Scientists have resurrected an idea from more than a century ago to turn bugs into "biosurgeons" that can target and destroy deadly tumours.
The radical approach has already shown astounding results in pet dogs that were being treated for naturally-occurring tumours, completely eradicating the cancer in three animals.
In a pilot clinical trial, it also significantly reduced the size of a tumour in one human patient. Work investigating whether the treatment is suitable for humans is still going on.
US lead scientist Dr Saurabh Saha, from BioMed Valley Discoveries said: "We have encouraging signs that this bacteria could be used to treat certain inoperable tumours."
Solid tumour cancers are especially dangerous when they alter their metabolism to survive in the absence of oxygen. They then become resistant to radiotherapy and anti-cancer drugs.