Inhibition of Bacterial Biofilm Formation

Abstract

Biofilm is a complex matrix consisting of extracellular polysaccharides, DNA, and proteins that protect bacteria from a variety of physical, chemical, and biological stresses allowing them to survive in hostile environments. Biofilm formation requires three different stages: cell attachment to a solid substrate, adhesion, and growth. The inhibition of one of these steps by small molecules, such as antimicrobial peptides, or their action on specific targets will leave pathogens armless against classical antibiotics. Any drug impairing crucial processes for bacterial life will inevitably lead to the development of drug-resistant strains, whereas the inhibition of biofilm formation might prevent the onset of bacterial resistance. In this section, we will focus on proteins involved in biofilm formation as useful targets for the development of new drugs that can effectively and specifically impair biofilm formation with slight effects on cell survival, thus avoiding the generation of drugresistant strains.

Biofilm formation and extracellular microvesicles—The way of foodborne pathogens toward resistance

“…Biofilms contain microbial cells [14,15,101,197], members of the biofilm community that are in constant molecular communication. They synthesize molecules like extracellular polysaccharides, DNA, teichoic acid (a ManNAc(β1→4)GlcNAc disaccharide), lipids, and proteins that protect microorganisms under stress conditions [15][16][17][18][19][20].…”

“…According to partially modified definition of Hoffman et al [16] and Di Somma et al [17], biofilms are adherent aggregates that contain microbial cells (mostly bacteria) and other molecules like extracellular polysaccharides, DNA, teichoic acid (a ManNAc(β1→4)GlcNAc disaccharide), and proteins that protect microorganisms under stress conditions. It must be stressed, that the extracellular DNA (eDNA) is an essential component of bacterial biofilms [18].…”

“…Di Somma et al [17] discussed the inhibition of proteins that are involved in primary attachment of cells to surfaces, as well as stopping of the action of the other ones that contribute to biofilm accumulation [24]. These processes can be prevented, for example, by use of specific peptides or other small molecules [25,26].…”

“…NanA protein is one of key factors for adhesion of E. coli cells [27,28]. The inhibition of the bifunctional enzyme Nacetyl-d-glucosamine-1-phosphate acetyltransferase disrupts the integrity of different bacterial biofilms [17,25,29]. Protein G (SasG) promotes aggregation of S. aureus and further biofilm formation [30].…”

“…Interestingly, SasG is not involved in primary attachment of this bacteria to solid surfaces, but it is involved in cell-cell aggregation during biofilm formation [31]. These proteins are interesting candidates for addressing the inhibition of biofilm formation and further bacterial growth of resistant strains [17,26].…”