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Pathogenic Microbiology Commons

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Full-Text Articles in Pathogenic Microbiology

Quorum Sensing Signals Produced By Heterotrophic Bacteria In Black Band Disease (Bbd) Of Corals And Their Potential Role In Bbd Pathogenesis, Chinmayee D. Bhedi Jun 2017

Quorum Sensing Signals Produced By Heterotrophic Bacteria In Black Band Disease (Bbd) Of Corals And Their Potential Role In Bbd Pathogenesis, Chinmayee D. Bhedi

FIU Electronic Theses and Dissertations

Black band disease (BBD) of corals is a temperature dependent, highly virulent, polymicrobial disease affecting reef-building corals globally. The microbial consortium of BBD is primarily comprised of functional physiological groups that include photosynthetic cyanobacteria, sulfate reducers, sulfide oxidizers and a vast repertoire of heterotrophic bacteria. Quorum sensing (QS), the cell-density dependent communication phenomenon in bacteria, is known to induce expression of genes for a variety of virulence factors in diseases worldwide. Microbes capable of QS release signals such as acyl homoserine lactones (AHLs) and autoinducer-2 (AI-2), which coordinate microbial interaction. The focus of the present study was to investigate the …


E,E-Farnesol Inhibits Swarming Motility In Burkholderia Cepacia Through Rhamnolipid Production, Stephanie E. Nicholls, Alayna N. Sanderson, Andrea P. Schwartz, Lauren E. Ward, Jessica N. Weisensee, Molly Yandrofski, Tracy L. Collins Apr 2017

E,E-Farnesol Inhibits Swarming Motility In Burkholderia Cepacia Through Rhamnolipid Production, Stephanie E. Nicholls, Alayna N. Sanderson, Andrea P. Schwartz, Lauren E. Ward, Jessica N. Weisensee, Molly Yandrofski, Tracy L. Collins

The Research and Scholarship Symposium (2013-2019)

Burkholderia cepacia and Candida albicans both exhibit cell-to-cell communication through the use of quorum-sensing molecules (QSM) known as autoinducers. E,E-farnesol is a QSM produced by C. albicans which regulates its conversion from yeast to mycelium. Because there is a positive correlation between the presence of B. cepacia and C. albicans in the lungs of individuals with cystic fibrosis (CF), we examined whether E,E-farnesol had an effect on swarming motility in B. cepacia. Swarming motility was inhibited when B. cepacia was exposed to 250 µM of E,E-farnesol. In addition, there was a 26.8% decrease in rhamnolipid production when cells were grown …


The Effects Of Quorum Sensing And Temperature On The Soluble Proteome Of Vibrio Salmonicida, Christopher L. Massey Jun 2016

The Effects Of Quorum Sensing And Temperature On The Soluble Proteome Of Vibrio Salmonicida, Christopher L. Massey

Master's Theses

Vibrio salmonicida causes cold-water vibriosis in salmon populations around the world and causes financial damage to fisheries designed to farm these salmon. Very little is known about the physiology of how V. salmonicida causes disease and measures to contain vibriosis are restricted to either vaccinating individual fish against disease or administering antibiotics when an outbreak is detected. These procedures are costly and increase the risk for selection of antibiotic-resistant V. salmonicida strains. A recent reoccurrence of outbreaks in Norwegian fisheries provided incentive to better understand the virulence mechanisms of V. salmonicida. In this thesis, a proteomic approach was used to …


Regulation Of Toxin Synthesis By Clostridium Difficile, Charles Darkoh Aug 2012

Regulation Of Toxin Synthesis By Clostridium Difficile, Charles Darkoh

Dissertations & Theses (Open Access)

Clostridium difficile is the leading definable cause of nosocomial diarrhea worldwide due to its virulence, multi-drug resistance, spore-forming ability, and environmental persistence. The incidence of C. difficile infection (CDI) has been increasing exponentially in the last decade. Virulent strains of C. difficile produce either toxin A and/or toxin B, which are essential for the pathogenesis of this bacterium. Current methods for diagnosing CDI are mostly qualitative tests that detect the bacterium, the toxins, or the toxin genes. These methods do not differentiate virulent C. difficile strains that produce active toxins from non-virulent strains that do not produce toxins or produce …


Host Pathogen Interactions: Is Arabidopsis Thaliana Remembered By Its Nemesis Pseudomonas Syringae?, Daniel Z. Kreiser May 2012

Host Pathogen Interactions: Is Arabidopsis Thaliana Remembered By Its Nemesis Pseudomonas Syringae?, Daniel Z. Kreiser

Lawrence University Honors Projects

Plants contain innate immune systems that deter pathogen infection. Pattern recognition receptors bind microbe-associated molecular patterns (MAMPs), triggering immunity. MAMPs are proteins exclusive to pathogens that are typically indispensable for their survival. For this reason, MAMPs cannot be mutated or removed without causing pathogen death. However, this does not necessitate constitutive expression of MAMPs. In this study, the MAMP response of Arabidopsis thaliana was utilized to determine differential detection of MAMPs expressed by Pseudomonas syringe pv. tomato DC3000 when pretreated with A. thaliana. Results demonstrated that more MAMPs are detected when P. syringae had previously encountered A. thaliana, …


Farnesol Restores Wild-Type Colony Morphology To 96% Of Candida Albicans Colony Morphology Variants Recovered Following Treatment With Mutagens, Ellen C. Jensen, Jacob M. Hornby, Nicole E. Pagliaccetti, Chuleeon M. Wolter, Kenneth Nickerson, Audrey L. Atkin Apr 2006

Farnesol Restores Wild-Type Colony Morphology To 96% Of Candida Albicans Colony Morphology Variants Recovered Following Treatment With Mutagens, Ellen C. Jensen, Jacob M. Hornby, Nicole E. Pagliaccetti, Chuleeon M. Wolter, Kenneth Nickerson, Audrey L. Atkin

Kenneth Nickerson Papers

Candida albicans is a diploid fungus that undergoes a morphological transition between budding yeast, hyphal, and pseudohyphal forms. The morphological transition is strongly correlated with virulence and is regulated in part by quorum sensing. Candida albicans produces and secretes farnesol that regulates the yeast to mycelia morphological transition. Mutants that fail to synthesize or respond to farnesol could be locked in the filamentous mode. To test this hypothesis, a collection of C. albicans mutants were isolated that have altered colony morphologies indicative of the presence of hyphal cells under environmental conditions where C. albicans normally grows only as yeasts. All …