Molecular mechanisms of compounds affecting bacterial biofilm formation and dispersal

Department of Biomolecular Sciences and Biotechnology, Università degli Studi di Milano, Milan, Italy.
Applied Microbiology and Biotechnology (Impact Factor: 3.34). 02/2010; 86(3):813-23. DOI: 10.1007/s00253-010-2468-8
Source: PubMed


Bacteria can switch between planktonic forms (single cells) and biofilms, i.e., bacterial communities growing on solid surfaces and embedded in a matrix of extracellular polymeric substance. Biofilm formation by pathogenic bacteria often results in lower susceptibility to antibiotic treatments and in the development of chronic infections; thus, biofilm formation can be considered an important virulence factor. In recent years, much attention has been directed towards understanding the biology of biofilms and towards searching for inhibitors of biofilm development and of biofilm-related cellular processes. In this report, we review selected examples of target-based screening for anti-biofilm agents: We focus on inhibitors of quorum sensing, possibly the most characterized target for molecules with anti-biofilm activity, and on compounds interfering with the metabolism of the signal molecule cyclic di-GMP metabolism and on inhibitors of DNA and nucleotide biosynthesis, which represent a novel and promising class of biofilm inhibitors. Finally, we discuss the activation of biofilm dispersal as a novel mode of action for anti-biofilm compounds.

Download full-text


Available from: James Grant Burgess, Jul 01, 2015
49 Reads
  • Source
    • "Also, the biofilm and their counterpart planktonic cells contrast considerably in their physiology, gene expression pattern, and even morphology. Since they are less sensitive to antimicrobial agents, controlling their growth could be significantly challenging once they are formed (Landini et al., 2010). Furthermore, this biofilm lifestyle ' s associated exogenous stress high tolerance , ineffectiveness to antibiotics or other biocide treatments in their eradication (Rendueles et al., 2013) makes use of antibiotics or other antimicrobial agents against a biofilm infection unproductive. "
  • Source
    • "Bacteria form complex multicellular structures called biofilms [1]. Biofilm formation is commonly considered to occur in four main stages: (1) bacterial attachment to a surface, (2) microcolony formation, (3) biofilm maturation and (4) detachment (also termed dispersal) of bacteria which may then colonize new areas [2]. Bacteria within the biofilm, termed sessile bacteria, exist in a stationary or dormant growth phase [3] and exhibit phenotypes that are distinct from planktonic bacteria [4]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Background Bacterial biofilms are predominant in natural ecosystems and constitute a public health threat because of their outstanding resistance to antibacterial treatments and especially to antibiotics. To date, several systems have been developed to grow bacterial biofilms in order to study their phenotypes and the physiology of sessile cells. Although relevant, such systems permit analysis of various aspects of the biofilm state but often after several hours of bacterial growth.ResultsHere we describe a simple and easy-to-use system for growing P. aeruginosa biofilm based on the medium adsorption onto glass wool fibers. This approach which promotes bacterial contact onto the support, makes it possible to obtain in a few minutes a large population of sessile bacteria. Using this growth system, we demonstrated the feasibility of exploring the early stages of biofilm formation by separating by electrophoresis proteins extracted directly from immobilized cells. Moreover, the involvement of protein synthesis in P. aeruginosa attachment is demonstrated.Conclusions Our system provides sufficient sessile biomass to perform biochemical and proteomic analyses from the early incubation period, thus paving the way for the molecular analysis of the early stages of colonization that were inaccessible to date.
    BMC Microbiology 09/2014; 14(1):253. DOI:10.1186/s12866-014-0253-z · 2.73 Impact Factor
    • "Most efforts to inhibit the regulation of virulence factor expression have focused on quorum sensing (QS), a complex regulatory process that is dependent on the bacterial cell density. QS is involved in physiological processes, such as biofilm formation, bioluminescence, antibiotic synthesis, and virulence factor expression (Landini et al. 2010). QS systems employ a wide range of signaling molecules. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Brominated furanone and epigallocatechin gallate (EGCG) are naturally occurring polyphenolic compounds that can be derived from sources such as Delisea pulchra algae and green tea, respectively. These compounds may have potential health benefits and antimicrobial properties. Biofilm formation and bacterial motility are virulence factors that seem to be involved in the autoinducer 2 (AI-2)-mediated quorum sensing (QS) response of Campylobacter. In this study, the anti-QS activities of 2(5H)-furanone, EGCG, and a citric-based disinfectant were tested against Campylobacter jejuni. The minimal bactericidal concentration (MBC) was determined by a microdilution method, and the AI-2 activity was measured by bioluminescence. For motility tests, subinhibitory concentrations of each compound were mixed with semisolid Muller Hinton agar. Biofilm formation was quantified in broth-containing microplates after staining with safranin. The MBC of tested compounds ranged from 0.3 to 310 μg/mL. Subinhibitory concentrations of all of the antimicrobial compounds significantly decreased (19 to 62 %) the bacterial motility and reduced biofilm formation. After treatment with EGCG, furanone, and the disinfectant, AI-2 activity was decreased by 60 to 99 % compared to control. In conclusion, 2(5H)-furanone, EGCG, and the disinfectant exert bactericidal effects against C. jejuni and disturb QS activity and reduce motility and biofilm formation. These compounds may be naturally occurring alternatives to control C. jejuni.
    Folia Microbiologica 09/2014; 60(1). DOI:10.1007/s12223-014-0344-0 · 1.00 Impact Factor
Show more