Organisms Commons^™

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 …

Tracking The Source Of Helicobacter Pylori In Watersheds Of San Juan, Puerto Rico, Mary Elizabeth Sailors

Biology Theses

Helicobacter pylori is a pathogenic bacterium that infects more than half of the world’s population. The large number of H. pylori infections in Puerto Rico could be related to the waterborne transmission of the pathogen. While the San Juan Bay Estuary (SJBE) system is home to over three million people, water quality studies in this area of Puerto Rico are lacking. The goal of this study is to determine seasonal and yearly (2020-2021) shifts and relationships between the presence of H. pylori and host-specific (human and dog) Bacteroides in streams that flow through the northern coastal zone of Puerto Rico …

The Role Of Coagulase-Negative Staphylococcal Secreted Products On Staphylococcus Aureus And Staphylococcus Lugdunensis Infections, Denny Chin

Electronic Thesis and Dissertation Repository

The Staphylococcus genus is comprised of over 40 bacterial species. The most well-studied species in this genus is the notorious human pathogen Staphylococcus aureus, a bacterium that produces coagulase among many other virulence factors. Since S. aureus is a major health burden and causes a plethora of diseases in humans, it has received significant attention and much research has been done to understand its biology to treat diseases caused by this pathogen. However, the coagulase-negative staphylococci (CoNS) make up most of the staphylococcal species and have received less attention since they are thought to have a lesser impact on …

Examining The Pulmonary Response To Repeated Vishniacozyma Victoriae Exposure And Its Association With Allergic Airway Disease, Rachael Erin Rush

Graduate Theses, Dissertations, and Problem Reports

Allergic airway diseases such as asthma continue to increase in incidence in industrialized nations like the United States. These diseases are complex inflammatory processes involving numerous cells and mediators and are strongly influenced by fungal exposures. Recent developments in fungal detection methods have highlighted the contribution of Basidiomycota yeast species in indoor environments such as Vishniacozyma (syn. Cryptococcus) victoriae. However, despite the high levels of this yeast detected in indoor environments, very little is known about it or its role in respiratory morbidity. V. victoriae is phylogenetically similar to pathogenic Cryptococcus neoformans but lacks a capsule and is …

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 …

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 …

The Migration Of Carbapenem-Resistant Acinetobacter Baumannii From The Battlefields Of Iraq And Afghanistan To The Healthcare Facilities Of The Veterans Health Administration, Jeffery Rogers

Capstone Experience

Multidrug-resistant organisms (MDRO) pose a great threat to health across the globe. That threat is also felt in the Veterans Health Administration (VHA). Wounded warriors returning home from the battlefields of Iraq and Afghanistan may have brought with them MDROs, such as the bacterium Acinetobacter baumannii, as they have transitioned from military service into the VHA facilities. This study investigates the interconnectedness of military service in the Department of Defense (DoD) and a lifetime of care at VHA through a longitudinal tracking of a linked cohort of combat veterans with battlefield injuries and subsequent MDR infections of A. baumannii. …

Utilizing The Coughing Rat Model Of Pertussis To Improve Vaccine Efficacy, Jesse M. Hall

Graduate Theses, Dissertations, and Problem Reports

Pertussis, also known as whooping cough, is a respiratory disease caused by the highly contagious, Gram-negative pathogen Bordetella pertussis (Bp). Infection occurs through inhalation of aerosolized droplets containing Bp, which then colonizes ciliated epithelial cells of the respiratory tract. Here, Bp expresses toxins and virulence factors that lead to leukocyte recruitment, paroxysmal cough, and impairment of host innate responses. Currently, in developed countries, acellular pertussis vaccines (aP; DTaP; Tdap) are used to prevent Bp infection and whooping cough disease. However, we currently realize that the aP vaccine efficacy quickly wanes resulting in a reemergence of pertussis. Recent …

The Development Of Bacterial Magnetic Resonance Imaging For Microbiota Analyses, Sarah C. Donnelly

