Medical Microbiology Commons^™

Defining The Role Of Powassan Virus In Evading Host Antiviral Immunity (September 2022), Melissa Molho, Phd, Holly Ramage, Phd

Department of Microbiology and Immunology Posters

Background

Powassan Virus (POWV) is an emerging neurotropic flavivirus transmitted to humans through the bite of an infected tick. Currently, there is no specific antiviral treatment nor approved vaccine for POWV. During infection, many interferon-independent host proteins and pathways sense and respond to viral infection. Flaviviruses have evolved multiple mechanisms to counteract host antiviral programs, often with individual viral proteins mediating this antagonism. However, it has not been determined if these mechanisms are conserved across diverse flaviviruses.

Is Strongyloides Stercoralis Hyperinfection Induced By Gglucocorticoids A Result Of Both Suppressed Host Immunity And Altered Parasite Genetics?, De'broski R Herbert, Jonathan D C Stoltzfus, Heather L Rossi, David Abraham

Department of Microbiology and Immunology Faculty Papers

The gastrointestinal (GI) nematode Strongyloides stercoralis (S.s.) causes human strongyloidiasis, a potentially life-threatening disease that currently affects over 600 million people globally. The uniquely pernicious aspect of S.s. infection, as compared to all other GI nematodes, is its autoinfective larval stage (L3a) that maintains a low-grade chronic infection, allowing undetectable persistence for decades. Infected individuals who are administered glucocorticoid therapy can develop a rapid and often lethal hyperinfection syndrome within days. Hyperinfection patients often present with dramatic increases in first- and second-stage larvae and L3a in their GI tract, with L3a widely disseminating throughout host organs leading to sepsis. How …

Distinguishing Intrathyroid Parathyroid Adenoma From Colloid Nodules And Papillary Thyroid Carcinomas Using Multiphasic Multidetector Computed Tomography, J Matthew Debnam, T Linda Chi, Michael Kwon, Jia Sun, Dawid Schellingerhout, Brandon T Golant, Salmaan Ahmed, Nancy D Perrier, Thinh Vu

Faculty, Staff and Student Publications

OBJECTIVE: The aim of the study is to determine whether multiphase multidetector computed tomography (4D-MDCT) can differentiate between intrathyroid parathyroid adenomas (ITPAs), colloid nodules, and papillary thyroid carcinoma (PTC).

METHODS: We studied 22 ITPAs, 22 colloid nodules, and 11 PTCs in 55 patients. Hounsfield unit (HU) values of the nodules were measured on 4D-MDCT in the precontrast, arterial, venous, and delayed phases. Raw HU values, phase with peak enhancement, and washout percentages between the phases were evaluated.

RESULTS: Regardless of size, all ITPAs (22/22) showed peak enhancement in the arterial phase, which was significantly greater than both colloid nodules (15/22) …

Hepatic Circadian And Differentiation Factors Control Liver Susceptibility For Fatty Liver Disease And Tumorigenesis, Baharan Fekry, Aleix Ribas-Latre, Rachel Van Drunen, Rafael Bravo Santos, Samay Shivshankar, Yulin Dai, Zhongming Zhao, Seung-Hee Yoo, Zheng Chen, Kai Sun, Frances M Sladek, Mamoun Younes, Kristin Eckel-Mahan

Faculty, Staff and Student Publications

Hepatocellular carcinoma (HCC) is a leading cause of cancer deaths, and the most common primary liver malignancy to present in the clinic. With the exception of liver transplant, treatment options for advanced HCC are limited, but improved tumor stratification could open the door to new treatment options. Previously, we demonstrated that the circadian regulator Aryl Hydrocarbon-Like Receptor Like 1 (ARNTL, or Bmal1) and the liver-enriched nuclear factor 4 alpha (HNF4α) are robustly co-expressed in healthy liver but incompatible in the context of HCC. Faulty circadian expression of HNF4α- either by isoform switching, or loss of expression- results in an increased …

Amphotericin B Resistance In Leishmania Mexicana: Alterations To Sterol Metabolism And Oxidative Stress Response, Edubiel A Alpizar-Sosa, Nur Raihana Binti Ithnin, Wenbin Wei, Andrew W Pountain, Stefan K Weidt, Anne M Donachie, Ryan Ritchie, Emily A Dickie, Richard J S Burchmore, Paul W Denny, Michael P Barrett

