Pathogenic Microbiology Commons^™

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 …

Identification Of Pneumococcal Membrane Proteins Involved In Colonization/Biofilm Formation And Cognate Host Cellular Receptors, Yoonsung Hu

Theses and Dissertations

Colonization is prerequisite for infection and transmission of Streptococcus pneumoniae, or pneumococcus. Currently available pneumococcal conjugate and pneumococcal polysaccharide vaccines can provide protection against a limited number of capsular serotypes. Implementation of vaccines has decreased the frequency of invasive pneumococcal disease and their colonization rates, but only in a serotype-dependent manner. This has led to serotype replacement in pneumococcal ecology and increased invasive disease caused by non-vaccine serotypes. Development of conserved protein-based vaccine that can provide protection against all pneumococcal serotypes is needed. Numerous surface proteins are conserved in all serotypes, and some are known to be involved in …

Eskape Pathogens: The Clinical Prevalence And Molecular Mechanisms Of Antibiotic Resistance, Anusha Attre

Honors Scholar Theses

The ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) are the leading cause of all nosocomial, or healthcare-associated (HAI), infections (Navidinia, 2016). The purpose of this research study is to determine the burden of ESKAPE infections on healthcare and study the antibiotic resistance in these high-risk pathogens to provide direction for researchers to develop new antimicrobial innovations to reduce ESKAPE infectivity and improve patient outcomes. To study the burden of ESKAPE infections, this review analyzes the current statistics explaining the clinical prevalence of each pathogen in causing HAIs. Additionally, each pathogen is …

Cat Covid, Cmv And Chemokines, Oh My!, Trevor Hancock

Doctoral Dissertations

Cytomegalovirus (CMV) is an important pathogen infecting most humans worldwide. CMV infection within immunocompromised individuals can cause severe morbidity and potential mortality. Disease during CMV infection is due to virus dissemination and subsequent inflammation. Host immune cells lie at the intersection potentially mediating both. The CMV-encoded viral chemokine vCXCL-1 is a proposed virulence factor in mouse models increasing immune cell recruitment and disease. However, the primary immune cell mediator is undetermined. To identify targets, Chapter 2 examines CXCR2 expression (receptor for vCXCL-1) among various mouse tissues and human peripheral blood under steady-state conditions. In vitro, isoforms of HCMV’s vCXCL-1 …

Mechanisms By Which Xenorhabdus Nematophila Interacts With Hosts Using Integrated -Omics Approaches, Nicholas C. Mucci

Doctoral Dissertations

Nearly all organisms exist in proximity to microbes. These microbes perform most of the essential metabolic processes necessary for homeostasis, forming the nearly hidden support system of Earth. Microbial symbiosis, which is defined as the long-term physical association between host and microbes, relies on communication between the microbial community and their host organism. These interactions among higher order organisms (such as animals, plants, and fungi) and their bacteria links metabolic processes between interkingdom consortia. Many questions on microbial behavior within a host remain poorly understood, such as the colonization efficiency among different microbial species, or how environmental context changes their …

Native And Non-Native Ant Impacts On Soil Microbes, Hannah A. Stewart

Biology Theses

Organisms produce chemical weapons for defense, but target organisms can develop resistance. In their introduced range, non-native species may bring “novel weapons” against which native organisms have not co-evolved resistance. The invasive European fire ant (Myrmica rubra) may have brought antimicrobial secretions to the Northeastern United States that are novel weapons against native fungal and bacterial soil organisms. I hypothesized that M. rubra would better inhibit seed pathogens resulting in greater emergence of native myrmecochorous Viola sororia seeds and, as a side effect, more strongly inhibit arbuscular mycorrhizal fungi than a native seed dispersing ant (Aphaenogaster picea …

Characterizing The Interaction Between Candida Albicans And Two Enterobacter Species, Abigail Cornett

Electronic Theses and Dissertations

Candida albicans is the most common human fungal pathogen. The relationship between C. albicans and Enterobacter bacteria have yet to be explored. The hypothesis of this study is that C. albicans and both E. aerogenes and E. cloacae have a positive relationship and work together to infect the host. In this study, the physical cell-to-cell interaction, molecular components of said interaction, and the impact of the interaction on a live organism were explored. Results indicate that Enterobacter adheres to C. albicans and inhibits growth with unidentified secreted molecules. Als1p has potential involvement in the attachment of E. cloacae to C. …

Lysosomal Evasion Of Legionella Pneumophilia The Effector., Bethany Vaughn

Electronic Theses and Dissertations

Legionella pneumophila is a Gram-negative facultative intracellular bacterium found in freshwater environments that has co-evolved to survive and proliferate in various amoeba and protozoan species, which serve as the natural host for the bacterium. Humans are an accidental host of L. pneumophila, where infection occurs upon inhalation of aerosolized water droplets that contain the bacteria. Intracellular proliferation of L. pneumophila in alveolar macrophages is essential for manifestation of pneumonia, designated as Legionnaires’ Disease. Biogenesis of the legionella containing vacuole (LCV) occurs via interception of ER-Golgi vesicle trafficking and avoids the default endosomal/lysosomal degradation pathway. Intracellular proliferation of L. pneumophila …

