scholarly journals Usnic Acid, a Natural Antimicrobial Agent Able To Inhibit Bacterial Biofilm Formation on Polymer Surfaces

2004 ◽  
Vol 48 (11) ◽  
pp. 4360-4365 ◽  
Author(s):  
I. Francolini ◽  
P. Norris ◽  
A. Piozzi ◽  
G. Donelli ◽  
P. Stoodley
Keyword(s):  
Biofilm Formation ◽  
Usnic Acid ◽  
Modern Medicine ◽  
The Body ◽  
Bacterial Biofilm ◽  
Polymer Surfaces ◽  
Gram Positive Bacteria ◽  
The Status ◽  
Bacteria And Fungi ◽  
Systemic Infections

ABSTRACT In modern medicine, artificial devices are used for repair or replacement of damaged parts of the body, delivery of drugs, and monitoring the status of critically ill patients. However, artificial surfaces are often susceptible to colonization by bacteria and fungi. Once microorganisms have adhered to the surface, they can form biofilms, resulting in highly resistant local or systemic infections. At this time, the evidence suggests that (+)-usnic acid, a secondary lichen metabolite, possesses antimicrobial activity against a number of planktonic gram-positive bacteria, including Staphylococcus aureus, Enterococcus faecalis, and Enterococcus faecium. Since lichens are surface-attached communities that produce antibiotics, including usnic acid, to protect themselves from colonization by other bacteria, we hypothesized that the mode of action of usnic acid may be utilized in the control of medical biofilms. We loaded (+)-usnic acid into modified polyurethane and quantitatively assessed the capacity of (+)-usnic acid to control biofilm formation by either S. aureus or Pseudomonas aeruginosa under laminar flow conditions by using image analysis. (+)-Usnic acid-loaded polymers did not inhibit the initial attachment of S. aureus cells, but killing the attached cells resulted in the inhibition of biofilm. Interestingly, although P. aeruginosa biofilms did form on the surface of (+)-usnic acid-loaded polymer, the morphology of the biofilm was altered, possibly indicating that (+)-usnic acid interfered with signaling pathways.

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.

scholarly journals Host Peptidic Hormones Affecting Bacterial Biofilm Formation and Virulence

2018 ◽  
Vol 11 (3) ◽  
pp. 227-241 ◽  
Author(s):  
Olivier Lesouhaitier ◽  
Thomas Clamens ◽  
Thibaut Rosay ◽  
Florie Desriac ◽  
Mélissande Louis ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Bacterial Biofilm ◽  
Critical Problem ◽  
Resistant Variant ◽  
Bacterial Physiology ◽  
Gram Positive Bacteria ◽  
Biofilm Production ◽  
The Impact ◽  
Original Approach ◽  
Antibacterial Potential

Bacterial biofilms constitute a critical problem in hospitals, especially in resuscitation units or for immunocompromised patients, since bacteria embedded in their own matrix are not only protected against antibiotics but also develop resistant variant strains. In the last decade, an original approach to prevent biofilm formation has consisted of studying the antibacterial potential of host communication molecules. Thus, some of these compounds have been identified for their ability to modify the biofilm formation of both Gram-negative and Gram-positive bacteria. In addition to their effect on biofilm production, a detailed study of the mechanism of action of these human hormones on bacterial physiology has allowed the identification of new bacterial pathways involved in biofilm formation. In this review, we focus on the impact of neuropeptidic hormones on bacteria, address some future therapeutic issues, and provide a new view of inter-kingdom communication.

scholarly journals Azalomycin F5a Eradicates Staphylococcus aureus Biofilm by Rapidly Penetrating and Subsequently Inducing Cell Lysis

2020 ◽  
Vol 21 (3) ◽  
pp. 862
Author(s):  
Ganjun Yuan ◽  
Pingyi Li ◽  
Xuejie Xu ◽  
Peibo Li ◽  
Qiwang Zhong ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Structural Integrity ◽  
Bacterial Biofilm ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Hospital Acquired Infections ◽  
Gram Positive Bacteria ◽  
Hospital Acquired