Electronic Thesis and Dissertation Repository

Current microbial analyses to assess either the commensal microbiota or microorganism infection and disease typically require ex vivo techniques that risk contamination and are not undertaken in real time. The possibilities for employing imaging techniques in the microbiology field is becoming more prominent as studies expand on the use of positron emission tomography, ultrasound and numerous microscopy techniques. However, magnetic resonance imaging (MRI), a non-invasive in vivo modality that can produce real-time results is falling behind. Here, we examined the feasibility of detecting bacteria using clinical field strength MRI. Commensal, probiotic and uropathogenic Escherichia coli were scanned by 3 Tesla …

The Inhibitory Effects Of An Antimicrobial Gel On The Staphylococcus Species, Mara Trinkle

Undergraduate Honors Theses

The prevalence of antibiotic resistant bacteria has made the choices for topical treatments for patients who experience burns wounds extremely limited. The Staphylococcus genus is naturally occurring in and on the human body but can become harmful once it enters the bloodstream. A novel antimicrobial gel has been shown by our laboratory to inhibit both the planktonic growth and biofilm formation of Staphylococcus aureus in previous studies. The antimicrobial gel is made of seven natural compounds including antioxidants (vitamin C and E). We wanted to examine the effects of the antimicrobial gel on numerous other Staphylococcal species because it is …

Plasmodium Impairs Antibacterial Innate Immunity To Systemic Infections In Part Through Hemozoin-Bound Bioactive Molecules., Christopher Lynn Harding

Electronic Theses and Dissertations

Despite efforts to decrease the global health burden of malaria, infections with Plasmodium species continue to cause over 200 million episodes of malaria each year which resulted in 405,000 deaths in 2018 [1]. One complication of malaria is increased susceptibility to invasive bacterial infections. Plasmodium infections impair host immunity to non-Typhoid Salmonella (NTS) through activities of heme oxygenase I (HO-I) )-induced release of immature granulocytes and myeloid cell-derived IL-10. Yet, it is not known if these mechanisms are specific to NTS. We show here, that Plasmodium yoelii 17XNL (Py) infected mice had impaired clearance of systemic Listeria monocytogenes (Lm) during …

Identifying Determinants Of Target Specificity In Two Related Bacterial Peptide Toxins, Andrew D. Holmes

Honors Thesis

Toxin-antitoxin (TA) systems were originally identified as two-component systems ensuring the stable inheritance of plasmids in bacterial populations. Recently, they have been identified on bacterial chromosomes where their functions remain mostly undefined. The par locus of E. faecalis plasmid pAD1 (par_pAD1) was the first TA system defined in a Gram-positive bacterium and a homolog encoded on the E. faecalis chromosome (par_EF0409) was later described. Related loci numbering in the hundreds have been identified throughout Gram-positive bacteria based on homology to the toxin of the system, Fst, and similarities in genetic organization and regulation. Despite …

Tick-Borne Infections In New Hampshire: An Evaluation Of The Diagnostic Process In A Local Patient Population, Katherine Anderson

Honors Theses and Capstones

Overall, approximately 95 percent of reported cases of vector-borne disease were associated with ticks, making these the most medically important group of arthropods in the United States.¹ Despite the prevalence of tick-borne infections, the process for the diagnosis of this condition is not well studied. This study aims to analyze data from a pool of 100 patients who underwent testing for tick-borne disease in the same institution in Dover, New Hampshire during the most recent peak tick season of 2019. Information utilized in this study included: patient age, sex, location of testing (inpatient versus outpatient), diagnostic testing methods used …

Understanding The Host Immune Response Against Pseudomonas Aeruginosa To Develop Novel Therapeutics And Vaccines, Emel Sen Kilic

Graduate Theses, Dissertations, and Problem Reports

Pseudomonas aeruginosa is a Gram-negative opportunistic bacterium that causes a broad range of acute and chronic infections. The high adaptability and emergence of multidrug-resistant strains of this bacterium pose a significant threat to human health. Particularly, pneumonia caused by this pathogen is associated with high morbidity and mortality in immunocompromised patients. To prevent these infections, we aimed to develop novel vaccine strategies by characterizing the host immune response against P. aeruginosa. During respiratory infections, P. aeruginosa first contacts with epithelial cells along the respiratory tract. Using RNA-sequencing, we were able to characterize transcriptional changes of the epithelial cells in …

