scholarly journals Bacterial Surface Colonization of Sputter-Coated Platinum Films

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2674
Author(s):  
Dominika Czerwińska-Główka ◽  
Wioletta Przystaś ◽  
Ewa Zabłocka-Godlewska ◽  
Sebastian Student ◽  
Beata Cwalina ◽  
...  
Keyword(s):  
Thin Layer ◽  
Orthopedic Implants ◽  
Bacterial Biofilm ◽  
Surgical Instruments ◽  
Bacterial Cells ◽  
Biomedical Devices ◽  
Surface Colonization ◽  
Bacterial Surface ◽  
Coated Glass ◽  
Short Time

Due to its biocompatibility and advantageous electrochemical properties, platinum is commonly used in the design of biomedical devices, e.g., surgical instruments, as well as electro-medical or orthopedic implants. This article verifies the hypothesis that a thin layer of sputter-coated platinum may possess antibacterial effects. The purpose of this research was to investigate the adhesion and growth ability of a model strain of Gram-negative bacteria, Escherichia coli, on a surface of a platinum-coated glass slide. Although some previous literature reports suggests that a thin layer of platinum would inhibit the formation of bacterial biofilm, the results of this study suggest otherwise. The decrease in the number of bacterial cells attached to the platinum-coated glass, which was observed within first three hours of culturing, was found to be a short-time effect, vanishing after 24 h. Consequently, it was shown that a thin layer of sputter-coated platinum did not exhibit any antibacterial effect. For this reason, this study indicates an urgent need for the development of new methods of surface modification that could reduce bacterial surface colonization of platinum-based biomedical devices.

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.

scholarly journals Impact of the Resistance Responses to Stress Conditions Encountered in Food and Food Processing Environments on the Virulence and Growth Fitness of Non-Typhoidal Salmonellae

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 617
Author(s):  
Silvia Guillén ◽  
Laura Nadal ◽  
Ignacio Álvarez ◽  
Pilar Mañas ◽  
Guillermo Cebrián
Keyword(s):  
Stress Resistance ◽  
Food Processing ◽  
Current Knowledge ◽  
Foodborne Pathogen ◽  
Stress Conditions ◽  
Bacterial Cells ◽  
Modified Atmospheres ◽  
Development Of Resistance ◽  
Salmonella Virulence ◽  
Short Time

The success of Salmonella as a foodborne pathogen can probably be attributed to two major features: its remarkable genetic diversity and its extraordinary ability to adapt. Salmonella cells can survive in harsh environments, successfully compete for nutrients, and cause disease once inside the host. Furthermore, they are capable of rapidly reprogramming their metabolism, evolving in a short time from a stress-resistance mode to a growth or virulent mode, or even to express stress resistance and virulence factors at the same time if needed, thanks to a complex and fine-tuned regulatory network. It is nevertheless generally acknowledged that the development of stress resistance usually has a fitness cost for bacterial cells and that induction of stress resistance responses to certain agents can trigger changes in Salmonella virulence. In this review, we summarize and discuss current knowledge concerning the effects that the development of resistance responses to stress conditions encountered in food and food processing environments (including acid, osmotic and oxidative stress, starvation, modified atmospheres, detergents and disinfectants, chilling, heat, and non-thermal technologies) exerts on different aspects of the physiology of non-typhoidal Salmonellae, with special emphasis on virulence and growth fitness.

scholarly journals Antimicrobial Resistance in Oral biofilm: Challenges and Alternatives

2021 ◽  
Vol 12 (1) ◽  
pp. 349-356
Author(s):  
Satish Kumar Sharma ◽  
Shmmon Ahmad
Keyword(s):  
Antimicrobial Resistance ◽  
Bacterial Infections ◽  
Molecular Mechanisms ◽  
Resistance Mechanisms ◽  
Bacterial Biofilm ◽  
Bacterial Biofilms ◽  
Target Cells ◽  
Bacterial Cells ◽  
Antimicrobial Drugs ◽  
Oral Infections