Antimicrobial resistance has emerged as a serious threat to public health. Bacterial biofilm, as a natural lifestyle, is a major contributor to resistance to antimicrobials. Azalomycin F5a, a natural guanidine-containing polyhydroxy macrolide, has remarkable activities against Gram-positive bacteria, including Staphylococcus aureus, a major causative agent of hospital-acquired infections. To further evaluate its potential to be developed as a new antimicrobial agent, its influence on S. aureus biofilm formation was evaluated using the crystal violet method, and then its eradication effect against mature biofilms was determined by confocal laser scanning microscopy, the drop plate method, and regrowth experiments. The results showed that azalomycin F5a could significantly inhibit S. aureus biofilm formation, and such effects were concentration dependent. In addition, it can also eradicate S. aureus mature biofilms with the minimum biofilm eradication concentration of 32.0 μg/mL. As extracellular deoxyribonucleic acid (eDNA) plays important roles in the structural integrity of bacterial biofilm, its influence on the eDNA release in S. aureus biofilm was further analyzed using gel electrophoresis. Combined with our previous works, these results indicate that azalomycin F5a could rapidly penetrate biofilm and causes damages to the cell membrane, leading to an increase in DNase release and eventually eradicating S. aureus biofilm.

scholarly journals Hubungan Biofilm dengan Infeksi: Implikasi pada Kesehatan Masyarakat dan Strategi Mengontrolnya

2018 ◽  
Vol 5 (1) ◽  
pp. 1
Author(s):  
Rini Purbowati
Keyword(s):  
Public Health ◽  
Biofilm Formation ◽  
Heart Valves ◽  
Extracellular Polymeric Substances ◽  
Antimicrobial Agents ◽  
Cell Attachment ◽  
The Body ◽  
Bacterial Biofilm ◽  
Tract Infections ◽  
Joint Prostheses

Biofilms are formed in the surfaces of mucosal of the body cavity can be a major source of infection . Infection by microbial biofilm formers are difficult to treat because of their greater resistance to antimicrobial agents than individual cells . Therefore biofilm -related infections and increased the economic burden of the country. The purpose of this literature review is to examine literature on biofilms and biofilm-associated microbes and their contribution to the disease burden of man with the aim of drawing attention to their public health implication.Biofilm are defined as “collections of microorganisms and their associated extracellular products at an interface and generally attached to a biological and non-biological substratum. Biofilm formation are influenced by factors controlling cell attachment, nature of surface, propertis of medium, and properties of the microbial cell surface. The ability of biofilm formation is genetically regulated by ica ABDC operon. Biofilm life cycle include adhesion of cells, formation of microcolonies, formation of biofilm and detachment anddispersal of biofilm. Structure of biofilm consists microorganisms and extracellular polymeric substances with vertical structures of microorganisms sometimes take the form of towers or mushrooms which are separated by interstitial spaces. Bacterial biofilm showed increased resistance to antibiotics, disinfectants and resistant to phagocytosis and other mechanisms of innate and adaptive immune system. Biofilms associated with food borne illness and affect to food security. Biofilms have been implicated in a wide variety of microbial infections in the body such as as urinary tract infections, catheter infections, middle-ear infections, formation of dental plaque, gingivitis, legionellosis ,infections involving contact lenses, and less common but more lethal processes such as endocarditis, infections in cystic fibrosis, and infections of permanent indwelling devices such as joint prostheses and heart valves. It is important for government agencies with a mandate for safeguarding public health and environment to develop and adopt ap propriate health risk assessment and biofilm-specific guidelines that are protective of both public health and the environment.

scholarly journals The effects of plasma treatment on bacterial biofilm formation on vertically-aligned carbon nanotube arrays

RSC Advances ◽  
2015 ◽  
Vol 5 (7) ◽  
pp. 5142-5148 ◽  
Author(s):  
Samuel Yick ◽  
Anne Mai-Prochnow ◽  
Igor Levchenko ◽  
Jinghua Fang ◽  
Michelle K. Bull ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Biofilm Formation ◽  
Bacterial Biofilm ◽  
Nanotube Arrays ◽  
Inductively Coupled Plasmas ◽  
Inductively Coupled ◽  
Gram Positive Bacteria ◽  
Carbon Nanotube Arrays ◽  
Vertically Aligned ◽  
Coupled Plasmas

Vertically-aligned carbon nanotube arrays treated with inductively-coupled plasmas demonstrate selective support of biofilms of Gram-negative and Gram-positive bacteria.

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.

