Meningococcal genome dynamics: an allele based, population approach to define lineage structure

Thesis

Advances in genome sequencing technologies have rapidly expanded the number of bacterial genome sequences available for study, permitting the emergence of the discipline of population genomics. Bioinformatics platforms were used to exploit this resource by the provision of data in an easily accessible and uniform format.

The de novo assembly, combined with gene-by-gene annotation, generated high quality draft genomes in which the majority of protein-encoding genes were present with high accuracy. The approach catalogued diversity efficiently and was a practical approach to interpreting whole genome sequence data for a large bacterial population.

The hyperinvasive meningococcal Lineage 3 core and accessory genome was described and mobile genetic elements and undescribed proteins were found to be influencing the shape of the lineages evolution and population structure.

Commensal carriage of the meningococcus was examined using temporally paired isolates. Long-term carriage was found and the comparison of the genomes pairs found a highly conserved set of core genes.

The methods used generated novel insights into the biology of the meningococcus and improved our understanding of the whole population structure, not just disease causing lineages. This work contributes to knowledge of genomic evolution of bacteria and population structure within a species.

Authors: Bratcher, H

• DOI: 10.5287/ora-8gao8okyg
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford