scholarly journals Direct Electrical Current Reduces Bacterial and Yeast Biofilm Formation

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Maria Ruiz-Ruigomez ◽  
Jon Badiola ◽  
Suzannah M. Schmidt-Malan ◽  
Kerryl Greenwood-Quaintance ◽  
Melissa J. Karau ◽  
...  

New strategies are needed for prevention of biofilm formation. We have previously shown that 24 hr of 2,000 µA of direct current (DC) reduces Staphylococcus epidermidis biofilm formation in vitro. Herein, we examined the effect of a lower amount of DC exposure on S. epidermidis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Propionibacterium acnes, and Candida albicans biofilm formation. 12 hr of 500 µA DC decreased S. epidermidis, S. aureus, E. coli, and P. aeruginosa biofilm formation on Teflon discs by 2, 1, 1, and 2 log10 cfu/cm2, respectively (p<0.05). Reductions in S. epidermidis, S. aureus, and E. coli biofilm formation were observed with as few as 12 hr of 200 µA DC (2, 2 and 0.4 log10 cfu/cm2, resp.); a 1 log10 cfu/cm2 reduction in P. aeruginosa biofilm formation was observed at 36 hr. 24 hr of 500 µA DC decreased C. albicans biofilm formation on Teflon discs by 2 log10 cfu/cm2. No reduction in P. acnes biofilm formation was observed. 1 and 2 log10 cfu/cm2 reductions in E. coli and S. epidermidis biofilm formation on titanium discs, respectively, were observed with 12 hr of exposure to 500 µA. Electrical current is a potential strategy to reduce biofilm formation on medical biomaterials.

2014 ◽  
Vol 21 (9) ◽  
pp. 1206-1214 ◽  
Author(s):  
Lin Yan ◽  
Lei Zhang ◽  
Hongyan Ma ◽  
David Chiu ◽  
James D. Bryers

ABSTRACTNosocomial infections are the fourth leading cause of morbidity and mortality in the United States, resulting in 2 million infections and ∼100,000 deaths each year. More than 60% of these infections are associated with some type of biomedical device.Staphylococcus epidermidisis a commensal bacterium of the human skin and is the most common nosocomial pathogen infecting implanted medical devices, especially those in the cardiovasculature.S. epidermidisantibiotic resistance and biofilm formation on inert surfaces make these infections hard to treat. Accumulation-associated protein (Aap), a cell wall-anchored protein ofS. epidermidis, is considered one of the most important proteins involved in the formation ofS. epidermidisbiofilm. A small recombinant protein vaccine comprising a single B-repeat domain (Brpt1.0) ofS. epidermidisRP62A Aap was developed, and the vaccine's efficacy was evaluatedin vitrowith a biofilm inhibition assay andin vivoin a murine model of biomaterial-associated infection. A high IgG antibody response againstS. epidermidisRP62A was detected in the sera of the mice after two subcutaneous immunizations with Brpt1.0 coadministered with Freund's adjuvant. Sera from Brpt1.0-immunized mice inhibitedin vitroS. epidermidisRP62A biofilm formation in a dose-dependent pattern. After receiving two immunizations, each mouse was surgically implanted with a porous scaffold disk containing 5 × 106CFU ofS. epidermidisRP62A. Weight changes, inflammatory markers, and histological assay results after challenge withS. epidermidisindicated that the mice immunized with Brpt1.0 exhibited significantly higher resistance toS. epidermidisRP62A implant infection than the control mice. Day 8 postchallenge, there was a significantly lower number of bacteria in scaffold sections and surrounding tissues and a lower residual inflammatory response to the infected scaffold disks for the Brpt1.0-immunized mice than for of the ovalbumin (Ova)-immunized mice.


2001 ◽  
Vol 69 (6) ◽  
pp. 4079-4085 ◽  
Author(s):  
Sarah E. Cramton ◽  
Martina Ulrich ◽  
Friedrich Götz ◽  
Gerd Döring

ABSTRACT Products of the intercellular adhesion (ica) operon in Staphylococcus aureus and Staphylococcus epidermidis synthesize a linear β-1,6-linked glucosaminylglycan. This extracellular polysaccharide mediates bacterial cell-cell adhesion and is required for biofilm formation, which is thought to increase the virulence of both pathogens in association with prosthetic biomedical implants. The environmental signal(s) that triggers ica gene product and polysaccharide expression is unknown. Here we demonstrate that anaerobic in vitro growth conditions lead to increased polysaccharide expression in both S. aureus and S. epidermidis, although the regulation is less stringent inS. epidermidis. Anaerobiosis also dramatically stimulates ica-specific mRNA expression inica- and polysaccharide-positive strains of both S. aureus and S. epidermidis.These data suggest a mechanism whereby ica gene expression and polysaccharide production may act as a virulence factor in an anaerobic environment in vivo.


