Microbiology 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 …

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 …

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 …

A Systematic Review: Toxoplasma Gondii Infection And Drugs Of Abuse, Amani Sastry

Annual Research Symposium

No abstract provided.

Genetic Determinants Involved In Acquisition Of Iron In The Opportunistic Pathogen Mycobacterium Abscessus, Manal F. Farhat

Dissertations, Theses, and Capstone Projects

The opportunistic pathogen Mycobacterium abscessus subsp. abscessus (Mab) has become an emerging public health threat due to the increasing number of Mab-associated chronic pulmonary disease cases. Infection cure rates are only 50% due to the complex resistance of Mab to most antimicrobial drugs and chemotherapy.

Deeper knowledge of Mab biology is needed to illuminate potential candidates for development of improved therapeutics against Mab infections. The ESX-3 type VII protein secretion system of Mab plays an important role in host inflammatory and pathological responses during infection.

In this study, we demonstrate a functional link between the ESX-3 secretion …

Clonal Diversity, Antibiotic Resistance, And Virulence Factor Prevalence Of Community Associated Staphylococcus Aureus In Southeastern Virginia, Katelyn D. Cranmer, Mohan D. Pant, Suzanne Quesnel, Julia A. Sharp

EVMS School of Health Professions Faculty Publications

Staphylococcus aureus is a significant human pathogen with a formidable propensity for antibiotic resistance. Worldwide, it is the leading cause of skin and soft tissue infections (SSTI), septic arthritis, osteomyelitis, and infective endocarditis originating from both community- and healthcare associated settings. Although often grouped by methicillin resistance, both methicillin-resistant (MRSA) and methicillin-sensitive (MSSA) strains are known to cause significant pathologies and injuries. Virulence factors and growing resistance to antibiotics play major roles in the pathogenicity of community-associated strains. In our study, we examined the genetic variability and acquired antibiograms of 122 S. aureus clinical isolates from SSTI, blood, and urinary …

Identification Of Novel Biosynthetic Gene Clusters Encoding For Polyketide/Nrps-Producing Chemotherapeutic Compounds From Marine-Derived Streptomyces Hygroscopicus From A Marine Sanctuary, Hannah Ruth Flaherty

Honors Theses and Capstones

Nearly one out of six deaths in 2020, around ten million people, were caused by cancer, making it a leading cause of death worldwide (WHO, 2022). This major public health issue, in addition to the rise of multidrug-resistant (MDR) pathogens, provides a high demand for the discovery of new pharmaceutical drugs to be used clinically to treat these conditions. The Streptomyces genus accounts to produce 39% of all microbial metabolites currently approved for human health, indicating its potential as an important species to study for antimicrobial and anticancer agents. The long linear genome of Streptomyces contains specialized sequences known as …

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 …

Location Of The Fibronectin Binding Domain On The Fibronectin Attachment Protein Of Mycobacterium Avium Subsp. Paratuberculosis, Chrissy Rose Hattery

All Graduate Theses, Dissertations, and Other Capstone Projects

Mycobacterium avium paratuberculosis (MAP) is an acid-fast bacillus that causes a fatal granulomatous ileocolitis called Johne’s Disease that affects primarily ruminants. The impact of MAP infection in the US dairy industry is particularly severe, with up to 70.4% of the herds being infected and annual losses as high as $1.5 billion. MAP is capable of persisting for months in the livestock environment and surviving the pasteurization process. While several vaccines are available, none can prevent infection and treatment with antimycobacterial chemotherapy does not result in a cure. Management and control of MAP infection requires characterization of host-pathogen interaction at the …

Marineepi: A Gui-Based Matlab Toolbox To Simulate Marine Pathogen Transmission, Gorka Bidegain, Tal Ben-Horin, Eric N. Powell, John M. Klinck, Eileen E. Hofmann

