scholarly journals Detection of ALS3 and EAP1 gene expresssion in Candida albicans and Candida maltosa biofilms by FISH

2016 ◽  
Vol 6 (2) ◽  
pp. 848-857
Author(s):  
Danitza Xiomara Romero ◽  
Oscar Víctor Cárdenas ◽  
María Teresa Álvarez
Keyword(s):  
Medical Devices ◽  
Biofilm Formation ◽  
Industrial Wastewater ◽  
Candida Maltosa ◽  
Modified Method ◽  
Composition Formation ◽  
Wastewater Systems ◽  
Candida Biofilm ◽  
Detect Gene Expression

Biofilm is regarded as universal forms of microorganism life in aquatic and industrial wastewater systems as well as in a large number of environments and medical devices relevant for public health, where the exact mechanisms by which biofilm-associated microorganisms elicit infection diseases are still poorly understood. Candida biofilm formation is regulated by different mechanisms where adhesins play a clue role in the yeast attachment to certain surfaces. These adhesins are encoding by ALS3, HWP1 and EAP1 genes among others and they are also considered as Candida virulence factors. Methodologies use to study biofilm productions are intended to verify the biofilm composition, formation steps, tridimensional structure and might facilitate the monitoring of biofilm regarding, antibiotic resistance, degradations, inhibitors, enhanciement biofilm formation and other features. Here, FISH expression a modified method to detect gene expression in situ was used in order to detect ALS3, HWP1 and EAP1 in C. albicans and C. maltosa biofilms, constituting a useful tool to monitor biofilm formations. In this regard, ALS3 expression was identified in C. albicans and C. maltosa biofilms.

Novel Synthetic Antimicrobial and Anti-biofilm Peptides (SAAPs)-containing coatings to prevent biomaterial-associated infection

2020 ◽  
Author(s):  
Martijn Riool ◽  
Anna de Breij ◽  
Moniek G.J. Schmitz ◽  
Leonie de Boer ◽  
Jan W. Drijfhout ◽  
...  
Keyword(s):  
Medical Devices ◽  
Biofilm Formation ◽  
Heart Valves ◽  
Antimicrobial Agents ◽  
Porous Scaffold ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Prosthetic Heart Valves ◽  
Scaffold Material

<p>The use of medical devices has grown significantly over the last decades, and has become a major part of modern medicine and our daily life. Infection of implanted medical devices (biomaterials), like catheters, prosthetic heart valves or orthopaedic implants, can have disastrous consequences, including removal of the device. For still not well understood reasons, the presence of a foreign body strongly increases susceptibility to infection. These so-called biomaterial-associated infections (BAI) are mainly caused by <em>Staphylococcus aureus</em> and <em>Staphylococcus epidermidis</em>. The risk of infection might even be higher in so-called <em>in situ</em> tissue engineering applications, where population or infiltration of the scaffold material by endogenous cells and thereby the formation of new/healed tissue occurs as a spatiotemporal process. Since the porous scaffold materials can form a niche for invading bacteria, the intended in situ production of novel tissue may be severely compromised by infection.</p> <p>Our work focuses on the development and characterization of novel antimicrobial agents and delivery systems, and their effectiveness in the prevention of BAI and other difficult-to-treat biofilm infections. The scarcity of current antibiotic-based strategies to prevent infections and their risk of resistance development prompted us to develop novel synthetic antimicrobial and anti-biofilm peptides (SAAPs) based on the primary sequences of the human antimicrobial proteins Thrombocin-1<sup>1</sup> and LL-37<sup>2</sup>, and to test their potential in the fight against implant-associated and wound infections by multidrug-resistant bacteria. The lead peptide, SAAP-148, kills multidrug-resistant pathogens without inducing resistance, prevents biofilm formation and eliminates established biofilms and persister cells, and is effective against both acute and established skin infections<sup>1</sup>. As a next step, we aim to develop a new polymeric supramolecular<sup>3</sup> scaffold material, exerting two important functions: preventing microbial adhesion - by incorporating SAAP-148 - and thereby preventing biofilm formation, and inducing endogenous (eukaryotic) cells to adhere and propagate, as a first step towards functional tissue repair.</p> <p>This work is supported by FP7-HEALTH-2011 grant 278890, Biofilm Alliance and by NWO NEWPOL grant SuperActive (Project No. 731.015.505) in collaboration with the Dutch Polymer Institute (DPI, P.O. Box 902, 5600 AX Eindhoven, the Netherlands).</p> <p><sup>1</sup>Riool M. & de Breij A. <em>et al.</em>, BBA – Biomembranes (2020); <sup>2</sup>de Breij A. & Riool M. <em>et al.</em>, Sci. Transl. Med. (2018); <sup>3</sup>Dankers P.Y.W. <em>et al.</em>, Nat. Mater. (2005).</p>