2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Carolyn Vitale ◽  
Tianhui Ma ◽  
Michael J Solomon ◽  
J. Scott VanEpps

Bacterial infection is known to increase the risk for thromboembolism. The mechanism underlying this correlation remains largely unknown. We recently showed that the common pathogen Staphylococcus epidermidis retards clot formation, increases clot elasticity and generates a heterogeneous clot structure that remodels over time. Here, we elucidate the mechanism of this process by evaluating the capacity for S. epidermidis to bind to fibrinogen as a function of its growth phase. We hypothesized that the effect of S. epidermidis on a fibrin clot is related to its propensity toward biofilm formation. Therefore, stationary phase (biofilm-like) S. epidermidis will have a more robust effect on clot kinetics and elasticity than exponential phase (planktonic). Furthermore, this difference is mediated by increased adhesion to fibrinogen. Rheometry was used to evaluate the formation and resultant elasticity of fibrin clots with exponential or stationary phase S. epidermidis . A functional in vitro model was developed to evaluate adhesion of S. epidermidis to a fibrinogen coated surface in a continuously flowing environment. Fluorescent labeled exponential and stationary phase S. epidermidis were visualized flowing through a parallel plate microfluidic chamber past immobilized fibrinogen. Images were obtained every 3 seconds for 30 min. Bacterial deposition rate and mean adhesion time were quantified by automated image analysis. A paired Student’s t-test was used for statistical analysis. Stationary phase S. epidermidis retards clot formation and increases resultant elasticity while exponential phase only slightly reduces elasticity. The bacterial deposition rate onto fibrinogen was significantly (p=0.03) greater for stationary phase (1741 ± 1513 cells/cm 2 · sec -1 ) vs exponential phase (676 ± 270 cells/cm 2 · sec -1 ). The average adhesion time however was similar for exponential and stationary phase cells. Coagulation proteins can provide a framework for bacterial adhesion, biofilm formation and infection. In turn infected thrombi with (biofilm-like) bacteria are stiffer which correlates to more frequent bacterial binding to fibrinogen. This provides a potential molecular mechanism for infection mediated thromboembolic events.


2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Erik T. Sandbakken ◽  
Eivind Witsø ◽  
Bjørnar Sporsheim ◽  
Kjartan W. Egeberg ◽  
Olav A. Foss ◽  
...  

Abstract Background In cases of prosthetic joint infections, culture of sonication fluid can supplement culture of harvested tissue samples for correct microbial diagnosis. However, discrepant results regarding the increased sensitivity of sonication have been reported in several studies. To what degree bacteria embedded in biofilm are dislodged during the sonication process has to our knowledge not been fully elucidated. In the present in vitro study, we have evaluated the effect of sonication as a method to dislodge biofilm by quantitative microscopy. Methods We used a standard biofilm method to cover small steel plates with biofilm forming Staphylococcus epidermidis ATCC 35984 and carried out the sonication procedure according to clinical practice. By comparing area covered with biofilm before and after sonication with epifluorescence microscopy, the effect of sonication on biofilm removal was quantified. Two series of experiments were made, one with 24-h biofilm formation and another with 72-h biofilm formation. Confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) were used to confirm whether bacteria were present after sonication. In addition, quantitative bacteriology of sonication fluid was performed. Results Epifluorescence microscopy enabled visualization of biofilm before and after sonication. CLSM and SEM confirmed coccoid cells on the surface after sonication. Biofilm was dislodged in a highly variable manner. Conclusion There is an unexpected high variation seen in the ability of sonication to dislodge biofilm-embedded S. epidermidis in this in vitro model.


1998 ◽  
Vol 42 (4) ◽  
pp. 895-898 ◽  
Author(s):  
Silvia Schwank ◽  
Zarko Rajacic ◽  
Werner Zimmerli ◽  
Jürg Blaser

ABSTRACT The impact of bacterial adherence on antibiotic activity was analyzed with two isogenic strains of Staphylococcus epidermidis that differ in the features of their in vitro biofilm formation. The eradication of bacteria adhering to glass beads by amikacin, levofloxacin, rifampin, or teicoplanin was studied in an animal model and in a pharmacokinetically matched in vitro model. The features of S. epidermidis RP62A that allowed it to grow on surfaces in multiple layers promoted phenotypic resistance to antibiotic treatment, whereas strain M7 failed to accumulate, despite initial adherence on surfaces and growth in suspension similar to those for RP62A. Biofilms of S. epidermidis M7 were better eradicated than those of strain RP62A in vitro (46 versus 31%;P < 0.05) as well as in the animal model (39 versus 9%; P < 0.01).


