scholarly journals In VitroActivities of Dermaseptins K4S4and K4K20S4against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa Planktonic Growth and Biofilm Formation

2014 ◽  
Vol 58 (4) ◽  
pp. 2221-2228 ◽  
Author(s):  
Amira Zaïri ◽  
Lionel Ferrières ◽  
Patricia Latour-Lambert ◽  
Christophe Beloin ◽  
Frédéric Tangy ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Alternative Therapies ◽  
Bacterial Biofilm ◽  
Flow Conditions ◽  
Dynamic Flow ◽  
Gram Negative ◽  
Cytotoxicity Assays ◽  
Attached Bacteria ◽  
Antibiofilm Agents ◽  
Intensive Search

ABSTRACTThe rising number of infections caused by biofilm formation and the difficulties associated with their treatment by conventional antimicrobial therapies have led to an intensive search for novel antibiofilm agents. Dermaseptins are antimicrobial peptides with a number of attractive properties that might offer alternative therapies against resistant microorganisms. In this study, we synthesized a set of dermaseptin-derived peptides and evaluated their activities against Gram-positive and Gram-negative bacterial biofilm formation. All dermaseptin-derived peptides demonstrated concentration-dependent antibiofilm activities at microgram concentrations, and their activities were dependent on the nature of the peptides, with the highest levels of activity being exhibited by highly charged molecules. Fluorescent binding and confocal microscopy demonstrated that dermaseptin K4S4, a substituted derivative of the native molecule S4, significantly decreased the viability of planktonic and surface-attached bacteria and stopped biofilm formation under dynamic flow conditions. Cytotoxicity assays with HeLa cells showed that some of the tested peptides were less cytotoxic than current antibiotics. Overall, these findings indicate that dermaseptin derivatives might constitute new lead structures for the development of potent antibiofilm agents.

scholarly journals New Adapted In Vitro Technology to Evaluate Biofilm Formation and Antibiotic Activity Using Live Imaging under Flow Conditions

Diagnostics ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1746
Author(s):  
Cassandra Pouget ◽  
Catherine Dunyach-Remy ◽  
Alix Pantel ◽  
Sophie Schuldiner ◽  
Albert Sotto ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Cell Imaging ◽  
Chronic Wounds ◽  
Chronic Wound ◽  
Live Imaging ◽  
Bacterial Biofilm ◽  
Flow Conditions ◽  
Promising Tool ◽  
Reference Strains

The polymicrobial nature of biofilms and bacterial interactions inside chronic wounds are keys for the understanding of bacterial cooperation. The aim of this present study was to develop a technique to study and visualize biofilm in live imaging under flow conditions (Bioflux™ 200, Fluxion Biosciences). The BiofluxTM system was adapted using an in vitro chronic wound-like medium (CWM) that mimics the environment encountered in ulcers. Two reference strains of Staphylococcus aureus (Newman) and Pseudomonas aeruginosa (PAO1) were injected in the BiofluxTM during 24 h to 72 h in mono and coculture (ratio 1:1, bacteria added simultaneously) in the CWM vs. a control medium (BHI). The quantification of biofilm formation at each time was evaluated by inverted microscopy. After 72 h, different antibiotics (ceftazidime, imipenem, linezolid, oxacillin and vancomycin) at 1x MIC, 10x MIC and 100x MIC were administrated to the system after an automatic increase of the flow that mimicked a debridement of the wound surface. Biofilm studies highlighted that the two species, alone or associated, constituted a faster and thicker biofilm in the CWM compared to the BHI medium. The effect of antibiotics on mature or “debrided” biofilm indicated that some of the most clinically used antibiotic such as vancomycin or imipenem were not able to disrupt and reduce the biofilm biomass. The use of a life cell imaging with an in vitro CWM represents a promising tool to study bacterial biofilm and investigate microbial cooperation in a chronic wound context.

Biofilm Formation of Legionella pneumophila in Complex Medium under Static and Dynamic Flow Conditions

Legionella ◽  
2014 ◽  
pp. 398-402
Author(s):  
Jörg Mampel ◽  
Thomas Spirig ◽  
Stefan S. Weber ◽  
Janus A.J. Haagensen ◽  
Søren Molin ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Biofilm Formation ◽  
Complex Medium ◽  
Flow Conditions ◽  
Dynamic Flow

scholarly journals New Thiazole Nortopsentin Analogues Inhibit Bacterial Biofilm Formation

Marine Drugs ◽  
2018 ◽  
Vol 16 (8) ◽  
pp. 274 ◽  
Author(s):  
Anna Carbone ◽  
Barbara Parrino ◽  
Maria Cusimano ◽  
Virginia Spanò ◽  
Alessandra Montalbano ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Microbial Growth ◽  
Bacterial Biofilm ◽  
Dependent Manner ◽  
Gram Negative ◽  
Ic50 Values ◽  
Planktonic Form ◽  
New Compounds ◽  
Dose Dependent

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 0.40–2.03 µM. The new compounds showed a typical anti-virulence profile, being able to inhibit the biofilm formation without affecting the microbial growth in the planktonic form.

