Outer membrane changes enable evolutionary escape from bacterial predation.

K-12 can develop genetic resistance to predation by B. bacteriovorus through mutations that down-regulate outer membrane porin OmpF and alter lipopolysaccharide, especially after two predator exposure cycles.

• Why it matters: Understanding if prey bacteria can evolve resistance to predatory bacteria like B. bacteriovorus is crucial for developing sustainable biocontrol strategies against antimicrobial-resistant pathogens, as resistance could undermine their effectiveness.
• What they did: The study used experimental evolution with repeated predator exposure and combined genetic analysis with proteomics to identify mutations associated with resistance, focusing on E. coli K-12.
• The result: Resistance was widespread and scaled with predation pressure, but it incurred fitness costs, suggesting that exploiting these costs could enhance the durability of predatory bacteria as "living antibiotics" against AMR pathogens.