Medical Microbiology Commons^™

Characterizing Immune Perturbations In Peripheral Blood Following The East Palestine, Ohio Train Derailment, Sheridan B. Wagner, Hami Hemati, Siva Gandhapudi, Timothy J. Hilbert, Candace J. Brancato, Erin N. Haynes, Ilhem Messaoudi

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Background: The East Palestine, Ohio, train derailment on February 3rd, 2023, resulted in the exposure of residents and the surrounding area to numerous hazardous chemicals, which included known acute irritants and human carcinogens. Despite evacuation and cleanup, both residents and responders reported high occurrences of symptoms associated with exposure in the months following, such as eye, skin, and respiratory irritation, headaches, and fatigue. The long-term health consequences for residents remain uncertain.

Objective: To assess the potential for immune perturbations resulting from the exposure, we performed a broad investigation of circulating immune cells and mediators from residents of East Palestine, OH, …

Combinatorial Immunotherapy Drives Exhaustion In Tumor Antigen–Specific Cd8+ T Cells Within The Mouse Renal Tumor Microenvironment, Holly R. Stephens, Elizabeth Elkins, Jing Li, Zoey N. Swalley, Henry Nnaemeka Ogbonna, Pia Muri, Zachary Roberts, Francesca R. Dempsey, Md Akkas Ali, Md Hasanul Banna Siam, Richard Kirkman, Jianqing Zhang, Sunil Sudarshan, Daniel J. Tyrrell, Hubert M. Tse, Daniel L. Smith Jr, Lyse A. Norian

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Immunotherapies have greatly improved outcomes for patients with renal cell carcinoma (RCC), yet response rates remain suboptimal and the factors promoting therapy resistance versus sensitivity are incompletely understood. Currently, no preclinical model of orthotopic renal cancer exists that permits evaluation of tumor antigen–specific (TAS) CD8⁺ tumor-infiltrating lymphocytes (TILs). To address this deficiency, we developed a mouse renal cancer model that permits tracking of adoptively transferred TAS CD8⁺ T cells. Renca-LUC tumor cells were transduced to express tumor ERK (tERK), a model antigen expressing a one-amino-acid change from wild-type ERK, resulting in recognition by tERK/H-2K^d-specific DUC Thy1.1 …

Granulomatous Cellular Signatures In Nontuberculous And Tuberculous Mycobacterial Infections, Brianna M. Doratt, Ethan G. Napier, Mahdi Eskandarian Boroujeni, Sarah Douglas, Michael H. Davies, Luiz Bermudez, Eliot Spindel, Erin F. Mccaffrey, Ilhem Messaoudi

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Mycobacterium tuberculosis (Mtb) and nontuberculous mycobacteria (NTM) are acid-fast bacilli that trigger granuloma formation, a hallmark immune response aimed at containing infection. While the biology of Mtb granulomas has been widely investigated, far less is known about granulomas caused by NTM infection, despite the increasing prevalence and clinical challenge of NTM cases worldwide. Because granulomas influence infection control, pathology, and treatment response, understanding their cellular organization and signaling is critical to improving therapeutic strategies. Therefore, we characterized granulomas formed following infection of rhesus macaques with Mycobacterium avium subsp. hominissuis (MAH) and compared them to granulomas from cynomolgus macaques infected with …

Glycoprotein-Specific Transcriptional Response Contributes To Differential Vaccine Protection Against Lethal Ebola Virus Infection, Sheridan B. Wagner, Delphine C. Malherbe, Ethan G. Napier, Andrea Marzi, Ilhem Messaoudi

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Since the West African Ebola virus (EBOV) epidemic in 2014-2016, recurrent outbreaks of the EBOV-Makona variant have been driven by recrudescence and human-to-human transmission emphasizing the need for effective vaccination strategies. A live-attenuated recombinant vesicular stomatitis virus (VSV)-based vaccine expressing the EBOV-Kikwit variant glycoprotein (VSV-Kik) received FDA approval in December 2019 and provides complete, rapid protection against EBOV-Makona as early as 7 days post-vaccination (DPV). During the 2018-2020 Ebola outbreak, the VSV-Kik vaccine, known as ERVEBO, was administered to lower-risk individuals at a 5-fold dose reduction of the standard 2 × 10 ⁷ PFU to provide broader population protection. Identification …

The Role Of Bacteriophage In The Rgg1-Mediated Virulence Control Of Streptococcus Pyogenes, Yuan Tian

