Oxygen tension during biofilm growth influences the efficacy antimicrobial agents

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.

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Effect of Algae and Plant Lectins on Planktonic Growth and Biofilm Formation in Clinically Relevant Bacteria and Yeasts

BioMed Research International ◽

10.1155/2014/365272 ◽

2014 ◽

Vol 2014 ◽

pp. 1-9 ◽

Cited By ~ 17

Author(s):

Mayron Alves Vasconcelos ◽

Francisco Vassiliepe Sousa Arruda ◽

Victor Alves Carneiro ◽

Helton Colares Silva ◽

Kyria Santiago Nascimento ◽

...

Keyword(s):

Staphylococcus Epidermidis ◽

Biofilm Formation ◽

Antimicrobial Agents ◽

Klebsiella Oxytoca ◽

Hypnea Musciformis ◽

Planktonic Growth ◽

Viable Cells ◽

Colony Forming Units ◽

Different Characteristics ◽

Vatairea Macrocarpa

This study aimed to evaluate the abilities of plant and algae lectins to inhibit planktonic growth and biofilm formation in bacteria and yeasts. Initially, ten lectins were tested onStaphylococcus epidermidis, Staphylococcus aureus, Klebsiella oxytoca, Pseudomonas aeruginosa, Candida albicans, andC. tropicalisat concentrations of 31.25 to 250 μg/mL. The lectins fromCratylia floribunda(CFL),Vatairea macrocarpa(VML),Bauhinia bauhinioides(BBL),Bryothamnion seaforthii(BSL), andHypnea musciformis(HML) showed activities against at least one microorganism. Biofilm formation in the presence of the lectins was also evaluated; after 24 h of incubation with the lectins, the biofilms were analyzed by quantifying the biomass (by crystal violet staining) and by enumerating the viable cells (colony-forming units). The lectins reduced the biofilm biomass and/or the number of viable cells to differing degrees depending on the microorganism tested, demonstrating the different characteristics of the lectins. These findings indicate that the lectins tested in this study may be natural alternative antimicrobial agents; however, further studies are required to better elucidate the functional use of these proteins.

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Bacterial Biofilm Growth on 3D-Printed Materials

Frontiers in Microbiology ◽

10.3389/fmicb.2021.646303 ◽

2021 ◽

Vol 12 ◽

Author(s):

Donald C. Hall ◽

Phillip Palmer ◽

Hai-Feng Ji ◽

Garth D. Ehrlich ◽

Jarosław E. Król

Keyword(s):

Medical Devices ◽

Biofilm Formation ◽

Antimicrobial Agents ◽

Bacterial Attachment ◽

Bacterial Biofilm ◽

Chronic Infections ◽

Biofilm Growth ◽

Wide Range ◽

3D Printed ◽

Printed Materials

Recent advances in 3D printing have led to a rise in the use of 3D printed materials in prosthetics and external medical devices. These devices, while inexpensive, have not been adequately studied for their ability to resist biofouling and biofilm buildup. Bacterial biofilms are a major cause of biofouling in the medical field and, therefore, hospital-acquired, and medical device infections. These surface-attached bacteria are highly recalcitrant to conventional antimicrobial agents and result in chronic infections. During the COVID-19 pandemic, the U.S. Food and Drug Administration and medical officials have considered 3D printed medical devices as alternatives to conventional devices, due to manufacturing shortages. This abundant use of 3D printed devices in the medical fields warrants studies to assess the ability of different microorganisms to attach and colonize to such surfaces. In this study, we describe methods to determine bacterial biofouling and biofilm formation on 3D printed materials. We explored the biofilm-forming ability of multiple opportunistic pathogens commonly found on the human body including Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus to colonize eight commonly used polylactic acid (PLA) polymers. Biofilm quantification, surface topography, digital optical microscopy, and 3D projections were employed to better understand the bacterial attachment to 3D printed surfaces. We found that biofilm formation depends on surface structure, hydrophobicity, and that there was a wide range of antimicrobial properties among the tested polymers. We compared our tested materials with commercially available antimicrobial PLA polymers.