scholarly journals Eradication of Candida albicans Biofilm Viability: In Vitro Combination Therapy of Cationic Carbosilane Dendrons Derived from 4-Phenylbutyric Acid with AgNO3 and EDTA

2021 ◽  
Vol 7 (7) ◽  
pp. 574
Author(s):  
Natalia Gómez-Casanova ◽  
Tania Lozano-Cruz ◽  
Juan Soliveri ◽  
Rafael Gomez ◽  
Paula Ortega ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Medical Devices ◽  
Biofilm Formation ◽  
Second Generation ◽  
Antifungal Agents ◽  
Human Pathogen ◽  
Other Substances ◽  
Phenylbutyric Acid ◽  
Candida Biofilm

Candida albicans is a human pathogen of significant clinical relevance. This pathogen is resistant to different drugs, and most clinical antifungals are not effective against the prevention and treatment of C. albicans infections. As with other microorganisms, it can produce biofilms that serve as a barrier against antifungal agents and other substances, contributing to infection in humans and environmental tolerance of this microorganism. Thus, resistances and biofilm formation make treatment difficult. In addition, the complete eradication of biofilms in implants, catheters and other medical devices, is challenging and necessary to prevent relapses of candidemia. Therefore, it is a priority to find new molecules or combinations of compounds with anti-Candida biofilm activity. Due to the difficulty of treating and removing biofilms, the aim of this study was to evaluate the in vitro ability of different generation of cationic carbosilane dendrons derived from 4-phenylbutyric acid, ArCO2Gn(SNMe3I)m, to eradicate C. albicans biofilms. Here, we assessed the antifungal activity of the second generation dendron ArCO2G2(SNMe3I)4 against C. albicans cells and established biofilms since it managed to seriously damage the membrane. In addition, the combinations of the second generation dendron with AgNO3 or EDTA eradicated the viability of biofilm cells. Alterations were observed by scanning electron microscopy and cytotoxicity was assessed on HeLa cells. Our data suggest that the dendritic compound ArCO2G2(SNMe3I)4 could represent an alternative to control the infections caused by this pathogen.

Bacterial biofilm behavior in water-supply lines of dental units

1992 ◽  
Vol 50 (1) ◽  
pp. 882-883
Author(s):  
B.D. Tall ◽  
K.S. George ◽  
R. T. Gray ◽  
H.N. Williams
Keyword(s):  
Water Supply ◽  
Medical Devices ◽  
Biofilm Formation ◽  
Bacterial Biofilm

Studies of bacterial behavior in many environments have shown that most organisms attach to surfaces, forming communities of microcolonies called biofilms. In contaminated medical devices, biofilms may serve both as reservoirs and as inocula for the initiation of infections. Recently, there has been much concern about the potential of dental units to transmit infections. Because the mechanisms of biofilm formation are ill-defined, we investigated the behavior and formation of a biofilm associated with tubing leading to the water syringe of a dental unit over a period of 1 month.