Cinema and the Haptic in Modern Japan

Screen Bodies ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 23-36
Author(s):  
Daisuke Miyao
Keyword(s):  
The Body ◽  
Film Culture ◽  
Visual Medium ◽  
German Cinema ◽  
The Status ◽  
The Senses ◽  
Modern Japan

The process of modernization in Japan appeared as a separation of the senses and remapping of the body, particularly privileging the sense of vision. How did the filmmakers, critics, and novelists in the 1920s and 1930s respond to such a reorganization of the body and the elevation of vision in the context of film culture? How did they formulate a cinematic discourse on remapping the body when the status of cinema was still in flux and its definition was debated? Focusing on cinematic commentary made by different writers, this article tackles these questions. Sato Haruo, Ozu Yasujiro, and Iwasaki Akira questioned the separation of the senses, which was often enforced by state. Inspired by German cinema released in Japan at that time, they explored the notion of the haptic in cinema and problematized the privileged sense of vision in this new visual medium.

Inhibition of Bacterial Biofilm Formation by Phytotherapeutics with Focus on Overcoming Antimicrobial Resistance

2020 ◽  
Vol 26 (24) ◽  
pp. 2807-2816 ◽  
Author(s):  
Yun Su Jang ◽  
Tímea Mosolygó
Keyword(s):  
Antimicrobial Resistance ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Bacterial Biofilm ◽  
Experimental Investigations ◽  
Resistant Bacteria ◽  
Salmonella Spp ◽  
Food Borne ◽  
High Prevalence ◽  
Scientific Attention

: Bacteria within biofilms are more resistant to antibiotics and chemical agents than planktonic bacteria in suspension. Treatment of biofilm-associated infections inevitably involves high dosages and prolonged courses of antimicrobial agents; therefore, there is a potential risk of the development of antimicrobial resistance (AMR). Due to the high prevalence of AMR and its association with biofilm formation, investigation of more effective anti-biofilm agents is required. : From ancient times, herbs and spices have been used to preserve foods, and their antimicrobial, anti-biofilm and anti-quorum sensing properties are well known. Moreover, phytochemicals exert their anti-biofilm properties at sub-inhibitory concentrations without providing the opportunity for the emergence of resistant bacteria or harming the host microbiota. : With increasing scientific attention to natural phytotherapeutic agents, numerous experimental investigations have been conducted in recent years. The present paper aims to review the articles published in the last decade in order to summarize a) our current understanding of AMR in correlation with biofilm formation and b) the evidence of phytotherapeutic agents against bacterial biofilms and their mechanisms of action. The main focus has been put on herbal anti-biofilm compounds tested to date in association with Staphylococcus aureus, Pseudomonas aeruginosa and food-borne pathogens (Salmonella spp., Campylobacter spp., Listeria monocytogenes and Escherichia coli).

Antibiotics Application Strategies to Control Biofilm Formation in Pathogenic Bacteria

2020 ◽  
Vol 21 (4) ◽  
pp. 270-286 ◽  
Author(s):  
Fazlurrahman Khan ◽  
Dung T.N. Pham ◽  
Sandra F. Oloketuyi ◽  
Young-Mog Kim
Keyword(s):  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Extracellular Polymeric Substances ◽  
Quorum Quenching ◽  
Resistance Mechanisms ◽  
Bacterial Biofilm ◽  
Bacterial Cells ◽  
High Concentration ◽  
Biofilm Inhibition ◽  
Abiotic Surfaces

Background: The establishment of a biofilm by most pathogenic bacteria has been known as one of the resistance mechanisms against antibiotics. A biofilm is a structural component where the bacterial community adheres to the biotic or abiotic surfaces by the help of Extracellular Polymeric Substances (EPS) produced by bacterial cells. The biofilm matrix possesses the ability to resist several adverse environmental factors, including the effect of antibiotics. Therefore, the resistance of bacterial biofilm-forming cells could be increased up to 1000 times than the planktonic cells, hence requiring a significantly high concentration of antibiotics for treatment. Methods: Up to the present, several methodologies employing antibiotics as an anti-biofilm, antivirulence or quorum quenching agent have been developed for biofilm inhibition and eradication of a pre-formed mature biofilm. Results: Among the anti-biofilm strategies being tested, the sub-minimal inhibitory concentration of several antibiotics either alone or in combination has been shown to inhibit biofilm formation and down-regulate the production of virulence factors. The combinatorial strategies include (1) combination of multiple antibiotics, (2) combination of antibiotics with non-antibiotic agents and (3) loading of antibiotics onto a carrier. Conclusion: The present review paper describes the role of several antibiotics as biofilm inhibitors and also the alternative strategies adopted for applications in eradicating and inhibiting the formation of biofilm by pathogenic bacteria.

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