patient-Centered Research and Reviews

Background: An estimated 51,000 health care-associated Pseudomonas aeruginosa infections occur in the United States annually. More than 13% are secondary to non-carbapenem multidrug-resistant strains, which result in 400 yearly deaths. Traditional risk factors for resistance include ICU stay, mechanical ventilation, previous hospitalization and major comorbidities. As microbes evolve, risk factors also may evolve.

Purpose: To determine if traditional and/or new risk factors for P. aeruginosa resistance are valid and predictive of infection with carbapenem-resistant P. aeruginosa.

Methods: We retrospectively studied inpatients and outpatients ≥ 18 years old who presented to an Aurora Health Care facility with a positive P. …

The Effect Of Interspecies Signaling On Stenotrophomonas Maltophilia Growth., Zachary Ethan Dickinson

College of Arts & Sciences Senior Theses

Cystic fibrosis (CF) is a genetic disorder that effects over 70,000 people worldwide, and is particularly prevalent in those of Caucasian descent. CF increases susceptibility to chronic infections of the lungs and GI tract, often leading to decreased quality of life and early death to afflicted individuals. No cure is available, and so treatment is limited to treating the frequent infections that afflict CF patients. Several species of bacteria are commonly implicated in these infections, including Stenotrophomonas maltophilia. Infections of this species is of particular interest as it has been shown to be highly antibiotic resistant. This is a concern …

Pseudomonas Aeruginosa Outer Membrane Vesicles Triggered By Human Mucosal Fluid And Lysozyme Can Prime Host Tissue Surfaces For Bacterial Adhesion, Matteo M. E. Metruccio, David J. Evans, Manal M. Gabriel, Jagath L. Kadurugamuwa, Suzanne M. J. Fleiszig

Faculty Publications & Research of the TUC College of Pharmacy

Pseudomonas aeruginosa is a leading cause of human morbidity and mortality that often targets epithelial surfaces. Host immunocompromise, or the presence of indwelling medical devices, including contact lenses, can predispose to infection. While medical devices are known to accumulate bacterial biofilms, it is not well understood why resistant epithelial surfaces become susceptible to P. aeruginosa. Many bacteria, including P. aeruginosa, release outer membrane vesicles (OMVs) in response to stress that can fuse with host cells to alter their function. Here, we tested the hypothesis that mucosal fluid can trigger OMV release to compromise an epithelial barrier. This was tested using …

Pseudomonas Aeruginosa-Induced Bleb-Niche Formation In Epithelial Cells Is Independent Of Actinomyosin Contraction And Enhanced By Loss Of Cystic Fibrosis Transmembrane-Conductance Regulator Osmoregulatory Function, Amber L. Jolly, Desire Takawira, Olufolarin O. Oke, Sarah A. Whiteside, Stephanie W. Chang, Emily R. Wen, David J. Evans

Faculty Publications & Research of the TUC College of Pharmacy

The opportunistic pathogen Pseudomonas aeruginosa can infect almost any site in the body but most often targets epithelial cell-lined tissues such as the airways, skin, and the cornea of the eye. A common predisposing factor is cystic fibrosis (CF), caused by defects in the cystic fibrosis transmembrane-conductance regulator (CFTR). Previously, we showed that when P. aeruginosa enters epithelial cells it replicates intracellularly and occupies plasma membrane blebs. This phenotype is dependent on the type 3 secretion system (T3SS) effector ExoS, shown by others to induce host cell apoptosis. Here, we examined mechanisms for P. aeruginosa-induced bleb formation, focusing on its …

Bioengineered Lysozyme Reduces Bacterial Burden And Inflammation In A Murine Model Of Mucoid Pseudomonas Aeruginosa Lung Infection, Charlotte C. Teneback, Thomas C. Scanlon, Matthew J. Wargo, Jenna L. Bement, Karl E. Griswold, Laurie W. Leclair

Dartmouth Scholarship

The spread of drug-resistant bacterial pathogens is a growing global concern and has prompted an effort to explore potential adjuvant and alternative therapies derived from nature's repertoire of bactericidal proteins and peptides. In humans, the airway surface liquid layer is a rich source of antibiotics, and lysozyme represents one of the most abundant and effective antimicrobial components of airway secretions. Human lysozyme is active against both Gram-positive and Gram-negative bacteria, ac

Regulating Rsma Expression In Pseudomonas Aeruginosa, Sean D. Stacey

Electronic Theses and Dissertations

Pseudomonas aeruginosa, a Gram-negative bacillus, commonly infects immunocompromised individuals and uses a variety of virulence factors to persist in these hosts. The posttranscriptional regulator, RsmA, plays a role in the expression of many virulence factors in P. aeruginosa. RsmA up regulates virulence factors used in colonizing hosts. However, regulation of rsmA is not well elucidated. Transposon mutagenesis was performed on P. aeruginosa containing a transcriptional rsmA-lacZ fusion to answer this question. Mutants were screened via β-galactosidase assay and transposon insertions identified via arbitrary PCR. A probable MFS transporter, we named mtpX, was one significant transposon mutant identified. …

Inhibition Of Adhesion And Invasion Of Pseudomonas Aeruginosa To Lung Epithelial Cells: A Model Of Cystic Fibrosis Infection, Ayman Noreddin, Ghada Sawy, Walid Elkhatib, Ehab Noreddin, Atef Shibl

Pharmacy Faculty Books and Book Chapters

"Over their life time, CF patients experience multiple infections by various pneumoniacausing bacteria [6]. With more patients surviving to adulthood, chronic infections with Pseudomonas aeruginosa are coming to the forefront as a leading cause of death [7]. Problems presented by infected CF lung are multi-dimensional; the electrolyte balance and pH of the fluids are abnormal. The mucus is thick and of an alternative composition compared to normal lung and may contribute to colonization with Pseudomonas aeruginosa [2, 3, 5]. As such, research is multi-pronged and includes gene therapy to correct the defective protein, amelioration of inflammatory response and thinning of …

Polysorbate 80 Inhibition Of Pseudomonas Aeruginosa Biofilm Formation And Its Cleavage By The Secreted Lipase Lipa, C M. Toutain-Kidd, S C. Kadivar, C T. Bramante, S A. Bobin, Michael E. Zegans

Dartmouth Scholarship

Surface-associated bacterial communities known as biofilms are an important source of nosocomial infections. Microorganisms such as Pseudomonas aeruginosa can colonize the abiotic surfaces of medical implants, leading to chronic infections that are difficult to eradicate. Our study demonstrates that polysorbate 80 (PS80), a surfactant commonly added to food and medicines, is able to inhibit biofilm formation by P. aeruginosa on a variety of surfaces, including contact lenses.