Staphylococcus aureus is a roughly spherical species of bacteria, some strains of which are referred to as MRSA, a drug resistant pathogen. This organism has major healthcare implications and huge financial resources are directed towards developing vaccines and therapies. However, despite recent rapid progress, our understanding of cell shape, growth and division is still limited. The bacterial cell wall, made mainly of the polymer peptidoglycan, has a major role in these processes. It acts as a bacterial exoskeleton, resisting turgor but capable of being remodelled throughout the cell cycle. Optical microscopy has revealed how cell shape changes are related to insertion of new peptidoglycan, however details of peptidoglycan architecture are on too small a scale to see by this technique. Atomic Force Microscopy (AFM) was therefore applied to investigate fine structure providing clues as to how peptidoglycan can play a role in spatially organizing cell division. AFM force measurements were used in combination with strains of Staphylococcus aureus lacking cell wall modifying enzymes to investigate the role of these proteins in growth. Ultimately, localisation based super resolution microscopy (i.e. PALM/STORM) is being applied to re-investigate peptidoglycan insertion and cell shape triggering another major rethink of how these are related.
This is a weekly series of informal talks given primarily by members of the soft condensed matter and statistical mechanics groups, but is also open to members of other groups and external visitors. The aim of the series is to promote discussion and learning of various topics at a level suitable to the broad background of the group. Everyone is welcome to attend..