Organisms Commons^™

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 …

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 …

Case Report: Sarcina Ventriculi, A Masquerade Of Motility, Katherine Westbrook Cates, Catherine Hudson

School of Medicine Faculty Publications

Sarcina ventriculi is a rare bacterium that has the potential to cause severe disease in the gastric mucosa. According to our search, there are less than 100 prior published case reports. This case discusses a 69-year-old man who presented to the hospital with severe gastric distention noted on CT of the abdomen with intractable nausea and emesis, for which endoscopy was performed and ruled out gastric outlet obstruction, with biopsies resulting as S. ventriculi. This bacterium has previously been reported to cause gastric dysmotility, as well as severe side effects including gastric perforation.

Viral Genome Delivery Across Bacterial Cell Surfaces, Stephano M. Iglesias, Fenglin Li, Federica Briani, Gino Cingolani

Department of Biochemistry and Molecular Biology Faculty Papers

In 1952, Hershey and Chase used bacteriophage T2 genome delivery inside Escherichia coli to demonstrate that DNA, not protein, is the genetic material. Over 70 years later, our understanding of bacteriophage structure has grown dramatically, mainly thanks to the cryogenic electron microscopy revolution. In stark contrast, phage genome delivery in prokaryotes remains poorly understood, mainly due to the inherent challenge of studying such a transient and complex process. Here, we review the current literature on viral genome delivery across bacterial cell surfaces. We focus on icosahedral bacterial viruses that we arbitrarily sort into three groups based on the presence and …

Oral Dosages Of The Nsaid Aspirin Decreased The Growth Rate Of Species Found In The Human Gut Microbiome Including Akkermansia Muciniphila, Bacteroides Fragilis, Clostridium Sordellii, And Clostridium Difficile, Wyatt H. Greenbaum, Garrett J. Greenbaum, Anna Spiezio

PANDION: The Osprey Journal of Research and Ideas

Over past few decades, new insight has been revealed in the scientific community about the importance of the human gut microbiome relating to general health. It is known that imbalances in the species that reside in the human gut can cause organism-wide problems in humans. When prescribing or injecting oral medications, the thought of the downstream effects on the gut microbiome are not always considered. By exposing known healthy members of the gut; Akkermansia muciniphila, Bacteroides fragilis, Clostridium sordellii, and Clostridium difficile to the Aspirin, this study attempted to provide insight into the effects of the drug on bacterial growth. …

Cyclic Peptides With Antifungal Properties Derived From Bacteria, Fungi, Plants, And Synthetic Sources, Naiera M. Helmy, Keykavous Parang

Pharmacy Faculty Articles and Research

Fungal infections remain a significant concern for human health. The emergence of microbial resistance, the improper use of antimicrobial drugs, and the need for fewer toxic antifungal treatments in immunocompromised patients have sparked substantial interest in antifungal research. Cyclic peptides, classified as antifungal peptides, have been in development as potential antifungal agents since 1948. In recent years, there has been growing attention from the scientific community to explore cyclic peptides as a promising strategy for combating antifungal infections caused by pathogenic fungi. The identification of antifungal cyclic peptides from various sources has been possible due to the widespread interest in …

The Last Of Us In Therapy: How Mind-Controlling Fungi And Gut Bacteria Affect Your Mental Health, Anastasia Lyon

Journal of Pharmacology & Nutritional Sciences

The "psilocybiome" represents the mutually beneficial relationship between ourselves, our bacteria, and psychedelic drugs. This short review briefly discusses the benefits and limitations surrounding the potential for psychedelic therapy to synergize with gut bacteria to help regulate and maintain proper balance in the immune system, diet, and stress levels. Psychedelic therapy is a novel treatment strategy that has the potential to improve patient mental health, and, by identifying the types of gut bacteria present in patients, it can aid in personalizing medicine by determining how well their "psilocybiome" may respond.

