Bacteria Commons^™

A Conserved Role For Cyclin C In Regulated Cell Death Across Yeast And Humans, Samar Emami, David Stieg, Daniel Smethurst, Justin Bauer, Randy Strich

Rowan-Virtua Research Day

Background: Programmed cell death (PCD) is a tightly regulated process that maintains tissue homeostasis and eliminates damaged, infected, or malignant cells. A key regulator of this process is Cyclin C (CCNC), which functions as a component of the mediator complex to regulate gene transcription. During cellular stress, CCNC translocates from the nucleus to the mitochondria, where it associates with Dnm1 to promote mitochondrial fragmentation and  apoptosis.

Objective: This study aimed to unravel conservation of CCNC’s function between yeast and humans by investigating whether human CCNC can induce apoptosis in yeast and whether it does so through interaction with …

Geographical And Anatomical Microbiome Variation In Invasive Green Iguanas (Iguana Iguana), Amanda A. Diaz

All HCAS Student Capstones, Theses, and Dissertations

The common green iguana (Iguana iguana) was introduced to South Florida in 1965 and has since been an especially pernicious threat both environmentally and economically. This highly invasive species is also expanding in range and populations at an astonishing rate. Understanding how this reptile is able to adapt and thrive in novel environments is of imperative need in order to begin managing their disruptive populations. Notwithstanding their negative impacts and significance, the microbiome of wild populations has not yet been characterized. Here, using 16S ribosomal RNA gene sequencing, this study is the first to characterize the microbiome composition …

Investigating Corollaries Between Streptococcus Gallolyticus Subsp. Gallolyticus Virulence And Colorectal Cancer, Tyler G. Myers

Pursuit - The Journal of Undergraduate Research at The University of Tennessee

Streptococcus gallolyticus subsp. gallolyticus (Sgg) is a gram-positive, non-beta-hemolytic bacterium that belongs to the Lancefield group D of streptococcal pathogens. For the past several decades, associations between Sgg bacteremia and colorectal cancer (CRC) have been apparent, with gastroenterologists routinely recommending colonoscopies for positive cases of Sgg in either blood or stool samples. However, current research has not wholly established whether Sgg acts as a causative agent of CRC or if pre-existing cancers make the lumen of the colon more hospitable to its colonization. Regardless, Sgg has been implicated in the modulation of host inflammatory pathways and subsequent remodeling …

Evaluation Of Mycoplasma Genitalium Positivity And Co-Infection With Chlamydia Trachomatis And/Or Neisseria Gonorrhoeae At Various Care Sites Across The United States, Rebecca Lillis, Rodney Arcenas, Christy M. Boraas, Steven E. Chavoustie, Lashonda Crane, Nicole D'Empaire, Aaron C. Ermel, Glenn Harnett, Federico Hinestrosa, Stacey House, Joseph Miller, Anthony Mills, Ronald Poblete, Stephen Young, Barbara Van Der Pol

School of Medicine Faculty Publications

OBJECTIVES: We evaluated Mycoplasma genitalium (MG) positivity and co-infection with Chlamydia trachomatis (CT) and/or Neisseria gonorrhoeae (NG), based on results from a trial assessing clinical performance of the Cobas® Liat CT/NG/MG point-of-care test. METHODS: A prospective, US, multicenter, noninterventional study assessed MG positivity in prospective urine samples (male) and clinician-collected vaginal swabs (female) from symptomatic/asymptomatic patients aged ≥14 years attending various clinical settings. Participants were designated positive or negative for MG, CT, and NG based on combined results from three US Food and Drug Administration-approved assays and one laboratory-developed test. MG co-infection with CT and/or NG was assessed. RESULTS: Among …

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 …

Antibiotic Resistance Trends In Coliform Bacteria Of Kittitas County Waters, Kaitlyn Holbrook, Bella Blasingim, Cruz Veronica Guillen Mejia, Holly Pinkart

Journal of the Symposium of University Research and Creative Expression

Project Mentor(s): Holly Pinkart, PhD

Since the mid-1900s, antibiotics have been developed to help fight against bacterial pathogens. However, bacteria can evolve rapidly and have evolved resistance to many types of antibiotics. Using coliform bacteria collected from waters around Kittitas County, BIOL 323 students at Central Washington University have identified a variety of antibiotic-resistant bacteria in Kittitas County streams and canals. Antibiotic resistance was measured from 2014-2019 and compared to data collected in 2024. This study focuses on three antibiotics, ampicillin, kanamycin, and trimethoprim-sulfamethoxazole. In the past (2014-2019) we saw no change in the trend of antibiotic resistance in collected …

Complete Genome Sequence Of Rothia Mucilaginosa D1, A Genetically Amenable Strain, Hemendra P. Dhaked, Isabella Andonie, Bo Yang, Vinayka M. Joshi, Zezhang T. Wen

School of Dentistry Faculty Publications

Here, we report the complete genome sequence of Rothia mucilaginosa D1. Unlike many other strains that have been sequenced, R. mucilaginosa D1, a clinical isolate, is genetically amenable. The complete sequencing of the genome provides potential for further studies on the genetics and pathophysiology of this emerging pathobiont.

