Microbiology Commons^™

Gastric Survivability Of Streptomyces Narbonensis, Laramie Johnson, Laurel Hilterbrand, Ephraim Mohr, Eliza Lewis

Student Research Symposium

Human sciences and medicine have continually been advancing, and taken off in the last few centuries. This has included the development of many new medicines, antibiotics, and disinfectants. Antibiotics have to be able to survive and perform its duty within the human body, despite the changes in pH that occur naturally within the body in response to stimuli (Cotter, 2003). If a bacteria is unable to adapt to the pH environment of the human body in which it is placed, it will not be able to survive and continue to reproduce. The bacteria may be able to adapt via membrane …

Peribacillus Simplex Does Not Exhibit Antimicrobial Properties Against Staphylococcus, Dallin Thomas, Jordan Wheeler, Natalie Yoho

Student Research Symposium

Antibiotics are powerful drugs that combat previously fatal diseases. These miracle drugs have saved countless lives, but have the tendency to be misused. They are used incorrectly to treat patients who don't need them, and given to animals for non therapeutic use. Antibiotics are also known to pollute soils and groundwater all around the world (3). As antibiotics are found more readily in the environment, they encourage evolution, recombination, and dissemination of antibiotic resistant bacteria (5). According to the Centers for Disease Control and Prevention (6) antibiotic resistance kills at least 1.27 million people worldwide for diseases that used to …

Do Chaperones Promote Protein Splicing?, Christopher Powell, Christopher Lennon Dr

Scholars Week

Intervening proteins (inteins) are translated within host proteins and removed by protein splicing. Inteins are abundant in the microbial world and are often found within essential genes involved in DNA replications, recombination, and repair. Recent studies have made efforts to understand conditional proteins splicing, whereby intein removal and subsequent host protein activation is regulated by environmental factors. However, within the cellular context, factors influencing protein splicing are still largely unknown. In this work, we probe whether the chaperonin system GroEL/ES promotes protein splicing in vivo. Chaperonins, a family of chaperone proteins, help proteins fold under normal and stressed conditions. …

Metabolite Analysis To Understand Factors Limiting Microbial Fermentation At High Substrate Concentrations, Bishal D. Sharma

Dartmouth College Ph.D Dissertations

Clostridium thermocellum, a thermophilic anaerobic bacterium, holds promise as a biocatalyst for conversion of lignocellulosic biomass into biofuels. This microbe has been subjected to various metabolic engineering strategies, including the deletion of genes encoding secondary fermentation products such as H₂, formate, acetate, and lactate, as well as the expression of heterologous genes to redirect carbon flux toward ethanol production. Despite these efforts, achieving economically viable ethanol titers remains a challenge. We hypothesized that studying how intracellular metabolite concentrations change as fermentation stops could reveal metabolic bottlenecks or regulatory mechanisms limiting ethanol production at high titers. However, metabolomics studies at …

Improved Protein Splicing Through Viral Passaging, John Smetana

Scholars Week

Intervening proteins (inteins) are translated as subdomains within host proteins and removed through an intein-driven splicing reaction where the flanking sequences (exteins) are joined with a peptide bond. Previously, we developed a self-removing translation reporter for labeling Ebola virus (EBOV). In this reporter, an intein (RadA) containing the fluorescent protein ZsGreen (ZsG) is inserted within the EBOV protein VP30. Upon VP30-RadA-ZsG expression from the viral genome, RadA-ZsG is removed from VP30 through the protein splicing activity of RadA, generating functional, non-tagged VP30 and functional ZsGreen. While incorporation of our VP30-RadA-ZsG fusion reporter into recombinant EBOV (rEBOV- RadA-ZsG) resulted in an …

Biochemical And Structural Insights Into The Yersinia Effector Yopm And Its Negative Regulation Of The Pyrin Inflammasome, Bethany Wairimu Mwaura

Dartmouth College Ph.D Dissertations

Bacteria utilize sophisticated secretion systems to inject effectors into host cells in order to facilitate their survival and replication in the host. Some pathogenic species of Gram-negative bacteria use a conserved contact-dependent T3SS to inject a wide array of effectors. While the effectors diverge in their structures, functions and cell-localization, the T3SS is well conserved. Several effectors discussed in this thesis target key host inflammasome responses. The focus of this work is how the Yersinia effector YopM inhibits the pyrin inflammasome. During Yersinia infection, two effectors, YopE and YopT inadvertently activate the pyrin inflammasome while targeting RhoA to avoid phagocytosis. …

Resistant & Persistent Bacterial Cells, Jean-Louis Bru

Open Educational Resources

An activity on the difference between resistant & persistent bacterial cells. This activity aims to build on the pre-lecture materials about resistant bacterial cells, so that students can make a connection toward persistent cells. In both cases, they make antibiotics less effective.