Nanocomposite antimicrobials prevent bacterial growth through the enzyme-like activity of Bi-doped cerium dioxide (Ce1−xBixO2−δ)

Nanoscale ◽  
2020 ◽  
Vol 12 (41) ◽  
pp. 21344-21358
Author(s):  
Hajo Frerichs ◽  
Eva Pütz ◽  
Felix Pfitzner ◽  
Tobias Reich ◽  
Athanasios Gazanis ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Surface Area ◽  
Bacterial Growth ◽  
Biofilm Formation ◽  
Cerium Dioxide ◽  
Maximum Activity ◽  
Bacterial Biofilm ◽  
Bet Surface Area ◽  
Gram Negative Bacteria ◽  
Gram Negative

Ce1−xBixO2−δ is an active halogenation catalyst with maximum activity for x ≈ 0.2 due to the effects of zeta-potential and BET surface area. Ce1−xBixO2−δ/polyethersulfone nanocomposites block bacterial biofilm formation of Gram-negative bacteria.

scholarly journals INHIBITION OF BIOFILM PRODUCING GRAM NEGATIVE CLINICAL ISOLATES AND THEIR ANTIBIOGRAM PATTERN

2021 ◽  
Author(s):  
Ojaswee Shrestha ◽  
Nabina Shrestha ◽  
Sadhana Khanal ◽  
Sushant Pokhrel ◽  
Sujina Maharjan ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Bacterial Biofilm ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Resistance Pattern ◽  
Antibiotics Resistance ◽  
Klebsiella Pneumonia ◽  
Isolation And Identification ◽  
Gram Negative ◽  
Biofilm Production

Background: Bacterial biofilm is a major virulence factor that posses a threat to patients leading to chronic infections. Therefore, it is crucial to identify biofilm production as well as their inhibition and reduction. This study was an attempt to investigate biofilm production among gram-negative isolates and assessment of inhibitory and reduction potential of EDTA and DMSO towards them and also observe the antimicrobial resistance pattern among biofilm producers and biofilm non-producer. Methods: Isolation and identification of bacterial isolates were performed by standard microbiological methodology. The antibiotic susceptibility pattern was determined by the Kirby Bauer disk diffusion method and β-lactamases by the combination disk method. Biofilm formation was detected through Tissue Culture Plate(TCP) method, and different concentrations of EDTA and DMSO were used to determine their inhibitory and reduction property against biofilm. Both inhibition and reduction by the various concentration of EDTA and DMSO were analyzed using paired t-test. Results: Among the 110 clinical isolates 61.8% were found to be Multidrug resistance(MDR) with the 33 (30%) produced Extended-spectrum β-lactamases(ESBL), 16 (14.5%)Metalloβ-lactamases(MBL) and 9 (8%)Klebsiella pneumonia carbapenemase(KPC). Biofilm formation was detected in 35.4% of isolates. Biofilm producing organisms showed antibiotics resistance to Cephalosporins, Chloramphenicol, Gentamycin, and Carbapenem. The inhibition and reduction of biofilm were significantly lower (p<0.05) for 1mM of EDTA and 2% of DMSO. Conclusions: EDTA and DMSO were found to possess potential activity against biofilm. Hence, EDTA and DMSO might be used invitro as an effective antibiofilm agent to control the biofilm-associated infection and for a possible therapeutic approach.

scholarly journals Molecular Identification of Fusobacterium Isolates and limitation of Biofilm Formation Adhesion Gene (fadA) in Dental Outpatients

2019 ◽  
Vol 16 (4) ◽  
pp. 0843
Author(s):  
Aws Ibrahim Sulaiman
Keyword(s):  
Periodontal Disease ◽  
16S Rdna ◽  
Molecular Identification ◽  
Biofilm Formation ◽  
Bacterial Biofilm ◽  
Gram Negative Bacteria ◽  
Anaerobic Conditions ◽  
16S Rdna Gene ◽  
Gram Negative ◽  
Rdna Gene

 Fusobacterium are compulsory anaerobic gram-negative bacteria, long thin with pointed ends, it causes several illnesses to humans like pocket lesion gingivitis and periodontal disease; therefore our study is constructed on molecular identification and detection of the fadA gene which is responsible for bacterial biofilm formation. In this study, 10.2% Fusobacterium spp. were isolated from pocket lesion gingivitis. The isolates underwent identification depending on several tests under anaerobic conditions and biochemical reactions. All isolates were sensitive to Imipenem (IPM10) 42.7mm/disk, Ciprofloxacin (CIP10) 27.2mm/disk and Erythromycin (E15) 25mm/disk, respectively. 100% of Fusobacterium spp. isolates had 16S rDNA gene (360bp.), whereas two isolates had fadA gene (232bp.)

