Bre-Cga-Activity-K-r

pneumoniae without inflicting any harm to its planktonic counterparts. In vitro assays supported the β-lactamase inhibitory effect of CGA and BRE while in silico docking showed that CGA bound strongly with the active sites of sulfhydryl-variable-1 β-lactamase. Furthermore, the mRNA transcript levels of two biofilm-associated genes (type 3 fimbriae mrkD and trehalose-6-phosphate hydrolase treC) were significantly downregulated in CGA- and BRE-treated samples. In addition, CGA inhibited biofilm formation by Escherichia coli and Candida albicans without affecting their planktonic cell growth. These findings show that BRE and its component CGA have potential use in antibiofilm strategies against persistent K. pneumoniae infections.

Measurements of accumulation and displacement at the single cell cluster level Quantitative descriptions of biofilm growth and dynamics at the individual cell level are largely missing from the literature. To fill this gap, research was done to describe growth, accumulation and displacement patterns in developing Pseudomonas aeruginosa biofilms. A parent strain of PAO1 was labelled with either a cyan or yellow fluorescent protein. These were then grown in a flow cell biofilm together so that pockets of dividing cells could be identified and their accumulation and displacement tracked. This analysis revealed a pattern of exponential accumulation for all clusters followed by a stationary accumulation phase. A background 'carpet' layer of cells uniformly colonizing the surface exhibited zero net accumulation of bio-volume. The individual clusters were found to have a mean accumulation rate of 04 h(-1) with a range of 08-01 h(-1).

Cluster accumulation rates were negatively correlated with cluster size; larger clusters accumulated volume at a slower rate (P < 001). Pockets of cells on the inside of clusters initially accumulated at a comparable rate to the cluster within which they resided, but later invariably exhibited zero to slightly negative accumulation despite continued exponential (positive) accumulation of the cluster. Expanding Bacterial polysaccharides were able to displace neighbouring cells from the surface, and larger clusters displaced smaller clusters. This work provides a more detailed quantitative experimental observation of biofilm behaviour than has been described previously. Antibacterial mechanisms of GN-2 derived peptides and peptoids against Escherichia coli is the main etiological agent of urinary trait infections, able to form biofilms in indwelling devices, resulting in chronic infections which are refractory to antibiotics treatment. In this study, we investigated the antimicrobial and anti-biofilm properties exerted against E. coli ATCC 25922, by a set of peptoids and peptides modeled upon the peptide GN-2, previously reported as a valid antimicrobial agent.

The putative antimicrobials were designed to evaluate the effect of cationicity, hydrophobicity and their partitioning on the overall properties against planktonic cells and biofilms as well as on LPS binding, permeabilization of Gram-negative bacteria membranes and hemolysis. The data demonstrated that peptides are stronger antimicrobials than the analogue peptoids which in return have superior anti-biofilm properties. In this study, we present evidence that peptides antimicrobial activity correlates with enhanced LPS binding and hydrophobicity but is not affected by partitioning. The data demonstrated that the enhanced anti-biofilm properties of the peptoids are associated with decreased hydrophobicity and increased penetration of the inner membrane, compared to that of their peptide counterpart, suggesting that the characteristic flexibility of peptoids or their lack of H-bonding donors in their backbone, would play a role in their ability The formation of spores in biofilms of Anoxybacillus flavithermus. AIMS: To examine the rate and the extent of spore formation in Anoxybacillus flavithermus biofilms and to test the effect of one key variable - temperature - METHODS AND RESULTS: A continuous flow laboratory reactor was used to grow biofilms of the typical dairy thermophile A. flavithermus (strain CM) in skim milk. The reactor was inoculated with either a washed culture or a spore suspension of A.

Order now , and was run over an 8 h period at three different temperatures of 48, 55 and 60 degrees C. Change in impedance was used to determine the cell numbers in the milk and on the surface of the stainless steel reactor tubes. The biofilm developed at all three temperatures within 6-8 h. Spores formed at 55 and 60 degrees C and amounted to approx. 10-50% of the biofilm. No spores formed at 48 degrees C.