Special Issue "Natural Anti-Biofilm Agents"

A special issue of Pharmaceuticals (ISSN 1424-8247). This special issue belongs to the section "Natural Products".

Deadline for manuscript submissions: 20 March 2024 | Viewed by 4300

Special Issue Editors

Department of Basic Biotechnological Sciences, Intensive and Perioperative Clinics Università Cattolica del Sacro Cuore, Rome, Italy
Interests: antimicrobial resistance; new antimicrobial compounds; biofilm; biofilm-related infections; anti-biofilm; nanomaterials; mycology; advanced diagnostic
Dr. Riccardo Torelli
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Guest Editor
Department of Laboratory and Infectious Disease Sciences, "A. Gemelli" University Hospital Foundation IRCCS, Rome, Italy
Interests: clinical mycology; antimicrobial resistance; antimicrobial compounds; biofilm-related infections; anti-biofilm nanomaterials

Special Issue Information

Dear Colleagues,

Biofilm is a complex structure composed of an organized aggregation of single or multiple microbial species, which is surrounded by an extra-cellular polymeric substance and attached to biotic or abiotic surfaces. Cells in biofilm are more resistant to environmental stresses such as nutrient depletion. Biofilm can be formed in the human body or medical devices, causing difficult-to-treat infections with a high risk of recalcitrant episodes. This is due to the different properties of the biofilm: evasion from the immune system, low metabolic rate, tolerance, and resistance to antimicrobial therapies. Research in recent years has aimed to identify new compounds with anti-biofilm activity; particularly, the use of “green” molecules, such as phytochemicals, antimicrobial peptides, green synthetized nanoparticles and nanomaterials, are of great interest. The scope of this Special Issue is to publish papers about the anti-biofilm activity of green compounds and their possible application in medicine, the food industry and livestock. Submitted manuscripts should include in vitro and/or in vivo studies of phytochemicals (phenolics, essential oils, terpenoids, lectins, alkaloids, polypeptides and polyacetylenes); antimicrobial peptides; naturally synthetized nanoparticles (silver nanoparticles, cooper, titanium, etc.); and green synthetized nanomaterials that are able to inhibit a microorganism’s adhesion and biofilm formation, along with their mechanism of action and/or possible application.

Dr. Margherita Cacaci
Dr. Riccardo Torelli
Guest Editors

Manuscript Submission Information

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Keywords

  • biofilm
  • drug-resistance
  • green anti-biofilm antimicrobial peptides
  • phytochemicals
  • new green nanomaterials for medical devices or animal food contact surfaces

Published Papers (3 papers)

