KKL-40

KKL-40 is a small-molecule inhibitor that targets the trans-translation process, effectively suppressing methicillin-sensitive and resistant Staphylococcus aureus (S. aureus) and other Gram-positive pathogens, including vancomycin-resistant Enterococcus faecium, Bacillus subtilis, and Streptococcus pyogenes. It works in synergy with the human antimicrobial peptide LL-37 to inhibit S. aureus, but does not show synergistic effects with other antibiotics such as daptomycin, kanamycin, or erythromycin. KKL-40 inhibits trans-translation, an extreme form of recoding, while being non-toxic to HeLa cells.