Microbial biofilm formation: a need to act

Römling, Ute; Kjelleberg, Staffan; Normark, Staffan; Nyman, Lars; Uhlin, Bernt Eric; Åkerlund, Börje

doi:10.1111/joim.12242

Cited by 153 publications

(139 citation statements)

References 150 publications

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“…Bacterial cells can adhere to each other or to an animate or inanimate surface (including that of medical devices); this function is involved in various processes in infections and poses a major challenge to antimicrobial therapy (881). This is because biofilm cells display significantly higher levels of resistance to antimicrobials than do planktonic cells.…”

Section: Role Of Efflux Pumps In Biofilm Formation and Resistancementioning

confidence: 99%

The Challenge of Efflux-Mediated Antibiotic Resistance in Gram-Negative Bacteria

2015

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SUMMARY The global emergence of multidrug-resistant Gram-negative bacteria is a growing threat to antibiotic therapy. The chromosomally encoded drug efflux mechanisms that are ubiquitous in these bacteria greatly contribute to antibiotic resistance and present a major challenge for antibiotic development. Multidrug pumps, particularly those represented by the clinically relevant AcrAB-TolC and Mex pumps of the resistance-nodulation-division (RND) superfamily, not only mediate intrinsic and acquired multidrug resistance (MDR) but also are involved in other functions, including the bacterial stress response and pathogenicity. Additionally, efflux pumps interact synergistically with other resistance mechanisms (e.g., with the outer membrane permeability barrier) to increase resistance levels. Since the discovery of RND pumps in the early 1990s, remarkable scientific and technological advances have allowed for an in-depth understanding of the structural and biochemical basis, substrate profiles, molecular regulation, and inhibition of MDR pumps. However, the development of clinically useful efflux pump inhibitors and/or new antibiotics that can bypass pump effects continues to be a challenge. Plasmid-borne efflux pump genes (including those for RND pumps) have increasingly been identified. This article highlights the recent progress obtained for organisms of clinical significance, together with methodological considerations for the characterization of MDR pumps.

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Section: Role Of Efflux Pumps In Biofilm Formation and Resistancementioning

confidence: 99%

The Challenge of Efflux-Mediated Antibiotic Resistance in Gram-Negative Bacteria

2015

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“…[2][3][4][5][6] This has motivated the development of materials with anti-infective properties, such as biomaterials loaded with antibiotics. 7 However, with the increasing number of bacteria that are resistant to antibiotics, 8 silver with historically documented anti-microbial activity has re-gained its attractiveness as an alternative to antibiotics.…”

Section: Introductionmentioning

confidence: 99%

Safety and efficacy of composite collagen–silver nanoparticle hydrogels as tissue engineering scaffolds

et al. 2015

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The increasing number of multidrug resistant bacteria has revitalized interest in seeking alternative sources for controlling bacterial infection. Silver nanoparticles (AgNPs), are amongst the most promising candidates due to their wide microbial spectrum of action. In this work, we report on the safety and efficacy of the incorporation of collagen coated AgNPs into collagen hydrogels for tissue engineering.The resulting hybrid materials at [AgNPs] < 0.4 µM retained the mechanical properties and biocompatibility for primary human skin fibroblasts and keratinocytes of collagen hydrogels; they also displayed remarkable anti-infective properties against S. aureus, S. epidermidis, E. coli and P. aeruginosa at considerably lower concentrations than silver nitrate. Further, subcutaneous implants of materials containing 0.2 µM AgNPs in mice showed a reduction in the levels of IL-6 and other inflammation markers (CCL24, sTNFR-2, and TIMP1). Finally, an analysis of silver contents in implanted mice showed that silver accumulation primarily occurred within the tissue surrounding the implant. IntroductionBiomaterial-associated infections are a significant healthcare problem and have been linked to medical morbidity and death. [2][3][4][5][6] This has motivated the development of materials with anti-infective properties, such as biomaterials loaded with antibiotics. 7 However, with the increasing number of bacteria that are resistant to antibiotics, 8 silver with historically documented anti-microbial activity has re-gained its attractiveness as an alternative to antibiotics. 9 While toxic to bacteria, it unfortunately is also toxic to mammalian cells. 9,10 More recently, therefore, silver nanoparticles (AgNPs) have been evaluated as a safer alternative to ionic silver. 1,[11][12][13][14][15][16][17][18][19][20] The recent work from our team showed that in comparison with silver, biomolecule-coated, photochemically-produced AgNPs can have both bactericidal and bacteriostatic properties with almost negligible cytotoxic effects. 12 We also showed that oxidation of Ag to AgO is most likely the cause of the cytotoxic effects observed with AgNPs. Our overarching goal is to expand the safe use of AgNPs in the development of implantable hybrid-biomaterials with antiinfective properties for future use as scaffolds to enable regeneration of tissue and organs at a risk of bacterial colonization and concomitant biofilm formation like diabetic foot ulcers. Although some collagen-based materials including † Electronic supplementary information (ESI) available: Representative absorption spectra of AgNP@collagen nanoparticles before and after lyophilization. Absorption spectra for the washes obtained from a 1.0 µM AgNP hydrogel over the course of 5 days. Area under the curve (AUC) calculated from the absorption spectra of 500 µm thickness collagen hydrogels prepared using different concentrations of AgNP@collagen. Selected Cryo-SEM images of BDDGE type I collagen-based hydrogels in the absence or presence of 1.0 µM AgNP. An image of a sel...

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“…Some biofilms are beneficial to human health, for example as part of the healthy gut and skin microbiota (5,6) or in wastewater treatment systems (7). Other biofilms, however, cause serious problems in oral hygiene, chronic infections, and prosthetic contamination (8)(9)(10) and act as fouling agents in industrial flow systems (11).…”

mentioning

confidence: 99%

Architectural transitions in Vibrio cholerae biofilms at single-cell resolution

Drescher

Dunkel

Nadell

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

188

216

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Many bacterial species colonize surfaces and form dense 3D structures, known as biofilms, which are highly tolerant to antibiotics and constitute one of the major forms of bacterial biomass on Earth. Bacterial biofilms display remarkable changes during their development from initial attachment to maturity, yet the cellular architecture that gives rise to collective biofilm morphology during growth is largely unknown. Here, we use high-resolution optical microscopy to image all individual cells in Vibrio cholerae biofilms at different stages of development, including colonies that range in size from 2 to 4,500 cells. From these data, we extracted the precise 3D cellular arrangements, cell shapes, sizes, and global morphological features during biofilm growth on submerged glass substrates under flow. We discovered several critical transitions of the internal and external biofilm architectures that separate the major phases of V. cholerae biofilm growth. Optical imaging of biofilms with single-cell resolution provides a new window into biofilm formation that will prove invaluable to understanding the mechanics underlying biofilm development.biofilm | community | self-organization | emergent order | nematic order

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Microbial biofilm formation: a need to act

Cited by 153 publications

References 150 publications

The Challenge of Efflux-Mediated Antibiotic Resistance in Gram-Negative Bacteria

The Challenge of Efflux-Mediated Antibiotic Resistance in Gram-Negative Bacteria

Safety and efficacy of composite collagen–silver nanoparticle hydrogels as tissue engineering scaffolds

Architectural transitions in Vibrio cholerae biofilms at single-cell resolution

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