Inhibiting Menaquinone Biosynthesis and Biofilms in Staphylococcus aureus

Status: Complete
Year: 2018
Funded: $99,250
Grant Type: Major Project Grant

New Zealand has among the highest reported incidence of infections with the bacterium Staphylococcus aureus in the developed world. This bug causes a range of infections from common skin infections like boils, school sores and cellulitis, to infections associated with surgical implants like hip replacements, heart, bone and blood infections, toxic shock syndrome and pneumonia. These infections are often recurrent and increasing numbers are being caused by strains like methicillin-resistant Staphylococcus aureus (MRSA), which are resistant to nearly all known antibiotics.

The ability of the bacteria to persist inside the human body is one of the key drivers for recurrent infections. This is helped by their ability to make biofilms, where they adhere together on a surface. During biofilm formation the bacteria sense a range of environmental cues and interpret these as signals to cluster.

One of these signals is given by a small molecule called Vitamin K2 (menaquinone). This study aims to make inhibitors of the bacterial enzymes that make menaquinone to study how menaquinone affects biofilm formation which will lead to drugs to target and treat S. aureus infections and biofilms. 

Researcher // Dr Jodie Johnston – University of Canterbury

Dr Johnstons research interests are related to studying the structure and function of proteins, the aim being to obtain a better understanding of key biological questions at level of atoms and molecules.

More About Dr Jodie Johnston

What is Staphylococcus aureus?

Staphylococcus aureus is a Gram-positive, round-shaped bacterium that is a member of the Firmicutes, and it is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often positive for catalase and nitrate reduction and is a facultative anaerobe that can grow without the need for oxygen. Although S. aureus usually acts as a commensal of the human microbiota it can also become an opportunistic pathogen, being a common cause of skin infections including abscesses, respiratory infections such as sinusitis, and food poisoning. Pathogenic strains often promote infections by producing virulence factors such as potent protein toxins, and the expression of a cell-surface protein that binds and inactivates antibodies. The emergence of antibiotic-resistant strains of S. aureus such as methicillin-resistant S. aureus (MRSA) is a worldwide problem in clinical medicine. Despite much research and development, no vaccine for S. aureus has been approved.

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