Mechanisms of Antimicrobial Resistance in Bacteria

Tenover, Fred C.

doi:10.1016/j.amjmed.2006.03.011

Cited by 1,088 publications

(416 citation statements)

References 45 publications

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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. 9 While toxic to bacteria, it unfortunately is also toxic to mammalian cells.…”

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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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 bacterial cell will pump out the acid ion out of the cell, and this effort needs energy [17]. Bacterial cell will be more inhibited when they meet antibacterial activities in acid condition because the bacterial cells utilize their energy to keep their pH value inside the cells and to face the antibacterial activity [21]. According to Ardiansyah [22], NaCl concentration will reduce antibacterial activitiy of Plucea indica extract.…”

Section: Resultsmentioning

confidence: 99%

Antibacterial Activity of Papaya Leaf Extracts Against Pathogenic Bacteria

Romasi¹,

Karina²,

Parhusip³

2013

MST

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It was reported that the extracts of papaya leaves could inhibit the growth of Rhizopus stolonifer. Antibacterial activity of Carica papaya leaf extracts on pathogenic bacteria was observed in this study. Papaya leaves were extracted by using maceration method and three kinds of solvents: ethanol, ethyl acetate, and hexane. Papaya leaf extracts were tested against Bacillus stearothermophilus, Listeria monocytogenes, Pseudomonas sp., and Escherichia coli by agar diffusion method. The objectives of this study were to determine extract ability against pathogenic bacteria, to observe the influence of pH, NaCl, and heat on extracts ability, and to observe extract ability against B. stearothermophilus spores. The data showed that ethyl acetate extract could inhibit B. stearothermophilus, L. monocytogenes, Pseudomonas sp., and E. coli. The extract activity was influenced by pH, and it was more effective in low pH. The extract activity was influenced by NaCl against B. stearothermophillus and E. coli. However, it was not influenced by NaCl in bioassay against L. monocytogenes and Pseudomonas sp. The extract activity was influenced by heating process against all the bacteria tested. The extracts inhibited B. stearothermophilus spores as well. Papaya leaves are potential natural antibacteria, which might be used in certain kinds of food.

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“…Resistant bacteria can then spread and proliferate under antibiotic selective pressure [17]. Several different genes and pathways may be targeted during resistance acquisition.…”

Section: Mechanism Of Resistancementioning

confidence: 99%