Thesis (M. Phil.)--University of Hong Kong, 1989.

Background A pandemic clone, Escherichia coli sequence type 131 (ST131), has been disseminated worldwide and represents an important cause of antimicrobial resistant infections. The spread of this resistant clone has become a great public health concern. Objectives The aims of this study were to investigate the prevalence of ST131 in Escherichia coli isolates from human urinary cultures in Hong Kong and study the antimicrobial phenotypes of ST131. Methodology This study included 340 E. coli clinical urinary isolates obtained from patients in four district hospitals between May 2013 and July 2013 in Hong Kong. Antimicrobial susceptibilities were assessed by disk diffusion method with reference to CLSI. The isolates were investigated by phylogroup-specific and ST131-specific PCR assays. ST131 strains were further assessed for subclone distribution, antimicrobial resistance and extended-spectrum β-lactamase (ESBL) type. Results A total of 18.5% (63/340) of the E. coli population was identified as ST131. ST131 isolates were significantly more likely than non-ST131 isolates to be ciprofloxacin resistant (69.8%, 44/63 versus 31.0%, 86/277; P <0.001), gentamicin resistant (38.1%, 24/63 versus 24.9%, 69/277; P=0.03) and ESBL producers (41.3%, 26/63 versus 18.8%, 52/277; P <0.001). Among the ST131 E. coli isolates, 68.3% (43/63) belonged to the H30 subclone. Most H30 isolates were ST131-O25b (97.7%, 42/43). Also, the ST131-H30 E. coli subclone was statistically associated with ciprofloxacin resistance compared with the non-H30 ST131 isolates (P <0.001). Additionally, strains which were co-resistant to ciprofloxacin, co-trimoxazole and gentamicin were overwhelmingly associated with the H30 subclone than non-H30 (23.3%, 10/43 versus 0%, 0/20; P=0.02). Conclusion This study showed that ST131 isolates were widespread among human E. coli urinary isolates in Hong Kong. The increase in antimicrobial resistance phenotypes are highlighted with ST131, especially the H30 subclone isolates. The dissemination of the ST131 resistant clonal group has aroused clinical attention and limited the choice of empirical treatment. / published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

published_or_final_version / Microbiology / Master / Master of Philosophy

Cell-cell communication between bacteria, belonging to the same species or to different species (Intra-kingdom signaling), or communication between bacteria and their animal host (Inter-kingdom signaling) is mediated through different chemical signals that are synthesized and secreted by bacteria or the host and is crucial for the survival of bacteria inside their host. The overall goal of this work was to understand the role of inter- and intra-kingdom signaling in phenotypes such as chemotaxis, colonization and biofilm formation, and virulence that are associated with infections caused by the human gastrointestinal (GI) tract pathogens. A part of our work also aimed at developing microfluidics-based models to study inter- and intra-kingdom signaling in biofilm formation, inhibition, and dispersal. We showed that norepinephrine (NE), an important host signal produced during stress, increases human opportunistic pathogen Pseudomonas aeruginosa growth, motility, attachment, and virulence, and also showed that the actions of NE are mediated primarily through the LasR, and not the RhlR QS system. We investigated the molecular mechanism underlying the chemo-sensing of the intra-kingdom signal autoinducer-2 (AI-2) by pathogens Escherichia coli and Salmonella typhimurium by performing different chemotaxis assays (capillary, microPlug and microFlow assays), and discovered that AI-2 is a potent attractant for E. coli and S. typhimurium, and that the Tsr chemoreceptor and periplasmic AI-2 binding protein LsrB are necessary for sensing AI-2, although uptake of AI-2 into the cytoplasm is not required. We concluded that LsrB, when bound to AI-2, interacts directly with the periplasmic domain of Tsr primarily at the Thr-61 and Asp-63 residues of LsrB, making LsrB the first known periplasmic-protein partner for Tsr. We fabricated a simple user-friendly microfluidic flow cell (microBF) device that can precisely measure the effect of a wide range of concentrations of single or combinations of two or more soluble signals on bacterial biofilm formation and development. We also constructed a synthetic biofilm circuit that utilizes the Hha and BdcA dispersal proteins of E. coli along with a quorum sensing (QS) switch that works based on the accumulation of the signal N-(3-oxo-dodecanoyl)-L-homoserine lactone (3-o-C12HSL) and implemented it in an upgraded �BF device. We showed that a QS system may be utilized with biofilm dispersal proteins to control consortial biofilm formation by removing an existing biofilm and then removing the biofilm that displaced the first one. These types of synthetic QS circuits may be used to pattern biofilms by facilitating the re-use of platforms and to create sophisticated reactor systems that will be used to form bio-refineries.