Learning Objectives

Recognize the importance of antibiotics in fighting bacterial infections. Understand how bacterial species become antibiotic resistant. Determine the difference between resistant and persistent bacterial cells.

Social and Collaborative

Students work together on this in-class activity in groups of 2-4 (3, ideally). Each student will have one of the following roles: encourager, recorded, investigator, and time keeper. …

Clinical Characteristics And Outcomes Of Pediatric Staphylococcal Scalded Skin Syndrome (Ssss) At An Inner-City Tertiary Care Center, Nina Kb Gust Md, Ashley Frei Bs, Rebecca M. Adams Bs, Elika Ridelman Phd, Christina Shanti Md, Ronald Thomas Phd, Jocelyn Y. Ang Md

Medical Student Research Symposium

Introduction

Staphylococcal Scalded Skin Syndrome (SSSS) is a blistering skin condition caused by a toxin-producing staphylococcus species. Epidemiologic studies on pediatric SSSS in the United States are limited, with a reported incidence of 7.67 cases per million children and 45.1 per million infants. Immature renal function, lack of protective antibodies, and increased exotoxin target desmoglein-1 are hypothesized to increase incidence in younger children. We aimed to determine clinical and microbiological characteristics of pediatric SSSS and factors that could help predict disease severity.

Methods

A retrospective chart review was performed for admitted patients under 18 years old diagnosed with SSSS from …

Modeling The Cystic Fibrosis Intestinal Environment To Study Microbial Interactions, Kaitlyn Emma Barrack

Dartmouth College Ph.D Dissertations

The microbiome of the cystic fibrosis (CF) intestine is altered significantly in structure and function beginning in early life. Key taxa associated with health, digestion and immune-training are reduced in abundance, including but not limited to Bacteroides, Faecalibacterium, Akkermansia, Ruminococcus and other short-chain fatty acid producers. Conversely, there is an expansion of microbes with pathogenic potential, such as Escherichia, Veillonella, Pseudomonas and Staphylococcus. The shifts in microbiota composition direct community-wide changes with differences in beta diversity by genotype, whereby children with CF (cwCF) exhibit significantly different gut microbial compositions compared to nonCF children. Additionally, shifts in microbiota structure often …

Bone-Induced Her2 Promotes Secondary Metastasis In Hr+/Her2- Breast Cancer, Rahat Alam, Anna Reva, David G Edwards, Bree M Lege, Laura S Munoz-Arcos, Carolina Reduzzi, Swarnima Singh, Xiaoxin Hao, Yi-Hsuan Wu, Zeru Tian, Laura M Natalee, Gargi Damle, Deniz Demircioglu, Yixian Wang, Ling Wu, Elisabetta Molteni, Dan Hasson, Bora Lim, Zbigniew Gugala, Jerry E Chipuk, Julie E Lang, Joseph A Sparano, Chonghui Cheng, Massimo Cristofanilli, Han Xiao, Xiang H-F Zhang, Igor L Bado

Faculty, Staff and Students Publications

Bone metastases can disseminate to secondary sites and promote breast cancer progression creating additional clinical challenges. The mechanisms contributing to secondary metastasis are barely understood. Here, we evaluate the prediction power of Her2-expressing (Her2E) circulating tumor cells (CTCs) after analyzing over 13,000 CTCs from a cohort of 137 metastatic breast cancer (MBC) patients with initial HR+/Her2− status and employ preclinical models of bone metastasis (BM) to validate the role of Her2E CTCs in multi-organ metastases. While Her2 expression was higher in patients with bone metastasis, experimental analyses revealed that Her2E CTCs derived from bone lesions were more dependent on Her2 …

Life Line Spring 2025, Otterbein Biology And Earth Science Department

Life Line - The Biology Department Newsletter

In this issue:

Greetings and Farewell!; COSI 2024; Ketchup, Culture, and an Unforgettable Conference; Alumna Earns PhD; Tortoises, Butterflies, and Cockroaches, Oh My!; Licking River Roundup 2024; Aquarium Students Explore Coral Restoration in Fiji; The Galapagos Islands: Geology, Ecology, Conservation, and Culture; Dr. Svitana Presents on Otterbein Lake Well Field; Cell Bio Pilots Unique Approach to Learning; Hoggarth to Retire, June 2025; AED is BACK on Campus!; The Greenhouse Gets a Lifeline; Acoustic Rabies Identification (ARID): A Sound-Based Approach to Rabies Testing

