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University of South Florida

2013

Water Quality

Articles 1 - 2 of 2

Full-Text Articles in Life Sciences

Direct And Indirect Effects Of Agrochemicals On Bacterial Pathogens And Fecal Indicator Bacteria, Zachery Staley Jan 2013

Direct And Indirect Effects Of Agrochemicals On Bacterial Pathogens And Fecal Indicator Bacteria, Zachery Staley

USF Tampa Graduate Theses and Dissertations

The presence of agrochemical residues in both urban and agricultural water bodies has become ubiquitous, often producing deleterious effects in the impacted watershed including reductions in biodiversity, alterations in species interactions, and toxicity to non-target organisms. While these effects have been studied on metazoan consumers, the consequences of agrochemical contamination on microorganisms, such as bacteria, protozoa, and viruses, are poorly understood. Agrochemicals could act directly on microorganisms, including pathogens, by either facilitating their survival or decreasing their abundance. Further, a multitude of indirect effects of agrochemicals on microorganisms are possible, whereby agrochemicals alter predation, competition, or parasitism on or available …


Predation, Competition, And Nutrient Levels Affect The Survival Of Escherichia Coli, Enterococci And Enteric Pathogens In Aquatic Habitats, Pauline Wanjugi Jan 2013

Predation, Competition, And Nutrient Levels Affect The Survival Of Escherichia Coli, Enterococci And Enteric Pathogens In Aquatic Habitats, Pauline Wanjugi

USF Tampa Graduate Theses and Dissertations

Fecal indicator bacteria (FIB) such as Escherichia coli and enterococci are used to assess microbiological water quality in recreational waters worldwide. FIB are used with the assumption that their presence correlates with that of fecal-associated pathogens in recreational waters. In aquatic habitats, several factors can interfere with the predictive relationship between FIB and pathogens including extended survival of FIB in secondary habitats such as sediment, vegetation and sand. Furthermore, many biotic (e.g. predation from bacterivorous protozoa and competition from indigenous bacteria) and abiotic factors (e.g. temperature, salinity, ultraviolet (UV) light irradiation, and nutrient availability) can influence the fate of FIB …