scholarly journals Surface Immobilization of Nano-Silver on Polymeric Medical Devices to Prevent Bacterial Biofilm Formation

Pathogens ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 93 ◽  
Author(s):  
Riau ◽  
Aung ◽  
Setiawan ◽  
Yang ◽  
Yam ◽  
...  
Keyword(s):  
Medical Devices ◽  
Biofilm Formation ◽  
Culture Media ◽  
Silver Ions ◽  
Bacterial Biofilm ◽  
Surface Immobilization ◽  
Nano Silver ◽  
Gram Positive Bacteria ◽  
Tissue Microenvironment

: Bacterial biofilm on medical devices is difficult to eradicate. Many have capitalized the anti-infective capability of silver ions (Ag+) by incorporating nano-silver (nAg) in a biodegradable coating, which is then laid on polymeric medical devices. However, such coating can be subjected to premature dissolution, particularly in harsh diseased tissue microenvironment, leading to rapid nAg clearance. It stands to reason that impregnating nAg directly onto the device, at the surface, is a more ideal solution. We tested this concept for a corneal prosthesis by immobilizing nAg and nano-hydroxyapatite (nHAp) on poly(methyl methacrylate), and tested its biocompatibility with human stromal cells and antimicrobial performance against biofilm-forming pathogens, Pseudomonas aeruginosa and Staphylococcus aureus. Three different dual-functionalized substrates—high Ag (referred to as 75:25 HAp:Ag); intermediate Ag (95:5 HAp:Ag); and low Ag (99:1 HAp:Ag) were studied. The 75:25 HAp:Ag was effective in inhibiting biofilm formation, but was cytotoxic. The 95:5 HAp:Ag showed the best selectivity among the three substrates; it prevented biofilm formation of both pathogens and had excellent biocompatibility. The coating was also effective in eliminating non-adherent bacteria in the culture media. However, a 28-day incubation in artificial tear fluid revealed a ~40% reduction in Ag+ release, compared to freshly-coated substrates. The reduction affected the inhibition of S. aureus growth, but not the P. aeruginosa. Our findings suggest that Ag+ released from surface-immobilized nAg diminishes over time and becomes less effective in suppressing biofilm formation of Gram-positive bacteria, such as S. aureus. This advocates the coating, more as a protection against perioperative and early postoperative infections, and less as a long-term preventive solution.

Effect of food preservatives on in situ biofilm formation

2008 ◽  
Vol 12 (3) ◽  
pp. 203-208 ◽  
Author(s):  
Nicole Birgit Arweiler ◽  
Ronaldo Lenz ◽  
Anton Sculean ◽  
Ali Al-Ahmad ◽  
Elmar Hellwig ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Food Preservatives ◽  
Effect Of Food

RNAIII Inhibiting Peptide (RIP) and Derivatives as Potential Tools for the Treatment of S. aureus Biofilm Infections

2019 ◽  
Vol 18 (24) ◽  
pp. 2068-2079 ◽  
Author(s):  
Michele Ciulla ◽  
Antonio Di Stefano ◽  
Lisa Marinelli ◽  
Ivana Cacciatore ◽  
Giuseppe Di Biase
Keyword(s):  
Medical Devices ◽  
Biofilm Formation ◽  
Heart Valves ◽  
Cell Communication ◽  
Antibiofilm Activity ◽  
Host Immune System ◽  
Excellent Growth ◽  
Potential Applications ◽  
Novel Strategy ◽  
Derivatives Of

