Extra-intestinal pathogenic Escherichia coli (ExPEC) are a significant cause of urinary tract infections and bacteraemia in the UK and around the world. These E. coli primarily belong to phylogenetic groups B2 and D, with the clones ST131, ST127, ST95, ST73 and ST69 responsible for the majority of these infections. In the UK, studies of ExPEC have focused on isolates from the North of England, ST131 strains and ExPEC that possess extended-spectrum beta-lactamase (ESBL) enzymes. Therefore, very little is understood about the UK ExPEC population as a whole, the breadth of virulence factors contributing to these infections and the differences between urinary and bloodstream-derived ExPEC. In this study ST131 was more frequently detected in bloodstream isolates and ST95 was most prevalent in urinary isolates. Comparative virulence of the major clones in the Galleria mellonella infection model revealed ST131 isolates to effect the highest mortality, although serogroup O6, which is linked with ST73, was also associated with high mortality, potentially explaining the success of ST73-O6 in bacteraemia. Analysis of virulence factors identified pap, afa/dra and kpsMTII as important determinants in isolates causing urosepsis and those of ST131, while fyuA and fimH were distinctly lacking, demonstrating their role as colonisation factors rather than virulence factors. Although these findings are important, with appropriate treatment of urinary tract infections they can become redundant, as ExPEC would be eradicated before causing a severe infection such as bacteraemia or urosepsis. In urinary isolates, resistance to trimethoprim approached 50% and ampicillin resistance was >70%, while ST131 isolates as a whole demonstrated ciprofloxacin and trimethoprim resistance >50%. Together these indicate that empirical UTI guidelines need to be revisited, to prevent recurrence of infection and ascension to the kidneys and bloodstream. In addition, data from this study can be used to develop a point-of-care test to detect ST131, to guide appropriate treatment, without the delay associated with referring a urine specimen for microbiological investigation.

"American cranberry (Vacciniumm macrocarpon) has been long known for its benefits in maintaining urinary tract health. Clinical trials have shown that drinking cranberry juice can prevent urinary tract infections (UTIs) in various subpopulations that are prone to UTIs, especially women, but the mechanisms by which cranberry acts against uropathogenic bacteria are still unclear. Studies showed that when exposed to cranberry juice or A- PACs, a group of tannins that are unique to cranberry, the adhesion activity and biofilm formation of uropathogenic bacteria were reduced. However, the metabolism of cranberry juice has not be elucidated, therefore further study is needed to find out whether the anti-bacterial components in cranberry could survive the digestive system and reach the urinary tract, and how the components or metabolites remaining in urine act against uropathogenic bacteria. We used atomic force microscopy (AFM) to study the surface adhesion force of uropathogenic E. coli incubated with urine samples that were collected from volunteers after drinking 16 oz. of cranberry juice cocktail (CJC) or water. The urine samples were collected at 0, 2, 4, 6, and 8 hours after CJC or water consumption. When incubated with post-water urine, the adhesion forces of pathogenic bacteria that have fimbriae (E. coli B37, B73, B78, BF1023, CFT 073, and J96) did not change; whereas the adhesion forces of these strains decreased over the 8 hour period after CJC consumption. The control strain that does not have frimbriae, E. coli HB101, showed low adhesion force when incubated with post-water and post-CJC urine. In a human red blood cell agglutination (HRBC) assay, the attachment of pathogenic E. coli to red blood cells was significantly lower after exposed to post-CJC urine, compared to those exposed to post-water urine. These results indicate the anti-bacteria components or metabolites of CJC stay active in urine, and these compounds prevent adhesion of E. coli by reducing fimbriae-mediated adhesion. We also examined the effects of drinking CJC on biofilm formation of uropathogenic bacteria. Female volunteers were given 16 oz. of CJC or placebo, and their urine was collected at 0, 2, 8, 24, and 48 hours after consumption. Bacteria (E. coli B37, CFT073, BF1023, HB101, and S. aureus ATCC43866) were cultured in a mixture of urine and growth media in 96 well microtiters. The biofilm formed was quantified by staining the biofilm dissolved in a solvent with crystal violet and measuring the absorbance at 600 nm. The results showed that biofilm formation was reduced within 24 hours after CJC consumption, and it started to increase after 48 hours, possibly due to the washout of CJC in the system. These studies suggest that CJC can be an effective preventive measure for UTIs as it inhibits adhesion and biofilm formation of uropathogenic bacteria."