Mycorrhiza-Mediated Recruitment Of Complete Denitrifying Pseudomonas Reduces N2o Emissions From Soil, Xia Li, Ruotong Zhao, Dandan Li, Guangzhou Wang, Shuikuan Bei, Xiaotang Ju, Ran An, Long Li, Thomas W Kuyper, Peter Christie, Franz S Bender, Ciska Veen, Marcel G A Van Der Heijden, Wim H Van Der Putten, Fusuo Zhang, Klaus Butterbach-Bahl, Junling Zhang

Faculty, Staff and Student Publications

Background: Arbuscular mycorrhizal fungi (AMF) are key soil organisms and their extensive hyphae create a unique hyphosphere associated with microbes actively involved in N cycling. However, the underlying mechanisms how AMF and hyphae-associated microbes may cooperate to influence N2O emissions from "hot spot" residue patches remain unclear. Here we explored the key microbes in the hyphosphere involved in N2O production and consumption using amplicon and shotgun metagenomic sequencing. Chemotaxis, growth and N2O emissions of isolated N2O-reducing bacteria in response to hyphal exudates were tested using in vitro cultures and inoculation experiments.

Results: AMF hyphae reduced denitrification-derived N2O emission (max. 63%) …

Resolving The Repression Pathway Of Virulence Gene Hila In Salmonella, Alexandra King, Lon Chubiz Phd, Brenda Pratte, Lauren Daugherty

Undergraduate Research Symposium

Salmonella is a relatively abundant, virulent species of bacteria that is most known for spreading gastrointestinal diseases through food. These illnesses result in approximately 1.35 million infections, including over 25,000 hospitalizations each year, in the U.S. alone (CDC.gov). As antibiotic resistance becomes an increasingly urgent public health problem, the importance of developing alternative treatment methods is only becoming more crucial. One of the genes responsible for this virulence is known as hilA. HilA is the main transcriptional regulator of Salmonella Pathogenicity Island-1 gene (UniProt). SPI-1 plays an important role in the invasion of Salmonella into epithelial cells. The proteins encoded …

Safety And Efficacy Of Silver-Coated Biomaterials In Vivo, Megan Klem, Darien L. Seidman, Rahyan Mahmoud, Manuella Adu, Lei Yu, Jeffrey Hettinger, Renee M Demarest

Rowan-Virtua Research Day

Overtreatment and overuse of antibiotics in healthcare and agricultural settings have contributed to the selective pressure on bacterial strains to develop resistance. Resistance can develop as a result of mutations and subsequent resistance genes that allow bacteria to survive against antibiotics. Novel silver-oxide coatings were developed and were previously demonstrated to prevent adhesion of gram-negative bacteria (Escherichia Coli and Pseudomonas Aeruginosa) to the disc, but did not prevent gram-positive bacterial adherence (Streptococcus Aureus). In order to determine whether the silver-oxide coatings are bacterial static and may be preventing progression to biofilm formation, in vivo analysis of S. Aureus attached to …

Diversity Of Bacteriophage In Burkholderia Species, Abigail Price

Honors Projects

Bacteriophages are viruses that infect and replicate within bacteria and offer the potential of a therapeutic alternative to chronic infections that do not respond to antibiotic-based therapies. B. vietnamiensis is one of a number of Burkholderia species involved with chronic drug resistant infections in the lungs of individuals with compromised respiratory systems, as found in those with chronic obstructive pulmonary disease and, most especially, are of particular significance in patients with cystic fibrosis. The diversity of the Burkholderia species is explored by using online databases and looking at bacteriophage or phage-encoding viruses found in B. vietnamiensis. The open reading frames …

The Large And Small Of It: The Microbiome And Metagenomics, Austin Hopkins, Elaina Gollmar, Jessica Fernandez, Shawn Wolf, Austin Hilverding, Andrew M. Roecker

Pharmacy and Wellness Review

Metagenomics, the analysis of the microbial genome, permits scientists to understand the influences of external sources including diet, metabolism and antibiotics on the human microbiome. Research has revealed the possibility of a core symbiosis between humans and bacteria. The main role of the human microbiome is to aid in digestion, but identified ancillary roles include immunologic homeostasis and infection prevention. Quantifying the composition and variability of the microbiome will help lead to future treatments or preventive strategies against unhealthy change. A variety of methods may be used to define the microbiome, and 16S amplicon sequencing is primarily utilized today. Probiotics …

Identification Of A Rickettsial Endosymbiont In A Soft Tick Ornithodoros Turicata Americanus, Lichao Liu, Daniel E. Sonenshine, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

