Medical Microbiology Commons^™

Validation Of A Real-Time Pcr Laboratory Developed Test For The Detection Of Pneumocystis Jirovecii In Bronchoalveolar Lavage Samples, Caitlyn Moon

Honors Scholar Theses

Pneumocystis jirovecii is an opportunistic, host-obligate fungal pathogen responsible for causing P. jirovecii pneumonia (PJP) in humans. PJP is treated with trimethoprim-sulfamethoxazole (TMP-SMX), a strong broad-spectrum antibiotic that carries risk of renal and hepatotoxicity. Therefore, rapid diagnosis or exclusion of PJP is crucial to ensure PJP-positive patients receive effective treatment and PJP-negative patients avoid unnecessary antibiotics. Unlike most microorganisms, P. jirovecii cannot be cultured, presenting complications for the typical methods of diagnosing fungal pathogens. Historically, the gold standard for diagnosis was direct microscopic examination with stains such as methenamine silver and calcofluor white, but this diagnostic technique requires highly skilled …

Development Of A Dendritic Cell Model To Unravel The Secrets Of Cards Toxin, Lizbeth Gomez

Posters - 2026

Dendritic cells (DCs) are derived from hematopoietic stem cells of the bone marrow. They are the most efficient antigen presenting cell, presenting antigens to T cells to initiate clonal expansion and differentiation of the T cells into memory and effector cells. Thus, activating the effector functions of T cells in cell-mediated and humoral immune responses (2). Community-acquired respiratory distress syndrome (CARDS) toxin is produced by Mycoplasma pneumoniae that causes acute and chronic lung infections (4). Dendritic cells play a key role in the immune response to respiratory mycoplasmas (3). However, the mechanism underlying in DC and CARDS toxin interactions are …

Hyperglycemia And Mycoplasma Pneumoniae Cards Toxin Impacts On Lung Epithelial And Fibroblast Injury And Recovery, Alejandra Y. Delgado, Naila Villagomez, Shuri Magdalene

Posters - 2026

Mycoplasma pneumoniae CARDS toxin induces cytotoxicity and inflammation in lung epithelial cells²·¹⁰·¹¹, while hyperglycemia independently elevates ROS and disrupts fibroblast repair¹·⁵·⁸, contributing to the heightened respiratory infection severity seen in diabetic patients¹. However, the interaction between hyperglycemic conditions and CARDS toxin-induced lung injury remains unexplored.

This study investigates how increasing high-glucose (HG) pre-conditioning modifies CARDS toxin-induced injury and recovery in A549⁶ and IMR-90⁷ cells compared to normal glucose (NG ≈ 5mM) controls. We hypothesized that increasing glucose pre-conditioning concentrations would produce a dose-dependent increase in CARDS toxin-induced oxidative stress¹² and inflammatory cytokine production¹⁵ in IMR-90 and A549 compared with normal …

A Case Of Fatal Herpes Zoster Ophthalmicus And Encephalitis In An Immunocompetent Host With A Review Of Literature, Kellyn E. Wilkes, Rutwik Pradeep Sharma, Laurie Proia

Advances in Clinical Medical Research and Healthcare Delivery

Herpes zoster is a common disease that can have several complications. Here, we present a case of herpes zoster ophthalmicus with coexisting encephalitis that unfortunately resulted in patient mortality. A 70-year-old male with a past medical history of Parkinson’s disease and schizophrenia presented to the emergency department after being found altered at home. Physical exam was notable for left-sided crusted facial rash, left conjunctival injection, and purulent drainage coming from the right eye. Given the location and appearance of his rash, he was diagnosed with herpes zoster ophthalmicus. There was suspicion for encephalitis given his altered mental status but unfortunately, …

Mycobacterium Shimoidei: A Case Report Of A Rare Nontuberculous Mycobacterial Infection In An American Patient With A Favorable Outcome, Madison Baker, Farah Majdoub, Asad Nasir

Advances in Clinical Medical Research and Healthcare Delivery

Non-tuberculous mycobacteria (NTM) are common environmental pathogens, but they are an uncommon cause of illness. One such mycobacteria, Mycobacterium shimoidei, was discovered in 1968 and found to cause a respiratory illness in 1975. Since then, fewer than 100 cases have been reported worldwide. Symptoms can include cough, fever, weight loss, and hemoptysis This report describes an American patient with no travel history who was found to have significant pulmonary disease caused by this rare non-tuberculous mycobacteria.

