Antimicrobial Strategies Effective Against Infectious Bacterial Biofilms

Abstract

Bacteria are able to adapt to undesirable changes in nutrient availability, environmental conditions and presence of antimicrobial products, as well as to immunological defenses. One particularly important example of bacterial adaptation is the ability to grow as part of a sessile community, commonly referred to as biofilm. It is a natural tendency of microorganisms to attach to biotic or abiotic surfaces, to multiply and to embed themselves in a slimy matrix, resulting in biofilms. Biofilms are the leading example of physiological adaptation and are one of the most important sources of bacterial resistance to antimicrobials. It is now recognized that most bacterial-associated infections, including endocarditis, dental caries, middle ear infections, osteomyelitis, medical device-related infections and chronic lung infections in cystic fibrosis patients are problematic because of biofilms. Bacteria in biofilms demonstrate intrinsic resistance to antimicrobial stress more effectively than the planktonic counterparts. Antimicrobial concentrations necessary to inhibit bacterial biofilms can be up to 10-1000 times higher than those needed to inhibit the same bacteria grown planktonically. Thus, in the presence of therapeutically available antibiotic concentrations biofilms remain viable after treatment. Therefore, the identification of new antimicrobials that inhibit or destroy biofilms is needed. The aim of this review is to cover the recent advances on the studies of antimicrobial strategies effective against infectious bacterial biofilms, including the current developments in the structure-activity relationship of those effective antimicrobials.

Antifungal potential ofSideroxylon obtusifoliumandSyzygium cuminiand their mode of action againstCandida albicans

“…It was found that both products disrupted the structure and viability of biofilm cells. The association between biofilm formation and antimicrobial resistance remains to be a serious health issue in the current days (Simões 2011), which encourages the search for active molecules able to disrupt biofilm integrity. Hence, the harmful effects of the extract/fraction upon biofilm assembly seen in this study could contribute to render the biofilm more susceptible to other antifungal drugs.…”

Outcome and Prevention of Pseudomonas aeruginosa-Staphylococcus aureus Interactions During Pulmonary Infections in Cystic Fibrosis

“…This fully justifies current research aimed at the development of therapeutic strategies that target biofilm formation and dispersal (Simões, 2011). Current management practices for P. aeruginosa infections include hygienic measures (Høiby & Pedersen, 1989), early aggressive eradication by antimicrobial therapy (Döring & Høiby, 2004), the use of nebulized DNAse (Frederiksen et al, 2006) and chronic suppressive antibiotic therapy (Bjarnsholt et al, 2009;Döring et al, 2000).…”

Collagen-Nanoparticles Composites for Wound Healing and Infection Control

“…From the moment that cells are under the protection of biofilm, they become resistant to antibiotics and to immune responses, which increase the difficulties for the clinical treatment of biofilm infections. It has been reported that bacteria in biofilms have a greater resistance to antimicrobial stress than their planktonic counterparts and the antimicrobial concentrations necessary to inhibit bacterial biofilms can be up to 10-1000 times higher than those needed to inhibit the same bacteria grown planktonically [4][5][6]. Strategies for biofilm-associated infections include: removal of the foreign bodies, prevention of initial contamination, minimization of microbial cell attachment, use of antimicrobials to penetrate the biofilm matrix and inactivate the embedded microorganisms [5].…”

“…It has been reported that bacteria in biofilms have a greater resistance to antimicrobial stress than their planktonic counterparts and the antimicrobial concentrations necessary to inhibit bacterial biofilms can be up to 10-1000 times higher than those needed to inhibit the same bacteria grown planktonically [4][5][6]. Strategies for biofilm-associated infections include: removal of the foreign bodies, prevention of initial contamination, minimization of microbial cell attachment, use of antimicrobials to penetrate the biofilm matrix and inactivate the embedded microorganisms [5]. One of the significant advantages of a rapid bactericidal action may be that it permits wound healing to proceed without bacterial interference and reduces the likelihood for resistance to develop [7].…”