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Full-Text Articles in Bacteria

Quality Improvement (Qi) Project Aimed At Reducing Unnecessary Antibiotic Usage Among Older Adult Patients By Addressing Inappropriate Antibiotic Prescribing In Primary And Long-Term Care Settings, Pamela M. Thomas May 2026

Quality Improvement (Qi) Project Aimed At Reducing Unnecessary Antibiotic Usage Among Older Adult Patients By Addressing Inappropriate Antibiotic Prescribing In Primary And Long-Term Care Settings, Pamela M. Thomas

Seton Hall University Dissertations and Theses (ETDs)

Antibiotic overuse among older adults remains a significant patient safety and public health concern. Recent national data indicate that approximately 30%–50% of outpatient antibiotic prescriptions may be unnecessary, particularly for viral or self-limiting conditions (Chua et al., 2021). Antimicrobial resistance has been associated with more than 1.27 million deaths globally (Murray et al., 2022). This quality improvement project evaluated a multifaceted antimicrobial stewardship intervention in primary and long-term care settings. Baseline review of 167 antibiotic cases revealed 37.1% were inappropriate or questionable, and 28.7% lacked adequate diagnostic documentation. The intervention incorporated provider education, electronic health record decision-support tools, audit and …


Investigating Corollaries Between Streptococcus Gallolyticus Subsp. Gallolyticus Virulence And Colorectal Cancer, Tyler G. Myers Mar 2026

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 …


The Structure, Dynamics, And Impact Of An Interbacterial Weapon Encoded By Human Gut Bacteria, Casey John Latario Jan 2026

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 …


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 Nov 2025

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 …


Complete Genome Sequence Of Rothia Mucilaginosa D1, A Genetically Amenable Strain, Hemendra P. Dhaked, Isabella Andonie, Bo Yang, Vinayka M. Joshi, Zezhang T. Wen Sep 2025

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.


Genome Sequence Of Lacticaseibacillus Paracasei G277-1.1, A Clinical Strain That Forms Enhanced Biofilms With Streptococcus Mutans, Xiaochang Huang, Hemendra Pal Dhaked, Yihong Li, Zezhang T. Wen Aug 2025

Genome Sequence Of Lacticaseibacillus Paracasei G277-1.1, A Clinical Strain That Forms Enhanced Biofilms With Streptococcus Mutans, Xiaochang Huang, Hemendra Pal Dhaked, Yihong Li, Zezhang T. Wen

School of Dentistry Faculty Publications

Lacticaseibacillus paracasei G277-1.1 was isolated from dental plaque of a patient with severe early childhood caries. It forms synergistic biofilms with Streptococcus mutans in vitro. Here, we report its high-quality genome sequence, revealing insights on its inter-species interaction with S. mutans.


Bcg Vaccine-Induced Innate And Adaptive Pulmonary Immunity Correlating With Protective Efficacy Against Mycobacterium Tuberculosis In The Lungs, Mayank Khanna, Alistair J. Ramsay Aug 2025

Bcg Vaccine-Induced Innate And Adaptive Pulmonary Immunity Correlating With Protective Efficacy Against Mycobacterium Tuberculosis In The Lungs, Mayank Khanna, Alistair J. Ramsay

School of Graduate Studies Faculty Publications

Background/Objectives: Effective prophylaxis for Mycobacterium tuberculosis (Mtb) requires greater understanding of immune correlates of protection. With renewed interest in BCG as an Mtb vaccine, particularly via the intravenous (IV) route, our objective was to characterize both innate and adaptive immune correlates of vaccine-induced pulmonary immunity as potential biomarkers for protective efficacy in a murine model of Mtb infection. Methods: Mice were given BCG via different routes and some boosted with recombinant virus constructs encoding Mtb Ag85B. Responding innate lymphoid cell (ILC) populations, T cells and B cells were analyzed by fluorescence activated cell sorting (FACS) for surface markers and by …


Exploring The Role Of Lysine Acetylation During Biofilm Formation In Bacillus Subtilis, Jennifer Nguyen, Briana Ericka Reid, Valerie Carabetta May 2025

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, …


Elucidating The Multi-Omics Of Early-Onset Colorectal Cancer, Jumanah Alshenaifi May 2025

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 Apr 2025

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 …


The Role Of Horizontal Gene Transfer In Antibiotic Resistance Amidst Prevalent Community And Healthcare-Associated Mrsa Rates, Gabrielle Nascimento Jan 2025