How The Biotic And Abiotic Factors In The Belle Forest Cave And Arboretum Soil Dictates Tree Species Prevalence, Amya A. Bingham

SPARK Symposium Presentations

A plethora of factors in the soil impact a plant’s health, including the presence of different biotic and abiotic factors. These include things like temperature, elevation, pH, microbial respiration and the presence of water, clay, loam, silt, sand, nitrogen, potassium, and phosphorus. Different soils will have varying amounts of these, which may dictate what is able to grow in them, and therefore also the surrounding area. This research project explores how the aforementioned biotic and abiotic factors affect the soil at the Belle Forest Cave and Arboretum. Three samples will be taken from four spots along a transect at this …

Automated Plant Morphological Assessment And Microbial Community Monitoring In Simulated Lunar Regolith, Collin R. Topolski

Doctoral Dissertations and Master's Theses

Upcoming lunar bases will need to leverage in-situ resources to ensure long-term sustainability and reduce mission costs. One key challenge is food production, which could be addressed by growing crops in lunar regolith-based substrates. However, lunar regolith lacks essential nutrients, requiring organic amendments to support continuous plant cultivation. This study examined the impact of manure-amended lunar regolith simulant on Mizuna mustard growth while assessing microbial community diversity and functionality. To support this effort, a custom software pipeline utilizing an open-source library, PlantCV, was developed to automatically track plant leaf area and height via image analysis. Results indicated that amended rhizosphere …

College Of Natural Sciences Newsletter, Spring 2025, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Page 1 Dean's Message from Dr. Sen Subramanian
Page 2 Student Spotlights
Page 3 Kaushik honored, Three-Minute Thesis, & Ice Cores revealed
Page 4 Alumni Spotlight
Page 5 Day of Scholars
Page 6 Cyanide research, Record Research Expenditures, Adhikari awarded Miller Research Award
Page 8 Hanson Receives NSF Grant
Page 9 Snow Lab Research Team
Page 10 Faculty Awards
Page 11 Drone Day
Page 13 Khalaf Awarded Presidential Award

Small-Molecule Mitotic Inhibitors As Anticancer Agents: Discovery, Classification, Mechanisms Of Action, And Clinical Trials, Yazmin Salinas, Subhash Chauhan, Debasish Bandyopadhyay

School of Medicine Publications

Despite decades of research, cancer continues to be a disease of great concern to millions of people around the world. It has been responsible for a total of 609,820 deaths in the U.S. alone in 2023. Over the years, many drugs have been developed to remove or reduce the disease’s impact, all with varying mechanisms of action and side effects. One class of these drugs is small-molecule mitotic inhibitors. These drugs inhibit cancer cell mitosis or self-replication, impeding cell proliferation and eventually leading to cell death. In this paper, small-molecule mitotic inhibitors are discussed and classified through their discovery, underlying …

Neutrophil Inflammatory Death Regulation By Bacterial Type Iii Secreted Effectors, Arianna D. Reuven

Dartmouth College Ph.D Dissertations

Yersinia and Pseudomonas use a T3SS to secrete effectors into host cells that inhibit phagocytosis and modulate immune responses, such as inflammasome activation. Inflammasomes promote the activation of the proinflammatory protease caspase-1. The activation of an inflammasome sensor in response to a signal or ligand initiates the assembly of the inflammasome leading to activation of caspase-1 which cleaves GSDMD and pro-inflammatory cytokines IL-1β and IL-18 into their mature forms. As neutrophils are recruited in large quantities to sites of infection, they are excellent candidates to drive inflammasome dependent responses. Neutrophils have been shown to produce multiple inflammasomes, like pyrin and …

Il-12-Producing Cytokine Factories Induce Precursor Exhausted T Cells And Elimination Of Primary And Metastatic Tumors, Amanda Nash, Jonathon Debonis, Danna Murungi, Bertha Castillo, Boram Kim, Fangheng Hu, Courtney Chambers, Annie Nguyen, Andrea Hernandez, Zeshi Wang, Peter D Rios, Sofia Ghani, Ira Joshi, Douglas Isa, Ningbo Zheng, Weiyi Peng, Oleg A Igoshin, Jose Oberholzer, H Courtney Hodges, Nathan Reticker-Flynn, Omid Veiseh

Faculty, Staff and Students Publications

Background: Curative responses to immunotherapy require the generation of robust systemic immunity with limited toxicity. Recruitment of T cell populations such as precursor exhausted T cells (Tpex) from lymphoid tissues to tumors is a hallmark of effective treatment. However, the ability to efficiently induce this recruitment is lacking in current immunotherapy approaches. Furthermore, systemic administration of immunotherapies frequently results in dose-limiting toxicities, yielding an inadequate therapeutic window for eliciting durable responses.