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Immobilizing hydrolytic active Papain on biodegradable PLLA for biofilm inhibition in cardiovascular applications

Current Directions in Biomedical Engineering ◽

10.1515/cdbme-2020-3044 ◽

2020 ◽

Vol 6 (3) ◽

pp. 172-175

Author(s):

Michael Teske ◽

Tina Kießlich ◽

Niels Grabow ◽

Sabine Illner ◽

Julia Fischer ◽

...

Keyword(s):

Biofilm Formation ◽

Antimicrobial Agents ◽

Hydrolytic Enzyme ◽

Bacterial Biofilm ◽

Biofilm Inhibition ◽

Biofilm Growth ◽

Clostridioides Difficile ◽

Adhesive Surface

AbstractThe use of biomaterials in medicine is becoming increasingly important. One of the main concerns is the foreign body associated infection caused by direct microbial contamination or clinical infections. The bacterial biofilm formation on biomaterials depends on their surface properties. Therefore, several anti-adhesive surface modifications were developed. Nevertheless, the demand for antimicrobial agents that prevent bacterial colonisation is still largely unmet. The immobilization of active antimicrobial agents, such as antibacterial peptides or enzymes, offers a potential approach to achieve long-lasting effectiveness. In this investigation, the hydrolytic enzyme papain with its published antibacterial activity was covalently immobilized on the well-established biodegradable biomaterial poly-L-lactic acid (PLLA). For the characterization of the enzymes on the PLLA surfaces, the protein content and enzyme activity were determined. A biofilm assay was performed to test the effect of the papain-modified PLLA samples on the biofilm-forming bacterial strain Clostridioides difficile, one of the most frequently occurring human nosocomial pathogens. The investigated hydrolytic enzyme papain could be immobilized by coupling via the crosslinker EDC to the PLLA surface. Detection was performed by determination of the amount of protein and the reduced biofilm growth after 24 h and 72 h compared to the reference.

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Potential application of phage therapy for prophylactic treatment against Pseudomonasaeruginosabiofilm Infections

10.1101/404145 ◽

2018 ◽

Author(s):

Aditi Gurkar ◽

Deepak Balasubramanian ◽

Jayasheela Manur ◽

Kalai Mathee

Keyword(s):

Biofilm Formation ◽

Defense Mechanisms ◽

Antibacterial Agents ◽

Prophylactic Treatment ◽

Phage Therapy ◽

Planktonic Cells ◽

Biofilm Growth ◽

Cellular Defense ◽

Bacterial Mass

ABSTRACTThe majority of the microbial activity in humans is in the form of biofilms, i.e., an exopolysaccharide-enclosed bacterial mass. Unlike planktonic cells and the cells on the surface of the biofilm, the biofilm-embedded cells are more resistant to the effects of the antibiotics and the host cellular defense mechanisms. A combination of biofilm growth and inherent resistance prevents effective antibiotic treatment ofPseudomonas aeruginosainfections including those in patients with cystic fibrosis. Antibiotic resistance has led to an increasing interest in alternative modalities of treatment. Thus, phages that multiplyin situand in the presence of susceptible hosts can be used as natural, self-limiting, and profoundly penetrating antibacterial agents. The objective of this study is to identify active phages against a collection ofP. aeruginosaisolates (PCOR strains) including the prototype PAO1 and the isogenic constitutively alginate-producing PDO300 strains. These PCOR strains were tested against six phages (P105, P134, P140, P168, P175B, and P182). The analysis shows 69 % of the PCOR isolates are sensitive and the rest are resistant to all six phages. These phages were then tested for their ability to inhibit biofilm formation using a modified biofilm assay. The analysis demonstrated that the sensitive strains showed increased resistance, but none of the susceptible strains from the initial screening were resistant. Using the minimum biofilm eradication concentration (MBEC) assay for biofilm formation, the biofilm eradication ability of the phages was tested. The data showed that a higher volume of phage was required to eradicate preformed biofilms than the amount required to prevent colonization of planktonic cells. This data supports the idea of phage therapy more as a prophylactic treatment.