Bacterial endosymbionts are abundantly found in both hard and soft ticks. Occidentia massiliensis, a rickettsial endosymbiont, was first identified in the soft tick Ornithodoros sonrai collected from Senegal and later was identified in a hard tick Africaniella transversale. In this study, we noted the presence of Occidentia species, designated as Occidentia-like species, in a soft tick O. turicata americanus. Sequencing and phylogenetic analyses of the two genetic markers, 16S rRNA and groEL confirmed the presence of Occidentia-like species in O. turicata americanus ticks. The Occidentia-like species was noted to be present in all developmental stages …

Antimicrobial Resistance: A Challenge Awaiting The Post-Covid-19 Era, Tekle Airgecho Lobie, Aklilu Abrham Roba, James Alexander Booth, Knut Ivan Kristiansen, Abraham Aseffa, Kirsten Skarstad, Magnar Bjørås

Research on Antimicrobial Resistance

Microbe exposure to pharmaceutical and non-pharmaceutical agents plays a role in the development of antibiotic resistance. The risks and consequences associated with extensive disinfectant use during the COVID-19 pandemic remain unclear. Some disinfectants, like sanitizers, contain genotoxic chemicals that damage microbial DNA, like phenol and hydrogen peroxide. This damage activates error-prone DNA repair enzymes, which can lead to mutations that induce antimicrobial resistance. Public health priority programs that have faced drug-resistance challenges associated with diseases, such as tuberculosis, HIV, and malaria, have given less attention to risks attributable to the COVID-19 pandemic. Pathogen-specific programs, like the directly observed treatment strategy …

Increasing Antibiotic Resistance In Shigella Bacteria In The United States, William J. Pharr

The Corinthian

Shigella bacteria cause half a million infections, 6,000 hospitalizations, and 70 deaths annually in the United States. These bacteria are of particular concern due to their high survivability, low infectious dose, and high adaptability. Cases of shigellosis from Shigella sonnei are becoming a more prevalent issue in the U.S. as the bacteria continues to develop higher resistance to today’s strongest antibiotics. Much of this resistance is connected to the exchange of genes between strains of Shigella due to insertion sequences (IS), intercontinental travel, and men who have sex with men (MSM). As a result of increased resistance, the use of …

Author Correction: Roadmap For Naming Uncultivated Archaea And Bacteria (Nature Microbiology, (2020), 5, 8, (987-994), 10.1038/S41564-020-0733-X), Alison E. Murray, John Freudenstein, Simonetta Gribaldo, Roland Hatzenpichler, Philip Hugenholtz, Peter Kämpfer, Konstantinos T. Konstantinidis, Christopher E. Lane, R. Thane Papke, Donovan H. Parks, Ramon Rossello-Mora, Matthew B. Stott, Iain C. Sutcliffe, J. Cameron Thrash, Stephanus N. Venter, William B. Whitman, Silvia G. Acinas, Rudolf I. Amann, Karthik Anantharaman, Jean Armengaud, Brett J. Baker, Roman A. Barco, Helge B. Bode, Eric S. Boyd, Carrie L. Brady, Paul Carini, Patrick S.G. Chain, Daniel R. Colman, Kristen M. Deangelis, Maria Asuncion De Los Rios, Paulina Estrada-De Los Santos

Life Sciences Faculty Research

No abstract provided.

Response Of Extensively Drug Resistant Salmonella Typhi To Treatment With Meropenem And Azithromycin, In Pakistan, Sonia Qureshi, Abdullah B. Naveed, Mohammad Tahir Yousafzai, Khalil Ahmad, Sarwat Ansari, Heeramani Lohana, Aiman Mukhtar, Farah Naz Qamar

Department of Paediatrics and Child Health

Introduction: Salmonella Typhi is one of the leading health problems in Pakistan. With the emergence of extensively drug resistant (XDR) Salmonella Typhi, treatment options are limited. Here we report the clinical manifestations and the response to treatment of patients with XDR Typhoid fever. The patients were treated with either Meropenem or Azithromycin or a combination of both.
Methods: We reviewed the records of culture confirmed XDR typhoid who visited Aga Khan University Hospital (AKUH), Karachi and Aga Khan Secondary Care Hospital, Hyderabad from April 2017 to June 2018. Symptoms developed during disease, unplanned treatment extension and complications developed while on …

Plasmodium Impairs Antibacterial Innate Immunity To Systemic Infections In Part Through Hemozoin-Bound Bioactive Molecules., Christopher Lynn Harding

