Exploring the Biodiversity of Rare Actinobacteria for Combating AMR: Screening for Anti-Quorum Sensing Properties

The rise of antimicrobial resistance (AMR) poses a significant global health challenge, necessitating the search for alternative therapeutic strategies. Targeting bacterial quorum sensing (QS), a communication system that regulates virulence and biofilm formation, has emerged as a promising anti-virulence approach. Actinobacteria, renowned for their prolific production of bioactive secondary metabolites, represent a valuable resource for discovering novel anti-quorum-sensing (AQS) compounds. This study explores the biodiversity of actinobacteria from diverse ecological niches to identify strains with anti-QS properties. Using Chromobacterium violaceum and Serratia marcescens as biosensors, actinobacterial extracts were screened for their ability to inhibit QS-regulated pigment production. Selected extracts were further evaluated for swarming motility inhibition and potent strains were identified. Four rare actinobacterial strains MG1, BD21, MG3 and VL9 identified as Kutzneria viridogrisea, Microbacterium barkeri, Amycolatopsis thermoflava and Yuhushiella sp. were studied for their biofilm inhibition activity and prodigiosin inhibition in pathogenic bacteria. Our findings are the first to highlight the potential of these rare actinobacteria as a source of novel anti-QS agents, contributing to the development of alternative strategies to mitigate AMR.