Q&A: ‘Suicidal bacteria’ alternative to antibiotics

Suicidal bacteria? Really?

Like all living organisms, bacteria are made up of cells, which in turn contain proteins responsible for nearly every cellular function, from maintaining the cell’s shape to monitoring chemical processes. Proteins come in many forms and frequently develop mutations. In our research, we came upon a genetic alteration that leads to the death of the cell where that protein is found.

This process has long been known to exist in human cells, and it is useful for a variety of functions, such as targeting cancerous cells and helping remove the soft tissue that connects the fingers and toes of a foetus. We have now shown that this mutation exists in much simpler organisms, such as the E coli bacteria.

How does it work?

Apparently there is a mechanism in the bacteria that can signal to cells that it’s more beneficial for them to terminate their existence. We know that the self-destruction can be triggered by the cell itself or by external factors, such as the immune system.

We also found this process in Salmonella, a bacteria that causes diarrhoea and fever, so the findings have broader consequences. The challenge now is to figure out how the process really works so that we can manipulate harmful bacteria into killing themselves. This could aid in the treatment of many infectious diseases.

Why did you decide to work with E coli?

For one, the bacteria is very common. Escherichia coli, or E coli, is found in our lower intestines and helps with digesting and breaking down food. When it misbehaves, however, it can cause bladder infections and food poisoning. Hospitals are prone to E coli outbreaks. But we also took into account more practical aspects; it is relatively simple to manipulate E coli’s genetic makeup.

Wouldn’t it be easier instead to develop more effective antibiotics?

No, because bacteria can build up a resistance to them, especially after extended treatment. We also know that frequent use of antibiotics puts the bacteria in a hibernation state that hides the harmful cells from the immune system.

In a healthy subject, the immune system kills these cells after a course of antibiotics, but in a person whose immune system has been compromised, the treatment can lead to infections that can turn chronic.