Dissertations and Theses

In Streptococcus pyogenes, bacteriophages and other horizontally transmissible elements (HTEs) comprise approximately 10% of the genome, and each clinical isolate carries a unique combination of these elements, contributing to genetic diversity, virulence, antibiotic resistance, and immune evasion. Previously, our laboratory identified binding sites of the transcriptional regulator Rgg1 in the clinical isolate NZ131 and demonstrated that Rgg1 influences genome-wide gene expression, including bacteriophage genes. In the clinical isolate SF370, the prophage SpyCIM1, positioned in the chromosome between the mutL and mutS genes, controls DNA mismatch repair through excision and reintegration into the chromosome. In the integrated form, the prophage displaces …

The Structure, Dynamics, And Impact Of An Interbacterial Weapon Encoded By Human Gut Bacteria, Casey John Latario

Dartmouth College Ph.D Dissertations

The human gut is densely colonized by diverse bacteria. Over a human’s growth, the GI tract becomes a dynamic community that is subjected to a continual in-flow of nutrients and would-be colonizers and an out-flow of microbes and waste products. Despite these dynamics, the bacterial community often displays stability, with particular strains persisting over decades. These stable colonizers have evolved mechanisms to bolster their colonization, resist disruption by other microbes, and persist through environmental flux.

Both interbacterial competition and horizontal gene transfer (HGT) contribute to colonization and survival within the GI tract. A major mechanism for interbacterial competition is the …

A Novel Tyrosine Kinase Axis In Innate Immune Signaling, Santanu Das, Pracheta Sengupta, Manoj Veleeparambil, Saurabh Chattopadhyay

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Tyrosine phosphorylation has emerged as a central regulatory mechanism in innate immunity. Building on our recent studies that Syk and EGFR sequentially phosphorylate TLR9 to fully activate it, we discuss how similar mechanisms operate across other Toll-like receptors and the cytosolic DNA sensor STING. Evidence from complementary systems reveals that receptor and nonreceptor tyrosine kinases, including Src-family kinases, Syk, BTK, and EGFR, form an integrated signaling network that triggers receptor activation, trafficking, and downstream gene expression. Scavenger receptors such as SR-A further drive this kinase cascade by coordinating viral recognition to TLR activation. These observations reveal a novel ‘tyrosine kinase …

Maternal Opioid Use Disorder And Hepatitis C Infection In Pregnancy Reshape The Peripheral Immune Landscape At Term, Brianna M. Doratt, Heather E. True, Sheridan B. Wagner, Delphine C. Malherbe, Zachary M. Reynolds, Cynthia Cockerham, John O'Brien, Ilhem Messaoudi

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Background: Pregnancy requires precisely timed immune adaptations to maintain foetal tolerance while enabling timely initiation of labour, a process often conceptualised as the ‘immune clock’ of pregnancy. Disruption of this immune clock contributes to adverse obstetric outcomes. While maternal opioid use disorder (OUD) is a recognised risk factor for poor maternal and neonatal health, its impact on maternal immune landscape at delivery remains poorly understood.

Methods: We analysed peripheral blood collected from pregnant individuals with and without OUD at time of admission for delivery before the onset of active labour. We employed multiparameter flow cytometry, cytokine profiling, and single-cell-RNA sequencing …

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. …

Post-Metabolites Of Two Commensal Bacteria Suppress Dna Damage In An Experimental Model Of Acid Reflux Disease, Maanya Pradeep

Honors Undergraduate Theses

Chronic heartburn or gastroesophageal reflux disease (GERD) affects approximately 25% of the US population [1]. Repeated bile acid exposure from the regurgitation of stomach contents leads to the production of reactive oxygen species (ROS), which can cause oxidative DNA damage and promote genomic instability [2]. Barrett’s esophagus (BE), which can develop as a response to chronic bile acid exposure, increases the risk of esophageal adenocarcinoma (EAC) by 30% to 125% [1].

There are more than 18,000 new cases of esophageal cancer in the United States each year, and while its incidence is relatively low compared to other cancers, its mortality …

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 …

Light-Induced Oslike1 Phosphorylation Enhances Rice Resistance Against Blast Disease, Jiangtao Liu, Lei Su, Wenya Wang, Jintao Wang, Weizhong Chen, Zhixiang Yang, Leiyun Yang, Gang Li, Xinyu Liu, Haifeng Zhang, Zhongqiang Qi, Yongfeng Liu, Yuqiang Liu, Ping Wang, Muxing Liu, Zhengguang Zhang