S. aureus under the biofilm mode of growth is often related to several nosocomial infections, more frequently associated with indwelling medical devices (catheters, prostheses, portacaths or heart valves). As a biofilm, the biopolymer matrix provides an excellent growth medium, increasing the tolerance to antibiotics and host immune system. To date, the antimicrobial therapy alone is not effective. A novel strategy to prevent biofilm formation is based on the interference with the bacterial cell–cell communication, a process known as quorum sensing (QS) and mediated by the RNA-III-activating peptide (RAP) and its target protein TRAP (Target of RAP). The RNAIII inhibiting peptide (RIP) is able to inhibit S. aureus pathogenesis by disrupting QS mechanism competing with RAP, thus inhibiting the phosphorylation of TRAP. This alteration leads to a reduced adhesion and to the inhibition of RNAIII synthesis, with the subsequent suppression of toxins synthesis. The present paper will provide an overview on the activity and potential applications of RIP as biofilm inhibiting compound, useful in the management of S. aureus biofilm infections. Moreover, medicinal chemistry strategies have been examined to better understand which modifications and/or structure alterations were able to produce new derivatives of this QS inhibitor with an improved antibiofilm activity.

scholarly journals Oxygen tension during biofilm growth influences the efficacy antimicrobial agents

2016 ◽  
Vol 45 (5) ◽  
pp. 302-307 ◽  
Author(s):  
Raquel Pippi ANTONIAZZI ◽  
Gabriela Ocampo TROJAHN ◽  
Maísa CASARIN ◽  
Camilla Filippi dos Santos ALVES ◽  
Roberto Christ Vianna SANTOS ◽  
...  
Keyword(s):  
Green Tea ◽  
Oxygen Tension ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Dental Students ◽  
Low Oxygen ◽  
Biofilm Growth ◽  
Model Method ◽  
Colony Forming Units

Abstract Objective To compare the antimicrobial efficacy of a 0.12% chlorhexidine (CHX) and herbal green tea (Camellia sinensis) solution on established biofilms formed at different oxygen tensions in an in situ model. Method Twenty-five dental students were eligible for the study. In situ devices with standardized enamel specimens (ES) facing the palatal and buccal sides were inserted in the mouths of volunteers for a 7 day period. No agent was applied during the first four days. From the fifth day onward, both agents were applied to the test ES group and no agent was applied to the control ES group. After 7 days the ES fragments were removed from the devices, sonicated, plated on agar, and incubated for 24 h at 37 °C to determine and quantify the colony forming units (CFUs). Result CHX had significantly higher efficacy compared to green tea on the buccal (1330 vs. 2170 CFU/µL) and palatal (2250 vs. 2520 CFU/µL) ES. In addition, intragroup comparisons showed significantly higher efficacy in buccal ES over palatal ES (1330 vs. 2250 CFU/µL for CHX and 2170 vs, 2520 CFU/µL for CV) for both solutions. Analysis of the ES controls showed significantly higher biofilm formation in palatal ES compared to buccal ES. Conclusion CHX has higher efficacy than green tea on 4-day biofilms. The efficacy of both agents was reduced for biofilms grown in a low oxygen tension environment. Therefore, the oxygen tension environment seems to influence the efficacy of the tested agents.

Sample preparations are important for fluorescence in situ hybridization of cells biopsied from preimplantation embryos

Zygote ◽  
2013 ◽  
Vol 22 (3) ◽  
pp. 300-304
Author(s):  
Lifei Li ◽  
Xuehong Zhang ◽  
Weihua Wang
Keyword(s):  
Sample Preparation ◽  
Chromosomal Abnormalities ◽  
Genetic Diagnosis ◽  
Preimplantation Embryos ◽  
Human Embryos ◽  
Fixation Time ◽  
Preparation Technique ◽  
Hypotonic Solution ◽  
Modified Method