Prediction Of The Vaginal Microbiome Using Urine Samples, Christopher R. Diachok

Theses and Dissertations

The vaginal microbiome is associated with women’s health, including but not limited to the pathogenesis of bacterial vaginosis, adverse pregnancy outcomes including preterm birth and sexually transmitted infections. However, there has been very limited research on the urinary microbiome and its relationship to the vaginal microbiome. We sought to predict the vaginal microbiome profile using clean catch urine samples from the same person. Here, paired vaginal and urine samples were collected and sequenced by 16S ribosomal RNA sequencing. Alpha and beta diversity analysis showed that there was no significant difference between the paired vaginal and urine microbiomes. In fact, a …

Elucidating Immune Signaling Of Influenza A Virus And Aspergillus Fumigatus Co-Infections Through Pioneered Model Development, Meagan Danyelle Rippee-Brooks

MSU Graduate Theses

Bacterial co-infections with influenza A virus (IAV) are extremely serious and life-threatening. However, there exists limited understanding about the importance of fungal infections with IAV. Clinical case reports indicate that fungal co-infections do occur and suggest the IAV pandemic of 2009 had a propensity to predispose patients to secondary fungal infections more than previous IAV strains. IAV-fungal co-infections are marked by high mortality rates of 47 to 61% in previously healthy individuals between the ages of 20 and 60. Yet, the variables involved in this co-infection remain undetermined. I achieved effective recapitulation of this co-infection using a C57Bl/6 murine (mouse) …

Infection Potential Of Rickettsia Felis Via Ingestion, Matthew M. Schexnayder

LSU Master's Theses

Rickettsia felis is the etiologic agent of flea-borne spotted fever (FBSF) in humans and a poorly described cause of fever in animals. It is transmitted by its primary arthropod vector and reservoir host, the cat flea Ctenocephalides felis. Known routes of Rickettsia felis transmission between Rickettsia felis-infected cat fleas and vertebrate hosts include cutaneous bites and contamination of cutaneous wounds with infective flea feces. The bulk of FBSF infections occur in young children in Africa, though infections of people at all ages all over the world have been confirmed. As mammals and young children frequently come into contact …

Effects Of Ambient And Laser Light On Water Evaporation From The Surface Of Polyurethane Swabs Doped With Surfactant, Collin Campbell

Chemical Engineering Undergraduate Honors Theses

Polyurethane swabs are a common instrument for environmental sampling in the food, medical, and forensic fields due to their high recovery of organisms like viruses, spores, and bacteria. For sampling microbes in food and medical facilities, storage of the collected samples occurs under the absence of light to promote growth for more accurate testing. In the forensic fields, microbial growth results in sample contamination so the inhibition of this growth requires the drying of the swabs. This work studies the evaporation rates of water from polyurethane swabs under zero watt incident light, 30 W fluorescent bulb, 50 mW 532 nm …

Characterizing The Role Of Fungal Shape In A Zebrafish Model Of Invasive Candidiasis, Brittany Seman

Electronic Theses and Dissertations

Candida albicans is a common hospital-acquired fungal infection, and disseminated disease claims up to one-half of those afflicted. C. albicans has a unique ability to differentiate its shape during infection, and this differentiation is thought to be a major virulence factor during invasive infections. Each shape is proposed to have a specialized role: filaments drive tissue invasion and yeast mediate dissemination to the bloodstream. However, it has been difficult to test these hypotheses for two reasons. First, rigorous testing of shape-specific roles requires diverse strategies of shape modulation that restrict the possibility of manipulation-specific artifacts. Second, although connecting shape to …

The Inhibitory Effects Of A Novel Gel On Staphylococcus Aureus Biofilms, Lindsey Vance