The Microbiome Characterization And Comparison Of Loggerhead (Caretta Caretta) And Green (Chelonia Mydas) Sea Turtle Eggs In Broward County, Florida, Colleen Mcmaken

All HCAS Student Capstones, Theses, and Dissertations

All seven extant species of sea turtles are classified as threatened or endangered due to natural and anthropogenic impacts. Sea turtle conservation efforts are largely dedicated to ensuring healthy nesting activity. Hatching success of sea turtle eggs can be affected by several factors including the proliferation of pathogenic microbes. However, it is unclear as to which microbes have the most impact on hatching success and how they are transmitted into the eggs. The primary aims of this study characterized and compared the bacterial communities (microbiomes) from the i) cloaca of nesting sea turtles; ii) sand within and surrounding the nests …

Genomic Analysis Of Metabolic Differences Found In Clostridium Perfringens That Cause Necrotic Enteritis In Poultry, Connor Aylor

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

Clostridium perfringens is a common member of gut microbiota in healthy animals, but can also be an important pathogen in human and veterinary medicine. It produces several protein toxins that contribute to both histotoxic and enteric diseases in animals. Necrotic enteritis in poultry has been associated with the NetB toxin of C. perfringens; however, this toxin alone is insufficient to cause disease in infected chickens. While considerable research has focused on the presence of toxins and virulence factors, little has been done to assess the function of metabolic factors on the ability of the bacteria to cause disease. In …

Periodic Spatial Disturbances Alter The Expression Of Quorum Sensing Virulence Factors In Pseudomonas Aeruginosa, Laura García-Diéguez

All HCAS Student Capstones, Theses, and Dissertations

Pseudomonas aeruginosa is an opportunistic pathogen associated with severe acute and chronic illnesses. Current antibiotic-based approaches fail to effectively treat P. aeruginosa infections due to the effectiveness and robustness of the quorum sensing signaling system (QS). Pathogenic bacteria, such as P. aeruginosa, employ this population density-dependent communication mechanism to confer antimicrobial resistance, propagate infection, and coordinate the expression of virulence factors, through the production and detection of autoinducing signaling molecules (AI). As such, there is a growing interest in developing novel non-antibiotic-based techniques to attenuate the pathogenicity of P. aeruginosa by disrupting the functionality of its QS system. Previous …

Aeromonas Phage Research And The Public Health Impact Of Antibiotics In Aquaculture Workers, Madelyn Merchant

Honors Projects

One of the most common fish diseases in aquaculture is Aeromonas infection. The most common way to treat this infection is through antibiotics. The bacteria in the fish can become antibiotic-resistant and perpetuate the disease. The diseases in fish create a huge financial loss and the industry loses $6 billion per year due to diseases in fish. An alternative to antibiotics is bacteriophage which causes less environmental degradation and is better for human gut flora. In aquaculture there have been examples of aquaculture workers becoming sick from the water in aquaculture ponds as well as from people eating the fish. …

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 …

Microbial Contamination On Ambulance Surfaces: A Systematic Literature Review, Adam Obenza, Patricia Cruz, Mark Buttner, D. Woodard

Environmental & Occupational Health Faculty Publications

Healthcare-associated infections (HAIs) are infections that patients acquire while receiving medical treatment in a healthcare facility. During ambulatory transport, the patient may be exposed to pathogens transmitted from emergency medical service (EMS) personnel or EMS surfaces. The aim of this study was to determine whether organisms commonly associated with HAIs have been detected on surfaces in the patient-care compartment of ambulances. Five electronic databases – PubMed, Scopus, Web of Science, Embase and Google Scholar were used to search for articles using inclusion and exclusion criteria following the PRISMA checklist. Inclusion criteria consisted of articles published in English, between 2009 and …

Sars-Cov-2 Reveals That Chimeric Agents Are The Bioweapons Of The Future, Rachel Craig

Senior Honors Theses

Bioweapons programs have existed since their development during the Cold War. These biowarfare programs initially utilized naturally occurring pathogens capable of infecting crops, livestock populations, and human populations. Anthrax is a widely exploited bioagent responsible for attacks ranging from the Germans’ deployment in World War I to the mailing of anthrax through the postal service in attempts on U.S. senators’ lives. With the development of genetic manipulations, the Soviet Union began modifying anthrax to resist detection and treatment. With the continued advancement of science and technology, a new bioagent has entered the scene – the man-made chimeric virus. Chimeric viruses …

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.

