Medical Microbiology Commons^™

The Kat Module Of The Saga Complex Maintains The Oncogenic Gene Expression Program In Mycn- Amplified Neuroblastoma, Clare F Malone, Nathaniel W Mabe, Alexandra B Forman, Gabriela Alexe, Kathleen L Engel, Melinda Soeung, Allen Basanthakumar, Bin Liu, Sharon Y R Dent, Kimberly Stegmaier

Faculty, Staff and Student Publications

Pediatric cancers are frequently driven by genomic alterations that result in aberrant transcription factor activity. Here, we used functional genomic screens to identify multiple genes within the transcriptional coactivator Spt-Ada-Gcn5-acetyltransferase (SAGA) complex as selective dependencies for MYCN-amplified neuroblastoma, a disease of dysregulated development driven by an aberrant oncogenic transcriptional program. We characterized the DNA recruitment sites of the SAGA complex in neuroblastoma and the consequences of loss of SAGA complex lysine acetyltransferase (KAT) activity on histone acetylation and gene expression. We demonstrate that loss of SAGA complex KAT activity is associated with reduced MYCN binding on chromatin, suppression of …

Nanobodies In The Fight Against Infectious Diseases: Repurposing Nature's Tiny Weapons, Dina Mohamed Moustafa, Soha S. Rizk, Shahira A. Elbanna, Hanzada Tawfik Nour El-Din, Ahmed Sherif Attia

Dentistry

Nanobodies are the smallest known antigen-binding molecules to date. Their small size, good tissue penetration, high stability and solubility, ease of expression, refolding ability, and negligible immunogenicity in the human body have granted them excellence over conventional antibodies. Those exceptional attributes of nanobodies make them promising candidates for various applications in biotechnology, medicine, protein engineering, structural biology, food, and agriculture. This review presents an overview of their structure, development methods, advantages, possible challenges, and applications with special emphasis on infectious diseases-related ones. A showcase of how nanobodies can be harnessed for applications including neutralization of viruses and combating antibiotic-resistant bacteria …

Comprehensive In Vitro And In Vivo Evaluation Of Therapeutic Potential Of Bacopa-Derived Asiatic Acid Against A Human Oral Pathogen Streptococcus Mutans, Rajendran Jeyasri, Pandiyan Muthuramalingam, Arumugam Priya, Rajaiah Alexpandi, N. R. Siva Shanmugam, Saminathan Nivetha, Hyunsuk Shin, Shunmugiah Karutha Pandian, Arumugam Veera Ravi, Manikandan Ramesh

Food for Health: Publications

Dental caries is a common human oral disease worldwide, caused by an acid-producing bacteria Streptococcus mutans. The use of synthetic drugs and antibiotics to prevent dental caries has been increasing, but this can lead to severe side effects. To solve this issue, developing and developed countries have resorted to herbal medicines as an alternative to synthetic drugs for the treatment and prevention of dental caries. Therefore, there is an urgent need for plant-derived products to treat such diseases. Bacopa monnieri, a well-documented medicinal plant, contains 52 phytocompounds, including the pentacyclic triterpenoid metabolite known as asiatic acid (ASTA). Hence, …

Antibiotic-Induced Changes In Efflux Transporter Expression: A Key Factor In Pseudomonas Aeruginosa Biofilm Resistance, Zara Imtiaz, Avinash Chatoo, Will Wang, Weiqi Li, Paramita Basu

Touro College of Pharmacy (New York) Publications and Research

Listed by WHO as an antibiotic-resistant priority pathogen, Pseudomonas aeruginosa(P.A.) is a serious threat in nosocomial infections. Its high antibiotic resistance is attributed to major mechanisms that can be categorized into intrinsic, acquired, and adaptive resistance. This study tests the ability of three commonly used antibiotics to inhibit new biofilm formation and eradicate mature biofilm growth, as well as investigate changes in the expression levels of selected genes coding for multidrug efflux pumps in P.A. planktonic cells and biofilms before and after treatment with antibiotics to provide a conceptual estimate of the activity of the efflux transporters that work to …

Standard Rodent Diets Differentially Impact Alcohol Consumption, Preference, And Gut Microbiome Diversity, Aline Zaparte, Evan Dore, Selby White, Franciely Paliarin, Cameron Gabriel, Katherine Copenhaver, Samhita Basavanhalli, Emily Garcia, Rishith Vaddavalli, Meng Luo, Christopher M. Taylor, David Allen Welsh, Rajani Maiya

