Medicine and Health Sciences Commons^™

Interplay Between Acetylation And Ubiquitination Of Imitation Switch Chromatin Remodeler Isw1 Confers Multidrug Resistance In Cryptococcus Neoformans, Yang Meng, Yue Ni, Zhuoran Li, Tianhang Jiang, Tianshu Sun, Yanjian Li, Xindi Gao, Hailong Li, Chenhao Suo, Chao Li, Sheng Yang, Tian Lan, Guojian Liao, Tongbao Liu, Ping Wang, Chen Ding

School of Medicine Faculty Publications

Cryptococcus neoformans poses a threat to human health, but anticryptococcal therapy is hampered by the emergence of drug resistance, whose underlying mechanisms remain poorly understood. Herein, we discovered that Isw1, an imitation switch chromatin remodeling ATPase, functions as a master modulator of genes responsible for in vivo and in vitro multidrug resistance in C. neoformans. Cells with the disrupted ISW1 gene exhibited profound resistance to multiple antifungal drugs. Mass spectrometry analysis revealed that Isw1 is both acetylated and ubiquitinated, suggesting that an interplay between these two modification events exists to govern Isw1 function. Mutagenesis studies of acetylation and ubiquitination sites …

The Implications Of Ferroptosis In Antibiotic Resistance, Marysol Hohl

Senior Honors Theses

Bacterial infections in the United States are becoming increasingly resistant to existing antibiotic treatments. Due to projected increases in resistance and the recent decrease in novel antibacterials, experts have determined that the United States is in the “post-antibiotic era.” The scientific community has failed to resolve resistance despite the continual discovery of new antibiotic compounds. In the past decade, a novel form of cell death called ferroptosis has been implicated in antibiotic treatment by employing the use of nanotechnology. This literature review will describe the problem of bacterial resistance and demonstrate how current research is pioneering a new age of …

Correlation Of Acetylcholinesterase Activity And Bone Biochemical Markers In Premature And Full-Term Neonates, Khaled Mohammed Elsayed, Abd Elaziz Abd Elrahman Alnokaly, Mohammed Abd El-Malik Hassan, Mabrouk Mahmoud Abo Elenin

Al-Azhar International Medical Journal

Background: Prematurity lowers body weight and bone mineral density in nearly 30% of preterm newborns. Premature newborns are not screened for metabolic bone disease, hence bone biochemical markers should be investigated. Acetylcholinesterase mediates bone remodeling in recent investigations. Bone biochemical indicators and acetylcholinesterase (AChE) levels in preterm newborns may be linked. Objective: The aim of our study is to evaluate the probable correlation of AChE levels with multiple bone biomarkers in full-term and premature neonates. Subjects and Methods: This study was designed as a case control study. We examined 80 newborns (40 preterm with gestational age less than 37 weeks, …

Uterine Artery Doppler Indices As Determinant Of Success In Intra Cytoplasmic Sperm Injection, Abd-Elqawy Hendawy Shams, Fahd Abd Elall El Omda, Noha Mohamed Sabry

Al-Azhar International Medical Journal

Background: In-Vitro Fertilization (IVF). Patients with infertility are usually advised to have intracytoplasmic sperm injections (ICSI). Doppler ultrasound, which uses high frequency transvaginal probes and coloured pictures, is one of the most frequently used methods in this field. One of the parameters supplied by an ultrasonographic test for determining the success of IVF includes endometrial thickness, endometrial pattern, endometrial volume, and endometrial blood flow. Aim: To detect implantation window using uterine artery indices in ICSI cycles. Subject and Methods: This study will be concluded at the assisted reproductive techniques unit of AlAzhar University on 100 patients. Results: Regarding BMI, there …

Protocol To Identify The Core Gene Supported By An Essential Gene In E. Coli Bacteria Using A Genome-Wide Suppressor Screen, Isao Masuda, Ya-Ming Hou

Department of Biochemistry and Molecular Biology Faculty Papers

We describe here a genome-wide screening approach to identify the most critical core reaction among a network of many that are supported by an essential gene to establish cell viability. We describe steps for maintenance plasmid construction, knockout cell construction, and phenotype validation. We then detail isolation of suppressors, whole-genome sequencing analysis, and reconstruction of CRISPR mutants. We focus on E. coli trmD, which encodes an essential methyl transferase that synthesizes m1G37 on the 3'-side of the tRNA anticodon. For complete details on the use and execution of this protocol, please refer to Masuda et al. (2022).