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 Jan 2025

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 …


Blood Culture Utilization: How Many Follow-Up Cultures Are Needed?, George Jones, Jennifer Hanrahan Jan 2025

Blood Culture Utilization: How Many Follow-Up Cultures Are Needed?, George Jones, Jennifer Hanrahan

Department of Medicine Faculty Publications

Background: Follow-up blood cultures (BCx) are ordered after an initial positive culture in many instances. The number of follow-up cultures needed is not clear. Obtaining unnecessary BCx may cause unintended consequences. The optimal balance between stewardship and patient safety warrants investigation. We sought to assess the frequency with which a third set is positive after a negative second BCx. Methods: We conducted a retrospective study of BCx submitted to the microbiology laboratory from 1/1/18-11/1/23. We included all patients ≥18 years who had at least two follow-up BCx drawn 24-72 hours after an initial positive culture. Data were collected from electronic …


Improving Treatment Outcomes For Bacterial Vaginosis By Affecting The Vaginal Microbiome, Aleya Devries, Jyotsna Chawla Assistant Professor, Microbiology, Jackeline Moljo Assistant Professor, Family Medicine Nov 2024

Improving Treatment Outcomes For Bacterial Vaginosis By Affecting The Vaginal Microbiome, Aleya Devries, Jyotsna Chawla Assistant Professor, Microbiology, Jackeline Moljo Assistant Professor, Family Medicine

HCA-NSU MD Research Day

Objective: The goal of this review is to educate providers about the importance of maintaining the balance of the vaginal microbiome (VMB) and how modifiable factors may be used to improve treatment outcomes of patients with bacterial vaginosis. Background: Bacterial vaginosis (BV) is the most common vaginal infection in women of reproductive age and is treated with Metronidazole, which has a high recurrent infection rate. Preliminary studies highlighted the balance of VMB species affects the development of BV and therapeutic outcomes of Metronidazole. Furthermore, previous studies have described how VMB composition can be shaped by various factors. Methods: Here, we …


Effects Of Limosilactobacillus Reuteri Strains Pta-126787 And Pta-126788 On Intestinal Barrier Integrity And Immune Homeostasis In An Alcohol-Induced Leaky Gut Model, Dharanesh Gangaiah, Min Gu, Aline Zaparte, Olaf Will, Laurie C. Dolan, Anthony Goering, Jason Pillai, Shrinivasrao P. Mane, German Plata, Emily B. Helmes, David A. Welsh, Arvind Kumar Mahajan Aug 2024

Effects Of Limosilactobacillus Reuteri Strains Pta-126787 And Pta-126788 On Intestinal Barrier Integrity And Immune Homeostasis In An Alcohol-Induced Leaky Gut Model, Dharanesh Gangaiah, Min Gu, Aline Zaparte, Olaf Will, Laurie C. Dolan, Anthony Goering, Jason Pillai, Shrinivasrao P. Mane, German Plata, Emily B. Helmes, David A. Welsh, Arvind Kumar Mahajan

School of Graduate Studies Faculty Publications

Intestinal barrier is a first line of defense that prevents entry of various harmful substances from the lumen into the systemic environment. Impaired barrier function with consequent translocation of harmful substances into systemic circulation (“leaky gut”) is a central theme in many gastrointestinal, autoimmune, mental, and metabolic diseases. Probiotics have emerged as a promising strategy to maintain intestinal integrity and address “leaky gut”. Using in silico, in vitro and avian in vivo analyses, we previously showed that two novel L. reuteri strains, PTA-126787 (L. reuteri 3630) and PTA-126788 (L. reuteri 3632), isolated from broiler chickens possess favorable safety profiles. Consistent …


Investigating The Role Of The Gut Microbiota On Immune Checkpoint Inhibitor-Mediated Colitis, Taylor Halsey, Robert Jenq May 2024

Investigating The Role Of The Gut Microbiota On Immune Checkpoint Inhibitor-Mediated Colitis, Taylor Halsey, Robert Jenq

Dissertations and Theses (Open Access)

Immune checkpoint inhibitors (ICIs) have been revolutionary in the fight against cancer by recruiting the host immune system as an agent for attack on malignant cells. Unfortunately, immune-related adverse events (irAEs), including ICI-mediated colitis (IMC), are common side effects that result from immune cell mediated damage on healthy tissues. Recent studies have highlighted a role for the gut microbiota in modulating ICI-mediated anti-tumor responses, but less is known regarding how the gut microbiota may impact on irAEs. Considering that the gastrointestinal tract harbors thousands of unique microbial species, many of which are known to modulate the immune system, microbes and …


Typhlitis In A Neutropenic Patient, Alice He Bs, Wern Lynn Ng Md, Lay She Ng Md, Si Yuan Khor Md, Chandi Garg Md Apr 2024

Typhlitis In A Neutropenic Patient, Alice He Bs, Wern Lynn Ng Md, Lay She Ng Md, Si Yuan Khor Md, Chandi Garg Md

Tower Health Research Day

No abstract provided.


