Biofilm Formation Mechanisms and Targets for Developing Antibiofilm Agents

Abstract

Biofilms are communities of microorganisms that are attached to a surface and play a significant role in the persistence of bacterial infections. Bacteria within a biofilm are several orders of magnitude more resistant to antibiotics, compared with planktonic bacteria. Thus far, no drugs are in clinical use that specifically target bacterial biofilms. This is probably because until recently the molecular details of biofilm formation were poorly understood. Bacteria integrate information from the environment, such as quorum-sensing autoinducers and nutrients, into appropriate biofilm-related gene expression, and the identity of the key players, such as cyclic dinucleotide second messengers and regulatory RNAs are beginning to be uncovered. Herein, we highlight the current understanding of the processes that lead to biofilm formation in many bacteria.

Microbial biofilm in human health - an updated theoretical and practical insight

“…These microbial communities are included and interconnected within an organic structure designated with the term of extracellular polymeric substance (EPS), also known as "slime", composed of proteic substances, polysaccharides, and DNA (1,2,3).…”

“…Additionally, biofilm formation apparently plays a role in dental caries, with the proven involvement of bacteria such as Streptococcus sobrinus and Streptococcus mutans. Another interesting area requiring further research is represented by the mechanisms of biofilm development in cases of implant contamination by microorganisms such as Proteus mirabilis (3).…”

Relationship between the probiotic Lactobacillus rhamnosus and Enterococcus faecalis during the biofilm formation

“…The extracellular polymeric matrix prevents the host cells defenses or restraint to the penetrations of antimicrobials agents (Donlan and Costerton, 2002). L. rhamnosus and E. faecalis occupy inverse extremities in the current microbiological scene, E. faecalis is responsible for innumerable cases of infection in imunossupressed individuals, with strains resistant to antibiotics of broad spectrum, while L. rhamnosus is commonly used in probiotic therapy (Vandenplas et al, 2015;Rabin et al, 2015).…”

“…A matrix of exopolysaccharides surrounding offers protection against the action of antibiotics and cells of immune system (Aparna and Yadava, 2008). It stimulates the persistence of bacterial infections and supports the cells of this community (Jefferson, 2004;Mohamed and Huang, 2007;Paganelli et al, 2012;Rabin et al, 2015).…”

Biofilm: An Important Bacterial Feature Still to Deal With

“…Despite the biofilm polymeric matrix acts as a barrier that slows the diffusion of antimicrobial agents, protecting it from antibiotics and host immune system [89] studies have shown that the introduction of antibiotics into the bacterial biofilm modifies the bacterial metabolism, their cell-cell communication, its virulence and the biofilm formation [90,91]. Polymorphonuclear (PMN) are the first cells to reach the site of infection, attracted by the cytokines.…”