CCPO Publications

The Graphical User Interface (GUI) MarineEpi is presented as a Matlab toolbox for easily (i) constructing disease transmission models for different marine host-pathogen systems, (ii) running simulations by specifying initial conditions and model parameters, and (iii) interpreting the resulting time series of the host and pathogen population dynamics. MarineEpi users can generate models for systems in which pathogen transmission occurs through contact with infected individuals (SI), contact with dead infected individuals (SID), contact with environmental pathogens released by infected individuals (SIP), and contact with environmental pathogens released by dead infected individuals (SIPD). MarineEpi is a freely available GUI that provides …

Multipatch Stochastic Epidemic Model For The Dynamics Of A Tick-Borne Disease, Milliward Maliyoni, Holly D. Gaff, Keshlan S. Govinder, Faraimunashe Chirove

Biological Sciences Faculty Publications

Spatial heterogeneity and migration of hosts and ticks have an impact on the spread, extinction and persistence of tick-borne diseases. In this paper, we investigate the impact of between-patch migration of white-tailed deer and lone star ticks on the dynamics of a tick-borne disease with regard to disease extinction and persistence using a system of Itô stochastic differential equations model. It is shown that the disease-free equilibrium exists and is unique. The general formula for computing the basic reproduction number for all patches is derived. We show that for patches in isolation, the basic reproduction number is equal to the …

Characterization Of The Function And Regulation Of The Hmpv Phosphoprotein, Rachel Thompson

Theses and Dissertations--Molecular and Cellular Biochemistry

Human metapneumovirus (HMPV) is a non-segmented, negative strand RNA virus (NNSV) that frequently causes respiratory tract infections in infants, the elderly, and the immunocompromised. Despite the initial identification of HMPV in 2001, there are currently no FDA approved antivirals or vaccines available. Therefore, understanding the mechanism of HMPV replication is critical for the identification of novel therapeutic targets. A key feature in the replication cycle of HMPV and other NNSVs is the formation of membrane-less, liquid-like replication and transcription centers in the cytosol termed inclusion bodies (IBs). Recent work on NNSV IBs suggests they display characteristics of biomolecular condensates formed …

Proposing An Rna Interference (Rnai)-Based Treatment For Human Immunodeficiency Virus (Hiv) By Analyzing The Post-Transcriptional Gene Targeting Of Sars-Cov-2, Hepatitis C Virus, And A549 Lung Cancer Cells, Arjun Jagdeesh

Undergraduate Research Posters

Human Immunodeficiency Virus (HIV) is a retrovirus that infects CD4+ T cell lymphocytes in humans, leading to the development of Acquired Immunodeficiency Syndrome (AIDS) if left untreated. While current treatment methods, including antiretroviral combination treatments, effectively limit HIV replication, HIV can evade these treatments due to its high mutation rate. Long-term antiretroviral treatment can also be toxic to patients, meaning patients would benefit from a new mechanism of HIV treatment. RNA interference (RNAi) is an antiviral pathway found in mammals, plants, and insects that involves a small-interfering RNA that is incorporated into a protein complex called the RNA-induced Silencing Complex …

The Rsv F P27 Peptide: Current Knowledge, Important Questions, Wanderson Rezende, Hadley E Neal, Rebecca E Dutch, Pedro A Piedra

Faculty, Staff and Students Publications

Respiratory syncytial virus (RSV) remains a leading cause of hospitalizations and death for young children and adults over 65. The worldwide impact of RSV has prioritized the search for an RSV vaccine, with most targeting the critical fusion (F) protein. However, questions remain about the mechanism of RSV entry and RSV F triggering and fusion promotion. This review highlights these questions, specifically those surrounding a cleaved 27 amino acids long peptide within F, p27.

