Health officials are warning that a superbug that is widespread in other parts of the world may be circulating in Scotland.
Until October all cases of the NDM-1 bacteria, a mutation of E-coli, had been brought in to the country from outside, but the most recent case concerned a patient with no history of recent travel.
The bacteria is believed to have originated on the Indian subcontinent and has spread to other countries including the United States, Canada, Australia and the Netherlands.
Camilla Wiuff, of the Health Protection Agency Scotland, said: "At the moment there's a minimal risk to the general population in Scotland but it is a worldwide concern.
"It can establish itself as a mild disease, a moderate disease, sometimes even a severe disease."
Professor Hugh Pennington, emeritus professor of bacteriology at Aberdeen University, said the bacteria was a danger because it had become resistant to antibiotics.
He said: "Many of these bugs have actually come from countries where you could just go into the chemist and buy any old antibiotics you like, they're not controlled.
"At the end of the day that's always the nightmare scenario that we worry about, that for some bugs we just might run out of all the antibiotics and then we would be back to the 1930s."
Health boards across Scotland have now been put on alert for further signs of NDM-1 spreading within the community.