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Full-Text Articles in Molecular Biology
Characterization Of The Clostridioides Difficile Glycosyl Hydrolase Ccsz, Brian Lowrance
Characterization Of The Clostridioides Difficile Glycosyl Hydrolase Ccsz, Brian Lowrance
Theses and Dissertations (Comprehensive)
Bacteria inhabit many of the harshest environments on Earth; persisting and thriving in conditions thought to be unsuitable for life. One common strategy to withstand these environments is the formation of a biofilm. Biofilm composition varies greatly, depending on the underlying community that produces it. Cellulose, a polymer consistently prevalent in biofilms, has been identified as a virulence factor in many pathogens and is suspected to be involved in pathogenesis by Clostridioides difficile. C. difficile is the #1 cause of hospital acquired diarrhea, which can range from mild to life-threatening infections. Biofilm formation is hypothesized to be involved in …
Identification And Characterization Of Genetic Elements That Regulate A C-Di-Gmp Mediated Multicellular Trait In Pseudomonas Fluorescens, Collin Kessler
Identification And Characterization Of Genetic Elements That Regulate A C-Di-Gmp Mediated Multicellular Trait In Pseudomonas Fluorescens, Collin Kessler
Electronic Theses and Dissertations
Microbial communities contain densely packed cells where competition for space and resources are fierce. These communities are generally referred to as biofilms and provide advantages to individual cells against immunological and antimicrobial intervention, dehydration, and predation. High intracellular pools of cyclic diguanylate monophosphate (c-di-GMP) cause cells to aggregate during biofilm formation through the production of diverse extracellular polymers. Genes that encode c-di-GMP catalytic enzymes are commonly mutated during chronic infections where opportunists display enhanced resistance to phagocytosis and antibiotics. Our lab uses an emergent multicellular trait in the model organism Pseudomonas fluorescens Pf0-1 to study the emergence of c-di-GMP mutations …
Transcriptomic And Functional Investigation Of Bacterial Biofilm Formation, Brooke R. Nemec
Transcriptomic And Functional Investigation Of Bacterial Biofilm Formation, Brooke R. Nemec
USF Tampa Graduate Theses and Dissertations
Staphylococcus aureus and Acinetobacter baumannii are two highly successful human pathogens, which have adopted very different, but effective survival strategies. The success of S. aureus is attributed to the tight regulation of an arsenal of virulence factors. Conversely, A. baumannii lacks what would be considered traditional virulence factors and, instead, has developed a high tolerance for environmental stress, which allows it to persist in unforgiving environments, including nosocomial settings and the human body. One common characteristic of these two organisms is their proclivity for biofilm formation. Herein, we discuss the diverse mechanisms governing biofilm formation for A. baumannii and S. …
Characterization Of Early Biofilm Formation And Physiology In Neisseria Gonorrhoeae, Kelly Eckenrode
Characterization Of Early Biofilm Formation And Physiology In Neisseria Gonorrhoeae, Kelly Eckenrode
Dissertations, Theses, and Capstone Projects
Many bacteria rely on the dynamics of their extracellular appendages to perform important tasks, like motility and biofilm formation. Interestingly, these dynamics have been linked to physiological responses in some pathogenic bacteria; therefore, it is important to understand more about the role of physical forces in bacteria. I used the causative agent of the human disease gonorrhea, Neisseria gonorrhoeae, as a model system to study the role of physical force on early biofilm formation. The advantage of this system is that cell-cell interactions are controlled by extracellular filaments called type IV pili (tfp). Tfp is composed of monomers that give …
Structural Investigation Of Bcsc: Insight Into Periplasmic Transport During Cellulose Export, William Scott, Joel T. Weadge
Structural Investigation Of Bcsc: Insight Into Periplasmic Transport During Cellulose Export, William Scott, Joel T. Weadge
Theses and Dissertations (Comprehensive)
A biofilm can be defined by a community of microbes coexisting within a self-produced protective polymeric matrix. Exopolysaccharide (EPS) is a key component in biofilms and a contributor to their virulence and pathogenicity. The cellulose bacterial synthesis complex is one such EPS system that is found in many Enterobacteriaceae,including Escherichia coli and Salmonella spp., and is responsible for the production and secretion of the EPS cellulose. BcsC is the periplasmic protein responsible for the export of the exopolysaccharide cellulose and was the focus of this research. Sequence homology comparisons and structural predictions between BcsC, and the previously characterized alginate …
Assessment Of Salmonella Enterica Biofilms And Expression Differences Among Serovars, Zhaohao Shi
Assessment Of Salmonella Enterica Biofilms And Expression Differences Among Serovars, Zhaohao Shi
Graduate Theses and Dissertations