Host-Pathogen Interactions In A Changing World: Microbes, Mucosal Defenses, And Multiple Hosts, Brandon C. Labumbard

Graduate Doctoral Dissertations

As fungal diseases continue to emerge, research increasingly focuses on host-microbiome interactions and links to disease. Certain skin-associated microbes may benefit hosts by protecting them from invading pathogens. Seasonal changes in the host environment can also result in shifts in the microbial community and pathogen virulence – potentially influencing disease dynamics. I investigated how cutaneous microbial communities differ across hosts, seasons, and Batrachochytrium dendrobatidis (Bd) infection status by sequencing the microbial communities of 1,100 leopard frogs at five locations across the US. Percent anti-Bd function varied seasonally and with Bd infection status. Bacterial communities also varied across locations and time. …

Alternative Precautionary Measures Yielding Lower C. Diff Infection Rates In Healthcare Facilities, Matthew Kramer

Symposium of Student Scholars

Background: An international healthcare concern is the persistent spread of Clostridium difficile, a Gram-positive spore forming bacterium that is responsible for the most common hospital-acquired infection, amongst patients.

Objective: A systematic review was performed to summarize evidence that the interventions utilized in healthcare facilities which indicate a patient’s precautionary status are insufficient, outdated, and commonly lead to infection in neighboring patient rooms. Databases such as PubMed, NCBI, Google Scholar, and APHA’s Medical Care were searched, covering the period from 2017-2022. Studies were included if their focus concentrated on C. diff and the precautionary measures taken by employees at healthcare …

The Mechanisms Of Mitochondrial Dysfunction In T Cell Aging During Chronic Viral Infection, Madison B. Schank

Electronic Theses and Dissertations

Human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infections induce a myriad of disturbances to CD4 T cell functions, including mitochondrial compromise, excessive inflammation, increased telomeric DNA damage and attrition, cellular exhaustion and senescence, and accelerated aging. In this dissertation, the mechanisms underlying metabolic failure, accelerated aging, and cellular dysfunctions were evaluated in CD4 T cells from healthy subjects (HS) treated with a telomere-targeting drug (KML001) or HCV-infected individuals or people living with HIV (PLHIV) compared to HS. We observed that KML001-induced telomere injury resulted in mitochondrial swelling and decreased mitochondrial membrane potential, cellular respiration, mitochondrial DNA (mtDNA) copy …

The Role Of Microbiota-Biotransformed Bile Acid Metabolites On Campylobacter Jejuni- And Clostridium Perfringens-Infection, Ying Fu

Graduate Theses and Dissertations

Campylobacter jejuni (C. jejuni) and Clostridium perfringens (C. perfringens) are two leading pathogenic bacteria responsible for both human and animal diseases. In chapters Ⅱ to Ⅳ, I presented an overview of current knowledge on the role of immune response, microbiota, bile acids and their microbial metabolites on campylobacteriosis, and C. perfringens induced necrotic diseases.In chapter Ⅴ, I investigated effects of deoxycholic acid-modulated anaerobes (DCA-Anaero) on attenuating chicken transmission-exacerbated campylobacteriosis. SPF Il10-/- mice were gavaged with clindamycin for 7 days followed by infected with three C. jejuni strains, Cj-P0 (C. jejuni AR101), Cj-P1 (from chicken pre-infected with C. jejuni AR101), and …

Investigating The Pi3k/Akt/Atm Pathway, Telomeric Dna Damage, T Cell Death, And Crispr/Cas9-Mediated Gene Editing During Acute And Chronic Hiv Infection, Sushant Khanal

Electronic Theses and Dissertations

Human Immunodeficiency Virus (HIV) infection initiates major metabolic and cell- survival complications. Anti-retroviral therapy (ART) is the current approach to suppress active HIV replication to a level of undetected viral load, but it is not a curative approach. Newer and sophisticated gene editing technologies could indeed be a potent antiviral therapy to achieve a clinical sterilization/cure of HIV infection. Chronic HIV patients, even under a successful ART regimen, exhibit a low-grade inflammation, immune senescence, premature aging, telomeric DNA attrition, T cell apoptosis, and cellular homeostasis. In this dissertation, we investigated CD4 T cell homeostasis, degree of T cell apoptosis, an …

Abnormalities In Cardiac And Inflammatory Biomarkers In Ambulatory Subjects After Covid-19 Infection, Joshua A Keefe, Vasanthi Avadhanula, Erin G Nicholson, Sridevi Devaraj, Pedro A Piedra, Biykem Bozkurt, Xander H T Wehrens

Faculty, Staff and Students Publications

BACKGROUND: Coronavirus-2019 (COVID-19) is known to affect the heart and is associated with a pro-inflammatory state. Most studies to date have focused on clinically sick subjects. Here, we report cardiac and proinflammatory biomarkers levels in ambulatory young adults with asymptomatic or mild COVID-19 infection compared to those without infection 4-8 weeks after severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) testing.