Cellular Dynamics And Disease Outcome Of Type 3 Streptococcus Pneumoniae Clinical Isolates Differ Between Strains, Taylor Rae Plunkett White

Theses and Dissertations (ETD)

Streptococcus pneumoniae is a bacterial pathogen that continues to be a major cause of disease around the world. It is not only the number one cause of bacterial pneumonia but also the cause of about 15% of the deaths of children under 5 around the world. There is a lot of research done on this organism, but with around 100 known serotypes and each one producing a unique capsule, there is still much more to be studied. The Etiology of Pneumonia in the Community (EPIC) study conducted by the CDC observed the burden of hospitalizations caused by pneumonia while determining …

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 …

Evaluation Of Stratified Antibiograms For Use In Laboratory And Antimicrobial Stewardship, Linsey Donner

Theses & Dissertations

Antibiograms are critical for choosing empiric antimicrobial therapy. Cumulative antibiograms, which aggregate susceptibility data, can mask differences within specific patient subsets or clinical syndromes. This dissertation was done to determine if antibiotic susceptibilities showed substantial differences when comparing stratified antibiograms to cumulative antibiograms.

Antibiotic susceptibility data was retrospectively obtained from Nebraska Medicine January 1, 2017 – December 31, 2019 for Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, and Enterococcus faecalis. The University of Nebraska Medical Center’s web antibiogram clinical decision support tool was used to export the data. Bacteria-antibiotic susceptibility rates of stratified antibiograms …

Expression And Purification Of Phage T7 Ejection Proteins For Cryo-Em Analysis, Nicholas A. Swanson, Ravi K Lokareddy, Fenglin Li, Chun-Feng Hou, Mikhail Pavlenok, Michael Niederweis, Gino Cingolani

Department of Biochemistry and Molecular Biology Faculty Papers

Bacteriophages of the Podoviridae family densely package their genomes into precursor capsids alongside internal virion proteins called ejection proteins. In phage T7 these proteins (gp14, gp15, and gp16) are ejected into the host envelope forming a DNA-ejectosome for genome delivery. Here, we describe the purification and characterization of recombinant gp14, gp15, and gp16. This protocol was used for high-resolution cryo-EM structure analysis of the T7 periplasmic tunnel and can be adapted to study ejection proteins from other phages. For complete details on the use and execution of this protocol, please refer to Swanson et al.

Loss Of N1-Methylation Of G37 In Trna Induces Ribosome Stalling And Reprograms Gene Expression, Isao Masuda, Jae-Yeon Hwang, Thomas Christian, Sunita Maharjan, Fuad Mohammad, Howard Gamper, Allen R. Buskirk, Ya-Ming Hou

Department of Biochemistry and Molecular Biology Faculty Papers

N¹-methylation of G37 is required for a subset of tRNAs to maintain the translational reading-frame. While loss of m¹G37 increases ribosomal +1 frameshifting, whether it incurs additional translational defects is unknown. Here, we address this question by applying ribosome profiling to gain a genome-wide view of the effects of m¹G37 deficiency on protein synthesis. Using E coli as a model, we show that m¹G37 deficiency induces ribosome stalling at codons that are normally translated by m¹G37-containing tRNAs. Stalling occurs during decoding of affected codons at the ribosomal A site, indicating …

Molecular Interactions Of Human Cell Proteins With Sars-Cov-2 Versus Influenza Viruses, Linze Cowman

Honors Thesis

Molecular Interactions of Human Cell Proteins with SARS-CoV-2 versus Influenza

Viruses

Linze Cowman

Director: Victor Huber, Ph.D.