School of Graduate Studies Faculty Publications

Alcohol use disorder (AUD) is a complex and widespread disease with limited pharmacotherapies. Preclinical animal models of AUD use a variety of voluntary alcohol consumption procedures to recapitulate different phases of AUD, including binge alcohol consumption and dependence. However, voluntary alcohol consumption in mice is widely variable, making it difficult to reproduce results across labs. Accumulating evidence indicates that different brands of commercially available rodent chow can profoundly influence alcohol intake. In this study, we investigated the effects of three commercially available and widely used rodent diet formulations on alcohol consumption and preference in C57BL/6 J mice using the 24 …

Evaluation Of Fusobacterium Nucleatum Enoyl-Acp Reductase (Fabk) As A Narrow-Spectrum Drug Target, Bibek Gc, Julian G Hurdle

Faculty, Staff and Student Publications

Fusobacterium nucleatum, a pathobiont inhabiting the oral cavity, contributes to opportunistic diseases, such as periodontal diseases and gastrointestinal cancers, which involve microbiota imbalance. Broad-spectrum antimicrobial agents, while effective against F. nucleatum infections, can exacerbate dysbiosis. This necessitates the discovery of more targeted narrow-spectrum antimicrobial agents. We therefore investigated the potential for the fusobacterial enoyl-ACP reductase II (ENR II) isoenzyme FnFabK (C4N14_ 04250) as a narrow-spectrum drug target. ENRs catalyze the rate-limiting step in the bacterial fatty acid synthesis pathway. Bioinformatics revealed that of the four distinct bacterial ENR isoforms, F. nucleatum specifically encodes FnFabK. Genetic studies revealed …

A Bioinformatic Analysis Of T-Cell Epitope Diversity In Sars-Cov-2 Variants: Association With Covid-19 Clinical Severity In The United States Population, Grace J. Kim, Jacob H. Elnaggar, Mallory Varnado, Amy K. Feehan, Darlene Tauzier, Rebecca Rose, Susanna L. Lamers, Maya Sevalia, Najah Nicholas, Elizabeth Gravois, Daniel Fort, Judy S. Crabtree, Lucio Miele

School of Graduate Studies Faculty Publications

Long-term immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) requires the identification of T-cell epitopes affecting host immunogenicity. In this computational study, we explored the CD8+ epitope diversity estimated in 27 of the most common HLA-A and HLA-B alleles, representing most of the United States population. Analysis of 16 SARS-CoV-2 variants [B.1, Alpha (B.1.1.7), five Delta (AY.100, AY.25, AY.3, AY.3.1, AY.44), and nine Omicron (BA.1, BA.1.1, BA.2, BA.4, BA.5, BQ.1, BQ.1.1, XBB.1, XBB.1.5)] in analyzed MHC class I alleles revealed that SARS-CoV-2 CD8+ epitope conservation was estimated at 87.6%–96.5% in spike (S), 92.5%–99.6% in membrane (M), and 94.6%–99% in …

Optimization Of The Antifungal Properties Of The Bacterial Peptide Entv By Variant Analysis, Michael C Lorenz

Faculty, Staff and Student Publications

Fungal resistance to commonly used medicines is a growing public health threat, and there is a dire need to develop new classes of antifungals. We previously described a peptide produced by Enterococcus faecalis, EntV, that restricts Candida albicans to a benign form rather than having direct fungicidal activity. Moreover, we showed that one 12-amino acid (aa) alpha helix of this peptide retained full activity, with partial activity down to the 10aa alpha helix. Using these peptides as a starting point, the current investigation sought to identify the critical features necessary for antifungal activity and to screen for new variants …

Serine Deamination By Human Serine Racemase Synergizes With Antibiotics To Curtail The Replication Of Chlamydia Trachomatis, Patricia D. Mott, Arnold H. Zea, Jamiya Lewis, Oygul Mirzalieva, Ashok A. Aiyar

School of Medicine Faculty Publications

The obligate intracellular bacterium, Chlamydia trachomatis, has evolved to depend on its human host for many metabolites, including most amino acids and three of the four nucleotides. Given this, it is not surprising that depletion of a single amino acid in the host cell growth medium blocks chlamydial replication. Paradoxically, supra-normal levels of some amino acids also block productive replication of Chlamydia. Here, we have determined how elevated serine levels, generated by exogenous supplementation, impede chlamydial inclusion development and reduce the generation of infectious progeny. Our findings reveal that human serine racemase, which is broadly expressed in multiple tissues, potentiates …

Autologous Bone Marrow Mononuclear Cells To Treat Severe Traumatic Brain Injury In Children, Fabio Triolo, Claudia Pedroza, Scott D Olson, Michael C Scott, Akshita Kumar, Benjamin M Aertker, Henry W Caplan, Margaret L Jackson, Brijesh S Gill, Robert A Hetz, Michael S Lavoie, Linda Ewing-Cobbs

Faculty, Staff and Student Publications

Autologous bone marrow mononuclear cells (BMMNCs) infused after severe traumatic brain injury have shown promise for treating the injury. We evaluated their impact in children, particularly their hypothesized ability to preserve the blood–brain barrier and diminish neuroinflammation, leading to structural CNS preservation with improved outcomes.

