biostudies-literatureZampara ACopenhagen UniversityMinisteriet for Fø devarer, Landbrug og FiskeriH2020 Marie Skłodowska-Curie Actions484https://www.ebi.ac.uk/biostudies/studies/S-EPMC11464564biostudies-literatureUnknown108(1)Pyocins are high molecular weight bacteriocins produced by Pseudomonas aeruginosa that can be retargeted to new bacterial species by exchanging the pyocin tail fibers with bacteriophage receptor binding proteins (RBPs). Here, we develop retargeted pyocins called campycins as new antibacterials to precisely and effectively kill the major foodborne pathogen Campylobacter jejuni. We used two diverse RBPs (H-fibers) encoded by CJIE1 prophages found in the genomes of C. jejuni strains CAMSA2147 and RM1221 to construct campycin 1 and campycin 2, respectively. Campycins 1 and 2 could target all C. jejuni strains tested due to complementary antibacterial spectra. In addition, both campycins led to more than 3 log reductions in C. jejuni counts under microaerobic conditions at 42 °C, whereas the kiApplied microbiology and biotechnologyCampycins are novel broad-spectrum antibacterials killing Campylobacter jejuni.PMC1146456470581734009-14-0873Zampara ASorensen MCHBrondsted LGencay YEfalseCampycins are novel broad-spectrum antibacterials killing Campylobacter jejuni.Pyocins are high molecular weight bacteriocins produced by Pseudomonas aeruginosa that can be retargeted to new bacterial species by exchanging the pyocin tail fibers with bacteriophage receptor binding proteins (RBPs). Here, we develop retargeted pyocins called campycins as new antibacterials to precisely and effectively kill the major foodborne pathogen Campylobacter jejuni. We used two diverse RBPs (H-fibers) encoded by CJIE1 prophages found in the genomes of C. jejuni strains CAMSA2147 and RM1221 to construct campycin 1 and campycin 2, respectively. Campycins 1 and 2 could target all C. jejuni strains tested due to complementary antibacterial spectra. In addition, both campycins led to more than 3 log reductions in C. jejuni counts under microaerobic conditions at 42 °C, whereas the ki2024-01-01T00:00:00Z2024 Oct2026-06-02T23:14:30.329Z2025-04-19T19:27:59.08ZS-EPMC114645643938270210.1007/s00253-024-13317-w