The novel Coronavirus Disease 2019, or COVID- 19, shows considerable similarity to a common influenza infection. Over the past year, innumerable studies have been investigating the Vitus in various capacities, from big-picture public health repercussions to the virus' biochemical interactions with human cells for infection. This research provides invaluable information in the ongoing war against infectious diseases. While the influenza virus is fairly well-understood, much surrounding the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains unclear, including its longevity, long-term health effects, methods …

Evaluating The Microbial Experience Influence On Anti-Tumor Immune Response, Jessica A. Ensing

Student Summer Scholars Manuscripts

Despite the steady increase of hygienic standards, the CDC continues to report an increase of immune-mediated diseases such as allergies and asthma. Human avoidance of microbial exposure and subsequently less experienced immune systems may be the cause for this increase. We investigated if increased microbial exposure results in increased immunity to cancer (B16 melanoma) by measuring activated lymphocytes between two groups of C57Bl/6 mice: specific pathogen free (SPF) mice (which had little microbial exposure) and cohoused (COH) mice (which were exposed to numerous microbes). Previous research shows that the CoH mouse model mimics a human adult’s immune system, while the …

Educational Case: A Case Of Transfusion-Transmitted Babesiosis: Diagnostic Perspectives Across The Clinical Laboratory., Kaitlyn Dykes, Alexis R. Peedin

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology.

Understanding Human Astrovirus From Pathogenesis To Treatment, Virginia Hargest

Theses and Dissertations (ETD)

While human astroviruses (HAstV) were discovered nearly 45 years ago, these small positive-sense RNA viruses remain critically understudied. These studies provide fundamental new research on astrovirus pathogenesis and disruption of the gut epithelium by induction of epithelial-mesenchymal transition (EMT) following astrovirus infection. Here we characterize HAstV-induced EMT as an upregulation of SNAI1 and VIM with a down regulation of CDH1 and OCLN, loss of cell-cell junctions most notably at 18 hours post-infection (hpi), and loss of cellular polarity by 24 hpi. While active transforming growth factor- (TGF-) increases during HAstV infection, inhibition of TGF- signaling does not hinder EMT induction. …

Testing The Ancestral Function Of Divergent Candida Albicans Virulence-Associated Proteins Via Expression In Saccharomyces Cerevisiae Mutants, Curtis Mack

Student Scholars Day Posters

Candida albicans is an opportunistic fungal pathogen and a member of the normal human microbiota. It is closely related to the harmless fungus, Saccharomyces cerevisiae. Some genes associated with the virulent nature of C. albicans are similar to genes in S. cerevisiae. Three of these genes, PHO13, NRG1, and TUP1 are known to repress the change from yeast to filamentous growth in C. albicans, an important virulence trait. However, similar genes in S. cerevisiae are known to have functional differences. Our goal was to see if the ancestral function of these genes have drifted apart by examining …

A Rapid Viability And Drug‑Susceptibility Assay Utilizing Mycobacteriophage As An Indicator Of Drug Susceptibilities Of Anti‑Tb Drugs Against Mycobacterium Smegmatis Mc2 155, Gillian Catherine Crowley, Jim O'Mahony, Aidan Coffey, Riona G. Sayers, Paul D. Cotter

Department of Biological Sciences Publications

Background: A rapid in-house TM4 mycobacteriophage-based assay, to identify multidrug resistance against various anti-tuberculosis drugs, using the fast-growing Mycobacterium smegmatis mc² 155 in a microtiter plate format was evaluated, based on phage viability assays. Methods: A variety of parameters were optimized before the study including the minimum incubation time for the drugs, phage and M. smegmatis mc² 155 to be in contact. An increase in phage numbers over 2 h was indicative that M. smegmatis mc² 155 is resistant to the drugs under investigation, however when phage numbers remained static, M. smegmatis mc² 155 found to …

Factors Affecting Biofilm Formation In Oral Pathogenic Bacteria Of The Red Complex, Sidney Nechacov

Theses and Dissertations (Comprehensive)

