The rapid increase in drug-resistant infections has presented a serious challenge to antimicrobial therapies. failure of the most potent antibiotics kill "superbugs" emphasizes urgent need develop other control agents. Here we review history and new development peptides (AMPs), growing class natural synthetic with wide spectrum targets including viruses, bacteria, fungi, parasites. We summarize major types AMPs, their modes action, common mechanisms AMP resistance. In addition, discuss...

The quorum-sensing disrupter (5Z)-4-bromo-5-(bromomethylene)-3-butyl-2(5H)-furanone (furanone) of the alga Delisea pulchra was found to inhibit swarming motility Escherichia coli completely at 13 microg cm-2 (also 20 ml-1) but did not its growth rate 13-52 or from 100 ml-1. Swimming inhibited by furanone 20-40 In addition, confocal scanning laser microscopy revealed that this 60 ml-1 biofilm formation E. coli, as it decreased thickness 55%, reduced number water channels and percentage live...

After 13,000 samples of compounds purified from plants were screened, a new biofilm inhibitor, ursolic acid, has been discovered and identified. Using both 96-well microtiter plates continuous flow chamber with COMSTAT analysis, 10 microg acid/ml inhibited Escherichia coli formation 6- to 20-fold when added upon inoculation 24-h biofilm; however, acid was not toxic E. coli, Pseudomonas aeruginosa, Vibrio harveyi, hepatocytes. Similarly, by >87% for P. aeruginosa in complex minimal medium 57%...

Abstract The quorum sensing disrupter ( 5Z )‐4‐bromo‐5‐(bromomethylene)‐3‐butyl‐2( 5H )‐furanone (furanone) of the alga Delisea pulchra was previously found by us Environ Microbiol 3:731–736, 2001) to inhibit in Escherichia coli via autoinducer‐2 (AI‐2, produced LuxS). In this study, DNA microarrays were used study genetic basis natural furanone inhibition AI‐2 signaling (significant values with p < 0.05 are reported). Using microarrays, mutant DH5α compared wild‐type strain, E. K12,...

In this study, Escherichia coli RP437 and Pseudomonas aeruginosa PAO1 were used as model strains to investigate the early stage biofilm formation on poly(dimethylsiloxane) (PDMS) surfaces with varying stiffness, which prepared by controlling degree of cross-linking (base:curing agent ratios 5:1, 10:1, 20:1, 40:1 tested). An inverse correlation between cell adhesion substrate stiffness was observed for both species. Interestingly, it found that cells attached relatively stiff substrates (5:1...

Biofilms are involved in 80% of human bacterial infections and up to 1000 times more tolerant antibiotics than their planktonic counterparts. To better understand the mechanism bacteria−surface interactions, polydimethylsiloxane (PDMS) surfaces with microtopographic patterns were tested study effects surface topography on adhesion biofilm formation. The patterned PDMS prepared by transferring complementary from a silicon wafer etched via photolithography introduce 10 μm tall square-shape...

Host‐defense peptides (HDPs) feature evolution‐tested potency against life‐threatening pathogens. While piscidin 1 (p1) and 3 (p3) are homologous potent fish HDPs, only p1 is strongly membranolytic. Here, we hypothesize that another mechanism imparts p3 strong potency. We demonstrate the N‐termini of both coordinate Cu 2+ p3‐Cu cleaves isolated DNA at a rate on par with free but significantly faster than p1‐Cu. On planktonic bacteria, more antimicrobial features copper‐dependent cleavage....

Abstract Microbial biofilm formation on indwelling medical devices causes persistent infections that cannot be cured with conventional antibiotics. To address this unmet challenge, we engineer tunable active surface topographies micron-sized pillars can beat at a programmable frequency and force level in an electromagnetic field. Compared to the flat static controls, optimized design prevent remove established biofilms of uropathogenic Escherichia coli (UPEC), Pseudomonas aeruginosa ,...