Differential Sensitivity Of Leukocyte Populations To Staphylococcus Aureus Biofilm, Nichole D. Brandquist, Tammy Kielian

Journal Articles: Pathology and Microbiology

Staphylococcus aureus is a leading cause of prosthetic joint infection (PJI) typified by biofilm formation. Anti-inflammatory granulocytic myeloid-derived suppressor cells (G-MDSCs) represent the main leukocyte population in a mouse model of S. aureus PJI, followed by neutrophils (PMNs), and macrophages (Mφs), which is also seen during human PJI. Defining how each leukocyte population responds to S. aureus biofilm vs planktonic bacteria could have important implications for how S. aureus evades immune detection to facilitate biofilm persistence. This study compared the kinetics of leukocyte death and relationship to mitochondrial ROS (mtROS) production following exposure to planktonic S. aureus or biofilm. Mφs …

Clinical Microbiology & Infectious Diseases: A Concise Guide On The Fundamentals Of Infectious Disease In Podiatric Medical Education, Paramita Basu

Open Touro Created

2026

This Open Educational Resource (OER), Clinical Microbiology & Infectious Diseases, is a student-centered textbook designed to support pre-clinical podiatric medical students enrolled in PCLP 610 Infectious Diseases at the New York College of Podiatric Medicine. The book is structured as a collection of concise “chapter briefs” or high‑yield notes that align closely with the course syllabus, lecture objectives, and student learning outcomes, while also reflecting the Microbiology learning objectives outlined in the AACPM Council of Faculties Curricular Guide.

The content covers core principles of medical microbiology and infectious diseases, including bacteria, viruses, fungi, parasites, host–pathogen interactions, antimicrobial therapy, resistance …

Mitochondrial Transfer To Granulocytic Myeloid-Derived Suppressor Cells Augments Immunosuppressive Activity, Prabhakar Arumugam, Cortney E. Heim, Rachel W. Fallet, Dhananjay Shinde, Vinai Chittezham Thomas, Rafael J. Argüello, Tammy Kielian

Journal Articles: Pathology and Microbiology

The anti-inflammatory properties of granulocytic myeloid-derived suppressor cells (G-MDSCs) promote Staphylococcus aureus (S. aureus) biofilm persistence. Evidence suggests that G-MDSC activity is shaped not only by S. aureus products but also by intrinsic metabolic programs. This study explores whether G-MDSC activity can be modulated by increasing mitochondrial abundance using a co-culture paradigm with macrophages as a mitochondrial donor. Macrophages transfer mitochondria directly to G-MDSCs via tunneling nanotubes, enhancing G-MDSC respiration, as reflected by increased basal, maximal, and spare respiratory capacity. Augmenting mitochondrial abundance in G-MDSCs enhances T cell-suppressive activity and reduces tumor necrosis factor (TNF) and interleukin 6 (IL-6) production. …

Exploring Biopsychosocial Influences On Hookup Culture And Disrupting Compulsory Behaviors In Emerging Adults: A Multidisciplinary Analysis Of A Contemporary Public Health Concern, Catherine Benjamin

Honors Theses and Capstones

Multidisciplinary analysis, including biology, psychology, and sociology, to better understand the compulsory Hookup Culture that exists as a contemporary public health concern among the age group defined as emerging adults. Sexually Transmitted Infections (STIs) diagnoses are steadily rising in the United States and disproportionately affecting college students. Early socialization and current educational resources that contribute to shame and stigma are discussed to explain how lifestyle and social conditions can act as risk factors for individual health outcomes.

An Anti-Adhesive Compound Modulating The Production Of Staphylococcus Aureus Cell Wall-Anchored Proteins, Allison C. Leonard, Ruina Bao, Cindy Menjivar, Megan J. Myers, Telmo O. Paiva, Zhiyong Zheng, Kirsten A. Berry, Kenneth W. Bayles, Ronald S. Flannagan, Yves F. Dufrêne, Jeffrey L. Bose, David E. Heinrichs, Georgina Cox

Journal Articles: Pathology and Microbiology

As one of the leading global causes of death associated with antimicrobial resistance, Staphylococcus aureus frequently colonizes the human nasal cavity and adheres to keratinized skin, establishing reservoirs that drive subsequent infections and emphasize the need for new decolonization strategies. Using a high-throughput, whole-cell screening platform, here we identify geranylgeranoic acid (GGA), a naturally occurring polyunsaturated, branched-chain fatty acid, as having dual activity against methicillin-resistant S. aureus (MRSA). At elevated concentrations, GGA exhibits microbicidal effects, whereas at sub‑microbicidal doses, it effectively inhibits MRSA adhesion to keratin, fibronectin, fibrinogen, and immunoglobulins. GGA possesses anti-adhesive activity against a panel of multidrug-resistant S. …

Multiparametric Flow Cytometry Immune Profiling Of Pulmonary And Extra-Pulmonary Tuberculosis Reveals Distinct Blood-Based Biomarker Signatures, Kalaiarasan Ellappan, Prakash Babu Narasimhan, Harriet N. Garlant, Seshadri Vasan, Komal Jain, Saka Vinod Kumar, Vishnukanth Govindaraj, Vir Singh Negi, Karen E. Kempsell

Research outputs 2022 to 2026

This study investigated immune cell distributions, cell-specific immune markers, and selected biomarker targets in pulmonary tuberculosis (PTB) and extrapulmonary tuberculosis (EPTB) using multiparametric flow cytometry (MFC). Whole blood was collected from 45 individuals, including healthy controls (HC), EPTB, and PTB patients (n = 15/group). Peripheral blood leukocytes were analysed by MFC to characterize CD4+ and CD8+ T cells, natural killer (NK), invariant NKT (iNKT) and NKT cells, classical (CM), intermediate (IM) and non-classical monocytes (NCM), and activated monocytes (AM). Expression of GBP1, CALCOCO2, IFIT3, SNX10, ARG1, PD-1, and PD-L1 was assessed across these immune subsets. Increased frequencies of NK, NKT, …

Role Of Gut Microbiome In Oncogenesis And Oncotherapies, Renuka Sri Sai Peddireddi, Sai Kiran Kuchana, Rohith Kode, Saketh Khammammettu, Aishwarya Koppanatham, Supriya Mattigiri, Harshavardhan Gobburi, Suresh K. Alahari

School of Graduate Studies Faculty Publications

The gut microbiome has emerged as a key regulator of human health, influencing not only metabolism and immunity but also the development and treatment of cancer. Mounting evidence suggests that microbial dysbiosis contributes to oncogenesis by driving chronic inflammation, producing genotoxic metabolites, altering bile acid metabolism, and disrupting epithelial barrier integrity. At the same time, the gut microbiome significantly modulates the host response to oncotherapies including chemotherapy, radiotherapy, and especially immunotherapy, where microbial diversity and specific taxa determine treatment efficacy and toxicity. This review synthesizes current evidence on the role of the gut microbiome in both oncogenesis and oncotherapies, focusing …

Sensitivity And Specificity Of The Cobas Liat Ct/Ng/Mg Nucleic Acid Test In A Clinical Laboratory Setting And Point-Of-Care Location, B Van Der Pol, R Arcenas, C Boraas, S Chavoustie, L L. Crane, N D'Empaire, A C. Ermel, G Harnett, F Hinestrosa, S House, Rebecca A. Lillis, J Miller, A Mills, R Poblete, S A. Young

School of Medicine Faculty Publications

Sexually transmitted infections, e.g., Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Mycoplasma genitalium (MG), present with similar signs/symptoms and are often treated empirically due to delays in receiving diagnostic test results. This study evaluated the clinical performance of the Cobas Liat CT/NG/MG nucleic acid amplification test (NAAT) in detecting these pathogens in a point-of-care (POC) setting. This non-interventional, multicenter study recruited symptomatic/asymptomatic participants from 13 geographically diverse POC sites across the USA. Prospective clinician- and self-collected specimens (urine/vaginal swabs) were used to determine the sensitivity and specificity of the Cobas Liat CT/NG/MG test relative to the composite reference standard (CRS), …

