Biofilms by bacterial human pathogens: Clinical relevance - development, composition and regulation - therapeutical strategies

Abstract

Notably, bacterial biofilm formation is increas-ingly recognized as a passive virulence factor facilitating many infectious disease processes. In this review we will focus on bacterial biofilms formed by human pathogens and highlight their relevance for diverse diseases. Along biofilm composition and regulation emphasis is laid on the intensively studied biofilms of Vibrio cholerae, Pseu-domonas aeruginosa and Staphylococcus spp., which are commonly used as biofilm model organisms and therefore contribute to our general understanding of bacterial bio-film (patho-)physiology. Finally, therapeutical interven-tion strategies targeting biofilms will be discussed.

An Introduction to Bacterial Biofilms and Their Proteases, and Their Roles in Host Infection and Immune Evasion

“…Extracellular proteases execute crucial roles throughout the biofilm life cycle, and they frequently represent virulence factors. Likewise, bacterial biofilm formation and modulation capacities are increasingly recognized as so-called passive virulence factors [ 109 ]. Proteolytic activity against proteins of the host extracellular matrix (ECM) often represents a first crucial cornerstone during colonization, as seen for example in clostridial infections and the rapid collagen degradation mediated by their secreted collagenases [ 110 , 111 , 112 ], or for enteroaggregative E. coli (EAEC) and its serine peptidase Pic, which readily cleaves mucins, heavily O-glycosylated linear glycoproteins that are secreted by higher organisms to protect the surfaces of epithelial cells [ 113 ].…”

High Genomic Identity between Clinical and Environmental Strains of Herbaspirillum frisingense Suggests Pre-Adaptation to Different Hosts and Intrinsic Resistance to Multiple Drugs

“…Mutations in these genes can lead to deficiencies in biofilm formation [ 24 ]. Biofilm formation is important for the survival of pathogenic bacteria in the human body as it protects the bacteria against immunological defenses during host infection and promotes antibiotic resistance [ 26 ]. The National Institutes of Health (NIH) estimates that the percentage of human infections related to biofilm production caused by microorganisms is between 65% and 80% [ 27 ].…”

Advances in Nanostructures for Antimicrobial Therapy

“…Biofilms, i.e., microcolonies of microbes that establish communities with a diversity of microbes, have the same gene composition but various gene expressions, and are usually more virulent than their planktonic counterparts. Biofilm makes bacteria resistant to individuals’ immune systems and conventional treatment [ 108 , 109 ]. For therapies of biofilm-associated skin disorders besides photodynamic therapy application of nanosized formulations including micelles, SLNPs or quatsomes can be used.…”