51 research outputs found
Differences in genotype and virulence among four multidrug-resistant <i>Streptococcus pneumoniae</i> isolates belonging to the PMEN1 clone
We report on the comparative genomics and characterization of the virulence phenotypes of four <i>S. pneumoniae</i> strains that belong to the multidrug resistant clone PMEN1 (Spain<sup>23F</sup> ST81). Strains SV35-T23 and SV36-T3 were recovered in 1996 from the nasopharynx of patients at an AIDS hospice in New York. Strain SV36-T3 expressed capsule type 3 which is unusual for this clone and represents the product of an in vivo capsular switch event. A third PMEN1 isolate - PN4595-T23 - was recovered in 1996 from the nasopharynx of a child attending day care in Portugal, and a fourth strain - ATCC700669 - was originally isolated from a patient with pneumococcal disease in Spain in 1984. We compared the genomes among four PMEN1 strains and 47 previously sequenced pneumococcal isolates for gene possession differences and allelic variations within core genes. In contrast to the 47 strains - representing a variety of clonal types - the four PMEN1 strains grouped closely together, demonstrating high genomic conservation within this lineage relative to the rest of the species. In the four PMEN1 strains allelic and gene possession differences were clustered into 18 genomic regions including the capsule, the blp bacteriocins, erythromycin resistance, the MM1-2008 prophage and multiple cell wall anchored proteins. In spite of their genomic similarity, the high resolution chinchilla model was able to detect variations in virulence properties of the PMEN1 strains highlighting how small genic or allelic variation can lead to significant changes in pathogenicity and making this set of strains ideal for the identification of novel virulence determinant
A Functional Genomics Approach to Establish the Complement of Carbohydrate Transporters in Streptococcus pneumoniae
The aerotolerant anaerobe Streptococcus pneumoniae is part of the normal nasopharyngeal microbiota of humans and one of the most important invasive pathogens. A genomic survey allowed establishing the occurrence of twenty-one phosphotransferase systems, seven carbohydrate uptake ABC transporters, one sodiumβΆsolute symporter and a permease, underlining an exceptionally high capacity for uptake of carbohydrate substrates. Despite high genomic variability, combined phenotypic and genomic analysis of twenty sequenced strains did assign the substrate specificity only to two uptake systems. Systematic analysis of mutants for most carbohydrate transporters enabled us to assign a phenotype and substrate specificity to twenty-three transport systems. For five putative transporters for galactose, pentoses, ribonucleosides and sulphated glycans activity was inferred, but not experimentally confirmed and only one transport system remains with an unknown substrate and lack of any functional annotation. Using a metabolic approach, 80% of the thirty-two fermentable carbon substrates were assigned to the corresponding transporter. The complexity and robustness of sugar uptake is underlined by the finding that many transporters have multiple substrates, and many sugars are transported by more than one system. The present work permits to draw a functional map of the complete arsenal of carbohydrate utilisation proteins of pneumococci, allows re-annotation of genomic data and might serve as a reference for related species. These data provide tools for specific investigation of the roles of the different carbon substrates on pneumococcal physiology in the host during carriage and invasive infection
Contribution of a genomic accessory region encoding a putative cellobiose phosphotransferase system to virulence of Streptococcus Pneumoniae
Streptococcus pneumoniae (the pneumococcus) is a formidable human pathogen, responsible for massive global morbidity and mortality. The ability to utilize carbohydrates in a variety of host niches appears to be integral to pneumococcal pathogenesis. In this study we investigated a genomic island, which includes a ROK family protein, a putative cellobiose phosphotransferase system (PTS) and a putative sulfatase. This accessory region is widespread in the pneumococcus in strains of various serotypes and levels of virulence. We have performed simple bioinformatic analysis of the region and investigated its role in vivo in 2 strains with markedly different virulence profiles (WCH206 of serotype 3, ST180; Menzies5 of serotype 11A, ST662). Deleting and replacing the entire island with an antibiotic resistance cassette caused the virulent serotype 3 strain to become attenuated in a murine pneumonia/sepsis model. Further mutants were constructed and used to show that various components of the island contribute significantly to the fitness of WCH206 in a variety of niches of this model, including the nasopharynx, ears and blood, but especially in the lungs. In addition, the island conferred a competitive advantage in nasopharyngeal colonization for the serotype 11A strain, which was essentially avirulent in the pneumonia/sepsis model. The contribution of this island to both pathogenesis and colonization may explain why this accessory region is widespread in the pneumococcus.Lauren J. McAllister, Abiodun D. Ogunniyi, Uwe H. Stroeher and James C. Pato