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Research

24 pages, 5364 KiB  
Article
Polyglactin 910 Meshes Coated with Sustained-Release Cannabigerol Varnish Inhibit Staphylococcus aureus Biofilm Formation and Macrophage Cytokine Secretion: An In Vitro Study
Pharmaceuticals 2023, 16(5), 745; https://doi.org/10.3390/ph16050745 - 13 May 2023
Viewed by 1106
Abstract
Synthetic surgical meshes are commonly used in abdominal wall reconstruction surgeries to strengthen a weak abdominal wall. Common mesh-related complications include local infection and inflammatory processes. Because cannabigerol (CBG) has both antibacterial and anti-inflammatory properties, we proposed that coating VICRYL (polyglactin 910) mesh [...] Read more.
Synthetic surgical meshes are commonly used in abdominal wall reconstruction surgeries to strengthen a weak abdominal wall. Common mesh-related complications include local infection and inflammatory processes. Because cannabigerol (CBG) has both antibacterial and anti-inflammatory properties, we proposed that coating VICRYL (polyglactin 910) mesh with a sustained-release varnish (SRV) containing CBG would prevent these complications. We used an in vitro infection model with Staphylococcus aureus and an in vitro inflammation model of lipopolysaccharide (LPS)-stimulated macrophages. Meshes coated with either SRV-placebo or SRV-CBG were exposed daily to S. aureus in tryptic soy medium (TSB) or macrophage Dulbecco’s modified eagle medium (DMEM). Bacterial growth and biofilm formation in the environment and on the meshes were assessed by changes in optical density, bacterial ATP content, metabolic activity, crystal violet staining, spinning disk confocal microscopy (SDCM), and high-resolution scanning electron microscopy (HR-SEM). The anti-inflammatory effect of the culture medium that was exposed daily to the coated meshes was analyzed by measuring the release of the cytokines IL-6 and IL-10 from LPS-stimulated RAW 264.7 macrophages with appropriate ELISA kits. Additionally, a cytotoxicity assay was performed on Vero epithelial cell lines. We observed that compared with SRV-placebo, the segments coated with SRV-CBG inhibited the bacterial growth of S. aureus in the mesh environment for 9 days by 86 ± 4% and prevented biofilm formation and metabolic activity in the surroundings for 9 days, with respective 70 ± 2% and 95 ± 0.2% reductions. The culture medium that was incubated with the SRV-CBG-coated mesh inhibited LPS-induced secretion of IL-6 and IL-10 from the RAW 264.7 macrophages for up to 6 days without affecting macrophage viability. A partial anti-inflammatory effect was also observed with SRV-placebo. The conditioned culture medium was not toxic to Vero epithelial cells, which had an IC50 of 25 µg/mL for CBG. In conclusion, our data indicate a potential role of coating VICRYL mesh with SRV-CBG in preventing infection and inflammation in the initial period after surgery. Full article
(This article belongs to the Special Issue Natural Anti-Biofilm Agents)
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17 pages, 7178 KiB  
Article
Effects of Piper betle Extracts against Biofilm Formation by Methicillin-Resistant Staphylococcus pseudintermedius Isolated from Dogs
Pharmaceuticals 2023, 16(5), 741; https://doi.org/10.3390/ph16050741 - 12 May 2023
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Abstract
Emergence of methicillin-resistant Staphylococcus pseudintermedius (MRSP) isolated from dogs with cutaneous and wound infections has significantly impacted veterinary medicine. This study aimed to isolate S. pseudintermedius from canine pyoderma and investigate the effects of ethanolic extracts of Piper betle (PB), P. sarmentosum (PS), [...] Read more.
Emergence of methicillin-resistant Staphylococcus pseudintermedius (MRSP) isolated from dogs with cutaneous and wound infections has significantly impacted veterinary medicine. This study aimed to isolate S. pseudintermedius from canine pyoderma and investigate the effects of ethanolic extracts of Piper betle (PB), P. sarmentosum (PS), and P. nigrum (PN) on the bacterial growth and biofilm formation of S. pseudintermedius and MRSP. Of the isolated 152 isolates, 53 were identified as S. pseudintermedius using polymerase chain reaction, and 10 isolates (6.58%) were identified as MRSP based on the presence of mecA. Based on phenotype, 90% of MRSPs were multidrug-resistant. All MRSP had moderate (10%, 1/10) and strong (90%, 9/10) biofilm production ability. PB extracts were the most effective in inhibiting planktonic cells, and the minimum inhibitory concentration at which ≥50% of the isolates were inhibited (MIC50) was 256 µg/mL (256–1024 µg/mL) for S. pseudintermedius isolates and 512 µg/mL (256–1024 µg/mL) for MRSP isolates. The MIC90 for S. pseudintermedius and MRSP was 512 µg/mL. In XTT assay, PB at 4× MIC showed an inhibition rate of 39.66–68.90% and 45.58–59.13% for S. pseudintermedius and MRSP, respectively, in inhibiting biofilm formation. For PB at 8× MIC, the inhibition rates for S. pseudintermedius and MRSP were 50.74–81.66% and 59.57–78.33%, respectively. Further, 18 compounds were identified in PB using gas chromatography–mass spectrometry, and hydroxychavicol (36.02%) was the major constituent. These results indicated that PB could inhibit bacteria growth of and biofilm formation by S. pseudintermedius and MRSP isolated from canine pyoderma in a concentration-dependent manner. Therefore, PB is a potential candidate for the treatment of MRSP infection and biofilm formation in veterinary medicine. Full article
(This article belongs to the Special Issue Natural Anti-Biofilm Agents)
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17 pages, 4777 KiB  
Article
Curcumin-Functionalized Graphene Oxide Strongly Prevents Candida parapsilosis Adhesion and Biofilm Formation
Pharmaceuticals 2023, 16(2), 275; https://doi.org/10.3390/ph16020275 - 11 Feb 2023
Cited by 4 | Viewed by 1592
Abstract
Candida parapsilosis is the major non-C. albicans species involved in the colonization of central venous catheters, causing bloodstream infections. Biofilm formation on medical devices is considered one of the main causes of healthcare-associated infections and represents a global public health problem. In [...] Read more.
Candida parapsilosis is the major non-C. albicans species involved in the colonization of central venous catheters, causing bloodstream infections. Biofilm formation on medical devices is considered one of the main causes of healthcare-associated infections and represents a global public health problem. In this context, the development of new nanomaterials that exhibit anti-adhesive and anti-biofilm properties for the coating of medical devices is crucial. In this work, we aimed to characterize the antimicrobial activity of two different coated-surfaces, graphene oxide (GO) and curcumin-graphene oxide (GO/CU) for the first time, against C. parapsilosis. We report the capacity of GO to bind and stabilize CU molecules, realizing a homogenous coated surface. We tested the anti-planktonic activity of GO and GO/CU by growth curve analysis and quantification of Reactive Oxigen Species( ROS) production. Then, we tested the antibiofilm activity by adhesion assay, crystal violet assay, and live and dead assay; moreover, the inhibition of the formation of a mature biofilm was investigated by a viability test and the use of specific dyes for the visualization of the cells and the extra-polymeric substances. Our data report that GO/CU has anti-planktonic, anti-adhesive, and anti-biofilm properties, showing a 72% cell viability reduction and a decrease of 85% in the secretion of extra-cellular substances (EPS) after 72 h of incubation. In conclusion, we show that the GO/CU conjugate is a promising material for the development of medical devices that are refractory to microbial colonization, thus leading to a decrease in the impact of biofilm-related infections. Full article
(This article belongs to the Special Issue Natural Anti-Biofilm Agents)
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