Organisms Commons^™

A Potential Klebsiella Bacteriocin With Efficacy Toward The Enterbacteriaceae Family, Kasey Barber

Undergraduate Honors Theses

Drug resistance is unfortunately becoming a prevalent issue in the course of patient treatment, ranging from chemotherapy resistance to antimicrobial resistance. The Centers for Disease Control and Prevention (CDC) estimated in 2016 that at least 23,000 people die every year in the United States from an infection with an antibiotic-resistant organism (Munita, et al, 2016). Carl Friedlander was the first scientist to describe Klebsiella pneumoniae in 1882 as an encapsulated bacillus after isolating the bacterium from the lungs of patients who had died from pneumonia (Ashurst and Dawson, 2022). Klebsiella pneumoniae is the type species for the Klebsiella genus and …

Sexual Dimorphism Of Glomerular Capillary Morphology In Rats, Zackarias Coker

Undergraduate Honors Theses

Chronic kidney disease (CKD) progresses faster in males than females; however, the underlying mechanisms remain poorly understood. Sex differences in glomerular capillary morphology has been hypothesized to contribute, in part, to the increased susceptibility to hypertension-induced renal injury and CKD progression in males, but this has not been investigated. The goal of the present study was to assess glomerular capillary morphology in male vs. female rats with intact kidneys and after uninephrectomy (UNX). We hypothesized that glomerular capillary radii (R_CAP) and length (L_CAP) would be greater in male rats.

Male (n=4) and female (n=4) with intact …

Effect Of Temperature On The Microbiome Of A Laboratory-Reared Colony Of Haemaphysalis Longicornis Ticks, Brianna L. Mitchell

Undergraduate Honors Theses

Haemaphysalis longicornis ticks are invasive to the United States with potential to transmit several tick-borne pathogens that are native to the United States. Based on existing locations of H. longicornis in its native regions in Asia, as well as its invasive populations that are established in the United States, several geographic range prediction models have been produced to help understand future range expansion and distribution of this invasive tick in North America. Unfortunately, these models do not all agree and there is uncertainty associated with the potential geographic range expansion of H. longicornis ticks in North America. Climate can affect …

Investigation On Bacterial Signaling Through Generation Of A Ppgpp Biosensor, Andrew Robinson

Undergraduate Honors Theses

Guanosine tetraphosphate (ppGpp) is a bacterial signaling molecule involved in activating the stringent response, a cellular reaction to environmental stress that downregulates cell division and metabolism processes to conserve nutrients. The stringent response is implicated in some instances of antibiotic persistence, so broadening the current understanding of ppGpp signaling is useful. This thesis seeks to generate a ppGpp biosensor that will bind ppGpp and emit fluorescent light in its presence, which will allow for improved research into the pathways and functions of the signaling molecule. To generate a novel ppGpp biosensor, I converted a biosensor previously used to detect cyclic …

Cyclic-Di-Gmp-Binding Proteins Regulate Acinetobacter Baumannii Motility, Gabriel Smith

Undergraduate Honors Theses

Acinetobacter baumannii is a prevalent nosocomial pathogen where, like many other infectious bacteria, A. baumannii is increasingly considered a multi-drug resistant pathogen. This research study was designed to find a way to affect the persistence of A. baumannii such that it can be applied to a hospital setting to prevent further nosocomial infections. One regulatory mechanism potentially used by A. baumannii to persist on hospital surfaces is through the use of the bacterial second messenger cyclic-di-GMP (c-di-GMP). This nucleotide signal is regulated in response to environmental conditions, and then activates c-di-GMP-binding proteins that induce phenotypic changes. One c-di-GMP-regulated phenotype is …

Genetic Characterization Of A Klebsiella Pneumoniae Secreted Anti-Microbial Protein, Ethan Becker

Undergraduate Honors Theses

Antimicrobial-resistant bacteria are a major source of ailment in modern-day nosocomial settings, with numerous risks including leading to possible further drug resistance or spreading to those who cannot fight off the infection due to immune suppression or dysfunction. Previous work in our laboratory has determined that Klebsiella pneumoniae possesses inhibitory effects on the growth of a variety of bacteria that contain antimicrobial-resistant properties in the Enterobacteriaceae family, a major source of nosocomial antimicrobial-resistance. This novel property of K. pneumoniae inhibits the growth of Citrobacter freundii, Enterobacter aerogenes, and Enterobacter cloacae through an anti-microbial protein. The antimicrobial protein secreted from K. …