We performed a randomized, double-blind, placebo-sham-controlled Bayesian dose-escalation clinical trial at two children's hospitals in Houston, TX and Phoenix, AZ, USA (NCT01851083). Patients 5–17 years of age with severe traumatic brain injury (Glasgow Coma Scale score ≤ 8) were randomized to BMMNC or placebo (3:2). Bone marrow harvest, cell isolation and infusion were …

Investigating The Role Of The Gut Microbiota On Immune Checkpoint Inhibitor-Mediated Colitis, Taylor Halsey, Robert Jenq

Dissertations and Theses (Open Access)

Immune checkpoint inhibitors (ICIs) have been revolutionary in the fight against cancer by recruiting the host immune system as an agent for attack on malignant cells. Unfortunately, immune-related adverse events (irAEs), including ICI-mediated colitis (IMC), are common side effects that result from immune cell mediated damage on healthy tissues. Recent studies have highlighted a role for the gut microbiota in modulating ICI-mediated anti-tumor responses, but less is known regarding how the gut microbiota may impact on irAEs. Considering that the gastrointestinal tract harbors thousands of unique microbial species, many of which are known to modulate the immune system, microbes and …

Molecular Basis Of Cell Membrane Adaption Against Daptomycin In Enterococcus Faecalis, April Nguyen

Dissertations and Theses (Open Access)

Daptomycin is a last-resort lipopeptide antibiotic that disrupts cell membrane (CM) and peptidoglycan homeostasis (Grein et al., 2020a; Müller et al., 2016a). Enterococcus faecalis has developed a sophisticated mechanism to avoid daptomycin killing by redistributing CM anionic phospholipids away from the septum. The CM changes are orchestrated by a three-component regulatory system, designated LiaFSR, with a possible contribution of cardiolipin synthase (Cls) (Cesar A Arias et al., 2011a; Khan et al., 2019b; Palmer et al., 2011a; Panesso et al., 2015a; Reyes et al., 2015a). However, the mechanism by which LiaFSR controls the cell membrane response and the role of Cls …

Mir4435-2hg As A Possible Novel Predictive Biomarker Of Chemotherapy Response And Death In Pediatric B-Cell All, Yulieth Torres-Llanos, Jovanny Zabaleta, Nataly Cruz-Rodriguez, Sandra Quijano, Paula Carolina Guzmán, Iliana De Los Reyes, Nathaly Poveda-Garavito, Ana Infante, Liliana Lopez-Kleine, Alba Lucía Combita

School of Medicine Faculty Publications

Introduction: Although B-cell acute lymphoblastic leukemia (B-cell ALL) survival rates have improved in recent years, Hispanic children continue to have poorer survival rates. There are few tools available to identify at the time of diagnosis whether the patient will respond to induction therapy. Our goal was to identify predictive biomarkers of treatment response, which could also serve as prognostic biomarkers of death, by identifying methylated and differentially expressed genes between patients with positive minimal residual disease (MRD+) and negative minimal residual disease (MRD-). Methods: DNA and RNA were extracted from tumor blasts separated by immunomagnetic columns. Illumina MethlationEPIC and mRNA …

Quorum-Sensing Agr System Of Staphylococcus Aureus Primes Gene Expression For Protection From Lethal Oxidative Stress, Jisun Kim, Theodora K Karagounis, Chunyi Zhou, Andreas F Haag, Julia Shenderovich, Gregory A Wasserman, Junbeom Kwon, John Chen, Anthony R Richardson, Jeffrey N Weiser, Carla R Nowosad, Desmond S Lun, Dane Parker, Alejandro Pironti, Xilin Zhao, Karl Drlica, Itai Yanai, Victor J Torres, Bo Shopsin

Faculty, Staff and Student Publications

The agr quorum-sensing system links Staphylococcus aureus metabolism to virulence, in part by increasing bacterial survival during exposure to lethal concentrations of H2O2, a crucial host defense against S. aureus. We now report that protection by agr surprisingly extends beyond post-exponential growth to the exit from stationary phase when the agr system is no longer turned on. Thus, agr can be considered a constitutive protective factor. Deletion of agr resulted in decreased ATP levels and growth, despite increased rates of respiration or fermentation at appropriate oxygen tensions, suggesting that Δagr cells undergo a shift towards a hyperactive metabolic …