METHODS: 131 asymptomatic or mildly symptomatic subjects were enrolled following testing for SARS-COV-2. Fifty subjects tested negative, and 81 subjects tested positive. Serum samples were collected for measurement of C-reactive protein, ferritin, interleukin-6, NT-pro-B-type natriuretic peptide, and cardiac troponin 28-55 …

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 …

Optimization Of Clostridium Septicum Antigen Production And Evaluation Of Vaccine Administration Parameters For A Candidate Bacterin-Toxoid To Prevent Dermatitis In Commercial Turkeys, Aaron Forga

Graduate Theses and Dissertations

The objective of this thesis was to optimize the hemolytic activity of two isolates of Clostridium septicum to evaluate if hemolytic titer of C. septicum antigen at time of formalin inactivation corresponded to increased serum antibody titer to the C. septicum alpha-toxin of turkeys immunized with an experimental formalin inactivated bacterin-toxoid vaccine. Chapter 1 provides a brief overview of the thesis. Chapter 2 consists of a literature review focused on clostridial dermatitis, specifically C. septicum-associated dermatitis (cellulitis) that affects commercial turkeys. Chapter 3 outlines our attempts to optimize an experimental autogenous bacterin-toxoid vaccine as a potential strategy to mitigate clostridial …

Butyrate-Producing Bacteria And Insulin Homeostasis: The Microbiome And Insulin Longitudinal Evaluation Study (Miles), Jinrui Cui, Gautam Ramesh, Martin Wu, Elizabeth T Jensen, Osa Crago, Alain G Bertoni, Chunxu Gao, Kristi L Hoffman, Patricia A Sheridan, Kari E Wong, Alexis C Wood, Yii-Der I Chen, Jerome I Rotter, Joseph F Petrosino, Stephen S Rich, Mark O Goodarzi

Faculty, Staff and Students Publications

Gut microbiome studies have documented depletion of butyrate-producing taxa in type 2 diabetes. We analyzed associations between butyrate-producing taxa and detailed measures of insulin homeostasis, whose dysfunction underlies diabetes in 224 non-Hispanic Whites and 129 African Americans, all of whom completed an oral glucose tolerance test. Stool microbiome was assessed by whole-metagenome shotgun sequencing with taxonomic profiling. We examined associations among 36 butyrate-producing taxa (n = 7 genera and 29 species) and insulin sensitivity, insulin secretion, disposition index, insulin clearance, and prevalence of dysglycemia (prediabetes plus diabetes, 46% of cohort), adjusting for age, sex, BMI, and race. The genus Coprococcus …

Sars-Cov-2 Omicron (B.1.1.529) Variant: Structural Features, Biological Characteristics, Impact On Scientific Research, General Precautions And Protective Procedures; A Systematic Review, Prithivi Nagarajan, Anitha Vetrivel, Jayanthi Kumar, Anusheela Howlader, Kumar Rangarajalu, Satheesh Kumar Sabapathy, Muthu Gopal, Saravanaavel Kumar

Journal of Mind and Medical Sciences

The SARS-CoV-2 mutations that have occurred have alarmed the entire medical community. Thus, global concerns have been expressed regarding the transmission, pathogenicity and immune evasion of the Omicron strain, which shares mutations with the variants of concern Alpha, Beta, and Gamma strains. Still, Omicron transmission has crossed numerous borders worldwide compared to other types of SARS-CoV-2. The number of confirmed cases has increased and is reappearing in India. Given the worrisome situation created by the Omicron outbreak, scientists and postgraduates have had to make decisions about current research programs at institutions around the globe. The Omicron variants under development have …