Deciphering The Mechanisms Of Alcaligenes Faecalis’ Inhibition Of Staphylococcus Aureus And Synergism With Antibiotics, Cortlyn Holdren

Undergraduate Honors Theses

Staphylococcus aureus has developed resistance to several antibiotics including vancomycin, which is often used as a “last resort” treatment. There is an ever-increasing need to develop novel antimicrobial treatments to combat S. aureus and other drug resistant bacteria. Microorganisms are most often found in polymicrobial communities where they either exhibit synergistic or antagonistic relationships. Competition between microorganisms can lead to the discovery of new antimicrobial targets as the specific mechanisms of resistance are elucidated. In addition, synergistic treatments are being evaluated for their combined effect and potential to decrease the concentration of drugs needed, and thus the side effects also. …

The Inhibitory Effects Of An Antimicrobial Gel On The Staphylococcus Species, Mara Trinkle

Undergraduate Honors Theses

The prevalence of antibiotic resistant bacteria has made the choices for topical treatments for patients who experience burns wounds extremely limited. The Staphylococcus genus is naturally occurring in and on the human body but can become harmful once it enters the bloodstream. A novel antimicrobial gel has been shown by our laboratory to inhibit both the planktonic growth and biofilm formation of Staphylococcus aureus in previous studies. The antimicrobial gel is made of seven natural compounds including antioxidants (vitamin C and E). We wanted to examine the effects of the antimicrobial gel on numerous other Staphylococcal species because it is …

The Effect Of Alcaligenes Faecalis On Inhibition Of Candida Albicans Biofilm And Planktonic Growth, Nausheen A. Siddiqui

Undergraduate Honors Theses

Candida albicans is a fungal microorganism found on the human body and in the environment. An opportunistic pathogen causing local and systemic infection, this fungus is one of the leading causes of nosocomial infections. More alarming is its growing resistance against the limited number of antifungals we have for treatment Candida infections. An area of current research, termed polymicrobial interactions, focuses on how different microorganisms interact with each other for limited space, nutrients, and survival. The current study focuses on attempting to inhibit planktonic and biofilm growth stages by using the benign bacterium Alcaligenes faecalis, previously shown in our …

Subcellular Localization Of Tobacco Sabp2 Under Normal And Stress Conditions, Sanjeev Das

Undergraduate Honors Theses

Subcellular Localization of Tobacco SABP2 under Normal and Stress Conditions

Salicylic acid (SA), a phytohormone, plays an important role in plant physiology. SA mediated innate immune pathway is an important pathway for plant immunity against pathogens. Plants resisting pathogen infection synthesize higher levels of Methyl Salicylate (MeSA), which is then converted to SA by the esterase activity of Salicylic Acid Binding Protein 2 (SABP2). The high level of the converted SA leads to enhanced pathogen resistance. The study of subcellular localization of a protein is critical in explaining its potential biochemical functions. SABP2 tagged with eGFP was expressed transiently in …

The Effects Of Farnesol, A Quorum Sensing Molecule From Candida Albicans, On Alcaligenes Faecalis, Savannah Hutson

Undergraduate Honors Theses

Quorum sensing molecules have become a recent focus of study to learn if and how they can be used, both on their own and in conjecture with current antimicrobial methods, as a means of bacterial control. One such quorum sensing molecule is the sesquiterpene alcohol, Farnesol, which is synthesized and released by the fungus, Candida albicans. In most in-vivo cases, our laboratory has shown that Alcaligenes faecalis overtakes C. albicans, preventing its growth. However, as a way to counteract this inhibitory effect, Farnesol may be one way that Candida has found to fight back. In this study, we …

A Study Of The Polymicrobial Inhibitory Interactions Between Alcaligenes Faecalis And Staphylococcus Aureus, Blakeley Griffin

Undergraduate Honors Theses

Members of the Staphylococcus genus are found as a part of normal microflora in humans and can commonly be found on the skin or in the nasal cavity. However, these microorganisms can cause serious and life-threatening opportunistic infections when there is a break in the physical barrier of skin. These infections have become difficult to treat as resistant strains emerge, particularly Methicillin Resistant Staphylococcus aureus (MRSA). MRSA has become a commonly acquired nosocomial infection which is difficult to treat with conventional antibiotics of the blactam class. Even Vancomycin, a last resort antibiotic, has been ineffective on some infections. Furthermore, …

