Cyclic di-GMP as an antitoxin regulates bacterial genome stability and antibiotic persistence in biofilms

• DOI: 10.7554/elife.99194
• Publication Date: 2024-08-06T17:34:40Z
• Authors: Hebin Liao; Xiaodan Yan; Chenyi Wang; Chun Huang; Wei Zhang; Leyi Xiao; Jun Jiang; Yongjia Bao; Tao Huang; Hanbo Zhang; Chunming Guo; Yufeng Zhang; Yingying Pu
• Keywords: Microbiology and Infectious Disease; toxin-antitoxin system; persister; QH301-705.5; Science; Q; R; Toxin-Antitoxin Systems; c-di-GMP; Gene Expression Regulation, Bacterial; biofilm; Genomic Instability; Anti-Bacterial Agents; Bacterial Proteins; Biofilms; HipH; Medicine; Antitoxins; Biology (General); Cyclic GMP; Genome, Bacterial

Biofilms are complex bacterial communities characterized by a high persister prevalence, which contributes to chronic and relapsing infections. Historically, persister formation in biofilms has been linked to constraints imposed by their dense structures. However, we observed an elevated persister frequency accompanying the stage of cell adhesion, marking the onset of biofilm development. Subsequent mechanistic studies uncovered a comparable type of toxin-antitoxin (TA) module (TA-like system) triggered by cell adhesion, which is responsible for this elevation. In this module, the toxin HipH acts as a genotoxic deoxyribonuclease, inducing DNA double strand breaks and genome instability. While the second messenger c-di-GMP functions as the antitoxin, exerting control over HipH expression and activity. The dynamic interplay between c-di-GMP and HipH levels emerges as a crucial determinant governing genome stability and persister generation within biofilms. These findings unveil a unique TA system, where small molecules act as the antitoxin, outlining a biofilm-specific molecular mechanism influencing genome stability and antibiotic persistence, with potential implications for treating biofilm infections.