Cdk4/6 Inhibitors In Breast Cancer-Who Should Receive Them?, Anran Chen, Ze-Yi Zheng, Meenakshi Anurag, Ahmed Elkhanany, Natalie C Chen, Eric C Chang

Faculty, Staff and Students Publications

More than 70% of breast cancers are estrogen receptor-positive (ER+). Endocrine therapy that blocks estrogen signaling remains the cornerstone of treatment, yet relapses continue to affect many patients. Cyclin-dependent kinases 4 and 6 (CDK4/6) regulate the G1-S phase transition in the cell cycle, and pharmacological inhibition of this pathway has been successfully leveraged to reduce recurrence. CDK4/6 inhibitors combined with endocrine therapy are now the standard of care, although determining the optimal patient population for treatment remains a key challenge. A newly published study provides important insight, showing that loss of the NF1/neurofibromin tumor suppressor confers greater sensitivity to CDK4/6 …

Investigating Bacterial Vaginosis Pathogenesis Using Peptide Nucleic Acid-Fluorescence In Situ Hybridization With A Focus On The Roles Of Gardnerella Species, Prevotella Bivia, And Fannyhessea Vaginae, Sheridan D. George, Megan H. Amerson-Brown, Lúcia G.V. Sousa, Tyler M. Carter, Alexa H. Rinehart, Ashleigh N. Riegler, Sixto M. Leal, Kristal J. Aaron, Jiaying Hao, Ashutosh Tamhane, Chaoling Dong, John W. Lammons, Jacob H. Elnaggar, Keonte J. Graves, Paweł Łaniewski, Melissa M. Herbst-Kralovetz, Christopher M. Taylor, Nuno Cerca, Christina A. Muzny

School of Graduate Studies Faculty Publications

Background. Bacterial vaginosis (BV) is a vaginal dysbiosis characterized by polymicrobial communities of BV-associated bacteria (BVAB) adhered to the vaginal epithelium. Despite decades of research, its etiology remains unknown. We aimed to investigate BV biofilm formation over time among women who developed incident BV (iBV) using peptide nucleic acid-fluorescence in situ hybridization (PNA-FISH), focusing on 3 key BVAB (Gardnerella species, Prevotella bivia, and Fannyhessea vaginae). Methods. Heterosexual, nonpregnant women ages 18–45 with optimal vaginal microbiota were enrolled to self-collect twice-daily vaginal specimens for 60 days. iBV was defined as a Nugent score of 7–10 on ≥ 4 consecutive specimens. For …

Multivalvular Native Valve E. Coli Endocarditis, Madison Baker, Jose Reyes, Natasha Singh, Samir Shah, Rohail A. Baig, Justin Nistico

Advances in Clinical Medical Research and Healthcare Delivery

E. coli is a rare cause of infective endocarditis. This report describes an 81-year-old-woman with a history of aortic stenosis and recurrent urinary tract infections who presented in sepsis secondary to E. coli urinary tract infection which was complicated by multivalvular infective endocarditis of the aortic and tricuspid native valves identified on transesophageal echocardiogram (TEE). The patient was managed medically with ceftriaxone, and resolution of both vegetations was seen on TEE without the need for cardiothoracic surgery. Literature review did not yield prior cases of multivalvular E. coli endocarditis.

Egg White Hydrolysate In Hypertension: A Mechanistic Investigation Of Gut Microbiota Dependent And Independent Pathways, Emerson David Nolasco

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Cardiovascular diseases are one of the leading causes of mortality worldwide in which hypertension is a risk factor. Present pharmacological interventions require long-term adherence to the therapy and are often associated with undesirable side effects. Moreover, treatments have overlooked the role of the microbiome in the development of hypertension. Egg white hydrolysate (EWH) has exhibited antihypertensive properties with potential to be used as a natural alternative for the prevention and management of hypertension. However, EWH peptide’s effect on the gut microbiome remains yet to be elucidated. Studies have described that a portion of the ingested protein can remain undigested as …