Periodontal disease, also known as periodontitis, is a dental disease that is estimated to affect 2.4 billion people worldwide. This disease is characterized by chronic inflammation and bleeding of gums, as well as loss of tooth bone density. Currently, treatments for the disease include dental surgeries and various types of antibiotics, but few are targeted specifically at the Red Complex bacteria which are strongly associated with chronic periodontitis. The Red Complex consists of three bacteria: Tannerella forsythia, Porphyromonas gingivalis and Treponema denticola. Each of these bacteria, are anaerobic oral pathogens that reside in the subgingival pocket adjacent to …

Total Salivary Protein Concentration And Its Correlation To Dental Caries, Emyli Peralta

Honors Undergraduate Theses

Introduction: According to the World Health Organization, dental cavities are the number one chronic disease in children. Saliva coats the teeth all day and can serve many functions to maintain and protect teeth. Saliva has many proteins that can be both detrimental and essential to the preservation of tooth enamel. The purpose of this study is to determine if a correlation exists between the total protein concentration in saliva and the prevalence of cavities in the mouth. We hypothesized that there would be a positive correlation with total salivary protein concentration and the prevalence of cavities in the participant. Methods: …

Comparing The Effectiveness Of Alternative And Prescription Antibiotics Against Gram-Positive Bacteria, Rachel Jenkins, Roan Dickenson, Sam Turnbull, Marcela Torres

Senior Theses

The rapid emergence of antibiotic-resistant bacteria is a global public health concern that threatens the efficacy of antibiotic drugs. We found that natural remedies, specifically coconut oil, honey and cinnamon essential oil, have the potential to be used as a clinical alternative to treat antibiotic-resistant infections. In this experiment, we performed a disk diffusion test and measured the area of inhibition of each treatment to compare the effectiveness of natural and prescription antibiotics. Cinnamon essential oil showed significantly greater antibiotic activity compared to a prescription treatment, amoxicillin. With bacterial resistance continuously expanding, more work needs to be done to determine …

Production Of Putative Enhanced Oral Cholera Vaccine Strains That Express Toxin-Coregulated Pilus, Caitlyn A. Hauke, Ronald K. Taylor

Dartmouth Scholarship

The use of whole cell killed (WCK) oral cholera vaccines is an important strategy for cholera prevention in endemic areas. To overcome current vaccine limitations, we engineered strains of V. cholerae to be non-toxigenic and to express the protective protein colonization factor, toxin-coregulated pilus (TCP), under scale-up conditions potentially amenable to vaccine production. Two V. cholerae clinical strains were selected and their cholera toxin genes deleted. The tcp operon was placed under control of a rhamnose-inducible promoter. Production and stability of TCP were assessed under various conditions. The strains lack detectable cholera toxin production. The addition of 0.1% …

Boosting Of Hiv Envelope Cd4 Binding Site Antibodies With Long Variable Heavy Third Complementarity Determining Region In The Randomized Double Blind Rv305 Hiv-1 Vaccine Trial, David Easterhoff, M. Anthony Moody, Daniela Fera, Hao Cheng, Margaret Ackerman

Dartmouth Scholarship

The canary pox vector and gp120 vaccine (ALVAC-HIV and AIDSVAX B/E gp120) in the RV144 HIV-1 vaccine trial conferred an estimated 31% vaccine efficacy. Although the vaccine Env AE.A244 gp120 is antigenic for the unmutated common ancestor of V1V2 broadly neutralizing antibody (bnAbs), no plasma bnAb activity was induced. The RV305 (NCT01435135) HIV-1 clinical trial was a placebo-controlled randomized double-blinded study that assessed the safety and efficacy of vaccine boosting on B cell repertoires. HIV-1- uninfected RV144 vaccine recipients were reimmunized 6–8 years later with AIDSVAX B/E gp120 alone, ALVAC-HIV alone, or a combination of ALVAC-HIV and AIDSVAX B/E gp120 …