Bacterial biofilm has been a major contributor to severe bacterial infections in humans. Oral infections have also been associated with biofilm-forming microbes. Several antimicrobial strategies have been developed to combat bacterial biofilms. However, the complexity of the oral cavity has made it difficult to use common drug treatments. Most effective ways to control normal bacterial infections are rendered ineffective for bacterial biofilms. Due to limited drug concentration availability, drug neutralization or altered phenotype of bacterial cells, different drug have been ineffective to identify the target cells. This leads to the development of the multifaceted phenomenon of antimicrobial resistance (AMR). Biofilm research done so far has been focused on using antimicrobial drugs to target molecular mechanisms of cells. The severity and resistance mechanisms of extracellular matrix (ECM) have been underestimated. The present study describes different antimicrobial strategies with respect to their applications in dental or oral infections. A prospective strategy has been proposed targeting ECM which is expected to provide an insight on biofilm obstinacy and antimicrobial resistance.

scholarly journals Spatially Resolved Characterization of Biogenic Manganese Oxide Production within a Bacterial Biofilm

2005 ◽  
Vol 71 (3) ◽  
pp. 1300-1310 ◽  
Author(s):  
Brandy Toner ◽  
Sirine Fakra ◽  
Mario Villalobos ◽  
Tony Warwick ◽  
Garrison Sposito
Keyword(s):  
Careful Consideration ◽  
Bacterial Biofilm ◽  
Bacterial Cells ◽  
X Ray ◽  
Spatially Resolved ◽  
Nexafs Spectroscopy ◽  
Promising Tool ◽  
Scanning Transmission ◽  
X Ray Absorption

ABSTRACT Pseudomonas putida strain MnB1, a biofilm-forming bacterial culture, was used as a model for the study of bacterial Mn oxidation in freshwater and soil environments. The oxidation of aqueous Mn+2 [Mn+2 (aq)] by P. putida was characterized by spatially and temporally resolving the oxidation state of Mn in the presence of a bacterial biofilm, using scanning transmission X-ray microscopy (STXM) combined with near-edge X-ray absorption fine structure (NEXAFS) spectroscopy at the Mn L2,3 absorption edges. Subsamples were collected from growth flasks containing 0.1 and 1 mM total Mn at 16, 24, 36, and 48 h after inoculation. Immediately after collection, the unprocessed hydrated subsamples were imaged at a 40-nm resolution. Manganese NEXAFS spectra were extracted from X-ray energy sequences of STXM images (stacks) and fit with linear combinations of well-characterized reference spectra to obtain quantitative relative abundances of Mn(II), Mn(III), and Mn(IV). Careful consideration was given to uncertainty in the normalization of the reference spectra, choice of reference compounds, and chemical changes due to radiation damage. The STXM results confirm that Mn+2 (aq) was removed from solution by P. putida and was concentrated as Mn(III) and Mn(IV) immediately adjacent to the bacterial cells. The Mn precipitates were completely enveloped by bacterial biofilm material. The distribution of Mn oxidation states was spatially heterogeneous within and between the clusters of bacterial cells. Scanning transmission X-ray microscopy is a promising tool for advancing the study of hydrated interfaces between minerals and bacteria, particularly in cases where the structure of bacterial biofilms needs to be maintained.

scholarly journals Chemical Characterization and Antibiofilm Activities of Bulbs and Leaves of Two Aglione (Allium ampeloprasum var. holmense Asch. et Graebn.) Landraces Grown in Southern Italy

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5486
Author(s):  
Lucia Caputo ◽  
Giuseppe Amato ◽  
Florinda Fratianni ◽  
Raffaele Coppola ◽  
Vincenzo Candido ◽  
...  
Keyword(s):  
Southern Italy ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Chemical Characterization ◽  
Bacterial Biomass ◽  
Bacterial Biofilm ◽  
Minor Amount ◽  
Bacterial Cells ◽  
Total Polyphenols ◽  
Aerial Parts

The present study was carried out to determine some biochemical characteristics, in particular the total polyphenol content and the free radical scavenging activity, of the extracts recovered from bulbs and aerial parts (these last often considered as by-products) of two landraces of A. ampeloprasum var. holmense cultivated in Southern Italy. For the first time, the capacity of the extracts of these landraces to inhibit the formation of biofilm of different Gram-negative and Gram-positive bacteria and to affect the metabolism of the cells present within the bacterial biofilm was evaluated. All extracts exhibited an amount of total polyphenols not lower than 2.86 mg/g of dried product and revealed a noteworthy antioxidant activity, with EC50 values not exceeding 4.95 mg. In both cases, the aerial parts extracts were more effective than the bulb extracts, which also showed a minor amount of total polyphenols. The extracts inhibited mainly the adhesive capability of Pseudomonas aeruginosa and Staphylococcus aureus, by 95.78% and 85.01%, respectively. The extracts demonstrated to inhibit also the metabolism of the bacterial cells reaching levels up to 90%. Finally, as assessed by the assays performed on the 24-h preformed biofilms, all the extracts were also capable to cause a reduction in bacterial biomass and to affect their metabolism.