Convolutional Neural Network Based Analysis - An Aid To Diagnose Bacterial And Fungal Osteomyelitis, Saiprasad Alva, Dominic Augustine, Sowmya Sv, Mukul Saini, Sanjana Shetty Feb 2024

Convolutional Neural Network Based Analysis - An Aid To Diagnose Bacterial And Fungal Osteomyelitis, Saiprasad Alva, Dominic Augustine, Sowmya Sv, Mukul Saini, Sanjana Shetty

Annual Research Symposium

Osteomyelitis may be classified as Bacterial (Actinomycotic), Fungal (Mucormycotic), or combined based on the etiological agent. During histopathological examination, there is a high chance that bacterial colonies or fungal hyphae may be missed by the human eye, especially when there is a paucity of organisms. This may lead to a faulty diagnosis of the type of osteomyelitis which along with an improper treatment plan would cause further progression of the disease and various other complications. Therefore, the diagnosis of the exact etiological variant of osteomyelitis is of prime importance to design an appropriate treatment plan. In the present study, bone …


The Impact Of Gestational Diabetes Mellitus And Maternal Oral Microbiome: A Scoping Review, Jaclyn P. Langan Jan 2024

The Impact Of Gestational Diabetes Mellitus And Maternal Oral Microbiome: A Scoping Review, Jaclyn P. Langan

Honors Undergraduate Theses

Background: Gestational diabetes mellitus (GDM) is a common pregnancy-related metabolic disorder associated with adverse maternal and fetal outcomes. Recent research has highlighted the potential role of the oral microbiome in the pathophysiology of various systemic conditions, including diabetes mellitus. However, the impact of GDM on the maternal oral microbiome remains relatively understudied. Understanding alterations in the oral microbiome during pregnancy complicated by GDM could provide valuable insights into the mechanistic links between systemic metabolic disorders and oral health.

Objective: The objective of this scoping review was to comprehensively examine the existing literature on the relationship between GDM and maternal oral …


Unraveling The Effects Of The Covid-19 Pandemic On Staphylococcus Aureus Carriage: A Comparative Research Of Pre- And Post-Pandemic Samples, Catherine G. Johnston Jan 2024

Unraveling The Effects Of The Covid-19 Pandemic On Staphylococcus Aureus Carriage: A Comparative Research Of Pre- And Post-Pandemic Samples, Catherine G. Johnston

Honors Undergraduate Theses

The COVID-19 pandemic brought about significant changes in the epidemiology of Staphylococcus aureus carriage and disease. This study aims to assess these changes by leveraging respiratory samples collected from a longstanding cohort, comparing the genomic characteristics of S. aureus isolates from pre- and post-pandemic periods. We analyzed S. aureus genomes and phenotypically determined macrolide resistance to characterize population structure, antibiotic resistance, and virulence profiles. Changes in S. aureus carriage rates, macrolide resistance, disease occurrence, and population structure between samples collected pre- and post-pandemic were examined. By using respiratory samples, chart reviews, and risk factor questionnaires of 498 children from a …


Clostridioides Difficile: Identification Of Rival Organisms & Evaluation Of Non-Antibiotic Treatment Implementation, Justin Davis Jan 2024

Clostridioides Difficile: Identification Of Rival Organisms & Evaluation Of Non-Antibiotic Treatment Implementation, Justin Davis

Honors Undergraduate Theses

Clostrioides difficile is a common cause of nosocomial (hospital-acquired) infections. Patients receiving antibiotic treatment experience dysbiosis of gut microbiota, and C. difficile, normally held in check by the various other organisms, takes this opportunity to propagate. Symptoms of infection generally include diarrhea, colitis, dehydration, and fever. Understanding that C. difficile generally only causes illness when it is the dominant bacterium (i.e. when growth is relatively unchecked by other microbes), it is appropriate to investigate potential competitive organisms that may be introduced after antibiotic courses or during active C. difficile infection to effectively displace it. Fecal samples from the University …


Genome-Based Pathogenicity Potential Of Salmonella Isolated From Diverse Sources, Jared Mr Crocco Jan 2024

Genome-Based Pathogenicity Potential Of Salmonella Isolated From Diverse Sources, Jared Mr Crocco

Theses and Dissertations (Comprehensive)

Bacterial human pathogens are among the leading causes of death around the world, especially in low income and developing countries. One important element in a bacterium’s ability to cause disease are genes that directly contribute to pathogenicity called virulence factors. A second significant aspect are antimicrobial resistance genes which allow microorganisms to persist in the presence of antimicrobial agents. In this project I aimed to determine if Salmonella isolated from different sources differed in pathogenicity profiles based on the complement of genes identified through genomic analysis. Accordingly, Salmonella genomes were organized into 8 groups: animal, clinical, human, environmental, food, water …


Reducing Food Scarcity: The Benefits Of Urban Farming, S.A. Claudell, Emilio Mejia Dec 2023

Reducing Food Scarcity: The Benefits Of Urban Farming, S.A. Claudell, Emilio Mejia

Journal of Nonprofit Innovation

Urban farming can enhance the lives of communities and help reduce food scarcity. This paper presents a conceptual prototype of an efficient urban farming community that can be scaled for a single apartment building or an entire community across all global geoeconomics regions, including densely populated cities and rural, developing towns and communities. When deployed in coordination with smart crop choices, local farm support, and efficient transportation then the result isn’t just sustainability, but also increasing fresh produce accessibility, optimizing nutritional value, eliminating the use of ‘forever chemicals’, reducing transportation costs, and fostering global environmental benefits.

Imagine Doris, who is …


Catheter-Associated Urinary Tract Infections: Patient Characteristics, Treatment, And Clinical Outcomes In One South Texas Acute Care Hospital, Kimberly A. Ambrosini, Jose Campo Maldonado Oct 2023

Catheter-Associated Urinary Tract Infections: Patient Characteristics, Treatment, And Clinical Outcomes In One South Texas Acute Care Hospital, Kimberly A. Ambrosini, Jose Campo Maldonado

Research Colloquium

Background: Catheter-associated urinary tract infections (CA-UTIs) account for 40 percent of nosocomial infections worldwide. Their elimination is at the forefront of quality improvement in one South Texas acute care hospital.

Methods: Over a period of 6 months, five CA-UTIs occurred in one South Texas acute care hospital. These cases were identified via regular surveillance by Infection Prevention staff and the Laboratory Department of the hospital. This research reviews patient age, sex, length of stay, bacteria contracted, appropriate antibiotic use, patient characteristics, and overall outcomes.

Results: Between the months of July and December 2021, 5 CAUTIs were contracted. Patients ranged in …


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 Sep 2023

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. …


Analyzing Pseudomonas Aeruginosa With Bacteriophage Tags Using Photoacoustic Flow Cytometry, Jennifer C. Schinke Aug 2023

Analyzing Pseudomonas Aeruginosa With Bacteriophage Tags Using Photoacoustic Flow Cytometry, Jennifer C. Schinke

Electronic Theses and Dissertations

The number of daily bacterial infections is climbing and the CDC explains that this is due to the antibiotic-resistant threat in the United States. Finding a faster way of bacterial identification is necessary as it currently takes 1-4 days for a medical lab to culture and identify bacteria. Photoacoustic flow cytometry (PAFC) can be used as an alternative method resulting in swift identification within an hour (Edgar, 2019). Pseudomonas aeruginosa, cell line PA01, will be coated in up to a few hundred red dyed phages making it detectible by the photoacoustic flow cytometry system. Bacteriophages (phages) are viruses that …


Impacts Of A Duf2207 Family Protein On Streptococcus Mutans Stress Tolerance Responses And Biofilm Formation, Xiaochang Huang, Camile G. Laird, Paul P. Riley, Zezhang Tom Wen Aug 2023

Impacts Of A Duf2207 Family Protein On Streptococcus Mutans Stress Tolerance Responses And Biofilm Formation, Xiaochang Huang, Camile G. Laird, Paul P. Riley, Zezhang Tom Wen