Second Messenger Cyclic-Di-Gmp Regulation In Acinetobacter Baumannii, Justin Deal

Undergraduate Honors Theses

Over time, “superbugs,” or bacteria that have become resistant to antibiotics, have become a great concern in modern medicine. Viable alternates are currently being looked into as effective and safe ways to prevent or treat infections caused by these superbugs. One such method is through the utilization of the second messenger molecule cyclic-di-GMP (c-di-GMP) that has been shown to regulate phenotypes within other bacteria that may control surface colonization in Acinetobacter baumannii. Through a series of experiments, the active enzymes that create c-di-GMP - diguanylate cyclases - and break down c-di- GMP - phosphodiesterases - have been inactivated in …

The Inhibitory Effects Of A Novel Gel On Staphylococcus Aureus Biofilms, Lindsey Vance

Undergraduate Honors Theses

Antibiotic resistance is an ever-growing topic of concern within the medical field causing researchers to examine the mechanisms of resistance to develop new antimicrobials. Bacteria’s ability to form biofilms is one mechanism which aids in antimicrobial resistance. Staphylococcus aureus is of special interest as it is one of the most frequent biofilm-forming bacteria found on medical devices causing infections and posing dangerous threats in a clinical setting. A recently developed antimicrobial gel has been shown to have profound effects on treating bacterial infections and wound healing. This research is centered upon examining the antimicrobial effects of this gel on the …

Chat Expression In Chlamydia Muridarum-Infected Female Murine Genital Tract, Hallie Sartain

Undergraduate Honors Theses

Chlamydia trachomatis is the most prevalent agent of bacterial sexually transmitted infections in the world. However, a profuse number of cases are unreported, as the infection is often asymptomatic. Sequelae such as pelvic inflammatory disease, an increased risk of cervical cancer, premature birth, and perinatal infections in pregnant women can occur. Inflammation occurs in the body in response to infection or injury. Although inflammation can lead to some unwanted secondary effects, such as pain, it serves to return the body to homeostasis by restoring injured tissues and eliminating pathogens. One recently identified connection between the central nervous system and the …

Determination Of The Effects That A Previously Uncharacterized Secreted Product From Klebsiella Pneumoniae Has On Citrobacter Freundii And Enterobacter Cloacae Biofilms, Cody M. Hastings

Undergraduate Honors Theses

More so than ever, Multiple Drug Resistant (MDR) bacteria are on the rise due to overuse of antibiotics along with natural selection for adaptations that enhance drug-resistant properties. One particular bacterial family, Enterobacteriaceae, has been problematic, exhibiting several bacterial members that have developed a precipitous resistance to modern antibiotics and are also primary causative agents of nosocomial, or hospital acquired, infections. Citrobacter freundii (CF) and Enterobacter cloacae (ECL) are two species of the Enterobacteriaceae family causing significant medical concern due to their role in producing numerous opportunistic infections such as bacteremia, lower respiratory tract infections, urinary tract infections, and endocarditis. …

Potential Role Of Rta3 And Gnp3 Transport Genes In The Quorum Sensing Response Of Candida Albicans, John G. Magnuson

Undergraduate Honors Theses

Quorum sensing (QS) is a mechanism of communication between cells to coordinate biological activities. In the opportunistic fungal pathogen Candida albicans, QS is important for regulating the organism’s ability to change morphology from a yeast form to a hyphal form. Previously, our laboratory identified several genes involved in polymicrobial communication between C. albicans and three bacterial species. We hypothesize that interspecies communication and QS utilize the same genetic pathways to control C. albicans morphological behavior. In this study, two transport genes, RTA3 and GNP3, and their involvement in QS were examined. To test whether these two genes participate in QS, …

Identification Of Transcription Factors Gzf3, Rfx1, Orf19.3928 As Being Implicated In Candida-Bacterial Interactions., Joni Watson

Undergraduate Honors Theses

Candida albicans is an opportunistic pathogen that is present in the normal flora in a majority of individuals. One key factor in C. albicans virulence is the ability to change its morphology from yeast to an elongated or hyphal form. The regulation of this morphogenesis relies in part upon quorum sensing (QS) molecules. C. albicans often exists as part of a mixed culture alongside other microbes and is influenced by their presence as well as the presence of QS molecules that they produce. In this study, a library of diploid homozygous transcriptional regulator knockout (TRKO) mutants were screened to identify …