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Environmental Microbiology and Microbial Ecology Commons

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Full-Text Articles in Environmental Microbiology and Microbial Ecology

Investigating The Interactions Between Cyanobacteria And Vibrio Parahaemolyticus, Caroline E. Ward Jan 2014

Investigating The Interactions Between Cyanobacteria And Vibrio Parahaemolyticus, Caroline E. Ward

Honors Theses and Capstones

One well-known pathogen that has been the topic of many recent studies is Vibrio parahaemolyticus, which causes thousands of foodborne illnesses a year, mostly from the ingestion of raw or undercooked oysters. It has been shown cyanobacteria can act as a long-term reservoir of Vibrio cholerae, another pathogenic Vibrio, by encasing the cells within mucilaginous sheaths during which Vibrios enter a viable but non-culturable state. In this study we investigated the interaction of V. parahaemolyticus with cyanobacteria to determine whether cyanobacteria aid in the longevity and survival of V. parahaemolyticus. We found that non-pathogenic V. parahaemolyticus …


Pseudomonas Aeruginosa-Candida Albicans Interactions: Localization And Fungal Toxicity Of A Phenazine Derivative, Jane Gibson, Arpanah Sood, Deborah A. Hogan Nov 2008

Pseudomonas Aeruginosa-Candida Albicans Interactions: Localization And Fungal Toxicity Of A Phenazine Derivative, Jane Gibson, Arpanah Sood, Deborah A. Hogan

Dartmouth Scholarship

Phenazines are redox-active small molecules that play significant roles in the interactions between pseudomonads and diverse eukaryotes, including fungi. When Pseudomonas aeruginosa and Candida albicans were cocultured on solid medium, a red pigmentation developed that was dependent on P. aeruginosa phenazine biosynthetic genes. Through a genetic screen in combination with biochemical experiments, it was found that a P. aeruginosa-produced precursor to pyocyanin, proposed to be 5-methyl-phenazinium-1-carboxylate (5MPCA), was necessary for the formation of the red pigmentation. The 5MPCA-derived pigment was found to accumulate exclusively within fungal cells, where it retained the ability to be reversibly oxidized and reduced, and its …


Bacteriophage Migration Via Nematode Vectors: Host-Parasite-Consumer Interactions In Laboratory Microcosms, John J. Dennehy, Nicholas A. Friedenberg, Yul W. Yang, Paul E. Turner Mar 2006

Bacteriophage Migration Via Nematode Vectors: Host-Parasite-Consumer Interactions In Laboratory Microcosms, John J. Dennehy, Nicholas A. Friedenberg, Yul W. Yang, Paul E. Turner

Dartmouth Scholarship

Pathogens vectored by nematodes pose serious agricultural, economic, and health threats; however, little is known of the ecological and evolutionary aspects of pathogen transmission by nematodes. Here we describe a novel model system with two trophic levels, bacteriophages and nematodes, each of which competes for bacteria. We demonstrate for the first time that nematodes are capable of transmitting phages between spatially distinct patches of bacteria. This model system has considerable advantages, including the ease of maintenance and manipulation at the laboratory bench, the ability to observe many generations in short periods, and the capacity to freeze evolved strains for later …