As the CosmosID blog illustrates regularly, microbes are remarkable for their ability to shape and affect just about every aspect of the world we live in. Yet, each week we are newly awed by publications that highlight discoveries of microbial feats and applications. This week was no different, as we were captivated by a story about a researcher who aims to cure cancer using salmonella. The idea of treating cancer with bacteria is not new. In fact, research on this particular topic dates back to at least the 1890s. However, up until now, research efforts have been inhibited by the toxicity of salmonella.
The person behind this more recent effort is the research director for the Cancer Research Center in Columbia, Missouri, Abe Eisenstark, who has a background in salmonella research. It was this experience that drove him to direct Alison Dino, a scientist at the University of Missouri, to start experimenting with using old salmonella samples as weapons against cancer. Entertaining this wild notion, Dino began by putting these bacterial samples into the same petri dishes occupied by tumor cells. As she combined the two biological warriors for a showdown, she wanted to see if the salmonella would be drawn to the tumor cells, and if the bacteria would also leave healthy cells alone. A win would mean the bacteria attacked the cancer cells while leaving the healthy cells unharmed. To her amazement, she found a promising candidate in a strain labeled CRC 1674.
It helps to first understand that research had already shown that salmonella is drawn to tumor cells. But the novel idea behind this research story is Dr. Eisenstark’s insight to use aged salmonella. He predicted that the bacteria samples, having survived in isolated vials for decades, would have adapted to low energy environments by inhibiting their own toxicity, as that characteristic demands energy that the bacteria could not have spared.