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

10.5194/biofilms9-67 ◽

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

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 Staphylococcus aureus and Staphylococcus epidermidis. The risk of infection might even be higher in so-called in situ 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. 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-11 and LL-372, 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 infections1. As a next step, we aim to develop a new polymeric supramolecular3 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. 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). 1Riool M. & de Breij A. et al., BBA &#8211; Biomembranes (2020); 2de Breij A. & Riool M. et al., Sci. Transl. Med. (2018); 3Dankers P.Y.W. et al., Nat. Mater. (2005).

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Magneto-mechanically actuated microstructures to efficiently prevent bacterial biofilm formation

Scientific Reports ◽

10.1038/s41598-020-72406-8 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

S. Leulmi Pichot ◽

H. Joisten ◽

A. J. Grant ◽

B. Dieny ◽

R. P. Cowburn

Keyword(s):

Biofilm Formation ◽

Antimicrobial Agents ◽

Substrate Surface ◽

Low Frequency ◽

Initial Position ◽

Bacterial Biofilm ◽

Biofilm Growth ◽

E Coli ◽

Initial Stage ◽

Fouling Release

Abstract Biofilm colonisation of surfaces is of critical importance in various areas ranging from indwelling medical devices to industrial setups. Of particular importance is the reduced susceptibility of bacteria embedded in a biofilm to existing antimicrobial agents. In this paper, we demonstrate that remotely actuated magnetic cantilevers grafted on a substrate act efficiently in preventing bacterial biofilm formation. When exposed to an alternating magnetic field, the flexible magnetic cantilevers vertically deflect from their initial position periodically, with an extremely low frequency (0.16 Hz). The cantilevers’ beating prevents the initial stage of bacterial adhesion to the substrate surface and the subsequent biofilm growth. Our experimental data on E. coli liquid cultures demonstrate up to a 70% reduction in biofilm formation. A theoretical model has been developed to predict the amplitude of the cantilevers vertical deflection. Our results demonstrate proof-of-concept for a device that can magneto-mechanically prevent the first stage in bacterial biofilm formation, acting as on-demand fouling release active surfaces.

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Nanosized Building Blocks for Customizing Novel Antibiofilm Approaches

Journal of Dental Research ◽

10.1177/0022034516679397 ◽

2016 ◽

Vol 96 (2) ◽

pp. 128-136 ◽

Cited By ~ 10

Author(s):

A.J. Paula ◽

H. Koo

Keyword(s):

Bacterial Adhesion ◽

Biofilm Formation ◽

Rational Design ◽

Antimicrobial Agents ◽

Building Blocks ◽

Low Oxygen ◽

Bioactive Materials ◽

Functional Nanoparticles ◽

Oral Biofilms ◽

New Generation

Recent advances in nanotechnology provide unparalleled flexibility to control the composition, size, shape, surface chemistry, and functionality of materials. Currently available engineering approaches allow precise synthesis of nanocompounds (e.g., nanoparticles, nanostructures, nanocrystals) with both top-down and bottom-up design principles at the submicron level. In this context, these “nanoelements” (NEs) or “nanosized building blocks” can 1) generate new nanocomposites with antibiofilm properties or 2) be used to coat existing surfaces (e.g., teeth) and exogenously introduced surfaces (e.g., restorative or implant materials) for prevention of bacterial adhesion and biofilm formation. Furthermore, functionalized NEs 3) can be conceived as nanoparticles to carry and selectively release antimicrobial agents after attachment or within oral biofilms, resulting in their disruption. The latter mechanism includes “smart release” of agents when triggered by pathogenic microenvironments (e.g., acidic pH or low oxygen levels) for localized and controlled drug delivery to simultaneously kill bacteria and dismantle the biofilm matrix. Here we discuss inorganic, metallic, polymeric, and carbon-based NEs for their outstanding chemical flexibility, stability, and antibiofilm properties manifested when converted into bioactive materials, assembled on-site or delivered at biofilm-surface interfaces. Details are provided on the emerging concept of the rational design of NEs and recent technological breakthroughs for the development of a new generation of nanocoatings or functional nanoparticles for biofilm control in the oral cavity.

