Bacteriocins, foreground players in microbial interactions and alternatives to antibiotics

Sylvie Rebuffat

Muséum National d’Histoire Naturelle – CNRS ; Laboratory Molecules of Communication and Adaptation of Microorganisms (MCAM), UMR 7245, CP 54, 57 rue Cuvier, 75005 Paris, France. E-mail: sylvie.rebuffat@mnhn.fr

The raise of multidrug-resistant (MDR) pathogens is one of the biggest threats for human health worldwide, and the World Health Organization has warned of a post-antibiotic era, in which common infections will once again kill. Therefore, it is urgent to investigate alternatives to conventional antibiotics, in addition to continuing efforts in discovering novel molecules.

It is currently well established that multicellular organisms live in tight association with complex communities of microorganisms including a large amount of bacteria, which are immersed in interaction networks reflecting the relationships between them and with host organisms. And yet, little is known about the molecules and mechanisms involved. Among them antimicrobial peptides (AMPs), and especially bacterial AMPs called bacteriocins and microcins, have an important role. These ribosomally synthesized peptides, either unmodified or post-translationally modified, display potent activity toward competitors without generating significant resistance under ecological conditions. They have diverse mechanisms of action involving various targets, from the bacterial envelope and the membrane bilayer to most intimate enzymes inside the cell. Beyond their roles in competitions, they act as signalling molecules and contribute in maintaining balanced and dynamic polymicrobial communities (microbiota) in ecological niches. These features make them promising molecules to develop into alternative antibiotic strategies for use in the human and veterinary medicine, agriculture and food industries.

In the context of combating antimicrobial resistance within the One Health framework, where human, animal and environmental healths have to be considered as a whole, the Antimic 2022 conference is timely to bring together the latest advances in understanding the diversity and functions of bacteriocins and other AMPs in complex environments and stimulate multidisciplinary efforts towards their applications. In this presentation, we’ll unveil current knowledge on bacteriocins taking select examples, and the principal ecological functions they ensure in different organisms, which are the base for their potent antibacterial properties and their huge potential. We’ll also describe current efforts aimed at bringing bacteriocins to applications and address unanswered questions to provide a framework for inspiring future directions of research.