Popular Science Presentation

Antibiotic resistance is an increasing problem worldwide and new means of treating infections are of essence if we wish to treat bacterial infections in the future. Another factor that complicates treatment options is that we are starting to understand how important the normal flora is for our health. The human body contains more bacterial cells than human cells and these bacteria are an important first line of defense against bacterial pathogens. In addition, the bacteria of the normal flora help us digest our food and have been shown to be important for diverse processes, ranging from our mood to development of disease like cancer.

One example of a new way of treating infections in the future is to use bacterial probiotics to strengthen the first line of defense against incoming pathogens. But how this defense actually works is still unknown. Recently, a new system that bacteria use to stop the growth of other bacteria was identified and called contact dependent growth inhibition (CDI) after its mechanism of action. To be able to stop the growth of other bacteria, the bacteria with these systems must come in direct contact with the bacteria they wish to inhibit and deliver a toxin to it. In addition, the inhibition is restricted to bacteria of a certain species because the delivery of toxin requires species-specific receptors on the target cell surface.

To develop more effective probiotics, we wish to arm probiotic bacteria with CDI systems that target pathogenic bacteria specifically. This would mean that already beneficial bacterial probiotic can be developed into targeted killing machines that specifically identify and stop the growth of the bacterial pathogen in question.