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Full-Text Articles in Microbiology

Characterizing The Role Of Pa5189 Of Pseudomonas Aeruginosa In Deletion And Overexpression Mutants, Seh Na Mellick May 2024

Characterizing The Role Of Pa5189 Of Pseudomonas Aeruginosa In Deletion And Overexpression Mutants, Seh Na Mellick

Theses/Capstones/Creative Projects

In the context of rising multidrug resistance in biofilm-forming pathogens like Pseudomonas aeruginosa, this study investigates the role of the understudied transcription factor PA5189 in antibiotic resistance and biofilm formation. PA5189 deletion and overexpression mutants were created in a parent P. aeruginosa strain using pEX18Tc-based recombinant suicide vectors, with genotypic verification of putative triparental conjugants achieved through restriction digestion and PCR. The study revealed that PA5189 overexpression significantly increases resistance to commonly used broad spectrum antibiotics such as ciprofloxacin and imipenem. Additionally, differential expression of PA5189 was found to notably affect biofilm formation, with variations contingent on the nutrient …


The Role Of Coagulase-Negative Staphylococcal Secreted Products On Staphylococcus Aureus And Staphylococcus Lugdunensis Infections, Denny Chin Apr 2022

The Role Of Coagulase-Negative Staphylococcal Secreted Products On Staphylococcus Aureus And Staphylococcus Lugdunensis Infections, Denny Chin

Electronic Thesis and Dissertation Repository

The Staphylococcus genus is comprised of over 40 bacterial species. The most well-studied species in this genus is the notorious human pathogen Staphylococcus aureus, a bacterium that produces coagulase among many other virulence factors. Since S. aureus is a major health burden and causes a plethora of diseases in humans, it has received significant attention and much research has been done to understand its biology to treat diseases caused by this pathogen. However, the coagulase-negative staphylococci (CoNS) make up most of the staphylococcal species and have received less attention since they are thought to have a lesser impact on …


Regulation, Mechanism Of Action, And Function Of A Small Toxin Protein In Ehec, Bikash Bogati Dec 2021

Regulation, Mechanism Of Action, And Function Of A Small Toxin Protein In Ehec, Bikash Bogati

Doctoral Dissertations

The zor-orz locus identified in the chromosome of Escherichia coli O157:H7 EDL933 is a type I toxin-antitoxin system that consists of two homologous gene pairs zorO-orzO and zorP-orzP. The zor genes encode for small toxin proteins and the orz genes encode for small RNAs. Previously it was shown that overproduction of ZorO results in cell growth stasis whereas co-expression of orzO rescues cellular growth. Within, I demonstrate that in addition to growth inhibition, ZorO overproduction results in membrane depolarization and ATP depletion but does not impact the gross morphology of E. coli. In vivo translation and subsequent impacts …


The Role Of The Msaabcr Operon In Cell Wall Integrity And Programmed Cell Death During Biofilm Development, Bibek G C Aug 2021

The Role Of The Msaabcr Operon In Cell Wall Integrity And Programmed Cell Death During Biofilm Development, Bibek G C

Dissertations

Staphylococcus aureus is an important human pathogen in both community and health care settings. Biggest challenges with S. aureus as a pathogen is its ability to acquire antibiotic resistance and produce robust biofilms. In this work, we investigated the nature of the cell wall defect in the msaABCR operon mutant in the Mu50 (VISA) and USA300 LAC methicillin-resistant Staphylococcus aureus (MRSA) strains. Results showed that msaABCR-mutant cells had decreased cell wall thickness and cell wall crosslinking in both strains. These defects are most likely due to increased murein hydrolase activity and/or nonspecific processing of murein hydrolases mediated by increased …


The Effects Of Farnesol, A Quorum Sensing Molecule From Candida Albicans, On Alcaligenes Faecalis, Savannah Hutson May 2020

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 …