Undergraduate Honors Theses

Antibiotic resistance is an ever-growing topic of concern within the medical field causing researchers to examine the mechanisms of resistance to develop new antimicrobials. Bacteria’s ability to form biofilms is one mechanism which aids in antimicrobial resistance. Staphylococcus aureus is of special interest as it is one of the most frequent biofilm-forming bacteria found on medical devices causing infections and posing dangerous threats in a clinical setting. A recently developed antimicrobial gel has been shown to have profound effects on treating bacterial infections and wound healing. This research is centered upon examining the antimicrobial effects of this gel on the …

Nutritional Virulence Of Legionella Pneumophila., Ashley M. Best

Electronic Theses and Dissertations

Legionella pneumophila is an environment organism that parasitizes a wide range of protozoa. Growth within the environmental host primes L. pneumophila for infection of human alveolar macrophages when contaminated aerosols are inhaled. Intracellular replication within either host requires the establishment a replicative niche, known as the Legionella-containing vacuole (LCV). Biogenesis of the LCV depends on the type IVb translocation system, the Dot/Icm, to translocation >320 effectors into the host cytosol. Effectors are responsible for preventing lysosome fusion to the LCV, recruitment of ER-derived vesicles to the LCV, and modulation of a plethora of host processes to promote the intracellular …

Determination Of The Effects That A Previously Uncharacterized Secreted Product From Klebsiella Pneumoniae Has On Citrobacter Freundii And Enterobacter Cloacae Biofilms, Cody M. Hastings

Undergraduate Honors Theses

More so than ever, Multiple Drug Resistant (MDR) bacteria are on the rise due to overuse of antibiotics along with natural selection for adaptations that enhance drug-resistant properties. One particular bacterial family, Enterobacteriaceae, has been problematic, exhibiting several bacterial members that have developed a precipitous resistance to modern antibiotics and are also primary causative agents of nosocomial, or hospital acquired, infections. Citrobacter freundii (CF) and Enterobacter cloacae (ECL) are two species of the Enterobacteriaceae family causing significant medical concern due to their role in producing numerous opportunistic infections such as bacteremia, lower respiratory tract infections, urinary tract infections, and endocarditis. …

Chat Expression In Chlamydia Muridarum-Infected Female Murine Genital Tract, Hallie Sartain

Undergraduate Honors Theses

Chlamydia trachomatis is the most prevalent agent of bacterial sexually transmitted infections in the world. However, a profuse number of cases are unreported, as the infection is often asymptomatic. Sequelae such as pelvic inflammatory disease, an increased risk of cervical cancer, premature birth, and perinatal infections in pregnant women can occur. Inflammation occurs in the body in response to infection or injury. Although inflammation can lead to some unwanted secondary effects, such as pain, it serves to return the body to homeostasis by restoring injured tissues and eliminating pathogens. One recently identified connection between the central nervous system and the …

A Systems Biology Approach For Predicting Essential Genes And Deciphering Their Dynamics Under Stress In Streptococcus Sanguinis, Fadi El-Rami

Theses and Dissertations

Infectious diseases are the top leading cause of death worldwide. Identifying essential genes, genes indispensable for survival, has been proven indispensable in defining new therapeutic targets against pathogens, major elements of the minimal set genome to be harnessed in synthetic biology, and determinants of evolutionary relationships of phylogenetically distant species. Thus, essentiality studies promise valuable revenues that can decipher much of biological complexities.

Taking advantage of the available microbial sequences and the essentiality studies conducted in various microbial models, we proposed a framework for the prediction of essential genes based on our experimentally verified knowledge of the pathways involved in …

Dynamic Host-Pathogen Interactions Result In Fungal Epitope Unmasking, Alex Hopke

Electronic Theses and Dissertations

Molecular camouflage is used by a diverse set of pathogens to disguise their identity and avoid recognition by protective host receptors. The opportunistic fungal pathogen Candida albicans is a good example, as it masks the inflammatory component β-glucan in its cell wall to evade detection by the immune receptor Dectin-1. Interestingly, it has been seen that β-glucan becomes unmasked during infection in vivo, though the underlying mechanisms remained unclear. Exposure levels of this epitope may be important, as Dectin-1 mediates protection from some strains of C. albicans and alterations in the organization and composition of the Candida cell wall …

