Open Access. Powered by Scholars. Published by Universities.®
- Institution
Articles 1 - 4 of 4
Full-Text Articles in Entire DC Network
Influence Of Nutrients And The Native On E. Coli Survival In The Beach Environment, Brigid Meyers
Influence Of Nutrients And The Native On E. Coli Survival In The Beach Environment, Brigid Meyers
Theses and Dissertations
E. coli is used as an indicator for water quality to determine if water poses a health risk for pathogens. Past research has shown that E. coli is present in high numbers in freshwater beach sands distinct from fecal pollution events, yet the precise mechanism for their persistence in not well understood. Persistent E. coli populations in sand can resuspend into adjacent water and lead to increased beach closures when no threat is present. This work identifies factors that influence the survival of E. coli in sand using laboratory microcosms to replicate beach conditions. Microcosms were deployed to examine the …
Evaluating The Effects Of Pine And Miscanthus Biochar On Water Activity And Escherichia Coli Populations In Commercial Broiler Litter, Christopher Austin Marty
Evaluating The Effects Of Pine And Miscanthus Biochar On Water Activity And Escherichia Coli Populations In Commercial Broiler Litter, Christopher Austin Marty
Theses and Dissertations
The decrease in subtherapeutic antibiotic administration in poultry has increased the need to address production challenges caused by pathogens, such as E. coli. One potential way to improve bird health and reduce bacterial infection is through the addition of litter amendments that absorb moisture. Biochar (BC) has previously been shown to increase water holding capacity in poultry litter, but its effects on E. coli mitigation are unknown. The objectives of this research were to 1) evaluate water activity of poultry litter amended with pine and miscanthus BC, and 2) determine the effects of different BC inclusion rates on litter …
The Selective Survival Of Escherichia Coli In Freshwater Beach Sand, Natalie Ann Rumball
The Selective Survival Of Escherichia Coli In Freshwater Beach Sand, Natalie Ann Rumball
Theses and Dissertations
The quantification of Escherichia coli or E. coli is the most common method used to detect recent fecal pollution in recreational water, as this species is known for its high abundance in fecal matter and assumed host-associated nature. However, it has been determined that some strains are capable of long-term survival and potential propagation in non-host environments, such as the beach sand. These long-term environmental survivors are host-independent and are not associated with the same health risks as those E. coli from recent fecal pollution. However, they have been shown to impact how water quality is perceived as they are …
Genetic Analysis Of Conserved Residues In Phou Of Escherichia Coli, Stewart G. Gardner
Genetic Analysis Of Conserved Residues In Phou Of Escherichia Coli, Stewart G. Gardner
Theses and Dissertations
The Pho regulon is controlled by the PstSCAB transporter, PhoU, and the two-component proteins, PhoB and PhoR. PhoU is a negative regulator of the Pho regulon under phosphate-replete conditions. How PhoU functions is unknown. Many PhoU homologues are found widely throughout prokaryotic domains. There are several conserved amino acid residues in the PhoU protein. It is hypothesized that these residues play an important role in the function of PhoU. To test this hypothesis, several site directed mutations in the phoU gene have been produced with single amino acid changes in conserved residues. After testing these mutants, it was found that …