School of Graduate Studies Faculty Publications

Rice blast caused by Magnaporthe oryzae poses a major threat to world food supply. Conditions conducive to the disease include insufficient light. Our previous studies found that light-dependent phosphorylation of light-harvesting complex II protein (LHCB5) mediates rice immunity; however, the underlying mechanisms, in particular, the upstream regulators of LHCB5 phosphorylation, remain unknown. Here, we show that OsLIKE1 functions as a lectin receptor-like kinase (LecRLK) to play a critical role in rice resistance against M. oryzae. OsLIKE1 interacts with and phosphorylates LHCB5. In addition, we find two phosphorylation sites in the kinase domain of OsLIKE1 important for its auto-phosphorylation and phosphorylation …

Green Synthesis Of And Antimicrobial Susceptibility Testing Of (2z)-2-[(4-Fluorophenyl)Methylidene]-1-Benzofuran-3-One, Rod Albert C. Olofernes

Honors Theses

Antimicrobial resistance is a global health challenge, rendering once-effective antibiotics less potent or entirely ineffective. In response, there is increasing interest in developing antimicrobial agents through environmentally sustainable methods. In this study, a fluorinated aurone derivative, (2Z)-2-[(4-fluorophenyl)methylidene]-1-benzofuran-3-one, was synthesized using a green Knoevenagel condensation approach. Eco-friendly catalysts were employed to minimize environmental impact and avoid hazardous byproducts. Product formation was confirmed to avoid wasting resources. The compound was evaluated for antimicrobial properties using a Kirby-Bauer plate, but did not demonstrate consistent or significant antimicrobial activity, therefore lacking promise as a standalone antibiotic.

Development Of Broadly Protective Vaccines Against New World Arenaviruses, Brian B. Gowen

Funded Research Records

No abstract provided.

Dietary Fiber Modulates Gut Microbiota And Lipid Metabolism Ameliorating Alzheimer's Pathology In 5xfad Mice, Yuhai Zhao, Christopher M. Taylor, Walter J. Lukiw, Nicolas G. Bazan

School of Graduate Studies Faculty Publications

The gut-brain axis plays a critical role in maintaining neuronal integrity and influencing the progression of Alzheimer's disease (AD). Here, we investigated how commonly consumed dietary fibers modulate gut microbiota, lipid metabolism, and AD pathology in 5xFAD mice. Male mice were fed either fiber-free (FF) or fiber-plus (FP; 1% cellulose, 2% pectin, 2% inulin) diets for five months, followed by integrated analyses of gut microbiota (16 S rRNA sequencing), fecal lipid metabolites (LC-MS/MS), and neuropathological and behavioral outcomes. FP diets markedly altered microbial composition, characterized by increases in Muribaculaceae, Ileibacterium, and Lachnospiraceae NK4A136 group and reductions in Faecalibaculum and Coriobacteriaceae …

Elucidating The Relationship Between Water Quality And Antibiotic Resistance Of Rainwater Microbes Across Western Humboldt County, Theo P. Murphy, Eve Wendley, Justice Laskowski, Tyler Paredes

Humboldt Journal of Microbiology

Limited studies have been conducted regarding the fecal contamination and microbial dispersal through rainwater, with no known studies investigating the potential connection between antibiotic resistant microbes and water quality in rainwater. This study seeks to identify the presence of a correlation between water quality and incidence of antibiotic resistance in rainwater microbes. We hypothesize that there will be a correlation between these two variables. We additionally anticipate a high incidence of fecal contamination across rural and urban collection sites alike, with fecal contamination being more prevalent in rural areas than urban locals. To determine water quality, we measured the concentration …

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 …

Evaluation Of Anti-Bacterial Efficacy Of Ginger, Resin Gum, And Nigella Sativa Irrigants Against Enterococcus Faecalis: An In Vitro Study, Iman El Ghazzawy, Leen Imad Hasbini, Reem Chamseddine, Wael Betbout, Roula Abiad

International Arab Journal of Dentistry

Objectives: To evaluate the antibacterial efficacy of Ginger, Resin Gum, and Nigella Sativa, against Enterococcus Faecalis.

Methods: Thirty-eight extracted single-rooted premolars were inoculated with E.faecalis, except the negative control, and incubated for 4 weeks. After instrumentation samples were divided into 4 groups (n=7) according to final irrigation: NaOCl+EDTA (Group A), Nigella sativa (B), Resin Gum (C), Ginger (D), plus 2 control groups (n=5): Saline (E), and Saline without bacterial inoculation (F). Cultures were collected at baseline and after irrigation.

Results: One-way ANOVA showed that in groups A-D a statistically significant reduction of bacterial load was observed at …