Phage protein T9 inhibits the biofilm formation of A25 by regulating mrkA

Many proteins encoded by the phage phiA25 have unknown functions. In this study, we aimed to identify novel proteins that influence biofilm formation in bacterial strains. Through a systematic screening, we identified protein T9 as a potent inhibitor of biofilm formation in strain A25. As mrkA is critical for the production of type 3 fimbriae, a key structure directly contributing to biofilm formation, its downregulation by T9 likely accounts for the observed biofilm inhibition. These findings suggest that protein T9 inhibits biofilm formation in strain A25 by downregulating mrkA, providing valuable insights into the role of phage-derived proteins in biofilm regulation and their potential applications in combating biofilm-associated infections.