Comparative Genomic Analysis Of Two Serotype 1/2b Listeria Monocytogenes Isolates From Analogous Environmental Niches Demonstrates The Influence Of Hypervariable Hotspots In Defining Pathogenesis, Aidan Casey, Kieran Jordan, Aidan Coffey, Edward M. Fox, Olivia Mcauliffe

Department of Biological Sciences Publications

The vast majority of clinical human listeriosis cases are caused by serotype 1/2a, 1/2b, 1/2c, and 4b isolates of Listeria monocytogenes. The ability of L. monocytogenes to establish a systemic listeriosis infection within a host organism relies on a combination of genes that are involved in cell recognition, internalization, evasion of host defenses, and in vitro survival and growth. Recently, whole genome sequencing and comparative genomic analysis have proven to be powerful tools for the identification of these virulence-associated genes in L. monocytogenes. In this study, two serotype 1/2b strains of L. monocytogenes with analogous isolation sources, but …

Nucleoside-Diphosphate-Kinase Of P. Gingivalis Is Secreted From Epithelial Cells In The Absence Of A Leader Sequence Through A Pannexin-1 Interactome, Kalina Atanasova, Jungnam Lee, Joann Roberts, Kyulim Lee, David M. Ojcius, Özlem Yilmaz

All Dugoni School of Dentistry Faculty Articles

Nucleoside-diphosphate-kinases (NDKs) are leaderless, multifunctional enzymes. The mode(s) of NDK secretion is currently undefined, while extracellular translocation of bacterial NDKs is critical for avoidance of host pathogen clearance by opportunistic pathogens such as Porphyromonas gingivalis. P. gingivalis-NDK during infection inhibits extracellular-ATP (eATP)/P2X7-receptor mediated cell death in gingival epithelial cells (GECs) via eATP hydrolysis. Furthermore, depletion of pannexin-1-hemichannel (PNX1) coupled with P2X7-receptor blocks the infection-induced eATP release in GECs, and P. gingivalis-NDK impacts this pathway. Ultrastructural and confocal microscopy of P. gingivalis-co-cultured GECs or green-fluorescent-protein (GFP)-P. gingivalis-NDK transfected GECs revealed a perinuclear/cytoplasmic localization of NDK. eATP stimulation induced NDK recruitment to …

Changing Diagnostic Methods And Increased Detection Of Verotoxigenic Escherichia Coli, Ireland, Thomas Rice, Noreen Quinn, Roy D. Sleator, Brigid Lucey

Department of Biological Sciences Publications

The recent paradigm shift in infectious disease diagnosis from culture-based to molecular-based approaches is exemplified in the findings of a national study assessing the detection of verotoxigenic Escherichia coli infections in Ireland. The methodologic changes have been accompanied by a dramatic increase in detections of non-O157 verotoxigenic E. coli serotypes.

A Tail Of Two Phages: Genomic And Functional Analysis Of Listeria Monocytogenes Phages Vb_Lmos_188 And Vb_Lmos_293 Reveal The Receptor-Binding Proteins Involved In Host Specificity, Aidan Casey, Kieran Jordan, Horst Neve, Aidan Coffey, Olivia Mcauliffe

Department of Biological Sciences Publications

The physical characteristics of bacteriophages establish them as viable candidates for downstream development of pathogen detection assays and biocontrol measures. To utilize phages for such purposes, a detailed knowledge of their host interaction mechanisms is a prerequisite. There is currently a wealth of knowledge available concerning Gram-negative phage-host interaction, but little by comparison for Gram-positive phages and Listeria phages in particular. In this research, the lytic spectrum of two recently isolated Listeria monocytogenes phages (vB_LmoS_188 and vB_LmoS_293) was determined, and the genomic basis for their observed serotype 4b/4e host-specificity was investigated using comparative genomics. The late tail genes of these …

The Controversy Of Vaccinations, Nicholas G. Aboreden

The Kabod

Recently vaccination has become a controversial topic. There is a growing number of people who believe that vaccines carry great health risks to patients and therefore refuse to be vaccinated or to vaccinate their children. This ill-informed view of immunizations is beginning to cause serious problems in the United States as growing numbers of disease cases are being seen. A closer look into the science of vaccines and the benefits they have brought, clearly show that not only do vaccines carry very little risk to patients, but they are responsible for the eradication and reduction of multiple debilitating diseases.

