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Full-Text Articles in Biology

Periodically Disturbing The Spatial Structure Of Biofilms Can Affect The Production Of An Essential Virulence Factor In Pseudomonas Aeruginosa, Rebecca J. Quinn, Ivana Barraza, Laura García-Diéguez, Camryn Pajon, Lauren E. Krausfeldt, Kerollos Ibrahim, Laura A. Enzinna, Morgan E. Thorn, Omar Tonsi Eldakar, Travis J. A. Craddock, Robert P. Smith Sep 2021

Periodically Disturbing The Spatial Structure Of Biofilms Can Affect The Production Of An Essential Virulence Factor In Pseudomonas Aeruginosa, Rebecca J. Quinn, Ivana Barraza, Laura García-Diéguez, Camryn Pajon, Lauren E. Krausfeldt, Kerollos Ibrahim, Laura A. Enzinna, Morgan E. Thorn, Omar Tonsi Eldakar, Travis J. A. Craddock, Robert P. Smith

Biology Faculty Articles

Understanding the environmental factors that affect the production of virulence factors has major implications in evolution and medicine. While spatial structure is important in virulence factor production, observations of this relationship have occurred in undisturbed or continuously disturbed environments. However, natural environments are subject to periodic fluctuations, including changes in physical forces, which could alter the spatial structure of bacterial populations and impact virulence factor production. Using Pseudomonas aeruginosa PA14, we periodically applied a physical force to biofilms and examined production of pyoverdine. Intermediate frequencies of disturbance reduced the amount of pyoverdine produced compared to undisturbed or frequently disturbed conditions. …


Increasing The Frequency Of Periodic Spatial Disturbance Decreases Surface Attachment Protein Expression In Staphylococcus Aureus, Ivana M. Barraza Apr 2021

Increasing The Frequency Of Periodic Spatial Disturbance Decreases Surface Attachment Protein Expression In Staphylococcus Aureus, Ivana M. Barraza

All HCAS Student Capstones, Theses, and Dissertations

Staphylococcus aureus is an opportunistic pathogen that can cause a variety of acute and chronic illnesses. The severity of these illnesses such as sepsis, necrotizing pneumonia, and toxic shock syndrome is measured through the virulence that S. aureus inflicts on its host. Methicillin-resistant S. aureus (MRSA) is commonly associated with secondary infections and is challenging to treat given the limited selection of antibiotics that are effective against it. Accordingly, novel approaches to reduce S. aureus pathogenicity are required. S. aureus regulates pathogenesis through a cell-to-cell communication system referred to as quorum sensing. Effective communication determines the production of two broad …


Disruption Of Pyoverdine Synthesis In Pseudomonas Aeruginosa Through Periodic Disturbance Of Biofilm Structure, Rebecca J. Quinn Jul 2020

Disruption Of Pyoverdine Synthesis In Pseudomonas Aeruginosa Through Periodic Disturbance Of Biofilm Structure, Rebecca J. Quinn

All HCAS Student Capstones, Theses, and Dissertations

Infections due to bacteria were once easily treated using antibiotics. However, the effective shelf life of antibiotics is diminishing due to the rise and spread of antibiotic resistant bacteria. Accordingly, novel approaches to treating infections are required. Pseudomonas aeruginosa is a multi-drug resistant, biofilm forming opportunistic pathogen. A determinant of P. aeruginosa’s pathogenicity is pyoverdine, a siderophore that is used to sequester iron from the environment. After being produced by a bacterium, pyoverdine is secreted into the environment where it complexes with iron. The pyoverdine-iron complex is then returned to the bacteria through diffusion, where it drives the synthesis of …


The Successful Exploitation Of Urban Environments By The Golden Silk Spider, Nephila Clavipes (Araneae, Nephilidae), Jake Ripp, Omar T. Eldakar, Andrew C. Gallup, Paul T. Arena Apr 2018

The Successful Exploitation Of Urban Environments By The Golden Silk Spider, Nephila Clavipes (Araneae, Nephilidae), Jake Ripp, Omar T. Eldakar, Andrew C. Gallup, Paul T. Arena

Biology Faculty Articles

Urbanization typically leads to habitat destruction producing negative effects for native species, but some species may exploit these settings. This concept was investigated in the golden silk spider (Nephila clavipes), a large, formidable spider that commonly inhabits forest edges as well as open spaces in urban environments throughout its vast geographic range. Here, we compared variation of N. clavipes success as measured by body size, web size and web positioning along an urban–rural gradient in southern Florida. From morphological measurements collected in the field, urban spiders had 60% longer legs and 35% longer bodies than both park and …