Author(s):  
Miladys Esther Torrenegra Alarcón ◽  
Nerlis Paola Pájaro ◽  
Glicerio León Méndez

Se evaluó la actividad antibacteriana in vitro de aceites esenciales de diferentes especiesdel género Citrus frente a cepas ATCC de Staphylococcus aureus, Staphylococcus epidermidis,Klebsiella pneumoniae, Pseudomonas aeruginosa y Escherichia coli, determinandola concentración mínima inhibitoria (CMI) y la concentración mínima bactericida(CMB). Las bacterias se replicaron en medios de agar y caldos específicos. Se determinóel momento de máxima densidad óptica (DO620) para emplearlo como tiempode incubación; luego se hicieron pruebas de evaluación de sensibilidad con la exposiciónde las cepas a concentraciones a 1000 g/mL del extracto en caldo. Para solubilizarse empleó dimetilsulfóxido (DMSO) al 1%. Posteriormente, se le determinó laconcentración mínima inhibitoria mediante metodologías de microdilución en caldoy la concentración mínima bactericida. Encontrándose una actividad de los aceitesesenciales del género Citrus, con valores de CMI ≥ 600 mg/mL frente a S. aureus,S. epidermidis, K. pneumoniae, P. aeruginosa y E. coli. En función a los resultados obtenidos,se concluye que las diferentes especies del género Citrus son consideradas comopromisorias para el control del componente bacteriano.


2005 ◽  
Vol 73 (5) ◽  
pp. 3188-3191 ◽  
Author(s):  
Hualin Li ◽  
Lin Xu ◽  
Jianping Wang ◽  
Yumei Wen ◽  
Cuong Vuong ◽  
...  

ABSTRACT To test if biofilm formation in Staphylococcus epidermidis is dependent on the polysaccharide intercellular adhesin, whose biosynthesis is driven by the ica locus, a plasmid containing the ica locus was transferred to three ica-negative strains. Using in vitro biofilm assays and a rat central venous catheter infection model, we confirmed the importance of the ica locus for biofilm production and pathogenesis of S. epidermidis.


2020 ◽  
Vol 83 (7) ◽  
pp. 1261-1267
Author(s):  
TING LIU ◽  
JINGFAN WANG ◽  
XIAOMAN GONG ◽  
XIAOXIA WU ◽  
LIU LIU ◽  
...  

ABSTRACT The purpose of the present study was to determine the bioactive compounds in rosemary essential oil (REO) and tea tree essential oil (TEO) and to investigate their antibacterial and antibiofilm activities against Staphylococcus aureus and Escherichia coli in vitro. The MIC and MBC assays were performed to assess the antibacterial activity of these two EOs against S. aureus and E. coli with the broth microdilution method. A crystal violet assay was used to ascertain the effects of EOs on the biofilm formation of the test strains, and a tetrazolium bromide (MTT) assay was used to measure the level of inactivation of mature biofilms by EOs. Gas chromatography–mass spectrometry revealed 15 compounds in REO and 27 compounds in TEO, representing 97.78 and 98.13% of the total EO, respectively. Eucalyptol and α-pinene were found in high concentrations in REO, and the two major compounds in TEO were 4-terpineol and terpinolene. The MICs of REO for the two S. aureus and E. coli test strains were both 0.5 mg/mL, and the MICs of TEO for the two strains were both 0.25 mg/mL. Therefore, these EOs can significantly inhibit the formation of biofilms and induced morphological biofilm changes, as verified by scanning electron microscopy. Both EOs had destructive effects on the mature biofilm of the two test strains. TEO was more inhibitory than REO for biofilm formation by the two test strains. HIGHLIGHTS


2014 ◽  
Vol 58 (12) ◽  
pp. 7606-7610 ◽  
Author(s):  
Kaat De Cremer ◽  
Nicolas Delattin ◽  
Katrijn De Brucker ◽  
Annelies Peeters ◽  
Soña Kucharíková ◽  
...  

ABSTRACTWe here report on thein vitroactivity of toremifene to inhibit biofilm formation of different fungal and bacterial pathogens, includingCandida albicans,Candida glabrata,Candida dubliniensis,Candida krusei,Pseudomonas aeruginosa,Staphylococcus aureus, andStaphylococcus epidermidis. We validated thein vivoefficacy of orally administered toremifene againstC. albicans and S. aureusbiofilm formation in a rat subcutaneous catheter model. Combined, our results demonstrate the potential of toremifene as a broad-spectrum oral antibiofilm compound.


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