Screening For Binding Partners And Protein-Protein Interactions Of A Fungal Transcription Factor- Xdr1, Nishadi Punsara Gallala Gamage

Masters Theses

Clarireedia spp. (formerly Sclerotinia homoeocarpaF.T. Bennett) is the causal agent dollar spot, the most economically important turfgrass disease impacting golf courses in North America. The most effective strategy for dollar spot control is repeated application of multiple classes of fungicides. However, reliance on chemical application has led to resistance to four classes of fungicides as well as multidrug resistance (MDR). Fungi are known to detoxify xenobiotics, like fungicides, through transcriptional regulation of three detoxification phases: modification, conjugation and secretion. Little is known, however, of the protein-protein interactions that facilitate these pathways. Following next-generation RNA sequencing of Clarireedia spp., a …

The Coxsackievirus And Adenovirus Receptor Has A Short Half-Life In Epithelial Cells, Poornima Kotha Lakshmi Narayan, James M. Readler, Mahmoud S. Alghamri, Trisha L. Brockman, Ray Yan, Priyanka Sharma, Vladislav Snitsarev, Katherine J.D.A Excoffon, Abimbola O. Kolawole

Department of Biology Faculty Scholarship and Creative Works

The coxsackievirus and adenovirus receptor (CAR) is an essential cellular protein that is involved in cell adhesion, cell signaling, and viral infection. The 8-exon encoded isoform (CAREx8) resides at the apical surface of polarized epithelia, where it is accessible as a receptor for adenovirus entering the airway lumen. Given its pivotal role in viral infection, it is a target for antiviral strategies. To understand the regulation of CAREx8 and determine the feasibility of receptor down regulation, the half-life of total and apical localized CAREx8 was determined and correlated with adenovirus transduction. Total and apical CAREx8 has a relatively short half-life …

An Exploratory Study On The Microbiome Of Northern And Southern Populations Of Ixodes Scapularis Ticks Predicts Changes And Unique Bacterial Interactions, Deepak Kumar, Latoyia P. Downs, Abdulsalam Adegoke, Erika Machtinger, Kelly Oggenfuss, Richard S. Ostfeld, Monica Embers, Shahid Karim

Faculty Publications

The black-legged tick (Ixodes scapularis) is the primary vector of Borrelia burgdorferi, the causative agent of Lyme disease in North America. However, the prevalence of Lyme borreliosis is clustered around the Northern States of the United States of America. This study utilized a metagenomic sequencing approach to compare the microbial communities residing within Ix. scapularis populations from northern and southern geographic locations in the USA. Using a SparCC network construction model, we performed potential interactions between members of the microbial communities from Borrelia burgdorferi–infected tissues of unfed and blood-fed ticks. A significant difference in bacterial composition …

Thrombospondin-1 Expression And Modulation Of Wnt And Hippo Signaling Pathways During The Early Phase Of Trypanosoma Cruzi Infection Of Heart Endothelial Cells, Ashutosh Arun, Kayla J. Rayford, Ayorinde Cooley, Tanu Rana, Girish Rachakonda, Fernando Villalta, Siddharth Pratap, Maria F. Lima, Nader Sheibani, Pius N. Nde

Publications and Research

The protozoan parasite, Trypanosoma cruzi, causes severe morbidity and mortality in afflicted individuals. Approximately 30% of T. cruzi infected individuals present with cardiac pathology. The invasive forms of the parasite are carried in the vascular system to infect other cells of the body. During transportation, the molecular mechanisms by which the parasite signals and interact with host endothelial cells (EC) especially heart endothelium is currently unknown. The parasite increases host thrombospondin-1 (TSP1) expression and activates the Wnt/β-catenin and hippo signaling pathways during the early phase of infection. The links between TSP1 and activation of the signaling pathways and …

Links Between Electrophilic Stress And Antifungal Resistance In Pathogenic Candida Species, Amy R. Biermann

Dartmouth College Ph.D Dissertations

Collectively, Candida species are the most prevalent cause of both superficial and invasive fungal infections worldwide. Invasive Candida infections have a high mortality rate and predominantly affect individuals with underlying diseases, such as diabetes, HIV, or cancer. Unfortunately, many invasive Candida infections are recalcitrant to antifungal treatment, while intrinsically multidrug-resistant pathogens, like Candida auris, are increasing in prevalence. Although the canonical mechanisms of antifungal resistance in Candida species are well established, i.e., overexpression of efflux pumps and overexpression of or mutations in genes encoding drug targets, factors affecting the natural evolution and regulation of resistance mechanisms remain poorly understood. …

Dissecting The Role Of Actin-Myosin Motor And Calcium – Based Organelle Secretion In Motility Of Sarcocystis Neurona, Parul Suri