Phylogenetic Diversity Of Animal Oral And Gastrointestinal Viromes Useful In Surveillance Of Zoonoses, Anthony Michael Esposito, Michelle Marie Esposito, Albert Ptashnik

Publications and Research

Great emphasis has been placed on bacterial microbiomes in human and animal systems. In recent years, advances in metagenomics have allowed for the detection and characterization of more and more native viral particles also residing in these organisms. The digestive tracts of animals and humans—from the oral cavity, to the gut, to fecal excretions—have become one such area of interest. Next-generation sequencing and bioinformatic analyses have uncovered vast phylogenetic virome diversity in companion animals, such as dogs and cats, as well as farm animals and wildlife such as bats. Zoonotic and arthropod-borne illnesses remain major causes of worldwide outbreaks, as …

Igg Antibodies To Sars-Cov-2 In Asymptomatic Blood Donors At Two Time Points In Karachi, Muhammad Hasan, Bushra Moiz, Shama Qaiser, Kiran I. Masood, Zara Ghous, Areeba Hussain, Natasha Bahadur Ali, Syed Hani Abidi, Kulsoom Ghias, Erum Khan, Zahra Hasan

Department of Pathology and Laboratory Medicine

Introduction: An estimated 1.5 million cases were reported in Pakistan until 23 March, 2022. However, SARS-CoV-2 PCR testing capacity has been limited and the incidence of COVID-19 infections is unknown. Volunteer healthy blood donors can be a control population for assessment of SARS-CoV-2 exposure in the population. We determined COVID-19 seroprevalence during the second pandemic wave in Karachi in donors without known infections or symptoms in 4 weeks prior to enrollment.
Materials and methods: We enrolled 558 healthy blood donors at the Aga Khan University Hospital between December 2020 and February 2021. ABO blood groups were determined. Serum IgG reactivity …

Microplastics In Freshly Fallen Snow: How May It Adversely Impact Human Health And Exacerbate The Covid-19 Crisis?, Ayesha Liaquat, Aleena Kashif, Sushma Rathi, Alishba Raza

Medical College Documents

No abstract provided.

Effect Of Sub-Inhibitory Concentrations Of Nitrofurantoin, Ciprofloxacin And Trimethoprim On In-Vitro Biofilm Formation In Uropathogenic Escherichia Coli, Shane Whelan

ORBioM (Open Research BioSciences Meeting)

The purpose of the current study was to determine the effect of sublethal concentrations of nitrofurantoin, ciprofloxacin and trimethoprim on biofilm formation in 57 uropathogenic Escherichia coli strains (UPEC).

The MIC of nitrofurantoin, ciprofloxacin and trimethoprim was determined for 57 UPEC isolates. Biofilm formation for each isolate with and without sub-lethal concentrations of each antibiotic was then quantified, and the statistical significance of changes in biofilm formation was ascertained by way of a Dunnett's test.

The effects of sub-MIC antibiotics on biofilm formation of UPEC were variable. A total of 22.8% of strains were induced to form biofilm by nitrofurantoin, …

Temporal Changes In Gastrointestinal Fungi And The Risk Of Autoimmunity During Early Childhood: The Teddy Study, Thomas A Auchtung, Christopher J Stewart, Daniel P Smith, Eric W Triplett, Daniel Agardh, William A Hagopian, Anette G Ziegler, Marian J Rewers, Jin-Xiong She, Jorma Toppari, Åke Lernmark, Beena Akolkar, Jeffrey P Krischer, Kendra Vehik, Jennifer M Auchtung, Nadim J Ajami, Joseph F Petrosino

Faculty, Staff and Students Publications

Fungal infections are a major health problem that often begin in the gastrointestinal tract. Gut microbe interactions in early childhood are critical for proper immune responses, yet there is little known about the development of the fungal population from infancy into childhood. Here, as part of the TEDDY (The Environmental Determinants of Diabetes in the Young) study, we examine stool samples of 888 children from 3 to 48 months and find considerable differences between fungi and bacteria. The metagenomic relative abundance of fungi was extremely low but increased while weaning from milk and formula. Overall fungal diversity remained constant over …

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 …