Study On A Strong Polymer Gel By The Addition Of Micron Graphite Oxide Powder And Its Plugging Of Fracture, Zhonghui Li, Fangping Chen

Faculty, Staff and Student Publications

It is difficult to plug the fracture water channeling of a fractured low-permeability reservoir during water flooding by using the conventional acrylamide polymer gel due to its weak mechanical properties. For this problem, micron graphite powder is added to enhance the comprehensive properties of the acrylamide polymer gel, which can improve the plugging effect of fracture water channeling. The chemical principle of this process is that the hydroxyl and carboxyl groups of the layered micron graphite powder can undergo physicochemical interactions with the amide groups of the polyacrylamide molecule chain. As a rigid structure, the graphite powder can support the …

Headache And Vision Loss As Initial Symptoms For An Acute Invasive Rhino-Orbital-Cerebral Mucormycosis, Thanh Le Od, Gregg Wentworth Od

Optometric Clinical Practice

Background: Acute invasive rhino-orbital-cerebral mucormycosis (ROCM) is a rare fungal infection commonly caused by Rhizopus species. It occurs in immune- compromised individuals who have acquired immune deficiency syndrome (AIDS), leukemia, uncontrolled diabetes mellitus, or organ transplant patients who are on immunosuppressive therapy. Diagnosing invasive ROCM is challenging because its clinical presentation can be nonspecific, and it is not frequently observed in ophthalmic practices. Case Report: A 66-year-old Hispanic male with poorly controlled diabetes mellitus presented with the complaint of severe headache and retrobulbar pain in the right eye. An ophthalmic examination revealed normal ocular health in both eyes. Computerized tomography …

Modern Approaches To Treating Hospital Acquired Infections: An Overview Of Current Treatments Using Antibiotics And New Therapies Centered Around Photo-Activated Porphyrins, Meghan Johns

Senior Honors Theses

Annually, hospital-acquired infections (HAIs) affect hundreds of thousands of people in the U.S. and impose a great economic burden. The current problem is further exacerbated due to the failure of traditional treatment strategies considering the rise in antimicrobial resistance rates. Besides the fact that antimicrobial resistances complicates clinical treatment strategies, patients are also more vulnerable to secondary infections and complications from prolonged antibiotic use. As a result, research investigating novel treatment strategies for bacterial infections has recently increased. A strategy using porphyrin-based compounds is showing promise. Porphyrins and their derivatives have exhibited bactericidal effects against Gram-positive bacteria by the destruction …

The Inflammatory Response Of Patients With Major Burns And Traumatic Injuries, Jared M. Robinson, Sophia Trinh, Jenna Dennis, Cameron Fontenot, Jeffrey Hobden, Jonathan E. Schoen, Herb A. Phelan Iii, Jeffrey E. Carter, Alison A. Smith

School of Medicine Faculty Publications

56th Annual Meeting of the American Burn Association, 2024; April 9 - April 12, 2024; Chicago, IL

Eye Infection Risks From Pseudomonas Aeruginosa Via Hand Soap And Eye Drops, Charles P Gerba

Faculty, Staff and Student Publications

Eye infections from bacterial contamination of bulk-refillable liquid soap dispensers and artificial tear eye drops continue to occur, resulting in adverse health outcomes that include impaired vision or eye enucleation. Pseudomonas aeruginosa (P. aeruginosa), a common cause of eye infections, can grow in eye drop containers and refillable soap dispensers to high numbers. To assess the risk of eye infection, a quantitative microbial risk assessment for P. aeruginosa was conducted to predict the probability of an eye infection for two potential exposure scenarios: (i) individuals using bacteria-contaminated eye drops and (ii) contact lens wearers washing their hands with …

Syntaxin 3 Is Haplosufficient For Long-Term Photoreceptor Survival In The Mouse Retina, Rabia Ayoub

Faculty, Staff and Student Publications

Here, synthesis and thorough characterization of β-NaFeO2 nanoparticles utilizing a co-precipitation technique is presented. XRD analysis confirmed a hexagonal-phase structure of β-NaFeO2. SEM revealed well-dispersed spherical nanoparticles with an average diameter of 45 nm. The FTIR spectrum analysis revealed weak adsorption bands at 1054 cm-1 suggested metal-metal bond stretching (Fe-Na). UV-Visible spectroscopy indicates a 4.4 eV optical band gap. Colloidal stability of β-NaFeO2 was evidenced via Zeta potential (-28.5 mV) and Dynamic Light Scattering (DLS) measurements. BET analysis reveals a substantial 343.27 m2 g-1 surface area with mesoporous characteristics. Antioxidant analysis indicates efficacy comparable to standard antioxidants, while concentration-dependent antibacterial …