The relationship between cultural and biological diversity : implications for protecting indigenous knowledge
The signing of the Biodiversity Convention (1992) at the Earth Summit, Rio and the development of a New Zealand Biodiversity Strategy, represent a valuable opportunity to reassess how we conserve biodiversity. In particular, it is argued in this study, they provide an opportunity to reassess New Zealand's current approach to protecting indigenous knowledge of biodiversity. The problem addressed in this study, is that the current intellectual property legislation is unlikely to protect indigenous knowledge of biodiversity. A primary aim of the study is to examine the relationship between cultural and biological diversity, in order to ascertain the role of indigenous knowledge in the conservation of biodiversity. It is argued that indigenous knowledge, as part of cultural diversity, is, in fact, part of biodiversity. It is further argued that biodiversity is conserved and utilised through cultural frameworks, and that a New Zealand Biodiversity Strategy should reflect the variety of values and knowledge we hold towards the environment. Given that indigenous knowledge of biodiversity should be protected, the study analyses existing legislation for the protection of intellectual property. It is determined that the legislation will not adequately protect indigenous knowledge of biodiversity in that it does not protect what is valued by tangata whenua, nor reflect the reasons why it is valued. It is argued that in order to protect indigenous knowledge in a way which is appropriate to tangata whenua, it is necessary for tangata whenua to protect it themselves. A process for protecting indigenous knowledge is investigated, in the context of developing a New Zealand Biodiversity Strategy
Five hours with Raja: ethics and the documentary interview
This thesis is a study of a young woman coming to terms with her grief. It unpacks how an invitation to film an unusual and life-changing event developed into an opportunity to question the ethics of the interview. It examines how the intricacies of a trust relationship influence the very threads and textures of the resulting documentary.
This paper is a partnership between a practical documentary project and a more traditional written discussion. The documentary Five Hours with Raja is weighted at eighty per cent of the final thesis and the written exegesis makes up the remaining twenty per cent. Together these two elements investigate the developing relationship between Claudia β the documentaryβs key protagonist, and the filmmaker, investigating how their relationship has affected the style, method, content and even the fundamental story line of a documentary. It also discusses the consequential ethical considerations and dilemmas behind creative and practical decisions, investigating ways that a filmmaker can draw the participant into the process to allow a greater degree of ownership, a stronger voice and a more immediate sense of intimacy with the final audience
The Two-Component Regulatory System TCS08 Is Involved in Cellobiose Metabolism of Streptococcus pneumoniae R6
The two-component system TCS08 is one of the regulatory systems that is important for virulence of Streptococcus pneumoniae. In order to investigate the TCS08 regulon, we have analyzed transcription profiles of mutants derived from S. pneumoniae R6 by microarray analysis. Since deletion mutants are often without a significant phenotype, we constructed a mutation in the histidine kinase HK08, T133P, in analogy to the phosphatase mutation T230P in the H box of the S. pneumoniae CiaH kinase described recently (D. ZΓ€hner, K. Kaminski, M. van der Linden, T. Mascher, M. Merai, and R. Hakenbeck, J. Mol. Microbiol. Biotechnol. 4:211-216, 2002). In addition, a deletion mutation was constructed in rr08, encoding the cognate response regulator. The most heavily suppressed genes in the hk08 mutant were spr0276 to spr0282, encoding a putative cellobiose phosphoenolpyruvate sugar phosphotransferase system (PTS). Whereas the R6 Sm(r) parent strain and the Ξrr08 mutant readily grew on cellobiose, the hk08 mutant and selected mutants with deletions in the PTS cluster did not, strongly suggesting that TCS08 is involved in the catabolism of cellobiose. Homologues of the TCS08 system were found in closely related streptococci and other gram-positive cocci. However, the genes spr0276 to spr0282, encoding the putative cellobiose PTS, represent a genomic island in S. pneumoniae and homologues were found in Streptococcus gordonii only, suggesting that this system might contribute to the pathogenicity potential of the pneumococcus
Towards integration: A study of the integrated management of sedimentation in Lyttelton Harbour: Report presented in partial fulfilment of the requirements for the degree of Master of Science in Resource Management
Coastal management in the past has been fragmented. The Resource Management Act 1991 and the new statutory requirements for plans represents an attempt at a more integrated approach.
Our aim in this report is to see whether this new system will achieve integrated management. We recognise however, that integrated management is a process as well as an end, and that these two necessarily overlap
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