Salmonella is a bacterium responsible for several illnesses, including typhoid fever,
paratyphoid fever, and salmonellosis. It is commonly found in animal products, including
poultry. Determination of potential reservoirs of Salmonella contamination is important
to mitigate the risk of transmission and possible outbreaks. Outbreaks can negatively
impact the livelihood of local...
Corals provide a diversity of ecosystem services, are among the most biologically diverse ecosystems on Earth, and directly support ~500 million people globally; however, corals are increasingly experiencing significant threats and are undergoing severe bleaching events as the result of the warming climate. Using a two-year data set surrounding a...
High counts of fecal indicators, used to signal the potential presence of pathogens associated with untreated waste, result in the classification of water bodies throughout the United States as impaired. Nonpoint sources of unknown origin that contribute to fecal contamination make management of impaired waters challenging, as they are difficult...
Coral reef ecosystems continue to be significantly altered by disease epizootics, but why some host populations remain resistant while others succumb to outbreaks remains unknown. Research across diverse animal and plant host systems has revealed that disease severity is strongly influenced by host genetics and by environmental influences on both...
Cell-cell communication in bacteria is understood to facilitate the coordination of population-wide cooperative behavior in the form of concerted gene expression. The opportunistic pathogen Pseudomonas aeruginosa uses such a communication mechanism to regulate a large group of genes important to virulence strategies in this bacterium. This general mechanism of communication...
Diatoms play a major role in ocean biogeochemical cycles and are important tools in bioengineering for natural products and nanotechnology. Diatoms and other algae growing at varying resource-limited growth rates allocate carbon to different metabolic pathways to optimize growth; however, the molecular mechanisms controlling these pathway gating strategies are not...
Pseudomonas aeruginosa is a ubiquitous environmental microbe, opportunistic pathogen, and a highly social organism. P. aeruginosa utilizes a wide array of cooperative behaviors to adapt to the environmental conditions around it. These behaviors include quorum sensing (QS), a form a cell-to-cell signaling that coordinates the expression of secreted products in...
Members of the SAR11 clade of heterotrophic α-proteobacteria are ubiquitous and abundant in the world's oceans where they are thought to play a pivotal role in the global carbon cycle. The first SAR11 bacterium cultivated in vitro, 'Candidatus Pelagibacter ubique' HTCC1062 (Ca. P. ubique), was isolated by dilution into sterile...
When iron levels are low, the opportunistic pathogen Pseudomonas aeruginosa secretes the high-affinity iron-binding siderophore pyoverdine. The cognate ferripyoverdine receptor, FpvA, has gained attention as the most divergent gene in the organism’s genome, showing substantial evidence of positive selection. S-type pyocins, bacteriocins with specificity to Pseudomonads, enter cells through FpvA...
In this thesis, we examined the effects of the exposures to anthropogenic pollutants on the fish, primarily juvenile chinook salmon, immune system using newly and recently developed immune assays. In addition, we developed a new assay for measuring immunocompetence of fish. In the first chapter, the Alamar Blue assay was...