Biofilms are at the root of many infections largely because they are much more antibiotic resistant than their planktonic counterparts. Antibiotics that target the biofilm phenotype are desperately needed, but there is still no standard method to assess biofilm drug susceptibility. Staphylococcus epidermidis ATCC 35984 biofilms treated with eight different approved antibiotics and five different experimental compounds were exposed to the oxidation reduction indicator Alamar blue for 60 min, and reduction relative to untreated controls was determined visually and spectrophotometrically. The minimum biofilm inhibitory concentration was defined as <50% reduction and a purplish well 60 min after the addition of Alamar blue. All of the approved antibiotics had biofilm MICs (MBICs) of >512 g/ml (most >4,096 g/ml), and four of the experimental compounds had MBICs of <128 g/ml. The experimental aaptamine derivative hystatin 3 was used to correlate Alamar blue reduction with 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) reduction and viable counts (CFU/ml) for S. epidermidis ATCC 35984, ATCC 12228, and two clinical isolates. For all four strains, Alamar blue results correlated well with XTT (r ‫؍‬ 0.83 to 0.97) and with CFU/ml results (r ‫؍‬ 0.85 to 0.94). Alamar blue's stability and lack of toxicity allowed CFU/ml to be determined from the same wells as Alamar blue absorbances. If the described method of microplate Alamar blue biofilm susceptibility testing, which is simple, reproducible, cost-effective, nontoxic, and amenable to high throughput, is applicable to other important biofilm forming species, it should greatly facilitate the discovery of biofilm specific agents.Given the tremendous clinical importance of biofilms, it is somewhat surprising that there is no standard method for investigating the drug susceptibility of bacterial biofilms. Several methods are available but are limited by long processing times, incompatibility with high throughput, expensive reagents or equipment, or the fact that the method measures mass instead of viability (2,4,7,13,14,24,25). For bacteria, a common method of assessing susceptibility is to quantitate the mass of biofilms by crystal violet or safranin staining, followed by extraction of bound dye with a solvent and measurement of absorption (6,24). This method provides no information about viability. Another common method of assessing bacterial biofilm susceptibility is to disrupt the biofilm by sonication, vortexing, or scraping, followed by dilution plating for determination of CFU/ml (27,28,31). This method has serious limitations; biofilm clumps can be difficult to dissociate into single-cell suspensions for plate counting, it is extremely laborious, and antibiotic carryover is a concern. For fungi, the most common method is an XTT [2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] reduction assay (1,8,25), and this method has also been used for bacterial biofilms (1). While XTT reduction does measure metabolic activity,...

The prevalence of chronic wounds is increasing dramatically, as the populations of industrialized countries age and become more sedentary. Chronic wounds that respond poorly to conventional treatment, making them very difficult to manage [1]. It is well-known that fibroblasts provide desired growth factors and other substances to accelerate wound healing. However, fibroblasts from chronic wounds such as diabetic ulcers have been commonly demonstrated a lower rate of proliferation when compared with healthy ones [2]. Therefore, it is significant to increase fibroblast activity for accelerating wound healing. The care of chronic wounds has become its own specialty, with providers often using advanced therapies, including growth factors, extracellular matrices (ECMs), engineered skin, and negative pressure wound therapy (NPWT) [3]. Low-level laser therapy (LLLT) is a nonthermal technology that can be used to modulate cellular activity through light irradiation at specific pulse sequences [4]. In vitro and in vivo studies have been performed previously to determine the effect of LLLT on wound healing. However the results were inconsistent. Using a variety of red, blue, yellow, and infrared light wavelength, it has been reported that LLLT can

Background: Many chronic wounds have inadequate blood supply around the wounds and systemic antibiotics are less efficient. Topical antiseptic can cause cytotoxicity and irritation or allergic dermatitis. Therefore, topical antibiotics that can sustain their effects in an extended period are often needed to replace topical antiseptics. The present study evaluates the effect of antibiotic-saturated fibrin sealant against Methicillin-Resistant Staphylococcus Aureus (MRSA) by adjusting the concentration of the antibiotic as well as the duration exposure. Methods: Teicoplanin antibiotic was impregnated in the fibrin disc at concentrations of 50 µg/mL, 100 µg/mL, 200 µg/ mL, 400 µg/mL and control (0 µg/mL). The samples were incubated at 37ºC in CO2 incubator for 7, 14, 21, and 28 days. After the incubation period, the antibiotic-saturated fibrin discs were transferred to Mueller-Hinton agar surface scrubs with MRSA. The antimicrobial susceptibility testing was carried out according to Clinical and Laboratory Standards Institution document and using filter papers. Results: The antibiotic-saturated fibrin disc showed a greatest antibacterial activity during the first week. However, the 50µg/mL groups fell below suitability within 14 days. Other groups maintained their effect for 28 days, and these 3 groups showed suitable effects. Conclusion: Antibiotic-loaded fibrin sealants may act as vehicles to deliver antibiotics in a local wound infection. Optimal concentration of antibiotics is 100 µg/mL.