Kill bacteria with bacteria: Promising approach that could help combat antibiotic resistance?

A team of researchers, funded by the Defense Advanced Research Projects Agency (DARPA) tries to find out whether an unusual type of bacteria that eats other bacteria could be a new weapon in the fight against drug-resistant infections (investigated in the course of the Pathogen Predators Program). We interviewed Prof. Liz Sockett from the Nottingham University (U.K.), one of the scientists following this exciting question.  

Liz, can you briefly outline what your research is about? When did you start with the Pathogen Predator programme?

Our work is a promising approach that could help combat antibiotic resistance. We started in 2015 and end this year- it’s a 3 year programme. Our expectations are to learn about the interaction mechanisms and range of predatory bacteria against pathogens and their interactions inside hosts and with the host immune systems.

In one of the articles on the webpage I can read that the concept of enlisting pathogen predators to treat infection may show promise in the laboratory but presents fundamental challenges in clinical settings. What exactly are the challenges for the researchers?

The challenges may be – immune responses to the predatory Bdellovibrio bacteria* causing an inflammatory response with some health effects. This has not been shown but must be tested for in future work (The DARPA Program does not use humans). Adding a sufficient dose of the predatory Bdellovibrio bacteria to kill all the pathogens while that dose of Bdellovibrio is itself being reduced by the action of the host’s white blood cells. Adding a dose of the Bdellovibrio at a suitable site to reach the infection in the body. These are whole live bacteria and do not diffuse like drugs.
* Bdellovibrio and like organisms (BALOs) –  are small, predatory Deltaproteobacteria that prey on other Gram-negative pathogens.

What are your expectations for the near and middle future?

The idea is to discover what works and what does not work in treating infections in model lab systems and in some cases experimental animal systems (my lab published a collaborative paper recently working on zebrafish embryos and curing bacterial infections in them).