Faculty, Staff and Student Publications

Amphotericin B is increasingly used in treatment of leishmaniasis. Here, fourteen independent lines of Leishmania mexicana and one L. infantum line were selected for resistance to either amphotericin B or the related polyene antimicrobial, nystatin. Sterol profiling revealed that, in each resistant line, the predominant wild-type sterol, ergosta-5,7,24-trienol, was replaced by other sterol intermediates. Broadly, two different profiles emerged among the resistant lines. Whole genome sequencing then showed that these distinct profiles were due either to mutations in the sterol methyl transferase (C24SMT) gene locus or the sterol C5 desaturase (C5DS) gene. In three lines an additional deletion of …

Short Signature Rpob Gene Sequence To Differentiate Species In Mycobacterium Abscessus Group, Jian R Bao, Kileen L Shier, Ronald N Master, Robert S Jones, Richard B Clark

Faculty, Staff and Student Publications

Mycobacterium abscessus group (MAG) are rapidly growing acid-fast bacteria that consist of three closely related species: M. abscessus (Ma), M. bolletii (Mb), and M. massiliense (Mm). Differentiation of these species can be difficult but is increasingly requested owing to recent infectious outbreaks and their differential drug resistance. We developed a novel and rapid pyrosequencing method using short signature sequences (35 to 45 bp) at a hypervariable site in the rpoB gene to differentiate the three MAG species, along with M. chelonae (Mc), and M. immunogenum (Mi). This method was evaluated …

The Need For Sexual Health Clinics, Their Future Role, And Contribution To Public Health, Meena S. Ramchandani, Christopher Bourne, Lindley A. Barbee, Elske Hoornenborg, Preeti Pathela, Stephanie N. Taylor, Henry De Vries

School of Medicine Faculty Publications

Specialised sexual health clinics (SHCs) play an important role in addressing the staggering rates of STIs seen in many high-income nations. Despite increasing healthcare coverage in the US and nationalised health care in some countries, there is a continued need for SHCs to meet the needs of patients and the community, especially for high-priority populations: those at high risk of STI acquisition and/or groups historically marginalised and underserved in the traditional healthcare system. We need to mobilise resources to support a stronger clinical infrastructure in specialised SHCs. This review describes the importance of SHCs, their future role, and some of …

Gray And White Matter Abnormality In Patients With T2dm-Related Cognitive Dysfunction: A Systemic Review And Meta-Analysis, Teng Ma, Ze-Yang Li, Ying Yu, Bo Hu, Yu Han, Min-Hua Ni, Yu-Xiang Huang, Hao-Han Chen, Wen Wang, Lin-Feng Yan, Guang-Bin Cui

Faculty, Staff and Student Publications

Aims/hypothesis

Brain structure abnormality in patients with type 2 diabetes mellitus (T2DM)-related cognitive dysfunction (T2DM-CD) has been reported for decades in magnetic resonance imaging (MRI) studies. However, the reliable results were still unclear. This study aimed to make a systemic review and meta-analysis to find the significant and consistent gray matter (GM) and white matter (WM) alterations in patients with T2DM-CD by comparing with the healthy controls (HCs).

Methods

Published studies were systemically searched from PubMed, MEDLINE, Cochrane Library and Web of Science databases updated to November 14, 2021. Studies reporting abnormal GM or WM between patients with T2DM-CD and …

Microbiome Dynamics During Chemoradiation Therapy For Anal Cancer, Daniel Lin, Molly B. El Alam, Joseph Abi Jaoude, Ramez Kouzy, Jae L. Phan, Jacob H. Elnaggar, Brianna Resendiz, Andrea Y. Delgado Medrano, Erica J. Lynn, Nicholas D. Nguyen, Sonal S. Noticewala, Geena G. Mathew, Emma B. Holliday, Bruce D. Minsky, Prajnan Das, Van K. Morris, Cathy Eng, Melissa P. Mezzari, Joseph F. Petrosino, Nadim J. Ajami, Ann H. Klopp, Cullen M. Taniguchi, Lauren E. Colbert

School of Graduate Studies Faculty Publications

Purpose: Patients with localized squamous cell carcinoma of the anus (SCCA) who experience treatment toxicity or recurrences have few therapeutic options. Investigation into the microbiome's influence on treatment toxicity and its potential use as a predictive biomarker could improve these patients’ outcomes. Our study presents the first longitudinal characterization of the SCCA tumor microbiome and its associations with treatment-related toxicities. Methods and Materials: This prospective cohort study included patients with nonmetastatic SCCA receiving standard-of-care chemoradiation therapy. Anorectal swabs of the tumor site were collected before, during, and after treatment. Patient-reported quality-of-life metrics were collected at similar time points. 16S rRNA …