Host, Microbiome, And Parasite: How Apicomplexan Microorganisms Interact With Gut Microbiota, Senia Bu, Andrew T. Ozga

Mako: NSU Undergraduate Student Journal

The gut microbiome, a complex ecosystem of microorganisms residing in the human gastrointestinal tract, plays a crucial role in maintaining overall health. It functions in immune system regulation, digestion, and protection against pathogens. Apicomplexan parasites, such as Toxoplasma gondii, Plasmodium spp., and Cryptosporidium spp., are major pathogens that can significantly disrupt the gut microbiota, leading to alterations in microbial composition and function. This review explores the bidirectional interactions between Apicomplexan parasites and the gut microbiome, focusing on how these parasites influence microbial diversity, immune responses, and host metabolism. It examines the mechanisms by which infection-induced inflammation, altered …

Synergistic Cefiderocol-Containing Antibiotic Combinations Active Against Highly Drug-Resistant Acinetobacter Baumannii Patient Isolates With Diverse Resistance Mechanisms, Justin Halim, Andrew P. Keane, Jeannete Bouzo, Tope Aderibigbe, Jessica A. Chicola, Katie T. Nolan, Keertana Jonnalagadda, Jason X. Tran, Valerie J. Carabetta

Rowan-Virtua School of Osteopathic Medicine Departmental Research

BACKGROUND: Acinetobacter baumannii is a nosocomial pathogen known for rapidly developing resistance to nearly all antibiotics, including last-line agents. Cefiderocol, a novel siderophore cephalosporin, has shown in vitro activity against A. baumannii and is now used clinically, but resistance is emerging. Data on cefiderocol-based antibiotic combinations are limited.

OBJECTIVES: To evaluate the in vitro activity of cefiderocol alone and in combination with other antibiotics against XDR and PDR A. baumannii clinical isolates, and to explore resistance mechanisms underlying cefiderocol synergy.

METHODS: We tested 21 XDR/PDR clinical isolates and one NDM-1-producing strain using broth microdilution and checkerboard assays with cefiderocol and …

Exploring The Role Of Lysine Acetylation During Biofilm Formation In Bacillus Subtilis, Jennifer Nguyen, Briana Ericka Reid, Valerie Carabetta

Rowan-Virtua Research Day

Biofilms are structured communities of bacterial cells encased in a self-produced extracellular matrix, composed of polysaccharides, extracellular DNA, and proteins. Bacteria in a biofilm pose significant challenges in healthcare due to their resistance to disinfectants and tolerance to antibiotics. In some species, histone-like proteins were found to be important structural components of the biofilm. Nε-Lysine acetylation is a widespread post-translational modification (PTM) in bacteria, which can alter a protein’s function. The histone-like protein HBsu in Bacillus subtilis is acetylated at seven sites in vivo. We hypothesized that the acetylation state of HBsu may alter biofilm structure or the genetic programming, …

Implications Of Type Iv Pilus Retraction For Dna Uptake By Acinetobacter Baumannii, Yafan Yu

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

Horizontal gene transfer (HGT) via natural competence allows bacteria to incorporate extracellular DNA (eDNA) into their genomes, facilitating genetic diversity and adaptation. In Acinetobacter species, natural competence depends on DNA binding and uptake mediated by type IV pili (T4P). T4P are dynamic extracellular filaments composed primarily of the major pilin subunit PilA, along with a few minor subunits. T4P drive a range of cellular functions including twitching motility, biofilm formation, and DNA uptake, with some functions dependent on pilus retraction and others not. However, how Acinetobacter T4P bind DNA and how T4P/eDNA interactions impact biofilm formation remain unclear. Here, I …

Elucidating The Multi-Omics Of Early-Onset Colorectal Cancer, Jumanah Alshenaifi

Dissertations and Theses (Open Access)

The incidence and mortality rates of sporadic early-onset colorectal cancer have increased in recent decades, but there is no clear etiological basis for this trend. EOCRC is commonly defined as colon and rectal cancers diagnosed before the age of 50 years. The rising incidence of EOCRC has made it the second most common cancer and the third leading cause of cancer death in this age group. The rising incidence of EOCRC is also documented internationally in more than 20 countries across different continents. Clinically, EOCRC has a distinct, more aggressive clinical profile than LOCRC. While approximately 15% of EOCRC cases …