School of Dentistry Faculty Publications

Locus SMU.243 in Streptococcus mutans was annotated as a member of the DUF2207 family proteins highly conserved in all bacteria but with unknown function. To investigate its role in S. mutans physiology, a SMU.243-deficient mutant was constructed using allelic exchange mutagenesis, and the impacts of SMU.243 deletion on bacterial growth, stress tolerance response, and biofilm formation were analyzed. Compared to the wild-type UA159, S. mutans lacking SMU.243 displayed a reduced growth rate and a reduced overnight culture density (p < 0.01) when grown at low pH and in the presence of methyl viologen. Relative to the parent strain, the deficient mutant also had a reduced survival rate following incubation in a buffer of pH 2.8 (p < 0.01) and in a buffer containing hydrogen peroxide at 58 mM after 60 min (p < 0.001) and had a reduced capacity in biofilm formation especially in the presence of sucrose (p < 0.01). To study any ensuing functional/phenotypical links between SMU.243 and uppP, which is located immediately downstream of SMU.243 and encodes an undecaprenyl pyrophosphate phosphatase involved in recycling of carrier lipid undecaprenyl phosphate, a uppP deficient mutant was generated using allelic exchange mutagenesis. Unlike the SMU.243 mutant, deletion of uppP affected cell envelope biogenesis and caused major increases in susceptibility to bacitracin. In addition, two variant morphological mutants, one forming rough colonies and the other forming mucoid, smooth colonies, also emerged following the deletion of uppP. The results suggest that the SMU.243-encoded protein of the DUF2207 family in S. mutans plays an important role in stress tolerance response and biofilm formation, but unlike the downstream uppP, does not seem to be involved in cell envelope biogenesis, although the exact roles in S. mutans’ physiology awaits further investigation.


Species Delineation And Comparative Genomics Within The Campylobacter Ureolyticus Complex, Joel J Maki, Mondraya Howard, Sara Connelly, Matthew Pettengill, Dwight J Hardy, Andrew Cameron May 2023

Species Delineation And Comparative Genomics Within The Campylobacter Ureolyticus Complex, Joel J Maki, Mondraya Howard, Sara Connelly, Matthew Pettengill, Dwight J Hardy, Andrew Cameron

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Campylobacter ureolyticus is an emerging pathogen increasingly appreciated as a common cause of gastroenteritis and extra-intestinal infections in humans. Outside the setting of gastroenteritis, little work has been done to describe the genomic content and relatedness of the species, especially regarding clinical isolates. We reviewed the epidemiology of clinical C. ureolyticus cultured by our institution over the past 10 years. Fifty-one unique C. ureolyticus isolates were identified between January 2010 and August 2022, mostly originating from abscesses and blood cultures. To clarify the taxonomic relationships between isolates and to attribute specific genes with different clinical manifestations, we sequenced 19 available …


Aging Manuka Honey Improves Antimicrobial Activity Against Pathogenic Bacteria, Rayna M. Carlson May 2023

Aging Manuka Honey Improves Antimicrobial Activity Against Pathogenic Bacteria, Rayna M. Carlson

2023 Symposium

Manuka honey (MH) has been documented to possess powerful anti-microbial properties through multiple mechanisms. These mechanisms include a low pH, high osmolarity, iron chelation, and its unique manuka factor (UMF), methylglyoxal (MGO). Although MGO is purported to be a major pillar in the honey’s antimicrobial properties, its activity is variable against different bacterial species. We hypothesize that MH’s other antimicrobial mechanisms may also exhibit variable activity against different bacterial species. Preliminary experiments to determine the Manuka honey minimum inhibitory concentrations (MIC) for bacterial species, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus, suggested that some Manuka honey antimicrobial mechanisms …


Elucidating The Impact Of Sos-Response Timing In On Escherichia Coli Survival Following Treatment With Fluoroquinolone Topoisomerase Inhibitors, Stephanie Schofield May 2023

Elucidating The Impact Of Sos-Response Timing In On Escherichia Coli Survival Following Treatment With Fluoroquinolone Topoisomerase Inhibitors, Stephanie Schofield

Honors Scholar Theses

Antibiotic treatment failure is a public health crisis, with a 2019 report stating that roughly 35,000 deaths occur in the United States yearly due to bacterial infections that are unresponsive to antibiotics (1). One complication in the treatment of bacterial infection is antibiotic persistence which further compromises our battle to effectively treat infection. Bacterial persisters can exist in clonal bacterial cultures and can tolerate antibiotic treatment by undergoing reversible phenotypic changes. They can survive drug concentrations that their genetically identical kin cannot. Some persisters remain in a slow growing state and are difficult to target with current antibiotics. A specific …