University of Waikato’s Dr Joanna Hicks is finding a new way to wipe out the sexually transmitted infection gonorrhoea.
The biochemistry lecturer has received an Emerging Researcher First Grant of nearly $250,000 over three years from the Health Research Council.
Gonorrhoea is a major public health challenge, due to the high incidence of infections accompanied by a dwindling number of treatment options. The World Health Organization says it is the second most common bacterial STI and results in substantial economic cost worldwide. Gonorrhoea is spread by having unprotected sex with someone who has it, or from mother-to-child during childbirth. Of all the STIs, gonorrhea is the most antibiotic-resistant.
Dr Hicks says that gonorrhoea seems to have been around as long as humanity, there are even references to it in the bible. “It has so exquisitely co-evolved with humans over thousands of years. It just keeps getting more and more antibiotic resistant, as if it is keeping one step ahead of us. It’s the mastermind of bacteria.” She says gonorrhoea has the ability to take up DNA from the environment, including genes for antibiotic resistance, and incorporate them into its genome, which is a skill not all bacteria have. “It can evade your immune system. It is so perfectly tailored to humans, it is amazing.”
In terms of the three year research project, Dr Hicks is focusing on the production of the amino acid cysteine, which is important for the gonorrhoea bacterial cell. It is a key amino acid for infection, so stopping it from being produced would effectively disable the bacteria. Dr Hicks says there are no current antibiotics that target amino acid biosynthesis, but researchers are starting to look at it as a new direction because they have exhausted other options. “Humans don’t have enzymes that make cysteine, so you are not going to have problems with creating something that is going to hurt people as well as the disease.”
The plan is to characterise the cysteine making enzymes in the lab, which no-one has ever done for gonorrhoea before. Dr Hicks and her fellow researchers will work out what they do, then take that knowledge and work out the 3-dimensional structure. “Then we can design inhibitors to try and stop them from working. We can screen millions of inhibitors using computational screening with our collaborator at Victoria University in Wellington. Then with another collaborator in Auckland we can make the inhibitors, and come back to the lab here at Waikato and test them.”
Gonorrhoea infections are a global health problem with rates and resistance to antibiotics increasing worldwide. Dr Hicks says the rate of infection within New Zealand is also on the rise. “The rates in young Māori and Pacific women are three times that of others. For 15 to 29 year olds in those categories the rates are huge. It is a real problem here in our own communities.”
Dr Hicks’ aim is get the research to the point where someone is able to take what is found to be the lead inhibitor into further development and clinical trials.