Fatty Acids Synergize with Bacteriophages Against Multidrug-Resistant Pathogens

pH-neutral medium-chain fatty acids (C6–C10) synergize with diverse lytic phages against 18 Stenotrophomonas maltophilia strains, delaying or preventing phage-resistant rebound over 48 h.

• Why it matters: AMR limits antibiotic options, while phage therapy is constrained by biofilms, narrow host range, and rapid emergence of phage resistance.
• What they did: Using checkerboard synergy assays, growth curves, and biofilm assays, the study tested short- and medium-chain fatty acids with lytic phages against 18 S. maltophilia strains and extended to 120+ clinical isolates of Staphylococcus aureus, Enterococcus spp., and Pseudomonas aeruginosa.
• The result: MCFAs were bactericidal without diminishing phage viability, reduced attached and free biomass, and showed predominantly additive-to-synergistic phage cooperation across species, including widespread C8 synergy with phage CAR in 91 Enterococcus strains.