Theses and Dissertations--Veterinary Science

Sarcocystis neurona is a protozoan parasite that causes a rare neurological disorder in horses called Equine Protozoal Myeloencephalitis (EPM). Apicomplexa use actin-myosin based motor and organelle secretion to interact with the host cell and invade it. Despite the importance of motility and invasion-needed factors, the mechanisms by which S. neurona employs host cell association strategies to interact remains largely undefined. To address this knowledge gap, we hypothesize that just like other Apicomplexa, S. neurona utilizes actin polymerization for substrate-dependent gliding. Moreover, we also hypothesize that micronemes of S. neurona secrete proteins that are calcium-dependent. Based on previous studies in T. …

A Multidisciplinary Characterization Of The Enzymology And Biology Of Reversible Glucan Phosphorylation In Toxoplasma Gondii , Robert Murphy

Theses and Dissertations--Molecular and Cellular Biochemistry

Toxoplasma gondii is an opportunistic, protozoan parasite of all warm-blooded animals, infecting roughly one-third of humans worldwide. Humans acquire infections by consuming T. gondii tissue cysts in undercooked meat or from oocysts shed in cat feces. Encysted parasites convert into rapidly growing tachyzoites that disseminate throughout the body, defining the acute phase of infection. Under host immune pressure, tachyzoites convert into bradyzoites that populate tissue cysts found in CNS or muscle tissue and persist for the lifetime of the host, defining the chronic phase of infection. Tissue cysts are responsible for transmission via carnivory, but also possess the ability to …

The Role Of The Skin Microbiome In Amphibian Pathogen Susceptibility In Turnbull National Wildlife Refuge, Krista S. Dodd

EWU Masters Thesis Collection

The fungal pathogen, Batrachochytrium dendrobatidis (Bd), has led to the decline and extinction of many amphibian populations, but some bacteria in the skin microbiome can inhibit its growth. In Turnbull National Wildlife Refuge (TNWR) in eastern Washington, Bd is highly prevalent, but the role of the skin microbiome in Bd infection dynamics have not been examined in this region. We hypothesized that frogs with lower Bd infection intensities would have higher skin bacterial diversity and more abundant anti-Bd bacteria, indicative of a more protective function. Our study combined cultureindependent and culture-dependent methods to assess the relationship between Bd and the …

Evaluate The Efficacy Of A Mixture Of Peroxyacetic Acid And H2o2 Against The Survival And Cross-Contamination Of The Salmonella Surrogate Enterococcus Faecium On Tomatoes During Triple-Wash, Corey Waitman Coe

Graduate Theses, Dissertations, and Problem Reports

Triple-wash with a mixture of peroxyacetic acid and H2O2 (SaniDate-5.0) during post-harvest processing of fresh produce has been recommended by West Virginia Small Farm Center to improve microbial safety. It has been well recognized that the washing of produce is more important for preventing cross-contamination than reducing foodborne pathogens. Furthermore, it may help improve public confidence in that the produce they obtain from locally grown farmers is safe for their consumption. determine the efficacy of SaniDate-5.0 for reducing the survival and preventing cross-contamination of the Salmonella surrogate Enterococcus faecium on tomatoes during triple-wash.

E. faecium ATCC-8459 (resistant to 100-ppm nalidixic-acid) …

Elucidation Of Novel And Established Campylobacter Species With Clinical And Agricultural Significance Through Phenotypic, Genotypic, And Taxonomic Investigation, Caoimhe Lynch

Theses

Campylobacter spp. are well-established human, veterinary and economic pathogens, with a broad host range spanning from terrestrial and marine mammalian, avian and reptilian hosts. The scope of the study includes novel and notorious species within the genus, with reference to zoonotic agents Campylobacter jejuni and Campylobacter coli - the leading cause of human bacterial gastroenteritis in the EU and Ireland, Campylobacter fetus that represents the most common campylobacter causing bacteraemia and two novel species isolated from pigs not described in the literature previously. C. jejuni and C. coli isolates (n = 350) recovered from broiler caecal and neck skin samples, …

Investigating Public Support For Biosecurity Measures To Mitigate Pathogen Transmission Through The Herpetological Trade, Elizabeth F. Pienaar, Diane J. Episcopio-Sturgeon, Zachary T. Steele

Biological Sciences Faculty Publications

The expanding global trade in herpetofauna has contributed to new infectious disease dynamics and pathways that allow for the rapid spread of pathogens geographically. Improved biosecurity is needed to mitigate adverse biodiversity, economic and human health impacts associated with pathogen transmission through the herpetological trade. However, general lack of knowledge of the pathogen transmission risks associated with the global trade in herpetofauna and public opposition to biosecurity measures are critical obstacles to successfully preventing pathogen transmission. In 2019 we administered a survey to 2,007 members of the public in the United States of America to ascertain their support for interventions …