Search results for " biofilm"
showing 10 items of 109 documents
Antimicrobial and Antibiofilm Activity of a Recombinant Fragment of β-Thymosin of Sea Urchin Paracentrotus lividus
2018
With the aim to obtain new antimicrobials against important pathogens such as Staphylococcus aureus and Pseudomonas aeruginosa, we focused on antimicrobial peptides (AMPs) from Echinoderms. An example of such peptides is Paracentrin 1 (SP1), a chemically synthesised peptide fragment of a sea urchin thymosin. In the present paper, we report on the biological activity of a Paracentrin 1 derivative obtained by recombination. The recombinant paracentrin RP1, in comparison to the synthetic SP1, is 22 amino acids longer and it was considerably more active against the planktonic forms of S. aureus ATCC 25923 and P. aeruginosa ATCC 15442 at concentrations of 50 µ
Synthesis and biofilm formation reduction of pyrazole-4-carboxamide derivatives in some Staphylococcus aureus strains
2016
The ability of several N-phenyl-1H-pyrazole-4-carboxamide derivatives and other pyrazoles opportunely modified at the positions 3, 4 and 5, to reduce the formation of the biofilm in some Staphylococcus aureus strains (ATCC 29213, ATCC 25923 and ATCC 6538) were investigated. All the tested compounds were able, although to a different extent, to reduce the biofilm formation of the three bacterial strains considered. Among these, the 1-(2,5-dichlorophenyl)-5-methyl-N-phenyl-1H-pyrazole-4-carboxamide 14 resulted as the best inhibitor of biofilm formation showing an IC50 ranging from 2.3 to 32 μM, against all the three strains of S. aureus. Compound 14 also shows a good protective effect in vivo…
New Thiazole Nortopsentin Analogues Inhibit Bacterial Biofilm Formation.
2018
New thiazole nortopsentin analogues were conveniently synthesized and evaluated for their activity as inhibitors of biofilm formation of relevant Gram-positive and Gram-negative pathogens. All compounds were able to interfere with the first step of biofilm formation in a dose-dependent manner, showing a selectivity against the staphylococcal strains. The most active derivatives elicited IC50 values against Staphylococcus aureus ATCC 25923, ranging from 0.40&ndash
Innovative ready to use carrier-bacteria devices for bioremediation of oil contaminated water
2018
Bioremediation, that uses microorganisms to remove environmental pollutants, is the best way of restoring the environment due to its low cost and sustainability. Immobilization of microorganisms capable of degrading specific contaminants significantly promotes bioremediation processes. An innovative ready to use bioremediation system to clean up oil-contaminated water was developed immobilizing highly performant marine and soil HC degrading bacteria, on biodegradable oil-absorbing carriers. Two soil Actinobacteria (Gordonia sp. SoCg, Nocardia sp. SoB) and two marine Gammaproteobacteria (Alcanivorax sp. SK2, Oleibacter sp.5), were immobilized on biopolymeric membranes prepared by electrospin…
Phenotypic and genetic analysis of biofilm formation by Staphylococcus epidermidis.
2012
Objective. The most important virulence factor of Staphylococcus epidermidis is their capability to form a biofilm on the surfaces of implanted medical devices. The accumulative phase of biofilm formation is linked to the production of intercellular adhesin encoded by the icaADBC operon and accumulation-associated protein by the aap gene. The aim of the study was to investigate biofilm formation phenotypically and genetically in clinical strains of S. epidermidis in comparison with commensal strains. Material and Methods. The study was carried out in 4 hospitals in Riga, Latvia. In total, 105 clinical strains of Staphylococcus epidermidis isolated from patients’ blood (n=67) and intravenous…
Anaerobic moving bed biofilm reactor followed by aerobic granular sludge for brewery wastewater treatment
2018
Small and medium breweries discharging to municipal sewers without treatment generate significant loads with typical concentrations reported by Valta et al. (2014) as 2-6 g COD L-1, 25-80 mg TN L-1, 10-50 mg TP L-1, with pH between 4.5 and 12. Treatment of the high-strength wastewater requires specialized low footprint processes, such as aerobic granular sludge (AGS), capable of high-rate degradation, as well as simultaneous nitrogen and phosphorous removal (Wang et al., 2007). The objective of this study was to evaluate the start-up period of AGS receiving brewery wastewater after initial anaerobic pre-treatment.
Antimicrobial activity of biogenically produced spherical Se-nanomaterials embedded in organic material against Pseudomonas aeruginosa and Staphyloco…
2017
In an effort to prevent the formation of pathogenic biofilms on hydroxyapatite (HA)-based clinical devices and surfaces, we present a study evaluating the antimicrobial efficacy of Spherical biogenic Se-Nanostructures Embedded in Organic material (Bio Se-NEMO-S) produced by Bacillus mycoides SelTE01 in comparison with two different chemical selenium nanoparticle (SeNP) classes. These nanomaterials have been studied as potential antimicrobials for eradication of established HA-grown biofilms, for preventing biofilm formation on HA-coated surfaces and for inhibition of planktonic cell growth of Pseudomonas aeruginosa NCTC 12934 and Staphylococcus aureus ATCC 25923. Bio Se-NEMO resulted more e…
Synthetic small molecules as anti-biofilm agents in the struggle against antibiotic resistance
2018
Abstract Biofilm formation significantly contributes to microbial survival in hostile environments and it is currently considered a key virulence factor for pathogens responsible for serious chronic infections. In the last decade many efforts have been made to identify new agents able to modulate bacterial biofilm life cycle, and many compounds have shown interesting activities in inhibiting biofilm formation or in dispersing pre-formed biofilms. However, only a few of these compounds were tested using in vivo models for their clinical significance. Contrary to conventional antibiotics, most of the anti-biofilm compounds act as anti-virulence agents as they do not affect bacterial growth. I…
Candida biofilms on implanted biomaterials: a clinically significant problem.
2006
In recent years there has been an increasing appreciation that microbial biofilms are ubiquitous, which has resulted in a number of studies on infectious diseases from a biofilm perspective. Biofilms are defined as structured microbial communities that are attached to a surface and encased in a matrix of exopolymeric material. A wide range of biomaterials used in clinical practice have been shown to support colonization and biofilm formation by Candida spp., and the increase in Candida infections in the last decades has almost paralleled the increase and widespread use of a broad range of medical implant devices, mainly in populations with impaired host defenses. Formation of Candida biofil…
Effect of single-species and mixed-species leaf leachate on bacterial communities in biofilms
2009
Dissolved organic matter in the form of leaf leachate represents an important carbon and energy source in many lotic ecosystems. In this study, we investigated utilization of mono-specific and mixed-species leaf leachate and impacts on biofilm bacterial community structure. Ceramic tiles were incubated in a Northeast Ohio stream to allow for biofilm development and then exposed in the laboratory to glucose or leachate from: sugar maple (Acer saccharum), pin oak (Quercus palustris), maple oak, American beech (Fagus grandifolia), witch hazel (Hamamelis virginiana), or beech witch hazel. Bacterial responses to these amendments were compared to un-amended controls based on fluorescent in situ h…