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Full-Text Articles in Organisms

Managing Stress: A Study Of Stress Response Mechanisms In Mycobacteria, Augusto C. Hunt Serracin Jan 2024

Managing Stress: A Study Of Stress Response Mechanisms In Mycobacteria, Augusto C. Hunt Serracin

Biology Dissertations

Mycobacteria encompass many pathogenic species known to cause severe disease in humans. A well-known example is Mycobacterium tuberculosis (Mtb), the causative agent of the lung disease tuberculosis, which kills millions of humans worldwide yearly. Pathogenic mycobacteria like Mtb are challenging to treat because of their innate ability to adapt to environmental stress. Their unique cell physiology and conserved stress responses allow them to combat biological insults, regulate growth, and regulate genes involved in stress; all these responses increase tolerance to antibiotics. The current therapies to treat mycobacterial infections are lengthy and, at times, unsuccessful, partly due to antibiotic tolerance. A …


Investigating The Antibacterial And Immunomodulatory Properties Of Lactobacillus Acidophilus Postbiotics, Rachael M. Wilson Apr 2023

Investigating The Antibacterial And Immunomodulatory Properties Of Lactobacillus Acidophilus Postbiotics, Rachael M. Wilson

Graduate School of Biomedical Sciences Theses and Dissertations

Probiotics are nonpathogenic microorganisms that have been extensively studied for their ability to prevent various infectious, gastrointestinal, and autoimmune diseases. The mechanisms underlying these probiotic effects have not been elucidated. However, we and other researchers have evidence suggesting that probiotic bacteria secrete metabolites that are antimicrobial and anti-inflammatory. As such, we developed a methodology to collect the secreted metabolites from a probiotic bacterium, Lactobacillus acidophilus, and tested this cell free filtrate (CFF) both in vitro and in vivo. Using this CFF, we have demonstrated that L. acidophilus secretes a molecule(s) that has specific bactericidal activity against the opportunistic pathogen, Pseudomonas …


Deciphering The Mechanisms Of Alcaligenes Faecalis’ Inhibition Of Staphylococcus Aureus And Synergism With Antibiotics, Cortlyn Holdren May 2021

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 Effect Of Alcaligenes Faecalis On Inhibition Of Candida Albicans Biofilm And Planktonic Growth, Nausheen A. Siddiqui May 2020

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 …


Fatty Acid Mediated Alterations In Biofilm Formation With Vibrio Cholerae, Isabel Gray May 2020

Fatty Acid Mediated Alterations In Biofilm Formation With Vibrio Cholerae, Isabel Gray

Honors Theses

Vibrio cholerae is a Gram-negative bacterium known as a waterborne pathogen. It is often found in marine conditions and can infect humans through ingestion. V. cholerae is responsible for cholera, a disease characterized by profuse diarrhea, vomiting, and other dehydration symptoms. Ultimately, severe cases can cause extreme electrolyte imbalances, shock, and acute renal failure which lead to death in a short period of time. Annually, V. cholerae causes approximately 3 million cases of cholera and 100,000 deaths worldwide. V. cholerae can persist in motile and biofilm lifestyles under aquatic and host conditions, a unique biphasic lifestyle that contributes to Vibrio’s …


Investigation Of The In Vitro Interactions Between Two Common Cystic Fibrosis Pathogens, Staphylococcus Aureus And Stenotrophomonas Maltophilia., Matthew Hill May 2019

Investigation Of The In Vitro Interactions Between Two Common Cystic Fibrosis Pathogens, Staphylococcus Aureus And Stenotrophomonas Maltophilia., Matthew Hill

College of Arts & Sciences Senior Honors Theses

Cystic Fibrosis (CF) is one of the most common autosomal disorders in Caucasian populations. This disorder creates a very opportune environment for many pathogens within the patient’s lung. Two common pathogens that infect CF patient’s lungs are Staphylococcus aureusand Stenotrophomonas maltophilia. These two species of bacteria can colonize host environments and establish mats of cells known as biofilms that become very difficult to eradicate with antibiotics. Once inside a CF lung, these pathogens must not only evade the host immune response but they also interact and compete with each other; however, how bacterial pathogens interact inside the host lung …