Acid resistance of BW25113 wild-type (W/T) and various knockout mutants in LB medium (pH 2

<p><b>Copyright information:</b></p><p>Taken from "Indole is an inter-species biofilm signal mediated by SdiA"</p><p>http://www.biomedcentral.com/1471-2180/7/42</p><p>BMC Microbiology 2007;7():42-42.</p><p>Published online 18 May 2007</p><p>PMCID:PMC1899176.</p><p></p>5) at 37°C. Each experiment was repeated two or four times and one standard deviation is shown

Effect of indole (500 μM) on the motility of BW25113 wild-type (W/T), BW25113 , BW25113 , BW25113 , and BW25113

<p><b>Copyright information:</b></p><p>Taken from "Indole is an inter-species biofilm signal mediated by SdiA"</p><p>http://www.biomedcentral.com/1471-2180/7/42</p><p>BMC Microbiology 2007;7():42-42.</p><p>Published online 18 May 2007</p><p>PMCID:PMC1899176.</p><p></p> Motility halos were measured at 8 h. Each experiment was repeated two or four times, and one standard deviation is shown. DMF (0.1 %, v/v) was used as a negative control

Intracellular and extracellular indole concentration in LB for BW25113, BW25113 , BW25113 , BW25113 , and BW25113

<p><b>Copyright information:</b></p><p>Taken from "Indole is an inter-species biofilm signal mediated by SdiA"</p><p>http://www.biomedcentral.com/1471-2180/7/42</p><p>BMC Microbiology 2007;7():42-42.</p><p>Published online 18 May 2007</p><p>PMCID:PMC1899176.</p><p></p> Each experiment was performed in duplicate, and one standard deviation is shown

Effect of the , , , , and mutations on biofilm formation in LB glu media

<p><b>Copyright information:</b></p><p>Taken from "Indole is an inter-species biofilm signal mediated by SdiA"</p><p>http://www.biomedcentral.com/1471-2180/7/42</p><p>BMC Microbiology 2007;7():42-42.</p><p>Published online 18 May 2007</p><p>PMCID:PMC1899176.</p><p></p> Biomass measured at 540 nm after 24 h. Each experiment was repeated two or four times, and one standard deviation is shown

Biofilm formation in LB glu at 24 h in flow cells (A) with wild-type K-12 BW25113, (B) with wild-type K-12 BW25113 with 500 μM indole, and (C) with K-12 BW25113

<p><b>Copyright information:</b></p><p>Taken from "Indole is an inter-species biofilm signal mediated by SdiA"</p><p>http://www.biomedcentral.com/1471-2180/7/42</p><p>BMC Microbiology 2007;7():42-42.</p><p>Published online 18 May 2007</p><p>PMCID:PMC1899176.</p><p></p> Scale bar is 5 μm

Resveratrol Oligomers Inhibit Biofilm Formation of <i>Escherichia coli</i> O157:H7 and <i>Pseudomonas aeruginosa</i>

Biofilm formation is closely related to bacterial infection and is also a mechanism of antimicrobial resistance. Hence, the antibiofilm approach provides an alternative to an antibiotic strategy. In this study, the antibiofilm activities of resveratrol (<b>1</b>) and five of its oligomers, namely, ε-viniferin (<b>2</b>), suffruticosol A (<b>3</b>), suffruticosol B (<b>4</b>), vitisin A (<b>5</b>), and vitisin B (<b>6</b>), were investigated against enterohemorrhagic <i>Escherichia coli</i> O157:H7 and <i>Pseudomonas aeruginosa</i> PA14. Vitisin B (<b>6</b>), a stilbenoid tetramer, was found to inhibit biofilm formation by the two bacteria the most effectively and at 5 μg/mL inhibited <i>E. coli</i> O157:H7 biofilm formation by more than 90%

Inhibitory effects of the essential oils α-longipinene and linalool on biofilm formation and hyphal growth of <i>Candida albicans</i>

<p><i>Candida albicans</i> is one of the most common fungal pathogens, and causes systemic and invasive infections in humans. <i>C. albicans</i> biofilms are composed of yeast and hyphal and pseudohyphal elements, and the transition of yeast to the hyphal stage could be a virulence factor. In this study, diverse essential oils were initially investigated for anti-biofilm activity against <i>C. albicans</i> strains, and cascarilla bark oil and helichrysum oil and their components α-longipinene (a major constituent of both) and linalool were found to markedly inhibit biofilm formation without affecting planktonic cell growth. Moreover, α-longipinene and linalool were found to synergistically reduce biofilm formation. Notably, treatments with cascarilla bark oil, helichrysum oil, α-longipinene, or linalool clearly inhibited hyphal formation, and this appeared to be largely responsible for their anti-biofilm effect. Furthermore, the two essential oils, α-longipinene and linalool, reduced <i>C. albicans</i> virulence in <i>Caenorhabditis elegans</i>.</p