SummaryFluorescence in situ hybridization (FISH) is a cytogenetic technology used to detect chromosomal abnormalities in preimplantation human embryos. However, its efficiency is not stable due to improper sample preparation. The present study was designed to modify the current sample preparation technique and then to evaluate its efficiency in human preimplantation genetic diagnosis (PGD). Day 3 cleavage embryos as well as day 5 and 6 blastocysts were biopsied by mechanical aspiration method. In the present study, two methods were used for sample preparation of the biopsied cells. Method I was the traditional method, in which each blastomere was placed in a hypotonic solution for 5 min and then fixed on glass slides. The slides were kept at room temperature before the FISH procedures. Method II was a modified method, in which all blastomeres were placed individually in hypotonic solution drops covered by oil for at least 5 min and then fixed on slides with 0.1% Tween/HCl. After fixation, the slides were kept at –20°C for at least 30 min before the FISH procedures. The two methods were compared in terms of time consumption and proportions of blastomeres with FISH signals. In total, 329 blastomeres from day 3 embryos were fixed by Method I with an average fixation time of 8–10 min for each blastomere. By contrast, with Method II, 362 blastomeres were fixed and the average time was 3–4 min for each blastomere. After FISH, more nuclei had signals with Method II (97.2%) than with Method I (86.9%). All cells that were biopsied from blastocysts and prepared with Method II had FISH signals. However, Method I was not suitable for the fixation of multiple cells biopsied from blastocysts as cells were not traceable during the fixation. The present study indicates that proper sample preparation is critical for obtaining FISH signals in cells biopsied from preimplantation human embryos; hence these modifications can increase the efficiency of human PGD.

scholarly journals Effects of certain disinfectants and antibiotics on biofilm formation by Staphylococcus aureus isolated from medical devices at the University Hospital Center of Sidi Bel Abbes, Algeria

2020 ◽  
Vol 21 (4) ◽  
pp. 304-310
Author(s):  
I. Kara Terki ◽  
H. Hassaine ◽  
A. Kara Terki ◽  
B. Nadira ◽  
N. Kara Terki ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Medical Devices ◽  
Biofilm Formation ◽  
University Hospital ◽  
Centre Hospitalier ◽  
Treatment And Prevention ◽  
Centre Hospitalier Universitaire ◽  
Dispositif Médical ◽  
The University ◽  
Hospital Center

Background: Staphylococcus aureus is one of the species of bacteria most frequently isolated from medical devices. The ability to produce biofilm is an important step in the pathogenesis of these staphylococci infection, and biofilm formation is strongly dependent on environmental conditions as well as antibiotics and disinfectants used in the treatment and prevention of infections.Methodology: In this study, 28 S. aureus isolated from medical devices at the University Hospital Center of Sidi Bel Abbes in Northwestern Algeria were tested for biofilm formation by culture on Red Congo Agar (RCA). The tube method (TM) and tissue culture plate (TCP) techniques were also used to investigate the effect of penicillin, ethanol and betadine on pre-formed biofilm.Results: Nineteen S. aureus isolates produced biofilm on the RCA and 7 produced biofilms by the tube method, 2 of which were high producer. In addition, 9 S. aureus isolates produced biofilm on polystyrene micro-plates, and in the presence of penicillin and ethanol, this number increased to 19 and 11 biofilm producing S. aureus isolates respectively. On the other hand, no biofilm was formed in the presence of betadine.Conclusion: It is important to test for biofilm formation following an imposed external constraint such as disinfectants and antibiotics in order to develop new strategies to combat bacterial biofilms but also to better control their formation. Keywords : Staphylococcus aureus, biofilm, medical device, disinfectant, antibiotic French Title: Effets de certains désinfectants et antibiotiques sur la formation de biofilms par Staphylococcus aureus isolé à partir de dispositifs médicaux au Centre Hospitalier Universitaire de Sidi Bel Abbès, Algérie Contexte: Staphylococcus aureus est l'une des espèces de bactéries les plus fréquemment isolées des dispositifs médicaux. La capacité de produire du biofilm est une étape importante dans la pathogenèse de ces infections à staphylocoques, et la formation de biofilm dépend fortement des conditions environnementales ainsi que des antibiotiques et des désinfectants utilisés dans le traitement et la prévention des infections. Méthodologie: Dans cette étude, 28 S. aureus isolés à partir de dispositifs médicaux au Centre hospitalier universitaire de Sidi Bel Abbès dans le nord-ouest de l'Algérie ont été testés pour la formation de biofilm par culture sur gélose rouge du Congo (RCA). La méthode des tubes (TM) et les techniques de plaques de culture tissulaire (TCP) ont également été utilisées pour étudier l'effet de la pénicilline, de l'éthanol et de la bétadine sur le biofilm préformé. Résultats: Dix-neuf isolats de S. aureus ont produit un biofilm sur le RCA et 7 ont produit des biofilms par la méthode des tubes, dont 2 étaient très productifs. De plus, 9 isolats de S. aureus ont produit du biofilm sur des microplaques en polystyrène, et en présence de pénicilline et d'éthanol, ce nombre est passé à 19 et 11 isolats de S. aureus producteurs de biofilm respectivement. En revanche, aucun biofilm ne s'est formé en présence de bétadine. Conclusion: Il est important de tester la formation de biofilm suite à une contrainte externe imposée comme les désinfectants et les antibiotiques afin de développer de nouvelles stratégies pour lutter contre les biofilms bactériens mais aussi pour mieux contrôler leur formation. Mots-clés: Staphylococcus aureus, biofilm, dispositif médical, désinfectant, antibiotique  

