Bacteriology Commons^™

Pseudomonas Aeruginosa Exoenzyme Y Enzymatic Activity Inhibits Exoenzyme S-Induced Caspase Activation But Not Cytotoxicity In Pulmonary Microvascular Endothelial Cells, Connor Holm

Honors Theses

Pseudomonas aeruginosa (P. aeruginosa) is the most common cause of ventilator-associated pneumonia in intensive care unit patients. P. aeruginosa utilizes a type III secretion system that injects exoenzymes U, S, T, and/or Y into the host cell cytosol. A majority of clinically isolated P. aeruginosa strains express ExoY often in combination with ExoU and ExoT, or ExoS and ExoT. Host signaling mechanisms in response to intoxication with individual exoenzymes have been extensively studied, yet little is known about host cell response to co-intoxication. In this study, pulmonary microvascular endothelial cells (PMVECs) were infected with P. aeruginosa strains expressing different combinations …

Toxicity And Biodegradability Of Novel Boronium Vs Conventional Ammonium-Based Antimicrobial Compounds In Wastewater Treatment Systems, Noor Shalan

Honors Theses

Quaternary ammonium compounds (QACs) are highly effective as disinfectants, herbicides, and pesticides; thus, overuse causes elevated levels of residual toxicity in domestic and industrial wastewater. QACs can be toxic to essential bacteria breaking down pollutants in wastewater treatment plants (WWTPs) and can remain untreated in effluent, harming the environment, and contributing to antibiotic resistance, posing risks to human health. Novel boronium-based antimicrobial compounds have demonstrated efficacy in eliminating bacteria, fungi, and viruses. If the boronium compounds exhibit lower residual toxicity, they could offer a promising alternative to QACs. Because these compounds are still in development, their potential toxicity to the …

Survey And Analysis Of Rumen Microbiota In Yaks At Different Growth Stages, Shengwei Jin, Xinyue Liu, Yin-Cang Han, Yong-Gang Sun, Wei-Qin Ding, Ya-Qian Liu, Fa-Jie Gou, Jian-Yu Chen

The Thai Journal of Veterinary Medicine

This study investigated changes in the richness and composition of the rumen microbiome in yaks at various developmental stages. Eighteen healthy male yaks at the ages of 5 months (M5), 12 months (M12), and 24 months (M24) had samples of their rumen digesta taken for 16S rRNA gene sequencing. The 11087 amplicon sequence variations (ASVs) in total were found; the M5, M12, and M24 groups had 3585, 1146 and 5545 distinct ASVs, respectively. Alpha diversity indices Chao, Shannon, Sobs, and ace indicated significant differences among the groups. The principal coordinate analysis (PCoA) indicated significant changes in microbial community composition across …

Investigating The Effect Of Soil Origin On Antibiotic Production In Streptomyces, Emu Suzuki

Undergraduate Research Symposium 2025

Streptomyces bacteria produce antibiotics that inhibit competing microorganisms. We hypothesized that Streptomyces from the rhizosphere (around plant roots) would be more likely to produce antibiotics than those from bulk soil (further away from roots). Soil samples were collected from rhizosphere and bulk soils in transitional and long-term organic fields of corn and alfalfa. Streptomyces from these soils were cultured on glucose-asparagine agar media. Their antibiotic production was evaluated by testing whether they could inhibit the growth of two target Streptomyces strains. No significant effects of soil type (rhizosphere vs. bulk), crop, or management on antibiotic production were observed for one …

Pseudomonas Parafulva Confirmed To Have Antifungal Properties When Grown In Conjunction With Botrytis Cinerea, Caden Dupee, Kylee Eldredge, Zachary Elmer, Joshua Hartvigsen

Student Research Symposium

Widespread antibiotic use has led to antibiotic resistance of infectious bacteria. (Young, 2017) As part of the TinyEarth Program, the lab group collected and tested local soil samples for bacteria with hopes of finding novel antibiotic properties. From the soil samples, a bacteria was isolated, subsequently sequenced, and determined to be Pseudomonas parafulva. P. parafulva is a Gram-negative bacterium that has been known to frequent rice paddies of eastern Asian countries and has been collected in select regions of North America, including that of Cache Valley. P. parafulva has been linked to anti-fungal activities on plants. (Lui et …

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 …

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 …

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 …

Host Range And Efficiency Of Plating Determination Of Phages Infecting Caulobacter And Non-Caulobacter Species, Christopher Scott

Senior Theses

Seven bacteriophages were studied to determine their host range among Caulobacter and non-Caulobacter bacteria. Recently, Caulobacter-associated phages have been shown to have broader host ranges than previously believed. Thus, it is crucial to thoroughly verify the range of bacteria strains that these phages can infect. To understand the extent of each phage’s host range, phage lysates were spotted on bacterial lawns to determine whether lysis could occur. Host-range analyses in this project conclude that these Dolichocephalovirinae phages were able to infect multiple genera and species of host bacteria. Plating efficiency experiments were also conducted to compare the phage’s …

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 …