Biofilms are communities of microorganisms associated by a matrix of extracellular polymers. In this state, microorganisms occupy an ecological niche distinct from their free-floating, planktonic counterparts. Also, biofilm bacteria become biologically unique as they form communities and lose motility. The acquisition of these physiological attributes enables the biofilm to persist through harsh environmental conditions, including antimicrobial induced stress and to resist sanitization efforts. Because of these features, biofilms can rapidly disseminate across numerous surfaces and as they establish, become challenging to remove. This is a particular issue for the food industry as processing plants offer favorable conditions for biofilm formation …
Relationships Between Factors Influencing Biofilm Formation And Pathogen Retention In Complex Rhizosphere Microbial Communities, Aaron Coristine
Relationships Between Factors Influencing Biofilm Formation And Pathogen Retention In Complex Rhizosphere Microbial Communities, Aaron Coristine
Theses and Dissertations (Comprehensive)
Riparian wetlands are unique habitats facilitating all forms of life. The riverbanks of these environments provide ideal conditions for bacteria, plants, and higher organisms. Of particular interest to this research was the variation in microbial community structure at high, intermediate and poor water quality impacted areas. Assessing the capabilities of plants to retain microbial pathogens was identified. Root systems and corresponding soil are ideal locations for bacterial deposition, resulting in attachment at these areas. Biofilm production in these regions is important for long-term establishment, leading to persistence and potential naturalization. Opportunistic pathogens originating from mammalian fecal matter are introduced into …
A Novel Link Between The Chemotaxis And Biofilm Dispersion Systems Of Pseudomonas Aeruginosa, Jesse Michael Reinhardt
A Novel Link Between The Chemotaxis And Biofilm Dispersion Systems Of Pseudomonas Aeruginosa, Jesse Michael Reinhardt
Theses and Dissertations
Bacterial chemotaxis is the movement of a cell towards an attractant or away from a repellent. This controlled movement is possible due to the chemotaxis system, which is typically made up of several proteins that collectively sense the stimuli and transduce the signal within the cell to mediate a motility response. The chemotaxis proteins of Pseudomonas aeruginosa are encoded in two clusters, which are located at different regions of the chromosome: che I and che V. These gene clusters are known to control chemotaxis via swimming, or flagellar-based, motility. When expressed, these chemotaxis proteins associate with each other to form …
Purification And Characterization Of Bcsc; An Integral Component Of Bacterial Cellulose Export, Emily D. Wilson Ms
Purification And Characterization Of Bcsc; An Integral Component Of Bacterial Cellulose Export, Emily D. Wilson Ms
Theses and Dissertations (Comprehensive)
Biofilms are a growing concern in the medical field due to their increased resistance to antibiotics. When found in a biofilm, bacteria can have antibiotic resistance 10-1000 times that of their planktonic counterparts. Therefore, it is important to study the formation of biofilms. Cellulose biofilms are formed by Enterobacteriaceae, such as many Escherichia coli and Salmonella spp. strains. Biofilms provide these species with benefits including antimicrobial protection, development of bacterial communities, promotion of DNA exchange, uptake of nutrients, and, in the case of cellulose biofilms, immune system evasion. Cellulose biofilms are controlled by the Bacterial cellulose synthesis (Bcs) complex located …
Interaction Of Rhizobium Sp. Strain Irbg74 With A Legume (Sesbania Cannabina) And A Cereal (Oryza Sativa), Shubhajit Mitra
Interaction Of Rhizobium Sp. Strain Irbg74 With A Legume (Sesbania Cannabina) And A Cereal (Oryza Sativa), Shubhajit Mitra
Theses and Dissertations
Rhizobium sp. IRBG74 (IRBG74) develops a classical nitrogen-fixing symbiosis with the legume Sesbania cannabina and also promotes the growth of rice (Oryza sativa), but not much is known about the rhizobial determinants important for these interactions. We hypothesize that Rhizobium sp. IRBG74 utilizes similar mechanisms to endophytically colonize both legume and cereal hosts. In this study, we analyzed the colonization of rice and S. cannabina using a strain of IRBG74 marked with β-glucuronidase (GUS) and Green Fluorescent Protein (GFP). IRBG74 infected both of the host plants through crack entry under submerged conditions, but showed root hair mediated infection under aerobic …
A Messenger Molecule Governs Interdependency In An Evolved Pseudomonas Aeruginosa Biofilm Community, Thomas Macelliott Johnson
A Messenger Molecule Governs Interdependency In An Evolved Pseudomonas Aeruginosa Biofilm Community, Thomas Macelliott Johnson
Honors Theses and Capstones
Biofilm populations are known to harbor great diversity, but the importance of this diversity is not fully understood. A likely contributor to this variation is the second messenger molecule cyclic-di-GMP: low levels associate with a planktonic lifestyle while high levels favor biofilm formation. In ongoing studies of an evolving biofilm population of Pseudomonas aeruginosa (PA), we observed extensive ecological diversification that may relate to this lifestyle switch. In PA, the gene bifA encodes a phosphodiesterase that is known to degrade cyclic-di-GMP and reduce biofilm. This gene was cloned onto a plasmid under control of an inducible promoter and the plasmid …