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 …

Inactivation Of E. Faecium Nrrl B-2354 In Whole Black Pepper By Fluidization With Hydrogen Peroxide Vapor, Daniela Segura

Department of Food Science and Technology: Master of Science with Project Option

This study evaluated Enterococcus faecium NRRL B-2354 as a surrogate for Salmonella inactivation in black peppercorns treated with hydrogen peroxide (HP) vapor via fluidization. The selected parameter for dwell temperature was 60ºC for 60 minutes. The reduction of both Salmonella and E. faecium, along with changes in water activity, color, and residual hydrogen peroxide, were measured before, immediately after treatment and at 24 and 48 hours post-treatment. Results showed that E. faecium exhibited a significantly greater reduction (4.63 ± 0.55 log CFU/g) compared to Salmonella (2.94 ± 0.16 log CFU/g) (p < 0.05), making E. faecium unsuitable as …

Dental Disparities: An Analysis Of Dental Caries Risk Factors Promoting Disparities Between Rural And Urban Communities In Nebraska, Nick Lounsbery

Honors Program: Senior Projects (Public)

The prevalence of dental caries in the United States remains a public health concern, as it is one of the most common chronic conditions across people of all ages. Research shows that preventative measures including brushing, fluoridated water, and regular checkups are effective strategies to mitigate tooth decay. However, there appears to be a divide between rural and urban populations, as the presence of dental cavities is significantly greater in remote areas in the State of Nebraska. Research methods used in this analysis included analyzing accredited academic literature to illustrate how cavities form from a biochemical perspective. Research methods also …

The Role Of Horizontal Gene Transfer In Antibiotic Resistance Amidst Prevalent Community And Healthcare-Associated Mrsa Rates, Gabrielle Nascimento

Honors College Theses

In recent decades, cases of community-acquired MRSA (CA-MRSA) and healthcare-associated MRSA (HA-MRSA) have been on the rise. The ability of antibiotic resistance to transfer between microorganisms greatly expands its threat to the effective treatment and containment of bacterial infections. The mecA gene is found on a mobile cassette within the Staphylococcal cell and encodes for PBP2a, an alternate version of penicillin-binding protein (PBP) with less binding affinity for β-lactam antibiotics, increasing resistance to the effects of antibiotics. The goal of this research is to investigate the horizontal transfer of the mecA gene between various Staphylococcus species as well as to …

Investigating Regulation And The Regulome Of The Nucleic Acid Binding Protein Spovg Within Borrelia Burgdorferi, Timothy C. Saylor

Theses and Dissertations--Medical Sciences

Prior studies indicated Borrelia burgdorferi SpoVG protein was regulated, SpoVG binds specifically to a number of nucleic acids, and SpoVG binds to the non-variable section of the major virulence factor vlsE. Although a direct transcriptional activator or inhibitor was not elucidated, it is shown that SpoVG is regulated based on cell culture density independent of the growth rate of B. burgdorferi, indicating that SpoVG regulation is outside the scope of the alternative sigma factor RpoS. Using a dCas9 CRISPRi construct to target SpoVG resulted in protein expression trending towards upregulation of the BosR-RpoS regulon, and a marked decrease …

Bacterial Two-Hybrid Systems Evolved: Innovations For Protein-Protein Interaction Research, Rebecca M. Richardson, Steven M. Pascal

Chemistry & Biochemistry Faculty Publications

Bacterial two-hybrid (B2H) systems offer a versatile platform for detecting protein-protein interactions (PPIs) in vivo. Originally developed to study bacterial transcriptional regulators, these systems have evolved to support a wide range of applications, including interaction mapping, domain analysis, and high-throughput screening. This review surveys the development and expansion of B2H systems across diverse biological contexts. We highlight technical considerations, platform-specific innovations, and recent adaptations that extend the utility of B2H systems in both prokaryotic and eukaryotic protein interaction research environments. By comparing different B2H variants and discussing their integration with complementary approaches, we provide a framework for leveraging these …

Nucleotide-Derived Bacterial Alarmones Attenuate The Induction Of Type-I Interferon Responses In A Murine Macrophage Reporter Cell Line, Ryan P. Kilduff, Erin B. Purcell, Lisa M. Shollenberger

