The discovery could help scientists target treatments for the globally significant intestinal disease which kills more than 100,000 people every year.
The disease is caused by the bacterium Vibrio cholerae, which is able to colonise the intestine usually after consumption of contaminated water or food. Once infection is established, the bacterium secretes a toxin that causes watery diarrhoea and ultimately death if not treated rapidly. Colonisation of the intestine is difficult for incoming bacteria as they have to be highly competitive to gain a foothold among the trillions of other bacteria already in situ.
This work continues our discoveries of how bacteria that grow in our body exploit sialic acid for their survival
Dr Gavin Thomas
Scientists at York, led by Dr Gavin Thomas in the University’s Department of Biology, have investigated one of the important routes that V. cholera uses to gain this foothold. To be able to grow in the intestine the bacterium harvests and then eats a sugar, called sialic acid, that is present on the surface of our gut cells.
Collaborators of the York group at the University of Delaware, USA, led by Professor Fidelma Boyd, had shown previously that eating sialic acid was important for the survival of V. cholerae in animal models, but the mechanism by which the bacteria recognise and take up the sialic was unknown.
The York research, funded by the Biotechnology and Biological Sciences Research Council (BBSRC), demonstrates that the pathogen uses a particular kind of transporter called a TRAP transporter to recognise sialic acid and take it up into the cell. The transporter has particular properties that are suited to scavenging the small amount of available sialic acid. The research also provided some important basic information about how TRAP transporters work in general.
The leader of the research in York, Dr Gavin Thomas, said: “This work continues our discoveries of how bacteria that grow in our body exploit sialic acid for their survival and help us to take forward our efforts to design chemicals to inhibit these processes in different bacterial pathogens.”
The research is published in the latest issue of the Journal of Biological Chemistry and was primarily the work of Dr Christopher Mulligan, a postdoctoral fellow in the Dr Thomas’s laboratory.
Notes to editors:
- The paper ‘The Membrane Proteins SiaQ and SiaM Form an Essential Stoichiometric Complex in the Sialic Acid Tripartite ATP-independent Periplasmic (TRAP) Transporter SiaPQM (VC1777–1779) from Vibrio cholera’ is published in The Journal of Biological Chemistry, Vol. 287, Issue 5, 3598-3608
- For further information on the University of York’s Department of Biology visit www.york.ac.uk/biology
- BBSRC invests in world-class bioscience research and training on behalf of the UK public. Our aim is to further scientific knowledge, to promote economic growth, wealth and job creation and to improve quality of life in the UK and beyond. Funded by Government, and with an annual budget of around £445M, it supports research and training in universities and strategically funded institutes. BBSRC research and the people it funds are helping society to meet major challenges, including food security, green energy and healthier, longer lives. its investments underpin important UK economic sectors, such as farming, food, industrial biotechnology and pharmaceuticals. For more information about BBSRC see: www.bbsrc.ac.uk