The Susceptibility Of Proteus Mirabilis And Enterococcus Aecalis To Various Antimicrobial Agents In Polymicrobial Biofilms Formed Using A Drip Flow Reactor

Objectives: Interspecies interactions in poly-species biofilm are substantial. Our aim is to set up dynamic biofilm models of Enterococcus faecalis and Proteus rnirabilis using Drip Flow Biofilm Reactor (DFR) and to evaluate the effect of these dual population on anti-biofilms of some antimicrobials. Materials and Methods: E.fuecalis and Pmirabilis biofilms were formed in a DFR. Influences of the dual interactions on their susceptibilities to antimicrobial agents (disinfectants, antibiotics and probiotic strains) were determined. Results: Gluteraldehyde and quaternary ammonium compounds (QAC) effectively killed the cells in both bioffirns of E.faecalis and P. mirabilis. However, the efficacy of hydrogen peroxide (H2O2) was dependant on the microbial species present. P mirabilis was less susceptible to the ampicillin and ciprofloxacin in co-culture compared to when cultured alone. Here, the influence of the presence of E.faecalis on Pmirabilis susceptibility was determined. For high concentrations of ciprofloxacin (1024 and 512 mu g/ml), the log reduction in Pmirabilis cells was determined as approximately 4.5 and 3.5 in mono and dual-species biofilms respectively. Compared to B.lactis, L.acidophilus was found to be more effective both on single and dual species. Conclusion: The effect of antimicrobial agents on microbial cells in a polymicrobial biofilm may depend on the composition of the biofilm.WoSScopu

Determınatıon Of The Mıcrobıal Interactıons In Polymıcrobıal Bıofılms Actıng As A Role In Susceptıbılıty Agaınst To Dısınfectants Frequently Used In Hospıtals Wıth Phenotypıc And Genotypıc Analysıs

Biyofilm oluşumu insan sağlığını tehdit eden önemli bir problemdir. Yapılan son çalışmalarda persistan enfeksiyonlara yol açan klinik ile ilişkili biyofilmlerin çoğunun polimikrobiyal kaynaklı olduğu belirtilmiştir. Sesil biyofilm hücrelerinin antimikrobiyal ajanlara karşı yüksek direnç göstermelerinden dolayı bu enfeksiyonların tedavisi oldukça zordur. Polimikrobiyal biyofilmlerin önemi günden güne artmasına rağmen henüz bu biyofilmlerin özellikleri üzerine az sayıda çalışma bulunmaktadır. Çalışmamızın amacı, tekrar edilebilirliği yüksek in vitro polimikrobiyal biyofilm modeli geliştirmek, aynı zamanda da fenotipik ve moleküler yöntemlerle biyofilm ortamında bulunan C. albicans ve S. aureus varlığının P. aeruginosa nın çeşitli dezenfektanlara karşı duyarlılığı üzerindeki etkisini anlayabilmektir. Bu çalışmada 96 çukurlu mikrotitrasyon plaklarında tekrar edilebilirliği yüksek polimikrobiyal biyofilmler oluşturulmuştur. Piyasada bulunan 9 dezenfektanın polimikrobiyal biyofilm içinde bulunan S. aureus, C. albicans, and P. aeruginosa ya etkileri belirlenerek birbirleriyle karşılaştırılmıştır. Seçici besiyerleri kullanılarak plak döküm yöntemiyle hücre sayımları yapılmıştır. Hidrojen peroksit kalıntı miktarı, ROS birikimi ve oksidatif stres ilişkili genlerin ekspresyon seviyeleri hem monomikrobiyal hemde polimikrobiyal biyofilm hücrelerinden ölçülmüş ve sonuçlar birbirleriyle karşılaştırılmıştır. Sonuçlar polimikrobiyal biyofilmlerdeki mikrobiyal etkileşimin öneminin kullanılan dezenfektana ve ortamda bulunan mikrobiyal türe bağımlı olduğunu göstermiştir. Ayrıca literatürde sıklıkla bahsedilen monomikrobiyal biyofilmlerin polimikrobiyaller e göre daha duyarlı olduğu düşüncesinin her zaman geçerli olmadığı bu çalışma sonuçlarıyla ortaya koyulmuştur.Biofilms are substantial problem threatening the human health. It was shown that in recent studies, most of clinically relevant biofilms leading to persistent infections are polymicrobial. Because of sessile cells in biofilm are highly resistant against antimicrobial agents to treat these infections are troublesome. While increasingly being recognized as important, there are few studies on the properties of multispecies biofilms. Our aim is set up an in model to grow polymicrobial biofilms in a repeatable style and to find out the impact of the presence of S. aureus or C. albicans on the susceptibility of P. aeruginosa to a variety of disinfectants by using phenotypic and moleclar test methods. In the present study, polimicrobial biofilms were grown in a repeatable manner in a multi-well plate. S. aureus, C. albicans, and P. aeruginosa in polymicrobial biofilms were threated by nine commercial different disinfectants and the effects of these disinfectant were compared. The number of cells was quantified and counted by pour plating method on a selective growth media. Both in polymicrobial and monomicrobial biofilms, the residual hydrogen peroxide concentration, the accumulation of ROS and the expression level of oxidative stress related genes were measured and the results compared with each other. Our results demonstrated that the aspect and the importance of the effect in a polymicrobial biofilm depend on the strain and the disinfectant used. Moreover, it is conflict with the extensive belief that organisms in polymicrobial biofilms are always less susceptible than in monomicrobial

Investigation Of Gelatinase Gene Expression And Growth Of Enterococcus Faecalis Clinical Isolates In Biofilm Models

Objectives: Enterococcus faecalis is the major reason for biofilm-related infections and it also interacts with Staphylococcus aureus in biofilms. Gelatinase (gelE) enzyme is an important virulence factor of E. faecalis for biofilm formation. This study aimed to compare the biofilm producing E. faecalis isolates from urine and urinary catheters. The influence of S. aureus on the growth of E. faecalis biofilm cells was also investigated in a dual biofilm model in vitro. Another aim was to evaluate E. faecalis gelE gene expression during biofilm formation. Materials and Methods: Firstly, crystal violet staining was used to measure the total biofilm biomass of the isolates. Secondly, plate counting was performed to determine the biofilm formation ability of E. faecalis isolates and the effect of S. aureus on E. faecalis biofilm formation. Finally, the gelE expression profile of the isolates was assessed by quantitative real time-polymerase chain reaction. Results: According to crystal violet staining and plate counting, all E. faecalis isolates were biofilm producers and the number of E. faecalis sessile cells increased in the presence of S. aureus. Among the 21 E. faecalis isolates, ten expressed high levels of the gelE gene, while eight of them had low expression profiles (p<0.05). Conclusion: When they grow together, S. aureus may give some advantages to E. faecalis such as increasing sessile cell growth. The expression of the gelE gene was not affected by E. faecalis biofilm formation of the isolates collected from the patients with urinary tract infections.WoSScopu

Evaluation Of Antimicrobial Durability And Anti-Biofilm Effects In Urinary Catheters Against Enterococcus Faecalis Clinical Isolates And Reference Strains

Background: Enterococcus faecalis, Escherichia coli, Staphylococcus epidermidis, Pseudomonas aeruginosa and Candida albicans biofilms are major causes of catheter-associated urinary tract infections. Antimicrobial-coated or impregnated urinary catheters are seen as a possible way to prevent these infections. Aims: To determine the biofilm-forming ability of 89 E. faecalis isolates from urinary tract infections and to compare several urinary catheters for antimicrobial durability and the inhibitory effects on biofilm formation of different laboratory strains and clinical isolates of E. faecalis. Study Design: In vitro experimental study. Methods: The biofilm forming ability of E. faecalis isolates was determined by the crystal violet staining and plate counting methods. For comparison of urinary catheters, biofilms of 45 E. faecalis isolates from the catheter samples of hospitalized patients and five laboratory strains of E. coli ATCC25922, S. epidermidis ATCC35984, P. aeruginosa ATCC27853, E. faecalis ATCC29212 and C. albicans ATCC90028 were formed on the catheters in 24-well tissue culture plates. Scanning electron microscopy analysis was performed to observe biofilms. Results: All 89 E. faecalis isolates were found to be biofilm positive. Nitrofurazone-impregnated catheters significantly reduced the cell counts of E. faecalis isolates and completely inhibited the formation of P. aeruginosa and S. epidermidis biofilms compared with the others. Regarding reduction of biofilm cell counts, a hydrophilic-coated catheter was more effective against P. aeruginosa, whereas a silver-coated catheter was found to be more effective against S. epidermidis. The nitrofurazone-impregnated catheter had the best antimicrobial durability. Conclusion: Urine isolates of E. faecalis had considerable ability with respect to biofilm formation. The nitrofurazone-impregnated catheter was the most effective against all tested bacteria; however, the effect of a hydrophilic or silver-coated catheter depends on the species present in it.PubMedWoSScopu

Activity of disinfectants against multispecies biofilms formed by Staphylococcus aureus, Candida albicans and Pseudomonas aeruginosa

Microbial biofilms are a serious threat to human health. Recent studies have indicated that many clinically relevant biofilms are polymicrobial. In the present study, multispecies biofilms were grown in a reproducible manner in a 96-well microtiter plate. The efficacy of nine commercially available disinfectants against Staphylococcus aureus, Candida albicans, and Pseudomonas aeruginosa in multispecies biofilms was determined and compared. The results showed that the direction and the magnitude of the effect in a multispecies biofilm depend on the strain and the disinfectant used and challenge the common belief that organisms in multispecies biofilms are always less susceptible than in monospecies biofilms