Application Of Β-Lactamase Reporter Fusions As An Indicator Of Effector Protein Secretion During Infections With The Obligate Intracellular Pathogen Chlamydia Trachomatis , Konrad E. Mueller, Kenneth A. Fields

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Chlamydia spp. utilize multiple secretion systems, including the type III secretion system (T3SS), to deploy host-interactive effector proteins into infected host cells. Elucidation of secreted proteins has traditionally required ectopic expression in a surrogate T3SS followed by immunolocalization of endogenous candidate effectors to confirm secretion by chlamydiae. The ability to transform Chlamydia and achieve stable expression of recombinant gene products has enabled a more direct assessment of secretion. We adapted TEM-1 β-lactamase as a reporter system for assessment of chlamydial protein secretion. We provide evidence that this system facilitates visualization of secretion in the context of infection. Specifically, our findings …

A Self-Lysis Pathway That Enhances The Virulence Of A Pathogenic Bacterium, Kirsty A. Mcfarland, Emily L. Dolben, Michele Leroux, Tracy K. Kambara, Kathryn Ramsey, Robin Kirkpatrick, Joseph Mougous, Deborah Hogan, Simon Dove

Dartmouth Scholarship

In mammalian cells, programmed cell death (PCD) plays important roles in development, in the removal of damaged cells, and in fighting bacterial infections. Although widespread among multicellular organisms, there are relatively few documented instances of PCD in bacteria. Here we describe a potential PCD pathway in Pseudomonas aeruginosa that enhances the ability of the bacterium to cause disease in a lung infection model. Activation of the system can occur in a subset of cells in response to DNA damage through cleavage of an essential transcription regulator we call AlpR. Cleavage of AlpR triggers a cell lysis program through de-repression of …

Site-Specific Mutation Of The Sensor Kinase Gras In Staphylococcus Aureus Alters The Adaptive Response To Distinct Cationic Antimicrobial Peptides, Ambrose L. Cheung, Arnold S. Bayer, Michael R. Yeaman, Yan Q. Xiong, Alan J. Waring, Guido Memmi, Niles Donegan

Dartmouth Scholarship

The Staphylococcus aureus two-component regulatory system, GraRS, is involved in resistance to killing by distinct host defense cationic antimicrobial peptides (HD-CAPs). It is believed to regulate downstream target genes such as mprF and dltABCD to modify the S. aureus surface charge. However, the detailed mechanism(s) by which the histidine kinase, GraS, senses specific HD-CAPs is not well defined. Here, we studied a well-characterized clinical methicillin-resistant S. aureus (MRSA) strain (MW2), its isogenic graS deletion mutant (ΔgraS strain), a nonameric extracellular loop mutant (ΔEL strain), and four residue-specific ΔEL mutants (D37A, P39A, P39S, and D35G D37G D41G strains). The ΔgraS and …

Acidosis Potentiates The Host Proinflammatory Interleukin-1Β Response To Pseudomonas Aeruginosa Infection, I. M. Torres, Y. R. Patankar, Tamer B. Shabaneh, E. Dolben, Deborah Hogan, David Leib, Brent L. Berwin

Dartmouth Scholarship

Infection by Pseudomonas aeruginosa, and bacteria in general, frequently promotes acidification of the local microenvironment, and this is reinforced by pulmonary exertion and exacerbation. However, the consequence of an acidic environment on the host inflammatory response to P. aeruginosa infection is poorly understood. Here we report that the pivotal cellular and host proinflammatory interleukin-1β (IL-1β) response, which enables host clearance of the infection but can produce collateral inflammatory damage, is increased in response to P. aeruginosa infection within an acidic environment. Synergistic mechanisms that promote increased IL-1β release in response to P. aeruginosa infection in an acidic environment are …