Redesigning Gfp Reporter System For Utilization In Clostridium Difficile, Laura E. Fitzgerald

Biological Sciences Undergraduate Honors Theses

Clostridium difficile (C. difficile) is a gram-positive bacterium that comprises part of the healthy human gut microbiome. When it gains sufficient access to peptides, C. difficile flourishes and releases tissue-damaging toxins, which cause inflammation of the colon that can develop into a Clostridium difficile Infection (CDI).¹⁰ The Ivey Laboratory believes that the best tactic in preventing CDIs is stopping peptide ingestion, which theoretically could be accomplished by manipulating the oligopeptide permease (App) system.⁷ In order to verify that altering the App system would successfully impede peptide uptake, first the expression of the app Promoter Region ( …

Expression Levels Of Virulence Genes In Group A Streptococci: A Response To Aerosolized Propylene Glycol, Michael S. Costello

Honors Undergraduate Theses

Electronic cigarette usage is becoming increasingly prevalent among school age children and young adults. A known bactericidal agent, propylene glycol, is often used as a carrier for nicotine, flavoring, and additional constituents of electronic cigarette juice. This study examined the relationship between propylene glycol and virulence gene expression in Streptococcus pyogenes, a respiratory tract pathogen commonly found in school-age individuals. A variety of virulence genes controlled by the three stand alone regulators mga, RofA, and Rgg/RopB were sampled in an effort to understand the pathway by which virulence is affected. The genes chosen encode C5a peptidase, fibronectin binding protein, hyaluronate …

Inhibition Of Bacterial Growth And Prevention Of Bacterial Adhesion With Localized Nitric Oxide Delivery, Julia Osborne

Dissertations, Master's Theses and Master's Reports

Bacterial infections continue to be a problem at the site of an indwelling medical device, and over the years, various bacterial strains have become more resistant to current antibiotic treatments. Bacterial infection at an indwelling medical device can be dangerous and affect the performance of the medical device which can ultimately lead to the failure of the device due to bacterial resistance to treatment.

Nitric Oxide (NO) has been shown to possess antibacterial properties to prevent and inhibit bacterial growth. NO releasing coatings on indwelling medical devices could provide a reduction in bacterial infections that occur at the device site …

Genetic Control Of Survival And Weight Loss During Pneumonic Burkholderia Pseudomallei (Bp) Infection, Felicia D. Emery

Theses and Dissertations (ETD)

Burkholderia pseudomallei (Bp) is a saprophytic, gram-negative aerobe and the causative agent of the disease melioidosis. Melioidosis is an infectious disease that occurs in humans and animals and is prevalent in Southeast Asia, northern Australia and other tropical areas. Transmission occurs through direct contact with the organism via ingestion, inhalation, or through open wounds and skin abrasions. Clinical presentation is extremely variable and can range from acute septicemia with bacterial dissemination to distant sites, to an isolated pulmonary infection. Treatment of melioidosis can be problematic because it is often difficult to diagnose and Bp is resistant to a diverse group …

Granulocyte Colony-Stimulating Factor: Its Role In Gut-Homing Macrophage Generation And Colitis, And Production By Probiotics, Shahab Meshkibaf

Electronic Thesis and Dissertation Repository

The pleiotropic cytokine granulocyte-colony stimulatory factor (G-CSF) is mainly required for the generation of neutrophils, but its role in macrophage generation has also been reported. In addition, G-CSF is effective for the down-regulation of inflammatory cytokines and ameliorating gut disorders, such as colitis. However, the G-CSF function in macrophage generation and gut immunity remains unclear. The first focus of this thesis was to assess the role of G-CSF in macrophage generation and its contribution to gut immunity. G-CSF was found to promote the generation of Gr-1high/F4/80+ macrophages in macrophage (M)-CSF-treated bone marrow cells, most likely through suppressing cell death. Gr-1high …