Halogenated quinoline kill agent rapidly induces iron starvation of Staphylococcal biofilms

Bacterial biofilms are surface-attached communities comprised of slow- or non-replicating bacteria. Transcriptomic responses of bacterial biofilms to anti-biofilm small molecules have been largely unexplored, with existing studies typically involving long treatment periods (>18 h). In this study, we used a halogenated quinoline biofilm-killing agent (RA-HQ-12) to investigate the transcriptional responses of MRSA and S. epidermidis biofilms. Utilizing RT-qPCR, we observed RA-HQ-12 activated iron uptake pathways in both MRSA and S. epidermidis biofilms after 4 h treatment at 1 μM. A time-course analysis further revealed dynamic variation in up- and down-regulation patterns of various target genes (sbnC, isdB, opp1C, ribA, nasE, and crtM), shedding light on the time-dependent dynamics of biofilm responses to RA-HQ-12.