Synthesis, In Vitro Antimicrobial and Antioxidant Activities of Some New 4,5-Dihydro-1H-1,2,4-Triazol-5-One Derivatives

A series of compounds derived from 4,5-dihydro-1H-1,2,4-triazol-5-one were synthesized and characterized by spectral data. The 12 new compounds were analyzed for their potential in vitro antioxidant activities by three different methods. Compound 4f showed the best activity for the iron binding. In addition, the compounds 4 were titrated potentiometrically with tetrabutylammonium hydroxide in non-aqueous solvents. The RP-HPLC capacity factors (k0) of the series were also determined on a C18 column, with methanol/water as the mobile phase. The correlation between log k0 with the percentage of methanol in the mobile phase was used for the determination of the log kw values for these compounds. The antimicrobial activities of these compounds were also screened against bacteria and yeast

Polyethyleneimine brushes effectively inhibit encrustation on polyurethane ureteral stents both in dynamic bioreactor and in vivo

ERTAS, NUSRET/0000-0002-9770-3292WOS: 000390967200135PubMed: 27987673Polyurethane (PU) ureteral stents have been widely used as biomedical devices to aid the flow of the urine. Due to the biofilm formation and encrustation complications it has been hindered their long term clinical usage. To overcome these complications, in this study, cationic polyethyleneimine (PEI) brushes grafted on PU stents and their performances were tested both in a dynamic biofilm reactor system (in vitro) and in a rat model (in vivo). Thus, we hypothesized that PEI brushes inhibit bacterial adhesion owing to the dynamic motion of brushes in liquid environment. In addition, cationic structure of PEI disrupts the membrane and so kills the bacteria on time of contact. Cationic PEI brushes decreased the biofilm formation up to 2 orders of magnitude and approximately 50% of encrustation amount in respect to unmodified PU, in vitro. In addition, according to Atomic Absorption Spectroscopy (AAS) results, approximately 90% of encrustation was inhibited on in vivo animal models. Decrease in encrustation was clearly observed on the stents obtained from rat model, by Scanning Electron Microscopy (SEM). Also, histological evaluations showed that; PEI brush grafting decreased host tissue inflammation in close relation to decrease in biofilm formation and encrustation. As a results; dual effect of anti adhesive and contact-killing antibacterial strategy showed high efficiency on PEI brushes grafted PU stents both in vitro and in vivo. (C) 2016 Elsevier B.V. All rights reserved.Scientific and Technological Research Council Turkey of (TUBITAK) [112M293]This study is financially supported by The Scientific and Technological Research Council Turkey of (TUBITAK) (Grant no: 112M293)

Propolis loaded liposomes: evaluation of antimicrobial and antioxidant activities

###EgeUn###Propolis, a natural bee product, has both antimicrobial/antifungal and antioxidant characteristics. Active substances having antimicrobial and antifungal effects are used to avoid infections, which develop during long treatment process of chronic wounds. Antioxidant substances protect wound areas against the effect of free radicals and accelerate the healing process. For this purpose, propolis was used to develop topical liposome formulations for wound treatment. Characterization studies (particle size distribution, polydispersity index, Zeta Potential, morphology pH, loading capacity, encapsulation efficiency, in-vitro release behaviour) as well as stability studies were performed. Then in-vitro antioxidant (free radical scavenging capacity and trolox equivalent antioxidant capacity) and antimicrobial/antifungal activities of formulations have been evaluated. The particle size of formulations was found within the range of 300-750 nm depending on the concentration of lipid and water phase in the formulation. The Zeta Potential and pH values of optimum formulation were -23.0 +/- 0.666 and 6.34, respectively. Loading capacity and encapsulation efficiency were 66.535 +/- 2.705% and 57.321 +/- 2.448%. At the end of 8 h, 48.16% of propolis was released and the formulations were found stable during 3 months at +4 degrees C. Drug loaded liposome formulations significantly scavenged the ABTS(+) radical in a dose-dependent manner of propolis when compared with unloaded liposome formulations (p < 0.05). The minimum inhibitory concentration (MIC) values of liposomes ranged from 512 to 128 mu g/mL for bacteria and 256 to 128 mu g/mL for fungi. Overall results showed that effective and innovative alternative was developed for topical application in wound treatment with propolis loaded liposomal formulations having antioxidant and antimicrobial effects.Research Foundation of Ege UniversityEge University [17/ECZ/006]This study was supported by the Research Foundation of Ege University [Grant Number 17/ECZ/006]