A Lysosomal Surveillance Response To Stress Extends Healthspan, Terytty Yang Li, Arwen W Gao, Rendan Yang, Yu Sun, Yuxuan Lei, Xiaoxu Li, Lin Chen, Yasmine J Liu, Rachel N Arey, Kimberly Morales, Raya B Liu, Wenzheng Wang, Ang Zhou, Tong-Jin Zhao, Weisha Li, Amélia Lalou, Qi Wang, Tanes Lima, Riekelt H Houtkooper, Johan Auwerx

Faculty, Staff and Students Publications

Lysosomes are cytoplasmic organelles central for the degradation of macromolecules to maintain cellular homoeostasis and health. However, how lysosomal activity can be boosted to counteract ageing and ageing-related diseases remains elusive. Here we reveal that silencing specific vacuolar H+-ATPase subunits (for example, vha-6), which are essential for intestinal lumen acidification in Caenorhabditis elegans, extends lifespan by ~60%. This longevity phenotype can be explained by an adaptive transcriptional response typified by induction of a set of transcripts involved in lysosomal function and proteolysis, which we termed the lysosomal surveillance response (LySR). LySR activation is characterized by boosted lysosomal activity …

Inactivation Of The Fusobacterium Nucleatum Rnf Complex Reduces Fada-Mediated Amyloid Formation And Tumor Development, Timmie A Britton, Ju Huck Lee, Chungyu Chang, Aadil H Bhat, Yi-Wei Chen, Rusul Mohammed Ali, Chenggang Wu, Asis Das, Hung Ton-That

Faculty, Staff and Student Publications

The Gram-negative anaerobe Fusobacterium nucleatum is an oral oncobacterium that promotes colorectal cancer (CRC) development with the amyloid-forming cell surface adhesin FadA integral to CRC tumorigenesis. We describe here molecular genetic studies uncovering a novel mode of metabolic regulation of FadA-mediated tumor formation by a highly conserved respiratory enzyme known as the Rnf complex. First, we show that genetic disruption of Rnf, via rnfC deletion, significantly reduces the level of fadA transcript, accompanied by a near-complete abolishment of the precursor form of FadA (pFadA), reduced assembly of FadA at the mature cell pole, and severe defects in the osmotic stress-induced …

The Attitudes And Perspectives Of Laboratory Professionals On The Use Of Machine Learning Combined With Maldi For Viral Identification: A Qualitative Study, Grace Johnson

Honors Projects

The use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) with machine learning (ML) has been proposed by numerous studies as a novel approach for viral identification. However, the development and implementation of this instrumentation is still in its early stages, and laboratory professionals' perspectives on its feasibility, accuracy, implementation, and effect on current laboratory operating procedures remain underexplored.

This study aimed to investigate laboratory professionals’ attitudes and opinions regarding the use of MALDI-TOF-MS coupled with machine learning for viral identification, focusing on perceived benefits, barriers, and factors that would affect participants’ opinions on implementation.

A qualitative descriptive research …

Enriched Pathways In Gut Microbiome Predict Response To Immune Checkpoint Inhibitor Treatment Across Demographic Regions And Various Cancer Types, Xunhui Cai, Jennifer Y Cho, Lijun Chen, Yufeng Liu, Fenghu Ji, Katia Salgado, Siyi Ge, Dehua Yang, Hui Yu, Jianbo Shao, P Andrew Futreal, Boris Sepesi, Don Gibbons, Yaobing Chen, Guoping Wang, Chao Cheng, Meng Wu, Jianjun Zhang, Ansel Hsiao, Tian Xia

Faculty, Staff and Student Publications

Understanding the effect of gut microbiota function on immune checkpoint inhibitor (ICI) responses is urgently needed. Here, we integrated 821 fecal metagenomes from 12 datasets to identify differentially abundant genes and construct random forest models to predict ICI response. Gene markers demonstrated excellent predictive performance, with an average area under the curve (AUC) of 0.810. Pathway analyses revealed that quorum sensing (QS), ABC transporters, flagellar assembly, and amino acid biosynthesis pathways were enriched between responders (R) and non-responders (NRs) across 12 datasets. Furthermore,

