Staphylococcus aureus is a medically important pathogen responsible for a range of infectious diseases from minor skin and soft tissue infections, to more serious life-threatening infections such as septicaemia and meningitis. It is best known as the causative agent of MRSA (Methicillin-Resistant Staphylococcus aureus). With resistance to multiple antibiotics becoming an increasing problem, particularly in hospital settings, it is becoming ever more important to understand how this pathogen causes disease, such that new treatments can be developed in the future.

This work has characterised a mutant of S. aureus which is deficient in the ability to produce toxins which irreparably damage human cells during disease. The mutant is deficient in a particular metabolic enzyme which forces it to respire as if it were in anaerobic conditions where there is no oxygen. We show that loss of this enzyme significantly affects energy production, and in turn causes repression of a major regulatory pathway which controls production and secretion of toxins.

Emily Stevens, third year SWBio DTP student

Paper: ‘Cytolytic toxin production by Staphylococcus aureus is dependent upon the activity of the protoheme IX farnesyltransferase‘ by E. Stevens, M. Laabei, S. Gardner, G.A. Somerville and R.C. Massey in Scientific Reports.