Chemistry & Biochemistry Faculty Publications

The stringent response is a well-studied phenomenon in many bacterial systems and regulates resource-consuming activities such as transcription, translation, and replication. The stringent response is a well-conserved signaling framework, as are the nucleotide-derived signaling mediators, collectively referred to as (p)ppGpp or as alarmones. There is a wealth of research evaluating nucleotide-derived alarmone signaling in bacterial models, however, their potential to modulate innate immune signaling has not yet been evaluated. Several common pathogen-synthesized molecules, such as lipopolysaccharide (LPS) and cyclic-di-AMP (c-di-AMP), act as pathogen-associated molecular patterns (PAMPs), which are common patterns that alert the innate immune system of bacterial infection. The …

Copula-Based Bayesian Model For Detecting Differential Gene Expression, Prasansha Liyanaarachchi, N. Rao Chaganty

Mathematics & Statistics Faculty Publications

Deoxyribonucleic acid, more commonly known as DNA, is a fundamental genetic material in all living organisms, containing thousands of genes, but only a subset exhibit differential expression and play a crucial role in diseases. Microarray technology has revolutionized the study of gene expression, with two primary types available for expression analysis: spotted cDNA arrays and oligonucleotide arrays. This research focuses on the statistical analysis of data from spotted cDNA microarrays. Numerous models have been developed to identify differentially expressed genes based on the red and green fluorescence intensities measured using these arrays. We propose a novel approach using a Gaussian …

Mxene-Based Materials For Enhanced Water Quality: Advances In Remediation Strategies, Ali Mohammad Amani, Milad Abbasi, Atena Najdian, Farzaneh Mohamadpour, Seyed Reza Kasaee, Hesam Kamyab, Shreeshivadasan Chelliapan, Mostafa Shafiee, Lobat Tayebi, Ahmad Vaez, Atefeh Najafian, Ehsan Vafa, Sareh Mosleh-Shirazi

Electrical & Computer Engineering Faculty Publications

Two-dimensional MXenes are promising candidates for water treatment because of their large surface area (e.g., exceeding 1000 m²/g for certain structures), high electrical conductivity (e.g., >1000 S/m), hydrophilicity, and chemical stability. Their strong sorption selectivity and effective reduction capacity, exemplified by heavy metal adsorption efficiencies exceeding 95 % in several studies, coupled with facile surface modification, make them suitable for removing diverse contaminants. Applications include the removal of heavy metals (e.g., achieving >90 % removal of Pb(II)), dye removal (e.g., demonstrating >80 % removal of methylene blue), and radioactive waste elimination. Furthermore, 3D MXene architecture exhibit enhanced performance in antibacterial …

Design, Synthesis, And Nmr-Guided Characterization Of A Targeted Covalent Inhibitor-Like Molecule Against Ivyp1 From P. Aeruginosa, Samuel Taylor Moore

Master's Theses

Multi-drug resistance poses a serious threat to future generations and historical antibiotic pipelines; consequently, the medical and economic burdens associated with treating multidrug-resistant bacteria are substantiated. In this context, P. aeruginosa (PA) emerges as one of the most significant healthcare challenges, being a leading cause of resistance-associated mortality worldwide. Despite modern efforts to combat these poor outcomes, drug-resistant cases continue to rise, and the need for novel antibiotic treatment is apparent. To this end, we investigated relevant resistance mechanisms and past antibiotic targets within PA, and in doing so, we identified relationships between peptidoglycan biology and a periplasmic protein, Inhibitor …

Proteolytic Manipulation Of Neutrophil Responses And The Efferocytic Synapse By Porphyromonas Gingivalis., Kelley N. Cooper

Electronic Theses and Dissertations

Porphyromonas gingivalis (Pg) is etiologically associated with chronic periodontitis, a highly prevalent chronic inflammatory disease characterized by the destruction of hard and soft tissues of the periodontium. Pg is adapted to live in the human oral subgingival niche, a hostile environment dominated by excessive numbers of activated neutrophils and antimicrobial mediators. Its survival is contingent upon prompt and effective inactivation of neutrophil effector functions. In this dissertation, I uncover a novel pathogenic mechanism employed by Pg that disarms the antimicrobial capacity of live neutrophils and simultaneously sequesters them within macrophages. Mechanistically, RgpB, a cysteine protease produced by Pg …

Developing Coexpression Systems To Introduce Hydroxyproline Into Protein Engineered Collagen Peptides Utilizing Hydroxylase From Acanthamoeba Polyphaga Mimivirus, Jennifer Soldatich

Theses and Dissertations

A major challenge of developing collagen mimetic peptides (CMPs) by bacterial expression is to include hydroxyproline for biomedical applications. Coexpression of Prolyl-4-hydroxylase from A.mimivirus with CMPs was investigated. Additionally, four expression designs were created for potential applications in mammalian cells to utilize their natural ability of proline-hydroxylation by post-translational modification.