"Regular ingestion of American cranberry (Vaccinium macrocarpon) has been traditionally utilized for its health benefits against urinary tract infections. The proanthocyanidins (PACs), in particular, the unique A-type double linkages of PACs present in cranberry, have been identified as the active components. However, A-type PACs and any other active agents have not yet been detected or identified in urine. Additional experiments are required to investigate the inhibitory effects and persistence of cranberry metabolites present in urine collected following CJC consumption, and to determine how these compounds act against uropathogenic Escherichia coli for the prevention of urinary tract infections. Two separate bioassays (a biofilm formation assay and a bacterial cell viability assay) were used to determine the in vitro effect of cranberry juice cocktail (CJC) oral consumption on bacterial anti-adhesion activity in a double-blind, placebo-controlled pilot clinical trial. A single dose of 16 oz. of CJC or a placebo beverage was given to ten healthy women, ages ranging from 18 to 27, and urine samples were collected in the following 48 hours. A washout period of seven days was allowed. Bacteria (Escherichia coli B37, CFT073, BF1023, HB101, and Staphylococcus aureus ATCC43866) were cultured in the urine samples, supplemented with media, and the amount of biofilm formed was measured using a crystal violet absorbance assay in a 96-well plate. In the urine of volunteers who had consumed CJC, biofilm formation was inhibited within 24 hours after CJC consumption, and started to increase after 48 hours by 49-67%. S. aureus showed the least biofilm formation after incubation with post-CJC urine. The results indicated that drinking CJC can be an effective preventive measure for bacterial adhesion and biofilm formation in healthy women. The anti-biofilm activity peaks between 24 and 48 hours after drinking CJC. The viability assay showed that the colony count after culturing in urine collected following consumption of CJC or placebo were not significantly different, implying that CJC works as an inhibitor by blocking bacterial adhesion instead of killing the bacteria or restraining its growth. Another randomized, placebo-controlled, double-blind, crossover study was conducted to further investigate the molecular-scale effect of cranberry juice metabolites on two P-fimbriated E. coli strains: B37 and CFT 073, as assessed by atomic force microscopy (AFM). Three female subjects were asked to consume 8 oz. CJC or water. The washout period was 7 days. The urine samples were collected at 2, 4 and 6 hours post-ingestion of CJC or water. Urine collected before consumption of CJC was used as a control. For this control urine, the average adhesion force between E. coli and uroepithelial cells was 13.09 ± 11.60 nN for CFT073 and 10.30 ± 5.50 nN for B37. For post-CJC urine treatment, the adhesion forces decreased to 2.94 ± 1.82 nN at 2 hours after consumption then increased slightly to 5.51 ± 2.78 nN at 6 hours after ingestion for CFT073, while they decreased to 4.77 ± 3.33 nN after consuming for 2 hours and seemed to be stable in the next 4 hours following consumption (5.52 ± 4.04 nN after drinking for 4 hours; 5.05 ± 4.42 nN after drinking for 6 hours) for B37. The adhesion forces in post-water consumption urine were similar to those of the background for E. coli B37; meanwhile a downward trend for the adhesion forces in post-water consumption urine compared to the background was observed for E. coli CFT073. However, these adhesion forces in post-water consumption urine were still higher than those measured after CJC consumption at the same time intervals. The mean differences between the cranberry and placebo groups were statistically different according to the two way ANOVA procedure followed by Holm-Sidak test. Our results suggest a significant inhibitory interaction between the daily consumption of 8 oz. cranberry juice and bacterial adhesive activity. These results help form the mechanistic understanding of how cranberry products can be used to prevent bacterial attachment to host tissue, and may lead to new therapeutic strategies to prevent the rising problem of bacteria antibiotic resistance.  "

Thesis (Ph. D.)--University of Sydney, 2004. / Title from title screen (viewed 8 May 2008). A reference list of published articles is provided in Appendices. Includes copies of seven published papers, co-authored by Fanrong Kong. Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Dept. of Medicine. Includes bibliographical references. Also available in print form.

Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 186-197).

Thesis (doctoral)--Ludwig-Maximilians-Universität zu München, 1979.

Thesis (M.S.)--University of Wisconsin-Madison, 1980. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 47-52).

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 83-91).

In recent years, the role of metabolomics has become increasingly more important in the advancement of many research fields including medical studies. Due to lack of metabolomics research in the area of infectious disease and the rise in antibiotic resistance, there is a need for further studies on the modes of antibiotic action and the mechanisms of resistance of pathogenic microorganisms at the metabolome level. This study aimed to investigate effects of DNA synthesis inhibitors on the metabolome of E. coli and to develop a workflow for discrimination between E. coli isolates down to the sub-species level using a variety of methods, which can inform the choice of analytical techniques in metabolomics research. A metabolomics-based approach was used to elucidate metabolic alterations in E. coli K-12 upon challenge with trimethoprim at two pH levels (5 and 7) which mimic human urine acidity. FT-IR spectroscopy was used as a preliminary experiment to produce bacterial fingerprints and GC-MS was applied to generate global metabolic profiles in each condition. At pH 7, as the drug molecules exhibited higher permeability, stronger direct effects of the antibiotic were observed, i.e. decreased levels of nucleotides. Trehalose, an osmoprotectant, was up-regulated in these stress conditions and this up-regulation was mirrored by a decrease in glucose levels. This also correlated with up-regulation of pyruvate-related products (e.g. alanine, citrate and malate). Other off-target related effects were observed such as alterations in the levels of various amino acids upon trimethoprim challenge. This study offered a wider view of drug action at pH levels similar to healthy human urine. A high throughput FT-IR spectroscopy method was developed to discriminate between pathogenic E. coli isolates based on sequence type. This method employed a Bioscreen as a micro-culture incubator instead of traditional sample preparation (shaking flasks), which can be labour intensive and time consuming. Excluding the washing step in the protocol enabled discrimination between isolates of different sequence types. Moreover, a reproducible workflow of lipid analysis based on LC-MS was developed and applied on four pathogenic isolates with different sequence type and susceptibility to ciprofloxacin. This workflow enabled detection of a wide range of lipid classes and determination of significant alterations in lipid levels related to susceptibility to ciprofloxacin. Stressed and control isolates were also analysed using the developed Bioscreen FT-IR approach to assess phenotypic fingerprint differences, which were in line with the LC-MS-ve class distribution. Further investigation by means of four analytical platforms (FT-IR, GC-MS, LC-MS-ve and LC-MS+ve) was applied on E. coli ST131 isolates characterised using classical microbiological tests (virulence factors and metabolic tests). Procrustes transformation was used to compare between the analytical methods and the microbiological tests in terms of their capacity to discriminate between the different isolates. As indicated above, the results from FT-IR and LC-MS-ve were comparable and in line with virulence tests, while GC-MS and metabolic tests were in agreement. Complementary information generated by different analytical techniques and microbiological tests may indicate the requirement for careful selection of the method of investigation and may suggest the need to continue using a combination of methods which are applied to study different features of bacterial physiology.

This dissertation aims to explore the role of patient and family engagement in the context of two current health issues: catheter-associated urinary tract infections (CAUTI) and antibiotic resistance. Chapter One contains an introduction to patient and family engagement, CAUTI, and antibiotic resistance, followed by gaps in the science, a description of the theoretical framework, and specific aims addressed in this dissertation. Chapter Two is a systematic review of existing CAUTI prevention interventions that involve patient and family engagement. Chapter Three is a study designed to meet the learning needs of parents by developing a graphically-enhanced CAUTI-prevention educational resource using participatory design methods. Chapter Four is an environmental scan that summarizes the content and format of existing resources about antibiotic resistance and antibiotic use available from children’s hospital websites across the United States. Finally, Chapter Five contains an overall summary of the findings of this dissertation, a discussion of results within the guiding theoretical framework, practice and policy implications, and suggestions for future research.