The co-evolution of host cationic antimicrobial peptides and microbial resistance

Endogenous cationic antimicrobial peptides (CAMPs) are among the most ancient and efficient components of host defence. It is somewhat of an enigma that bacteria have not developed highly effective CAMP-resistance mechanisms, such as those that inhibit many therapeutic antibiotics. Here, we propose that CAMPs and CAMP-resistance mechanisms have co-evolved, leading to a transient host-pathogen balance that has shaped the existing CAMP repertoire. Elucidating the underlying principles of this process could help in the development of more sustainable antibiotics.