Electronic Theses and Dissertations

Despite efforts to decrease the global health burden of malaria, infections with Plasmodium species continue to cause over 200 million episodes of malaria each year which resulted in 405,000 deaths in 2018 [1]. One complication of malaria is increased susceptibility to invasive bacterial infections. Plasmodium infections impair host immunity to non-Typhoid Salmonella (NTS) through activities of heme oxygenase I (HO-I) )-induced release of immature granulocytes and myeloid cell-derived IL-10. Yet, it is not known if these mechanisms are specific to NTS. We show here, that Plasmodium yoelii 17XNL (Py) infected mice had impaired clearance of systemic Listeria monocytogenes (Lm) during …

Fecal Microbiota Transplantation And Gut Microbiome Effects On Psychiatric Illnesses, Mona Seresht

Physician Assistant Studies | Student Authored Articles

Despite the medical advances that have been made in regards to mental health, psychiatric medications, and alternative therapies, many patients continue to suffer day in and day out, unable to live the type of life they desire. Many times, the medication route includes many episodes of trial and error, side effects, and no significant improvement in actual symptoms. Therapy, although effective, typically necessitates a supplemental medication for the best results. Fecal microbiota transplantation (FMT) is a method where feces from a healthy donor is transferred to an affected patient, typically via colonoscopy. Theoretically, this alters the gut microbiome in a …

Hexadecane Petroleum, And Biofuel Utilization In Marine Bacteria Isolated From Ballast Tanks, Alex Yashchenko

Graduate Theses

This study characterized the growth of bacteria isolated from ballast tank fluids in hexadecane, petroleum, plant, and algae-derived fuels. The study was performed to explore the capacity of ballast tank isolates to survive and grow within fuels that may be stored within ballast tanks. Results of the hexadecane analysis indicated that most isolates had higher viable cell counts in media supplemented with hexadecane. Members of Alteromonas, Pseudoalteromonas, and a single Brevundimonas species had viable cell counts that were one or several orders ofmagnitude greater than that of controls. Results offuel analysis indicated higher viable cell counts in pure JP-5 and …

Characterization Of The Physical And Chemical Effect Of Membrane Disruption And Protein Inhibiting Treatments On E. Coli, Khadijah Wright

Honors Undergraduate Theses

The increase in antibacterial resistance has placed the issue of microbial multi-drug resistance on a global stage (Gurunathan, 2019). This issue poses a threat to human and animal health as well as to the environment (Aslam et al., 2018). It affects not only the efficacy of treatment but also how those treatments are conducted (Friedman, Temkin, & Carmeli, 2016). As a result of this ongoing threat, new treatments that have potent effects on bacteria are necessary. One scientific response to this issue has been the development of multifunctional nanoparticles (NPs)(H. Wang et al., 2018). NPs have the ability to be …

Genetic Signatures For Helicobacter Pylori Strains Of West African Origin, Kennady K. Bullock, Carrie L. Shaffer, Andrew W. Brooks, Ousman Secka, Mark H. Forsyth, Mark S. Mcclain, Timothy L. Cover

Veterinary Science Faculty Publications

Helicobacter pylori is a genetically diverse bacterial species that colonizes the stomach in about half of the human population. Most persons colonized by H. pylori remain asymptomatic, but the presence of this organism is a risk factor for gastric cancer. Multiple populations and subpopulations of H. pylori with distinct geographic distributions are recognized. Genetic differences among these populations might be a factor underlying geographic variation in gastric cancer incidence. Relatively little is known about the genomic features of African H. pylori strains compared to other populations of strains. In this study, we first analyzed the genomes of …

A Platform For The Discovery And Characterization Of Proteins That Associate With Pseudomonas Aeruginosa Rna Polymerase, Danielle N. Brogren

All NMU Master's Theses

Pseudomonas aeruginosa is an opportunistic bacterial pathogen notable for its ability to colonize the lungs of cystic fibrosis patients. Once the bacterium infects and colonizes humans, it is extremely difficult to eradicate. This leads to long-term infections that significantly damage the lungs and other tissues. P. aeruginosa infections are challenging to treat due to the bacterium’s natural antibiotic resistance and the rise of multidrug resistant strains. Development of novel drug treatments are a necessity.