Jehovah's Witnesses claim to be the sole advocates for God's truth at this point in redemptive history. Basing this belief on their interpretation of Matthew 24:45-47 and Luke 12:42-45, the Watchtower Society proclaims that their organization is led by "the faithful and discreet slave" (FDS) of the end times. This FDS is the Governing Body of the Society, which has been charged with the responsibility of providing spiritual food for Jehovah's people. According to the Witnesses, to discount the message of the FDS is to ignore the voice of God. History reveals that the identity and the message of the FDS have changed since the conception of the Watchtower organization. The movement's founder, Charles Taze Russell, was first known as the FDS of Matthew 24 but lost the title after his death when the new leader of the group shifted the identity away from an individualistic understanding to a corporate one. After proclaiming for the bulk of the organization's history that the 144,000 anointed Witnesses were the FDS, the Society recently changed their understanding of this end times' servant in 2012. Currently, the FDS is only the anointed Witness men that are serving on the Governing Body of the Society. This progressive shift in the organization's understanding of the FDS and the eventual disappearance of these anointed Witnesses continues to necessitate theological realignments, which in turn lays the apologetic groundwork for evangelism to the Jehovah's Witnesses. As redemptive history continues to unfold, the Watchtower Society will be forced to clarify or reinterpret many of their foundational teachings. Such reinvention further opens the apologetic door for evangelism among disillusioned Witnesses. When the Watchtower organization again searches to recast their leadership along with their message, authentic Christians must be ready and seeking to direct Witnesses to the unchanging message of the gospel.

Cóir Anmann is a late medieval Irish tract made up of numerous 'entries', each of which purports to explain the meaning of a particular epithet associated with a character in early history or mythology. Two separate recensions of this tract have long been known to exist, but in the course of the present study a third recension was identified. One of the main purposes of this thesis is to provide diplomatic editions of these three recensions based on all extant manuscript copies. On the way to producing these editions the manuscript tradition of the tract is reviewed, and a stemma is drawn up for each of the recensions preserved in more than one MS text. English translations have also been made available. In the introductory discussion linguistic and stylistic evidence is used to establish a chronology in which the recensions can be placed relative to one another. To this end verbal systems for the recensions have been prepared. Since the entries in <I>Cóir Anmann </I>are founded on borrowings from pre-existing sources, extracts from independent tracts corresponding to material contained in it have been identified, and suggestions on how these were handled and adapted for use in <I>Cóir Anmann</I> have been advanced. Together with the conclusions reached as to the chronology of the recensions, this study enables the way in which the tract was compiled from disparate sources and 'grew' through the extant recensions to be discerned. The dates of works quoted in <I>Cóir Anmann,</I> internal references and certain aspects of the language are then reviewed to determine the approximate compilation period for each recension. In a final consideration of the development of the tract, this thesis examines histories and genealogies written in the Early Modern period and after for which <I>Cóir Anmann </I>itself served as a source of material.

Thesis (MA(Religion))--University of South Australia, 2000

SYNOPSIS Included in this work, is a general historical overview of the development of astronomical knowledge in the West from the realms of Greek scholarship in classical times through to the Renaissance and the threshold of modern physics. The subject matter of both the Irish Tract and this review extends beyond the strict confines of astronomy, encompassing the physical sciences in general. The extent of astronomical knowledge in medieval Ireland is given specific attention with a review of scholarly works in Latin since the seventh century. This includes a number of specialist studies on astronomical topics and related cosmographical fields. Also included are numerous incidental references to astronomical matters from both Irish and Latin literature during the Middle Ages. Attention is devoted to the surviving manuscript copies of the Tract and the question of its sources, origin and purpose. A possible Dominican context for the compilation and dissemination of the Tract is considered. A detailed commentary of the technical content of each chapter is presented, together with reference to contemporary developments in the West and to the occasional clues as to the institutional, geographical and chronological origins of the Tract. A study of the technical terminology used by the Irish compiler is presented in detail. Reference is made both to earlier Irish terminology where appropriate, as well as to the limitations imposed by the fact that many of the scientific concepts were yet to attain clarity that came with the advent of Newtonian physics, Copernican astronomy and post-Colombian geography. The data entries on ms Stowe B are evaluated and compared with computer generated data of astronomical movements in the 14th and 15th centuries with a view to ascertaining the time of compilation of the Tract and its working life. A A revised English translation of the Tract is included in the appendices together with Maxwell Close's unpublished commentary to relevant portions. An Irish edition, closely following the ITS edition of 1914 is also included. Corruptions to the text are footnoted together with the likely run of the original text.

Thesis (M. Sc.)--University of Canterbury, 2007. / Typescript (photocopy). Includes bibliographical references (leaves 74-77). Also available via the World Wide Web.

Thesis (Ph.D.) -- Flinders University, Dept. of General and Digestive Surgery, School of Medicine. / Typescript (bound). Includes bibliographical references (leaves 254 - 270). Also available online.