(5Z)-4-Bromo-5-(bromomethylene)-3-butyl-2(5H)-furanone(furanone) of the marine alga Delisea pulchra was synthesized, and its inhibition swarming motility biofilm formation Bacillus subtilis investigated.Furanone found to inhibit both growth B. in a concentration-dependent way. In addition, as shown by confocal scanning laser microscopy, furanone inhibited subtilis. At 40 microg ml(-1), decreased thickness 25%, number water channels, reduced percentage live cells 63%.Natural has potential for...

The need exists for biomaterials that prevent biofilm formation and associated infections. In this report, we have studied the synthesis, processing, antimicrobial behavior of new silver-containing thermoplastic hydrogel nanofibrous webs. Thermoplastic hydrogels were synthesized from multiblock PEG-POSS polyurethanes (PEG: poly(ethylene gylcol); POSS: polyhedral oligosilsesquioxane) electrospun into webs (diameter ∼150 nm), with or without AgNO3. exhibited unusual shrinkage during water...

ABSTRACT Persister cells are dormant phenotypic variants inherent in a bacterial population. They play important roles chronic infections and present great challenges to therapy due extremely enhanced tolerance antibiotics compared that of normal the same genotype. In this study, we report cationic membrane-penetrating peptides containing various numbers arginine tryptophan repeats effective killing persister Escherichia coli HM22, hyper-persister producer. The activities three linear [(RW)...

Background Bacteria are well known to form dormant persister cells that tolerant most antibiotics. Such intrinsic tolerance also facilitates the development of multidrug resistance through acquired mechanisms. Thus a promising target for developing more effective methods control chronic infections and help prevent multidrug-resistant bacteria. However, is still an unmet challenge. Methodology/Principal Findings We show in this report (Z)-4-bromo-5-(bromomethylene)-3-methylfuran-2(5H)-one...

Abstract Bacterial response to surface topography during biofilm formation was studied using 5 μm tall line patterns of poly (dimethylsiloxane) (PDMS). Escherichia coli cells attached on top protruding were found align more perpendicularly the orientation when pattern narrowed. Consistently, cell cluster per unit area wide reduced by 14-fold compared flat PDMS. Contrasting colony formation, narrow longer and had higher transcriptional activities, suggesting that such unfavorable may present...

Material stiffness has been shown to have potent effects on bacterial attachment and biofilm formation, but the mechanism is still unknown. In this study, response material by Escherichia coli during was investigated with assays cell tracking using Automated Contour-base Tracking for in Vitro Environments (ACTIVE) computational algorithm. By comparing movement of E. cells attached poly(dimethylsiloxane) (PDMS) surfaces different Young's moduli (0.1 2.6 MPa, prepared controlling degree...

Recently, we reported that the stiffness of poly(dimethylsiloxane) (PDMS) affects attachment Pseudomonas aeruginosa, and morphology antibiotic susceptibility attached cells. To further understand how P. aeruginosa responses to material during attachment, wild-type PAO1 several isogenic mutants were characterized for their on soft stiff PDMS. Compared strain, mutation oprF gene abolished differences in growth, size cells between PDMS surfaces. These defects rescued by genetic complementation...

Escherichia coli Hha is an environmental-response regulator of the pathogenic hemolysin operon, and contiguous YbaJ are both induced 30-fold in E. biofilms (Appl. Microbiol. Biotechnol. 64:515, 2004). Here it shown that regulate biofilm formation since hha/ybaJ deletion reduces mass microtitre plates (81% minimal medium, 50% complex medium) flow cells (1,000-fold less surface coverage medium). The addition derepressed conjugative plasmid R1drd19, which increases significantly formation,...

Bacterial biofilms are ubiquitous and the major cause of chronic infections in humans persistent biofouling industry. Despite significance bacterial biofilms, mechanism biofilm formation associated drug tolerance is still not fully understood. A challenge research intrinsic heterogeneity structure, which leads to temporal spatial variation cell density gene expression. To understand control such structural heterogeneity, surfaces with patterned functional alkanthiols were used this study...