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Item Understanding Escherichia coli O157:H7 presence, pervasiveness, and persistence in constructed treatment wetland systems(Montana State University - Bozeman, College of Letters & Science, 2015) VanKempen-Fryling, Rachel Joy; Chairperson, Graduate Committee: Anne Camper; Otto R. Stein and Anne K. Camper were co-authors of the article, 'Presence and persistence of wastewater pathogen Escherichia coli O157:H7 in hydroponic reactors of treatment wetland species' in the journal 'Water science and technology' which is contained within this thesis.; Anne K. Camper was a co-author of the article, 'Escherichia coli O157:H7 attachment and persistence within root biofilm of common treatment wetlands plants' submitted to the journal 'Water research ' which is contained within this thesis.; Anne K. Camper was a co-author of the article, 'Using molecular and microscopic techniques to track the wastewater pathogen Escherichia coli O157:H7 within model treatment wetlands' submitted to the journal 'Applied and environmental microbiology' which is contained within this thesis.Treatment wetlands (TW) are a wastewater remediation technology that relies on the natural ability of wetland plant species and the associated microbial consortia to remove pollutants and improve water quality. Although there is substantial research on chemical pollutant remediation by TW, the removal of bacterial pathogens is much more varied and limited in scope. Escherichia coli O157:H7 is a bacterial pathogen that has caused numerous outbreaks and infections in the United States alone and is closely associated with improper water treatment. Understanding how E. coli O157:H7 could potentially persist and survive through a TW process is important in order to appropriately determine the efficacy of TW for treating water and protecting human health. This work used epifluorescent microscopy and qPCR relative DNA abundance to track E. coli O157:H7 tagged with a fluorescent DsRed protein in various environments pertaining to a TW. Two high performing wetland plant species, Carex utriculata and Schoenoplectus acutus, were used in hydroponic and simulated TW columns to better understand how the bacteria localize and persist. Teflon nylon strings (diameter 0.71-1.02 mm), cleaned and with established biofilm, were run hydroponically as control inert surfaces. Unplanted gravel columns were used as a nonplanted control for column experiments. E. coli O157:H7-DsRed were observed by microscopy on root surfaces both in hydroponic reactors and lab scale TW columns. The organisms persisted, forming microcolonies shortly after initial inoculation on both root and nylon surfaces. In the lab scale columns, cells persisted for three weeks, although strong biofilm formation was not observed. qPCR also provided evidence that E. coli O157:H7 was able to persist on the tested surfaces of plant roots, nylon inert surfaces, and gravel, showing higher abundance S. acutus roots than on the inert surface and gravel, however higher in unplanted gravel overall. For the plant types, C. utriculata was statistically lower for E. coli O157:H7 abundance than S. acutus over time. This work provides evidence that E. coli O157:H7 is able to colonize and persist in a TW environment, and plant surfaces may offer a higher inactivation than an inert matrix.Item Copper injury of Escherichia coli(Montana State University - Bozeman, College of Agriculture, 1984) Domek, Matthew JosephItem The toxic effect of ionic silver on the lower organisms(Montana State University - Bozeman, College of Agriculture, 1937) McElroy, JeanItem Effects of culture conditions on the susceptibility of Legionella pneumophila to iodine disinfection(Montana State University - Bozeman, College of Agriculture, 1991) Cargill, Kari LisaItem Changes in the virulence of chlorine-injured Yersinia enterocolitica(Montana State University - Bozeman, College of Agriculture, 1985) LeChevallier, Mark WilliamItem Growth of mycobacterium avium in dual species biofilms with Pseudomonas aeruginosa(Montana State University - Bozeman, College of Letters & Science, 2007) Karmacharya, Amresh Prasad; Chairperson, Graduate Committee: Tim E. FordInterest in the growth of M. avium in biofilms has increased in the last few years. Research has shown that M. avium cells in biofilms are more resistant to disinfectants than their planktonic counterparts. Although M. avium has been detected in biofilms in in situ and laboratory models, information available on M. avium is limited compared to biofilm model species such as Pseudomonas aeruginosa, Escherichia coli, Staphylococcus and Streptococcus. The main objective of the present research was to study the growth of M. avium in biofilms in the presence of P. aeruginosa. Biofilms were grown in sterile tap water on stainless steel coupons in batch mode. Two kinds of reactors were used; mason jars and a recirculation system. Each experiment lasted from 27 to 35 days depending upon the nature of the experiment. The two strains were inoculated in isolation (monospecies) and also in combination (dual species).