‘Should I stay or should I go?’ Bacterial attachment <i>vs</i> biofilm formation on surface-modified membranes

<div><p>A number of techniques are used for testing the anti-biofouling activity of surfaces, yet the correlation between different results is often questionable. In this report, the correlation between initial bacterial deposition (fast tests, reported previously) and biofilm growth (much slower tests) was analyzed on a pristine and a surface-modified reverse osmosis membrane ESPA-1. The membrane was modified with grafted hydrophilic polymers bearing negatively charged, positively charged and zwitter-ionic moieties. Using three different bacterial strains it was found that there was no general correlation between the initial bacterial deposition rates and biofilm growth on surfaces, the reasons being different for each modified surface. For the negatively charged surface the slowest deposition due to the charge repulsion was eventually succeeded by the largest biofilm growth, probably due to secretion of extracellular polymeric substances (EPS) that mediated a strong attachment. For the positively charged surface, short-term charge attraction by quaternary amine groups led to the fastest deposition, but could be eventually overridden by their antimicrobial activity, resulting in non-consistent results where in some cases a lower biofilm formation rate was observed. The results indicate that initial deposition rates have to be used and interpreted with great care, when used for assessing the anti-biofouling activity of surfaces. However, for a weakly interacting ‘low-fouling’ zwitter-ionic surface, the positive correlation between initial cell deposition and biofilm growth, especially under flow, suggests that for this type of coating initial deposition tests may be fairly indicative of anti-biofouling potential.</p></div

Biogenic Synthesis, Photocatalytic, and Photoelectrochemical Performance of Ag–ZnO Nanocomposite

The development of coupled photoactive materials (metal/semiconductor) has resulted in significant advancements in heterogeneous visible light photocatalysis. This work reports the novel biogenic synthesis of visible light active <i>Ag</i>–ZnO nanocomposite for photocatalysis and photoelectrode using an electrochemically active biofilm (EAB). The results showed that the EAB functioned as a biogenic reducing tool for the reduction of Ag⁺, thereby eliminating the need for conventional reducing agents. The as-prepared <i>Ag</i>–ZnO nanocomposite was characterized by X-ray diffraction, transmission electron microscopy, diffuse reflectance spectroscopy, photoluminescence spectroscopy, and X-ray photoelectron spectroscopy. The photocatalytic experiments showed that the <i>Ag</i>–ZnO nanocomposite possessed excellent visible light photocatalytic activity for the degradation of methyl orange, methylene blue, and 4-nitrophenol. Electrochemical impedance spectroscopy and linear scan voltammetry under dark and visible light irradiation confirmed the enhanced visible light activity of the <i>Ag</i>–ZnO as photocatalyst and photoelectrode. These results suggest that Ag nanoparticles induced visible light photocatalytic degradation and enhanced the visible light activity of the photoelectrodes by minimizing the recombination of photogenerated electrons and holes, thereby extending the response of pure ZnO to visible light

Table_1_Herring Oil and Omega Fatty Acids Inhibit Staphylococcus aureus Biofilm Formation and Virulence.docx

<p>Staphylococcus aureus is notorious for its ability to become resistant to antibiotics and biofilms play a critical role in antibiotic tolerance. S. aureus is also capable of secreting several exotoxins associated with the pathogenesis of sepsis and pneumonia. Thus, the objectives of the study were to examine S. aureus biofilm formation in vitro, and the effects of herring oil and its main components, omega fatty acids [cis-4,7,10,13,16,19-docosahexaenoic acid (DHA) and cis-5,8,11,14,17-eicosapentaenoic acid (EPA)], on virulence factor production and transcriptional changes in S. aureus. Herring oil decreased biofilm formation by two S. aureus strains. GC-MS analysis revealed the presence of several polyunsaturated fatty acids in herring oil, and of these, two omega-3 fatty acids, DHA and EPA, significantly inhibited S. aureus biofilm formation. In addition, herring oil, DHA, and EPA at 20 μg/ml significantly decreased the hemolytic effect of S. aureus on human red blood cells, and when pre-treated to S. aureus, the bacterium was more easily killed by human whole blood. Transcriptional analysis showed that herring oil, DHA, and EPA repressed the expression of the α-hemolysin hla gene. Furthermore, in a Caenorhabditis elegans nematode model, all three prolonged nematode survival in the presence of S. aureus. These findings suggest that herring oil, DHA, and EPA are potentially useful for controlling persistent S. aureus infection.</p