scholarly journals HPLC-PDA-ESI-MS/MS Profiling and Anti-Biofilm Potential of Eucalyptussideroxylon Flowers

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 761
Author(s):  
Mona M. Okba ◽  
Riham A. El-Shiekh ◽  
Mohammed Abu-Elghait ◽  
Mansour Sobeh ◽  
Rehab M. S. Ashour
Keyword(s):  
Biofilm Formation ◽  
Bacterial Infections ◽  
Multidrug Resistant ◽  
Alternative Therapies ◽  
Antibiofilm Activity ◽  
Inhibition Activity ◽  
Bacterial Strains ◽  
Promising Candidate ◽  
Antibiofilm Agents ◽  
Eucalyptus Sideroxylon

The development of multidrug-resistant bacterial strains is a worldwide emerging problem that needs a global solution. Exploring new natural antibiofilm agents is one of the most important alternative therapies in combating bacterial infections. This study aimed at testing the antimicrobial potential of Eucalyptus sideroxylon flowers extract (ESFE) against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans prior to testing the antibiofilm activity against S. aureus, P. aeruginosa and C. albicans. ESFE demonstrated antimicrobial activity and promising inhibition activity against methicillin-resistant S. aureus (MRSA) biofilm formation up to 95.9% (p < 0.05) at a concentration of 0.05 mg/mL and eradicated C. albicans biofilm formation up to 71.2% (p < 0.05) at a concentration of 0.7 mg/mL. LC-MS analysis allowed the tentative identification of eighty-three secondary metabolites: 21 phloroglucinol, 18 terpenes, 16 flavonoids, 7 oleuropeic acid derivatives, 7 ellagic acid derivatives, 6 gallic acid derivatives, 3 phenolic acids, 3 fatty acids and 2 miscellaneous. In conclusion, E. sideroxylon is a rich source of effective constituents that promote its valorization as a promising candidate in the management of multidrug-resistant bacterial infections.

scholarly journals Outer Membrane Vesicles Released From Aeromonas Strains Are Involved in the Biofilm Formation

2021 ◽  
Vol 11 ◽  
Author(s):  
Soshi Seike ◽  
Hidetomo Kobayashi ◽  
Mitsunobu Ueda ◽  
Eizo Takahashi ◽  
Keinosuke Okamoto ◽  
...  
Keyword(s):  
Amino Acid ◽  
Outer Membrane ◽  
Biofilm Formation ◽  
Bacterial Species ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Amino Acid Sequences ◽  
Bacterial Biofilm ◽  
Gram Negative Bacteria ◽  
Gram Negative

Aeromonas spp. are Gram-negative rod-shaped bacteria ubiquitously distributed in diverse water sources. Several Aeromonas spp. are known as human and fish pathogens. Recently, attention has been focused on the relationship between bacterial biofilm formation and pathogenicity or drug resistance. However, there have been few reports on biofilm formation by Aeromonas. This study is the first to examine the in vitro formation and components of the biofilm of several Aeromonas clinical and environmental strains. A biofilm formation assay using 1% crystal violet on a polystyrene plate revealed that most Aeromonas strains used in this study formed biofilms but one strain did not. Analysis of the basic components contained in the biofilms formed by Aeromonas strains confirmed that they contained polysaccharides containing GlcNAc, extracellular nucleic acids, and proteins, as previously reported for the biofilms of other bacterial species. Among these components, we focused on several proteins fractionated by SDS-PAGE and determined their amino acid sequences. The results showed that some proteins existing in the Aeromonas biofilms have amino acid sequences homologous to functional proteins present in the outer membrane of Gram-negative bacteria. This result suggests that outer membrane components may affect the biofilm formation of Aeromonas strains. It is known that Gram-negative bacteria often release extracellular membrane vesicles from the outer membrane, so we think that the outer membrane-derived proteins found in the Aeromonas biofilms may be derived from such membrane vesicles. To examine this idea, we next investigated the ability of Aeromonas strains to form outer membrane vesicles (OMVs). Electron microscopic analysis revealed that most Aeromonas strains released OMVs outside the cells. Finally, we purified OMVs from several Aeromonas strains and examined their effect on the biofilm formation. We found that the addition of OMVs dose-dependently promoted biofilm formation, except for one strain that did not form biofilms. These results suggest that the OMVs released from the bacterial cells are closely related to the biofilm formation of Aeromonas strains.

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