The Microbiome-Restorative Potential Of Ibezapolstat For The Treatment Of Clostridioides Difficile Infection Is Predicted Through Variant Polc-Type Dna Polymerase Iii In Lachnospiraceae And Oscillospiraceae, Jacob K Mcpherson, Julian G Hurdle, Matthew L Baker, Tahir Hussain, Ashok Kumar, Kevin W Garey

Faculty, Staff and Student Publications

Ibezapolstat (IBZ), a first-in-class antibiotic targeting the PolC-type DNA polymerase III alpha-subunit (PolC) in low G + C bacteria, is in clinical development for the treatment of Clostridioides difficile infection (CDI). In the phase 2 trials, IBZ had potent activity against C. difficile while sparing or causing regrowth of Lachnospiraceae, Oscillospiraceae, and Erysipelotrichales, common commensal low G + C bacteria. The purpose of this study was to utilize in silico approaches to better interpret the narrower than expected IBZ spectrum of activity. IBZ susceptibility to human commensal microbiota was predicted using genomic analysis and PolC phylogenetic tree construction in relation …

Dengue Cases In Hanoi, Vietnam: Unseasonal Surge Foreshadows Increased Incidence That Demands Organized Preventive Action, Andrew W. Taylor-Robinson

Chulalongkorn Medical Journal

Letter to the Editor - Abstract not required.

Exploring Oxylipins In Host–Microbe Interactions And Their Impact On Infection And Immunity, Robert J. Neff, Christopher D. Radka

Markey Cancer Center Faculty Publications

Plasma lipids are essential components of biological systems, transported through interactions with proteins to maintain cellular functions. These lipids exist in various forms, such as fatty acids, glycerolipids, glycerophospholipids, sphingolipids, sterols, and prenol lipids, derived from dietary intake, adipose tissue, and biosynthesis. While the association between certain fatty acids and cardiovascular diseases has been widely recognized, polyunsaturated fatty acids (PUFAs) exhibit cardioprotective effects, reducing risks of arrhythmias and heart-related mortality. This is due to their role in the production of eicosanoids, which modulate inflammation. Chronic inflammation, particularly in obesity, is significantly influenced by fatty acids, with saturated fatty acids promoting …

Nkapl Facilitates Transcription Pause-Release And Bridges Elongation To Initiation During Meiosis Exit, Zhenlong Kang, Chen Xu, Shuai Lu, Jie Gong, Ruoyu Yan, Gan Luo, Yuanyuan Wang, Qing He, Yifei Wu, Yitong Yan, Baomei Qian, Shenglin Han, Zhiwen Bu, Jinwen Zhang, Xian Xia, Liang Chen, Zhibin Hu, Mingyan Lin, Zheng Sun, Yayun Gu, Lan Ye

Faculty, Staff and Students Publications

Transcription elongation, especially RNA polymerase II (Pol II) pause-release, is less studied than transcription initiation in regulating gene expression during meiosis. It is also unclear how transcription elongation interplays with transcription initiation. Here, we show that depletion of NKAPL, a testis-specific protein distantly related to RNA splicing factors, causes male infertility in mice by blocking the meiotic exit and downregulating haploid genes. NKAPL binds to promoter-associated nascent transcripts and co-localizes with DNA-RNA hybrid R-loop structures at GAA-rich loci to enhance R-loop formation and facilitate Pol II pause-release. NKAPL depletion prolongs Pol II pauses and stalls the SOX30/HDAC3 transcription initiation complex …

Characterization Of Vaccine-Enhanced Humoral Immune Responses Against Emergent Sars-Cov-2 Variants In A Convalescent Cohort, Jared Sheehan, Amber J. Trauth, Michael E. Hagensee, Alistair J. Ramsay

School of Graduate Studies Faculty Publications

Vaccination of COVID-19–convalescent individuals may generate ‘hybrid’ immunity of enhanced magnitude, durability, and cross-reactive breadth. Our primary goal was to characterize hybrid antibody (Ab) responses in a patient cohort infected with ancestral Wuhan-Hu-1 virus and vaccinated between 6 and 10 months later with the Wuhan-Hu-1–based BNT162b2 mRNA vaccine. We were particularly interested in determining the efficacy of neutralizing Ab responses against subsequently emergent SARS-CoV-2 variants. Sera collected at 3-monthly intervals over a period of 12 months were analyzed by ELISA for SARS-CoV-2 RBD–specific Ab responses, and also for neutralizing Ab activity using pseudovirus-based neutralization assays. We found that convalescent RBD-reactive …