Homeostasis Of Cell Wall Integrity Pathway Phosphorylation Is Required For The Growth And Pathogenicity Of Magnaporthe Oryzae, Yongchao Cai, Xinyu Liu, Lingbo Shen, Nian Wang, Yangjie He, Haifeng Zhang, Ping Wang, Zhengguang Zhang

School of Graduate Studies Faculty Publications

The cell wall provides a crucial barrier to stress imposed by the external environment. In the rice blast fungus Magnaporthe oryzae, this stress response is mediated by the cell wall integrity (CWI) pathway, consisting of a well-characterized protein phosphorylation cascade. However, other regulators that maintain CWI phosphorylation homeostasis, such as protein phosphatases (PPases), remain unclear. Here, we identified two PPases, MoPtc1 and MoPtc2, that function as negative regulators of the CWI pathway. MoPtc1 and MoPtc2 interact with MoMkk1, one of the key components of the CWI pathway, and are crucial for the vegetative growth, conidial formation, and virulence of M. …

Infection And Transmission Determinants Of Flea-Borne Rickettsioses, Hanna J. Laukaitis

Graduate Theses and Dissertations (2019 - present)

The genus Rickettsia is comprised of Gram-negative, obligate intracellular bacteria that are spread by hematophagous arthropods. Elucidating the factors conferring rickettsial virulence has perplexed investigators for decades, complicated by the lack of efficient genetic tools necessary to uncover rickettsial- and vector-specific factors contributing to persistence. The advent of transposon mutagenesis has enabled the field to make vast developments in uncovering novel rickettsial mechanisms utilized in various host backgrounds. Thus, the aim of this study was to generate Rickettsia felis transposon mutants and characterize novel phenotypes associated with genetic disruption in an arthropod background. Distribution of rickettsiae is reliant on the …

Changes Of Brain Function In Patients With Type 2 Diabetes Mellitus Measured By Different Analysis Methods: A New Coordinate-Based Meta-Analysis Of Neuroimaging, Ze-Yang Li, Teng Ma, Ying Yu, Bo Hu, Yu Han, Hao Xie, Min-Hua Ni, Zhu-Hong Chen, Yang-Ming Zhang, Yu-Xiang Huang, Wen-Hua Li, Wen Wang, Lin-Feng Yan, Guang-Bin Cui

Faculty, Staff and Student Publications

OBJECTIVE: Neuroimaging meta-analysis identified abnormal neural activity alterations in patients with type 2 diabetes mellitus (T2DM), but there was no consistency or heterogeneity analysis between different brain imaging processing strategies. The aim of this meta-analysis was to determine consistent changes of regional brain functions in T2DM

METHODS: Since the indicators obtained using varied post-processing methods reflect different neurophysiological and pathological characteristics, we further conducted a coordinate-based meta-analysis (CBMA) of the two categories of neuroimaging literature, which were grouped according to similar data processing methods: one group included regional homogeneity (ReHo), independent component analysis (ICA), and degree centrality (DC) studies, while …

Cyclic Di-Gmp Regulates Motility, Biofilm Formation, And Desiccation Tolerance In Acinetobacter Baumannii, Garrett Reynolds

Electronic Theses and Dissertations

Acinetobacter baumannii is an increasingly multidrug-resistant pathogen contributing to hospital-acquired infections necessitating the discovery of novel treatments. A bacterial second messenger, cyclic diguanosine monophosphate (cyclic di-GMP), can regulate various persistence factors that are potentially advantageous for survival in hospital environments. Cyclic di-GMP–modulating enzymes and cyclic di-GMP–binding effectors predictively are encoded in the Acinetobacter baumannii genome. I hypothesized that cyclic di-GMP controls motility, biofilm formation, and desiccation tolerance in Acinetobacter baumannii. Disrupting cyclic di-GMP–modulating enzymes or cyclic di-GMP–binding effectors should alter the regulatory effectiveness of these phenotypes. I tested the multidrug-resistant isolate Acinetobacter baumannii strain AB5075 and identified several transposon …

"Don't Look Up" Your Science-Herd Immunity Or Herd Mentality?, Botond Z Igyártó

Department of Microbiology and Immunology Faculty Papers

This analysis piece will attempt to examine some of the critical pandemic-related measures implemented in the United States from an immunological perspective and pinpoint caveats that should have been considered before their implementation. I also discuss alternative measures grounded in scientific data that were not thoroughly explored and likely could have helped fight the pandemic.