Molecular Detection Of Pathogenic Bacteria In American Dog Ticks (Dermacentor Variabilis) In Brown County, Nebraska, Nicole Messbarger, Darby Carlson, Keith Geluso, Julie Shaffer

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Ticks carry and transmit disease pathogens that cause many human illnesses. Many of these diseases in humans are accompanied by a wide variety of symptoms making tick-borne illnesses often difficult to diagnose. The rate of reported tick-borne illnesses in humans has increased during the past decades in the United States, alongside a rise in concern for public health and safety. In northern Nebraska, the American dog tick (Dermacentor variabilis) is the primary tick encountered by humans and domestic animals in the region. This species is a known vector for spotted fever group (SFG) rickettsioses and tularemia (Francisella …

Assessment Of Foam Decontamination In Tomato Washing Process, Basim M. Alohali

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

The work of the dissertation investigated the efficacy of foam-based decontamination treatments to enhance microbial safety in Roma tomatoes, specifically targeting natural microflora and Salmonella contamination. Growing concerns over foodborne illnesses linked to fresh tomatoes and the limitations of conventional decontamination techniques, such as organic matter built-up and limited microbial reduction, are addressed. The primary objectives were to characterize the physiochemical properties of foams formed using various concentrations of Tween 20 (T20) and sodium dodecyl sulfate (SDS) with and without the addition of sodium hypochlorite (NaOCl) and peracetic acid (PAA), compare the efficacy of foam and traditional dump tank (DT) …

Investigating The Abilities Of Potentially Beneficial Bacteria For Increasing Nitrogen-Use Efficiency In Maize, Lexie R. Foster

School of Biological Sciences: Dissertations, Theses, and Student Research

Global agriculture relies heavily on the use of synthetic nitrogen fertilizer to meet the current global food demand. Unfortunately, the average nitrogen-use efficiency (NUE) of maize (Zea mays) is approximately 50 percent. Improving the NUE of maize is essential for meeting the growing global food demand while also decreasing the negative environmental impacts caused by losses of nitrogen fertilizer due to runoff and volatilization. Harnessing the symbiotic relationship between plants and the soil microbiome may be one method for increasing the NUE in crops such as maize. In the present study, a set of potentially beneficial bacterial species …

The Physiological Significance Of Nitric Oxide Synthase In Staphylococci, Ryan M. Singh

Theses & Dissertations

Staphylococci, particularly Staphylococcus epidermidis, are common causes of implant-associated infections that may result in notable morbidity and mortality. One of the ways the innate immune system attempts to combat these invading pathogens is via the respiratory burst, in which free radical species such as nitric oxide (NO^•), toxic to bacterial respiration, are released in large quantities. Despite the toxicity of NO^•, some bacteria, including staphylococci, encode an endogenous bacterial nitric oxide synthase (bNOS), whose physiological role has been unclear until now. In this dissertation, we demonstrate that S. epidermidis is able to overcome the toxicity …

Analysis Of Antibiotic Sensitivity Patterns In Pasteurellaceae Family Isolates: A Microbial And Molecular Investigation, Jillian Barron

Honors Scholar Theses

Bacteria in the Pasteurellaceae family are known to cause disease in both human and animal species. Like all species of bacteria, the pathogens in the Pasteurellaceae family evolve and acquire antimicrobial-resistant traits. Antimicrobial resistance of bacteria is a significant public health concern, as treatment of resistant pathogens becomes more difficult, if not impossible, with current medical capabilities. In this project, phenotypic and genotypic analyses were performed on Pasteurellaceae family isolates sourced from the Connecticut Veterinary Medical Diagnostic Laboratory. Phenotypic antibiotic sensitivity patterns of each isolate were assessed against a panel of antibiotics through a Kirby-Bauer disk diffusion test. Disk diffusion …

Screening Environmental Soil Samples For Antibiotic Production, Paige Mattick

SACAD: Scholarly Activities

Antibiotic resistance is a detrimental worldwide challenge, producing bacterial infections that are progressively more difficult to treat and cure. To attempt to help alleviate this issue, we screened soil samples for the presence of antibiotic-producing microorganisms. Soil samples were collected and diluted to 1:100 and 1:1000 ratios of soil and distilled water. These soil mixtures were then streaked onto tryptic soy agar (TSA) plates and incubated at 30℃ until colonies developed. These colonies were then selected and plated on a lawn of Serratia marcescens, which was utilized as the target organism.

Serratia marcescens was selected due to its known resistance …