In Vivo Evaluation Of Novel Nanoparticles And Repurposed Pharmaceuticals To Combat Antimicrobial Resistance, Sarah E. Evans

Theses, Dissertations and Capstones

In a 2019 report by the Centers for Disease Control and Prevention (CDC), infections resistant to antibiotic treatment amount to about three million infections and 48,000 deaths. Antimicrobial resistance is an escalating global threat as existing antibiotics lose efficacy over time. The project described is focused on partnering with pharmaceutical researchers and producers to test new nanoparticle-based or repurposed compounds. The central hypothesis of this thesis is that pharmaceutical formulations such as nanoparticles may provide a cost-effective means of combating the emerging antimicrobial resistance. The nanoparticle compounds allowed for a wide range of customization for the pharmaceutical design, since the …

A Thermodynamic Bottleneck In The Tca Cycle Contributes To Acetate Overflow In Staphylococcus Aureus, Nabia Shahreen, Jong-Sam Ahn, Adil Alsiyabi, Niaz Bahar Chowdhury, Dhananjay Shinde, Sujata S. Chaudhari, Kenneth W. Bayles, Vinai Chittezham Thomas, Rajib Saha

Journal Articles: Pathology and Microbiology

During aerobic growth, S. aureus relies on acetate overflow metabolism, a process where glucose is incompletely oxidized to acetate, for its bioenergetic needs. Acetate is not immediately captured as a carbon source and is excreted as waste by cells. The underlying factors governing acetate overflow in S. aureus have not been identified. Here, we show that acetate overflow is favored due to a thermodynamic bottleneck in the TCA cycle specifically involving the oxidation of succinate to fumarate by succinate dehydrogenase. This bottleneck reduces flux through the TCA cycle, making it more efficient for S. aureus to generate ATP via acetate …

Quaternized Chitosan Derivatives Inhibit Growth And Affect Biofilm Formation Of Staphylococcus Aureus, Alex Miranda, Nichole D. Brandquist, Kristen Johnson, Elena Muldiiarova, Aleksandr Fadeev, Mahboubeh Ghanbari, Jennifer L. Endres, Kenneth W. Bayles, Jason N. Mactaggart, Denis Svechkarev, Marat Sadykov, Yury Salkovskiy

Journal Articles: Pathology and Microbiology

Antimicrobial resistance (AMR) poses a global health threat, severely impeding the effective treatment of bacterial infections and jeopardizing the safety of routine medical procedures. Methicillin-resistant Staphylococcus aureus (MRSA) is particularly problematic because of its resistance to beta-lactams and the ability to form resilient biofilms. Conventional antibiotics, including last-resort options, have serious side effects and may contribute to further resistance. Chitosan, a natural biopolymer, offers a promising alternative due to its biocompatibility and antimicrobial properties, though its effectiveness against biofilms is limited. Recent studies suggest that increasing the positive charge density and adding hydrophobic moieties to chitosan, can enhance its antimicrobial …

Interferon-Gamma Receptor Signaling Regulates Innate Immunity During Staphylococcus Aureus Craniotomy Infection, Zachary Van Roy, Gunjan Kak, Rachel W. Fallet, Tammy Kielian

Journal Articles: Pathology and Microbiology

A craniotomy is a neurosurgical procedure performed to access the intracranial space. In 3-5% of cases, infections can develop, most caused by Staphylococcus aureus biofilm formation on the skull surface. Medical management of this infection is difficult, as biofilm properties confer immune and antimicrobial recalcitrance to the infection and necessitate additional surgical procedures. Furthermore, treatment failure rates can be appreciably high. These factors, compounded with rapidly expanding rates of antimicrobial resistance, highlight the need to develop alternative treatment strategies to target and reverse the immune dysfunction that occurs during biofilm infection. Our recent work has identified CD4+ Th1 and Th17 …