Following her ERC Starting Grant award, Simona Huwiler explores the potential of Bdellovibrio bacteriovorus, a predatory bacterium, to tackle the growing threat of antimicrobial resistance (AMR).
The WHO 2025 Global AMR Surveillance Report showed that 1 in 6 bacterial infections in 2023 were resistant to antibiotics. Around 5 million deaths were linked to AMR, with 3 million directly caused by it.
AMR complicates treatment in hospitals and threatens procedures like surgeries and cancer therapies. Governments are limiting unnecessary antibiotic use and restricting last-resort antibiotics in animal farming to combat this crisis.
How Bdellovibrio Bacteriovorus Works
B. bacteriovorus is a “living antibiotic.” It actively hunts gram-negative bacteria, attaches to the outer membrane, penetrates the cell wall, and consumes the prey from inside.
Unlike conventional antibiotics that diffuse to their target, Bdellovibrio divides inside the prey and releases new predator cells, making it a unique antibacterial tool.
It targets bacteria on the WHO Priority Pathogens List, including carbapenem-resistant Klebsiella pneumoniae and Escherichia coli.
Its multiple mechanisms of action reduce the chance that bacteria will develop resistance compared to traditional antibiotics with a single mechanism.
Limitations and Applications
The larger size of Bdellovibrio may limit its use to surface infections, such as wounds or mucosal surfaces in the lung or gut.
It may not penetrate deep tissue infections or intracellular bacteria as effectively as traditional antibiotics.
Despite this, living antibiotics could provide a crucial option against multidrug-resistant infections in chronic conditions like cystic fibrosis, or in experimental and compassionate-use cases.
Safety and Research Progress
Studies in mice, rats, zebrafish, and human cell cultures suggest Bdellovibrio is safe and effective against antibiotic-resistant gram-negative bacteria.
A non-medical product using Bdellovibrio is already sold in the UK and expanding into the EU for microbiome support.
Future goals include manufacturing GMP-compliant Bdellovibrio for clinical trials and human therapeutic applications.
Potential in Agriculture and Aquaculture
Bdellovibrio is also explored as a natural solution for bacterial infections in shrimp aquaculture and crops, including potatoes.
While effective against some bacterial plant pathogens, it does not combat fungal diseases.
This demonstrates the bacterium’s broader potential beyond human medicine.
Challenges and Future Directions
Key questions remain on how introducing Bdellovibrio affects the microbiome. It is crucial to target pathogenic bacteria while sparing beneficial microbes.
Regulatory pathways for approval may be complex due to their nature as living organisms, but guidance from EMA and FDA frameworks for phages or probiotics could help.
Research at the University of Bern, funded through an ERC Starting Grant 2025, will study predator-prey interactions in bacteria, enabled by Switzerland’s recent Horizon Europe association.
Conclusion
Bdellovibrio bacteriovorus shows promise as a next-generation living antibiotic.
It may play a key role in combating AMR, protecting human health, and supporting innovative therapies where conventional antibiotics fail.
