Sandra Hocking knows there is still a chance she could lose her leg to the superbug she picked up after badly breaking her ankle in Africa.
"They're 75 per cent confident that they will get rid of it but there's still a doubt," the Melbourne woman said.
Austin Health director of infectious diseases Professor Lindsay Grayson warns Australia needs to take action to slow the spread of antibiotic resistance.
"If we don't have drugs to kill these increasingly stubborn infections, we will be compelled to surgically remove infected limbs," he said on Wednesday.
"We need people to understand that if we continue to recklessly misuse and overuse antibiotics as we have for the past 50-70 years, doctors will be faced with the choice to amputate infected limbs or risk their patients' lives."
Ms Hocking stepped into an uncovered service hole during a trip to Zambia in October to inspect a school for orphans built with money raised by her church group.
"My ankle was a mangled mess and I was bleeding," she said.
She spent a month in a Johannesburg hospital and underwent further surgery in Melbourne, but four months later found her skin graft had failed.
"I sat on the bed and cried. I thought it had gone back to square one."
Prof Grayson said the bug, Pseudomonas aeruginosa, is resistant to almost all known antibiotics.
"We knew that the infection in Sandra's ankle would, unless stopped, spread to her leg."
Ms Hocking is six weeks into at least 12 weeks of treatment using a carefully measured combination of two old antibiotics. One can cause rapid kidney failure, which Ms Hocking has avoided.
She has also undergone extensive surgery to cut away dead and infected tissue and place a special tissue graft over the fracture site.
Prof Grayson estimated there was still a 25 per cent chance Ms Hocking could lose her leg.
"Even now she's still on therapy so we're not completely sure that she's out of the woods," he told AAP.
He said unless Australia is careful, it will catch up with other parts of the world where there has been an alarming spread of superbugs, citing hotspots such as Greece, Israel, China and India.
Two or three years ago most of the superbugs were found in people with weakened immune systems after transplants or cancer, he said.
"Increasingly we're seeing these infections in otherwise healthy people, particularly at the moment in people who have returned from overseas.
"Our concern is that once these germs become established, we'll start to see more of them that are home-grown whereas currently most of the superbugs have originally come into the country from overseas."
An emergency summit involving 300 infectious diseases professionals in Melbourne on Thursday will call for a new co-ordinating body to oversee the work to slow the spread of antibiotic resistance in Australia.
