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The human and bovine bacterial pathogen Streptococcus agalactiae (Group B Streptococcus, GBS) expresses a thick polysaccharide capsule that constitutes a major virulence factor and vaccine target. GBS can be classified into ten distinct serotypes differing in the chemical composition of their capsular polysaccharide. However, non-typeable strains that do not react with anti-capsular sera are frequently isolated from colonized and infected humans and cattle. To gain a comprehensive insight into the molecular basis for the loss of capsule expression in GBS, a collection of well-characterized non-typeable strains was investigated by genome sequencing. Genome based phylogenetic analysis extended to a wide population of sequenced strains confirmed the recently observed high clonality among GBS lineages mainly containing human strains, and revealed a much higher degree of diversity in the bovine population. Remarkably, non-typeable strains were equally distributed in all lineages. A number of distinct mutations in the cps operon were identified that were apparently responsible for inactivation of capsule synthesis. The most frequent genetic alterations were point mutations leading to stop codons in the cps genes, and the main target was found to be cpsE encoding the portal glycosyl trasferase of capsule biosynthesis. Complementation of strains carrying missense mutations in cpsE with a wild-type gene restored capsule expression allowing the identification of amino acid residues essential for enzyme activity.

Set against a background of technological change, national bargaining and union merger, this thesis considers the impact of a changing structural, economic and political climate on the resilience of national pay bargaining within general print, a little documented but important section of the economy. It seeks to examine contemporary workplace industrial relations where, against national trends, national bargaining has been resilient. It is in the light of there being a long association with strong, regulatory unionism within the sector that this study seeks to explore the reality of workplace industrial relations under national bargaining. There has been a wealth of theoretical and empirical data produced on the background to the wider debate on the declining influence of multi-employer bargaining across the UK economy. However, little work has been committed to the general printing sector that investigates why, in the face of fundamental changes to industrial relations practice, the national agreement for this sector appears to have continued relatively unscathed. The thesis draws on the experience of twelve branches with respect to the impact of the national agreement; three case studies in general print sector companies located in the South West, Humberside and Anglia regions; and on documentary evidence and participant observation. Analysis of the thesis was informed by classical and contemporary writers on industrial relations. The thesis finds a shift from traditional adversarial approaches to partnership in national agreement negotiations. The thesis reveals that at the workplace level, the chapel structure remains intact with its traditional, hierarchal structure and the accompanying issues of gender segregation and worker exclusion remaining firmly embedded within chapels. Behind this appearance of chapel strength an air of apathy and poor organisation impacts on union activity and local bargaining. The thesis concludes by critiquing shifts away from traditional bargaining and questions the state of workplace organisation with changes in union structure. Importantly, the thesis presents data on the state of collective bargaining in the sector, and in particular identifies a shift from the traditional adversarial approach to partnership in the national agreement; it also identifies the difference in the image and reality of workplace organisation in the sector where behind the appearance of chapel strength lies an air of apathy and poor organisation that ultimately impacts on chapel activity and local bargaining. Using Kelly’s model for union renewal the thesis assesses the level of union activity and considers the likelihood of increased union activity in the workplace in the general print sector.

Chronic antral gastritis following Helicobacter pylori (Hp) infection is characterized by a cellular inflammatory infiltrate whose cytokines may represent a host-dependent factor influencing the outcome of the infection. The pattern of cytokines produced by the immunologically active cells in the gastric antrum was analyzed at the mRNA level in antral biopsies from five Hp-infected patients with duodenal ulcer and three Hp-negative dyspeptic controls. T cell clones were generated from parallel antral biopsies of the same Hp-infected patients and assessed for reactivity to Hp Ags, cytokine profile, and effector functions. Antral biopsies from all Hp-infected patients showed IFN-gamma, TNF-alpha, and IL-12, but not IL-4, mRNA expression, whereas no cytokine mRNA signal was found in the mucosa of controls. A total of 24 out of the 163 CD4+ T cell clones (15%) derived from Hp-infected patients proliferated in response to a Hp lysate; 11 clones (46%) also reacted with Cag-A, 2 with Vac-A, and 1 with urease. Upon Ag stimulation, 20 out of the 24 Hp-reactive clones (83%) produced IFN-gamma, but not IL-4 or IL-5 (Th1-like), whereas 4 produced IFN-gamma, IL-4, and IL-5 (Th0-like). All Hp-specific clones secreted high levels of TNF-alpha. At low T:B cell ratio, Hp-specific clones expressed Ag-dependent helper function for B cell proliferation and Ig production, whereas at higher T:B cell ratios, 15 Th1 and 2 Th0 clones lysed Ag-pulsed autologous EBV-transformed B cells. Results provide evidence for Hp-specific Th1 effectors in the gastric antrum of Hp-infected patients, where they may play a role in the genesis of either peptic ulcer or Hp-associated gastric B cell lymphoma.