scholarly journals Understanding How Staphylococcal Autolysin Domains Interact With Polystyrene Surfaces

2021 ◽  
Vol 12 ◽  
Author(s):  
Radha P. Somarathne ◽  
Emily R. Chappell ◽  
Y. Randika Perera ◽  
Rahul Yadav ◽  
Joo Youn Park ◽  
...  
Keyword(s):  
Secondary Structure ◽  
Medical Devices ◽  
Biofilm Formation ◽  
Limited Proteolysis ◽  
Cd Spectroscopy ◽  
Bacterial Attachment ◽  
Binding Interaction ◽  
Biofilm Growth ◽  
Source Of Infection ◽  
Structural Details

Biofilms, when formed on medical devices, can cause malfunctions and reduce the efficiency of these devices, thus complicating treatments and serving as a source of infection. The autolysin protein of Staphylococcus epidermidis contributes to its biofilm forming ability, especially on polystyrene surfaces. R2ab and amidase are autolysin protein domains thought to have high affinity to polystyrene surfaces, and they are involved in initial bacterial attachment in S. epidermidis biofilm formation. However, the structural details of R2ab and amidase binding to surfaces are poorly understood. In this study, we have investigated how R2ab and amidase influence biofilm formation on polystyrene surfaces. We have also studied how these proteins interact with polystyrene nanoparticles (PSNPs) using biophysical techniques. Pretreating polystyrene plates with R2ab and amidase domains inhibits biofilm growth relative to a control protein, indicating that these domains bind tightly to polystyrene surfaces and can block bacterial attachment. Correspondingly, we find that both domains interact strongly with anionic, carboxylate-functionalized as well as neutral, non-functionalized PSNPs, suggesting a similar binding interaction for nanoparticles and macroscopic surfaces. Both anionic and neutral PSNPs induce changes to the secondary structure of both R2ab and amidase as monitored by circular dichroism (CD) spectroscopy. These changes are very similar, though not identical, for both types of PSNPs, suggesting that carboxylate functionalization is only a small perturbation for R2ab and amidase binding. This structural change is also seen in limited proteolysis experiments, which exhibit substantial differences for both proteins when in the presence of carboxylate PSNPs. Overall, our results demonstrate that the R2ab and amidase domains strongly favor adsorption to polystyrene surfaces, and that surface adsorption destabilizes the secondary structure of these domains. Bacterial attachment to polystyrene surfaces during the initial phases of biofilm formation, therefore, may be mediated by aromatic residues, since these residues are known to drive adsorption to PSNPs. Together, these experiments can be used to develop new strategies for biofilm eradication, ensuring the proper long-lived functioning of medical devices.

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