In all organisms, the regulation of gene expression is a highly controlled process. Remarkably, in P. aeruginosa bioinformatics studies showed that 20% of its genome is …

Role Of Intracellular Growth During The Gastrointestinal Stage Of Listeria Monocytogenes Infection, Grant Steven Jones

Theses and Dissertations--Microbiology, Immunology, and Molecular Genetics

Listeria monocytogenes is a facultative intracellular bacterium that causes foodborne disease in humans. L. monocytogenes invade the gut mucosa and then disseminate, causing systemic infections associated with high mortality rates in immunocompromised individuals. It is unknown how L. monocytogenes traffic to the mesenteric lymph nodes, which represent an important bottleneck for systemic spread. In addition, little is known about the gastrointestinal stage of infection due to the general resistance of mice to oral infection with L. monocytogenes. Our laboratory developed a novel foodborne mouse model of listeriosis utilizing a murinized strain of L. monocytogenes to investigate the gastrointestinal stage …

Laboratory Exercises In Microbiology: Discovering The Unseen World Through Hands-On Investigation, Joan Petersen, Susan Mclaughlin

Open Educational Resources

The exercises in this laboratory manual are designed to engage students in hand-on activities that reinforce their understanding of the microbial world. Topics covered include: staining and microscopy, metabolic testing, physical and chemical control of microorganisms, and immunology. The target audience is primarily students preparing for a career in the health sciences, however many of the topics would be appropriate for a general microbiology course as well.

Changing Diagnostic Methods And Increased Detection Of Verotoxigenic Escherichia Coli, Ireland, Thomas Rice, Noreen Quinn, Roy D. Sleator, Brigid Lucey

Department of Biological Sciences Publications

The recent paradigm shift in infectious disease diagnosis from culture-based to molecular-based approaches is exemplified in the findings of a national study assessing the detection of verotoxigenic Escherichia coli infections in Ireland. The methodologic changes have been accompanied by a dramatic increase in detections of non-O157 verotoxigenic E. coli serotypes.

Optimization Of A Genomic Editing System Using Crispr/Cas9-Induced Site-Specific Gene Integration, Jillian L. Mccool Ms., Nick Hum, Gabriela G. Loots

STAR Program Research Presentations

The CRISPR-Cas system is an adaptive immune system found in bacteria which helps protect against the invasion of other microorganisms. This system induces double stranded breaks at precise genomic loci (1) in which repairs are initiated and insertions of a target are completed in the process. This mechanism can be used in eukaryotic cells in combination with sgRNAs (1) as a tool for genome editing. By using this CRISPR-Cas system, in addition to the “safe harbor locus,” ROSAβ26, the incorporation of a target gene into a site that is not susceptible to gene silencing effects can be achieved through few …

Epidemiology Crucial To Cracking Elizabethkingia Crisis, Angela Tonozzi

Journal of Patient-Centered Research and Reviews

The author explains the epidemiological methods, tools and personnel required to pinpoint the source of Wisconsin’s 2016 outbreak of Elizabethkingia infections.

An Analysis Of Bacterial Contamination Of Chicken Eggs And Antimicrobial Resistance, Holly Spitzer

All College Thesis Program, 2016-2019

Chicken eggs are a major component of American diets, with an average yearly consumption of approximately 250 eggs per person (American Humane Society). While highly nutritious, eggs are also one of the leading causes of food poisoning and food borne illness in the United States. Eggs may become contaminated by a number of different types of bacteria during production, including Salmonella, a group of bacteria that, according to the CDC, causes more than 1.2 million cases of food borne illness in the United States every year. In an effort to decrease the frequency of bacterial contamination, many food producers …

Wake Me When It's Over- Bacterial Toxin-Antitoxin Proteins And Induced Dormancy, Nathan P. Coussens, Dayle A. Daines

Biological Sciences Faculty Publications

Toxin-antitoxin systems are encoded by bacteria and archaea to enable an immediate response to environmental stresses, including antibiotics and the host immune response. During normal conditions, the antitoxin components prevent toxins from interfering with metabolism and arresting growth; however, toxin activation enables microbes to remain dormant through unfavorable conditions that might continue over millions of years. Intense investigations have revealed a multitude of mechanisms for both regulation and activation of toxin-antitoxin systems, which are abundant in pathogenic microorganisms. This minireview provides an overview of the current knowledge regarding type II toxin-antitoxin systems along with their clinical and environmental implications.