The role of RNA regulators, quorum sensing and c‐di‐GMP in bacterial biofilm formation

Abstract

Biofilms provide an ecological advantage against many environmental stressors, such as pH and temperature, making it the most common life‐cycle stage for many bacteria. These protective characteristics make eradication of bacterial biofilms challenging. This is especially true in the health sector where biofilm formation on hospital or patient equipment, such as respirators, or catheters, can quickly become a source of anti‐microbial resistant strains. Biofilms are complex structures encased in a self‐produced polymeric matrix containing numerous components such as polysaccharides, proteins, signalling molecules, extracellular DNA and extracellular RNA. Biofilm formation is tightly controlled by several regulators, including quorum sensing (QS), cyclic diguanylate (c‐di‐GMP) and small non‐coding RNAs (sRNAs). These three regulators in particular are fundamental in all stages of biofilm formation; in addition, their pathways overlap, and the significance of their role is strain‐dependent. Currently, ribonucleases are also of interest for their potential role as biofilm regulators, and their relationships with QS, c‐di‐GMP and sRNAs have been investigated. This review article will focus on these four biofilm regulators (ribonucleases, QS, c‐di‐GMP and sRNAs) and the relationships between them.

Elongated Riboflavin‐Producing Shewanellaoneidensis in a Hybrid Biofilm Boosts Extracellular Electron Transfer

“…As previous attempts to promote EET by biofilm formation based on the modification of extracellular structural components and intracellular regulatory factors [ 44 ] had limited success, we followed a novel strategy that focused on cell morphology. We hypothesized that changes effected through morphological engineering could improve the adsorption of cells on the electrode.…”

“…The morphology of the resulting cells showed a marked elongation as compared with control cells and formed a thicker and denser biofilm. Electricity production via these cells was 1165 ± 46 mW m −2 ,which is 7 times than overexpressed ydeH , a c ‐di‐GMP biosynthesis gene in S. oneidensis (167.6 mW m −2 ); [ 44c ] 21 times than expressed curli hybrid proteins on the S. oneidensis cell surface (55 mW m −2 ). [ 46 ] In conclusion, for the first time, a morphologic engineering strategy was used to promote biofilm formation, clarifying that cell enlargement is beneficial to the formation of biofilms and thus improve EET in this study.…”

Serving the scientific community: FEBS Open Bio in 2024

“…In the first article, Sandra C. Viegas and colleagues highlight how ribonucleases in both host and pathogen influence disease: mutations in the human Dis3L2 gene are associated with a number of diseases, and bacterial ribonucleases are important for pathogenicity [3]. Bacterial ribonucleases, together with other RNA regulators, are also involved in biofilm formation, as reviewed by Vânia Pobre and colleagues in the second article in the issue [4]. In the final article, So Nakagawa, Takashi Gojobori and colleagues introduce new developments in bioinformatics software and databases for the identification of RNA viruses and discuss viromes from various sources [5].…”

In Vitro and In Vivo Assessment of the Infection Resistance and Biocompatibility of Small-Molecule-Modified Polyurethane Biomaterials

“…C-di-GMP is a key bacterial intracellular signaling molecule in many bacterial species that regulates the transition between production of EPS and formation of biofilms or a planktonic lifestyle. − High levels of c-di-GMP in bacterial cells generally promote the production of EPS, leading to biofilm formation while low levels of c-di-GMP increase bacterial cell motility and disperse the established biofilms . In the cell, the levels of c-di-GMP are controlled by extracellular cues that regulate c-di-GMP synthesis by diguanylate cyclases (DGCs) and/or hydrolysis by phosphodiesterases (PDEs). , Small molecules that are DGC inhibitors or PDE activators have been developed in an effort to reduce c-di-GMP levels and interrupt biofilm formation as a means to combating infections. ,, However, these molecules act as drugs to combat ongoing infections.…”