Salmonella food poisoning sickens 40,000 Americans a year and there may be 30 times more cases that never get reported, according to the CDC.
But some scientists think the nasty microbe could be turned to good purpose: to fight cancers. Sounds odd, but there's a rhyme and reason to such thinking, as described in a pretty interesting news article published in the journal Nature Medicine.
Salmonella, among a variety of other disease-causing bacteria, can live in places where oxygen is scarce -- like inside tumors, where the blood vessels that feed the cancers don't penetrate. Tumors are so starved for oxygen that the middle is filled with dying and dead cells, but there are still plenty of ones deep in the tumor that are alive and kicking and causing trouble.
Bacteria like salmonella can live happily inside spinach and pepper flesh and, yes, they can thrive inside tumors as well. Once inside, they can secrete toxins that attack the tumor or coax the body's own immune system to ramp up its anti-tumor attack.
The strategy worked well in past studies of mice with melanomas, doubling the animals' survival time when they were injected with salmonella, but failed in early clinical trials in people: The bugs (which were attenuated so they wouldn't cause serious infections) didn't colonize people's tumors well enough. A company pursuing the strategy, Vion, went belly-up.
Now researchers are back in the game again, this time trying to figure out ways to get higher levels of salmonella in the tumors and better understand how salmonella kills tumor cells. This time around, some intend to arm the bacteria with extra weapons -- toxic chemicals -- that are only made in large amounts once the bacteria are inside tumors.