Methods: In this investigation, we evaluated the safety and antitumor efficacy of locally administered interleukin 12 (IL-12) using a clinically translatable cytokine delivery platform (NCT05538624) to identify …

Single-Nucleus Transcriptional Profiling Of The Placenta Reveals The Syncytiotrophoblast Stress Response To Covid-19, Rachel A Keuls, Scott A Ochsner, Mary B O'Neill, Diana R O'Day, Akihiko Miyauchi, Kadeshia M Campbell, Natalie Lanners, Jeffery A Goldstein, Connor Yee, Neil J Mckenna, Ronald J Parchem, Jacqueline G Parchem

Faculty, Staff and Students Publications

Background: COVID-19 in pregnancy is associated with placental immune activation, inflammation, and vascular malperfusion, but its impact on syncytiotrophoblast biology and function is unclear.

Objective: This study aimed to determine the effects of maternal COVID-19 on placental syncytiotrophoblasts using single-nucleus transcriptional profiling and to compare placental stress responses in COVID-19 and preeclampsia.

Study design: For transcriptional characterization of syncytiotrophoblasts, we used the single-nucleus RNA sequencing platform, single-cell combinatorial indexing RNA sequencing (sci-RNA-seq3), to profile placental villi and fetal membranes from unvaccinated patients with symptomatic COVID-19 at birth (n = 4), gestational age-matched controls (n = 4), and a case of …

Unveiling Racial Disparities In Prostate Cancer Using An Integrative Genomic And Transcriptomic Analysis, Abdalla Elbialy, Akshay Sood, Shang-Jui Wang, Peng Wang, Ahmed Fadiel, Anil V Parwani, Steven Huang, Gennady Shvets, Nagireddy Putluri, Jenny Li, Xuefeng Liu

Faculty, Staff and Students Publications

Prostate cancer exhibits significant racial disparities, with African American (AA) individuals showing ∼64% higher incidence and 2.3 times greater mortality rates compared to their Caucasian (CA) counterparts. Understanding the complex interplay of genetic, environmental, lifestyle, socioeconomic, and healthcare access factors is crucial for developing effective interventions to reduce this disproportionate burden.

This study aims to uncover the genetic and transcriptomic differences driving these disparities through a comprehensive analysis using RNA sequencing (RNA-seq) and exome sequencing of prostate cancer tissues from both Black and White patients.

Our transcriptomics analysis revealed enhanced activity in pathways linked to immune response and cellular interactions …

Warm-Ischemia And Cold Storage Induced Modulation Of Ferroptosis Observed In Human Hearts Donated After Circulatory Death And Brain Death, Shiyi Li, Katherine V Nordick, Abdussalam E Elsenousi, Rishav Bhattacharya, Randall P Kirby, Adel M Hassan, Camila Hochman-Mendez, Todd K Rosengart, Kenneth K Liao, Nandan K Mondal

Faculty, Staff and Students Publications

We investigated ferroptosis, a type of programmed cell death mechanism, in human hearts donated after brain death (DBD) and those donated after circulatory death (DCD), focusing on warm ischemia time (WIT) and cold storage. A total of 24 hearts were procured, with six from the DBD group and 18 from the DCD group. The DCD group was divided into three subgroups, each containing six hearts, based on different WITs of 20, 40, and 60 min. All procured hearts were placed in cold storage for up to 6 h. Left ventricular biopsies were performed at 0, 2, 4, and 6 h. …

The Isolation And Characterization Of Acidovorax And Brevundimonas Bacteriophages With Preliminary Biocontrol Study On Arabidopsis Thaliana, Minh Quynh N. Vu

Senior Theses

As antibiotic-resistance becomes an increasing global concern, researchers are looking for alternatives to combat phytopathogenic rhizobacteria – one of which is through the application of phage biocontrol. To elucidate the complex tripartite relationships between phage, bacteria and plant interactions, nine novel phages were isolated from potential phytopathogenic strains of Acidovorax (RBW13) and Brevundimonas (RBW18). These phages were isolated from root samples obtained from the Rocky Branch Creek and the Broad River located in Columbia, SC. Using Pulsed-Field Gel Electrophoresis (PFGE), we identified seven “medium sized” phages (~40 kbp), one “large-sized” phage (~200 kbp), and one “small-sized” phage ( < 25 kbp). Three phages were determined to be lambda-like due to their “ladder-building” patterns on PFGE. Although spot-tests revealed that all phages seemed to have broad host ranges that spanned over multiple genera, plaque-formations must be observed in future experiments to determine if these phages can infect their hosts productively. Preliminary in planta experiments were performed on Arabidopsis thaliana …