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Biofilm Formation and Expression of Virulence Genes of Microorganisms Grown in Contact with a New Bioactive Glass

Pathogens ◽

10.3390/pathogens9110927 ◽

2020 ◽

Vol 9 (11) ◽

pp. 927

Author(s):

Viviane de Cássia Oliveira ◽

Marina Trevelin Souza ◽

Edgar Dutra Zanotto ◽

Evandro Watanabe ◽

Débora Coraça-Huber

Keyword(s):

Bioactive Glass ◽

Virulence Factors ◽

Virulence Factor ◽

Biofilm Formation ◽

Inhibitory Effect ◽

Titanium Implants ◽

Biofilm Growth ◽

Chain Reactions ◽

Polymerase Chain Reactions ◽

Colony Forming Units

Bioactive glass F18 (BGF18), a glass containing SiO2–Na2O–K2O–MgO–CaO–P2O5, is highly effective as an osseointegration buster agent when applied as a coating in titanium implants. Biocompatibility tests using this biomaterial exhibited positive results; however, its antimicrobial activity is still under investigation. In this study we evaluated biofilm formation and expression of virulence-factor-related genes in Candida albicans, Staphylococcus epidermidis, and Pseudomonas aeruginosa grown on surfaces of titanium and titanium coated with BGF18. C. albicans, S. epidermidis, and P. aeruginosa biofilms were grown on specimens for 8, 24, and 48 h. After each interval, the pH was measured and the colony-forming units were counted for the biofilm recovery rates. In parallel, quantitative real-time polymerase chain reactions were carried out to verify the expression of virulence-factor-related genes. Our results showed that pH changes of the culture in contact with the bioactive glass were merely observed. Reduction in biofilm formation was not observed at any of the studied time. However, changes in the expression level of genes related to virulence factors were observed after 8 and 48 h of culture in BGF18. BGF18 coating did not have a clear inhibitory effect on biofilm growth but promoted the modulation of virulence factors.

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The effects of tea polyphenols onCandida albicans: inhibition of biofilm formation and proteasome inactivation

Canadian Journal of Microbiology ◽

10.1139/w09-058 ◽

2009 ◽

Vol 55 (9) ◽

pp. 1033-1039 ◽

Cited By ~ 56

Author(s):

Nikki A. Evensen ◽

Phyllis C. Braun

Keyword(s):

Green Tea ◽

Biofilm Formation ◽

Antimicrobial Agents ◽

Tea Polyphenols ◽

Green Tea Polyphenols ◽

Yeast Cells ◽

Growth Rate Constant ◽

Phenotypic Traits ◽

Biofilm Inhibition

The adherence of Candida albicans to one another and to various host and biomaterial surfaces is an important prerequisite for the colonization and pathogenesis of this organism. Cells in established biofilms exhibit different phenotypic traits and are inordinately resistant to antimicrobial agents. Recent studies have shown that black and green tea polyphenols exhibit both antimicrobial and strong cancer-preventive properties. Experiments were conducted to determine the effects of these polyphenols on C. albicans. Standard growth curves demonstrated a 40% reduction in the growth rate constant (K) with a 2 mg/mL concentration of Polyphenon 60, a green tea extract containing a mixture of polyphenolic compounds. Cultures treated with 1.0 µmol/L –(–)epigallocatechin-3-gallate (EGCG), the most abundant polyphenol, displayed a 75% reduction of viable cells during biofilm formation. Established biofilms treated with EGCG were also reduced, by 80%, as determined through XTT (2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) colorimetric assays. Identical concentrations of epigallocatechin and epicatechin-3-gallate demonstrated similar biofilm inhibition. Further investigations regarding the possible mechanism of polyphenol action indicate that in vivo proteasome activity was significantly decreased when catechin-treated yeast cells were incubated with a fluorogenic peptide substrate that measured proteasomal chymotrypsin-like and peptidyl-glutamyl peptide-hydrolyzing activities. Impairment of proteasomal activity by tea polyphenols contributes to cellular metabolic and structural disruptions that expedite the inhibition of biofilm formation and maintenance by C. albicans.

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