Solid-State Nmr Analysis Of Unlabeled Fungal Cell Walls From Aspergillus And Candida Species, Liyanage D. Fernando, Malitha C. Dickwella Widanage, S. Chandra Shekar, Frederic Mentink-Vigier, Ping Wang, Sungsool Wi, Tuo Wang

School of Medicine Faculty Publications

Fungal infections cause high mortality in immunocompromised individuals, which has emerged as a significant threat to human health. The efforts devoted to the development of antifungal agents targeting the cell wall polysaccharides have been hindered by our incomplete picture of the assembly and remodeling of fungal cell walls. High-resolution solid-state nuclear magnetic resonance (ss NMR) studies have substantially revised our understanding of the polymorphic structure of polysaccharides and the nanoscale organization of cell walls in Aspergillus fumigatus and multiple other fungi. However, this approach requires 13C/15N-enrichment of the sample being studied, severely restricting its application. Here we employ the dynamic …

The Unique Seed Protein Composition Of Quality Protein Popcorn Promotes Growth Of Beneficial Bacteria From The Human Gut Microbiome, Nate Korth, Leandra Parsons, Mallory J. Van Haute, Qinnan Yang, Preston Hurst, James C. Schnable, David R. Holding, Andrew K. Benson

Food for Health: Publications

The effects of fiber, complex carbohydrates, lipids, and small molecules from food matrices on the human gut microbiome have been increasingly studied. Much less is known about how dietary protein can influence the composition and function of the gut microbial community. Here, we used near-isogenic maize lines of conventional popcorn and quality-protein popcorn (QPP) to study the effects of the opaque-2 mutation and associated quality-protein modifiers on the human gut microbiome. Opaque-2 blocks the synthesis of major maize seed proteins (α-zeins), resulting in a compensatory synthesis of new seed proteins that are nutritionally beneficial with substantially higher levels …

Comparison Of Flash-Free And Conventional Bonding Systems: A Systematic Review And Meta-Analysis, He Wang, Ge Feng, Bo Hu, Haonan Tian, Yunchun Kuang, Tingwei Zhang, Jinlin Song

Faculty, Staff and Student Publications

OBJECTIVES: To review the literature systematically to compare the performance of adhesive precoated flash-free bonding systems with conventional adhesive precoated (APC) and operator-coated (OPC) bonding systems.

MATERIALS AND METHODS: PubMed, Cochrane Library, Web of Science, and Embase were searched for potential eligible studies. Study selection and data collection were conducted independently. Statistical analysis was performed by Review Manager 5.3. The Cochran Q test was used to test heterogeneity in the included studies. Risk of bias was evaluated using Cochrane RoB 2.0 tool for randomized controlled trials.

RESULTS: Six studies were included and the overall risk-of-bias judgment was low risk of …

Integrating Conformational Dynamics And Perturbation-Based Network Modeling For Mutational Profiling Of Binding And Allostery In The Sars-Cov-2 Spike Variant Complexes With Antibodies: Balancing Local And Global Determinants Of Mutational Escape Mechanisms, Gennady M. Verkhivker, Steve Agajanian, Ryan Kassab, Keerthi Krishnan

Mathematics, Physics, and Computer Science Faculty Articles and Research

n this study, we combined all-atom MD simulations, the ensemble-based mutational scanning of protein stability and binding, and perturbation-based network profiling of allosteric interactions in the SARS-CoV-2 spike complexes with a panel of cross-reactive and ultra-potent single antibodies (B1-182.1 and A23-58.1) as well as antibody combinations (A19-61.1/B1-182.1 and A19-46.1/B1-182.1). Using this approach, we quantify the local and global effects of mutations in the complexes, identify protein stability centers, characterize binding energy hotspots, and predict the allosteric control points of long-range interactions and communications. Conformational dynamics and distance fluctuation analysis revealed the antibody-specific signatures of protein stability and flexibility of the …

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

Biology Theses

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

Molecular Mechanisms Underlying Mucosal Attachment And Colonization By Clostridioides Difficile, Ben Sidner

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Clostridioides difficile is a Gram-positive, spore-forming, anaerobic bacterium which causes gastrointestinal disease and is a leading cause of nosocomial infections. Although infection typically occurs following antibiotic therapy, in recent years there has been an increase in infections which are not preceded by antibiotic use. Additionally, community-associated infections and rates of disease recurrence have increased. While it is understood that a healthy gastrointestinal microbiota provides protection against infection, the molecular mechanisms which underly C. difficile's ability to colonize and persist in the gut are mostly unknown. Building on work from others that suggests C. difficile associates with the outer mucus …