scholarly journals Polymer drug release system for biofilm inhibition in medical application

2018 ◽  
Vol 4 (1) ◽  
pp. 213-216 ◽  
Author(s):  
Katharina Wulf ◽  
Daniela Arbeiter ◽  
Thomas Eickner ◽  
Katharina Riedel ◽  
Klaus-Peter Schmitz ◽  
...  
Keyword(s):  
Intestinal Flora ◽  
Medical Application ◽  
Bacterial Biofilm ◽  
Continuous Treatment ◽  
Local Drug Delivery ◽  
Antibiotics Resistance ◽  
Biofilm Inhibition ◽  
Degradable Polymer ◽  
Short Time

AbstractBacterial biofilm formation on surfaces is still a critical challenge regarding the application of implants. Generally, in order to avoid this, an additional systemic administration of antibiotics is given, which can lead to side effects, such as the reduction of the intestinal flora. Continuous treatment may lead to antibiotics resistance. Within this study we investigated the local drug delivery of N-acetyl-L-cysteine (NAC) from a Poly-L-lactide (PLLA) coating, an ished biodegradable polymer and a polyetherurethane (PEU) coating, a promising representative non-degradable polymer for cardiovascular applications as alternative to the administration of antibiotics. The incorporation of NAC influenced the surface properties of PEU in contrast to that of PLLA. The in vitro NAC release is almost completed after 24 h for PEU. For PLLA only small amounts of incorporated NAC, depending on the NAC loading, is released after a short time. Both systems are rather useful as local NAC delivery system directly after implantation.

scholarly journals Emergence of Rapid Methods for Identifying Microbial Pathogens in Foods

1996 ◽  
Vol 79 (3) ◽  
pp. 809-812 ◽  
Author(s):  
Peter Feng
Keyword(s):  
Food Analysis ◽  
Food Microbiology ◽  
Microbial Pathogens ◽  
Bacterial Cells ◽  
Culture Methods ◽  
Rapid Methods ◽  
Microbiological Methods ◽  
Assay Time ◽  
Short Time ◽  
Microbiological Procedures

Abstract Because of the complexities of food analysis, conventional microbiological methods must use timeconsuming enrichment steps for culturing viable bacterial cells in foods. With rapid advancements in technology, however, numerous so-called rapid methods were introduced into the field of food microbiology in a relatively short time. Culture methods that were once used to obtain profiles for bacterial identification were simplified or automated. Many microbiological procedures were also streamlined or automated to reduce assay time, labor, and materials. Nucleic acid-based assays are used to identify gene sequences in foodborne bacteria, and antibody-based assays are used in numerous formats to detect bacterial pathogens and toxins in foods. The difficulties of analyzing food, however, remain challenging, and rapid methods need to be evaluated thoroughly before they are used for routine food analysis.

Control of the Biofilms Formed by Curli- and Cellulose-Expressing Shiga Toxin–Producing Escherichia coli Using Treatments with Organic Acids and Commercial Sanitizers

2015 ◽  
Vol 78 (5) ◽  
pp. 990-995 ◽  
Author(s):  
YOEN JU PARK ◽  
JINRU CHEN
Keyword(s):  
Escherichia Coli ◽  
Stainless Steel ◽  
Organic Acids ◽  
Shiga Toxin ◽  
Cell Contact ◽  
Bacterial Cells ◽  
Bacterial Surface ◽  
Additional Information ◽  
Steel Surfaces ◽  
Biological Protection

Biofilms are a mixture of bacteria and extracellular products secreted by bacterial cells and are of great concern to the food industry because they offer physical, mechanical, and biological protection to bacterial cells. This study was conducted to quantify biofilms formed by different Shiga toxin–producing Escherichia coli (STEC) strains on polystyrene and stainless steel surfaces and to determine the effectiveness of sanitizing treatments in control of these biofilms. STEC producing various amounts of cellulose (n = 6) or curli (n = 6) were allowed to develop biofilms on polystyrene and stainless steel surfaces at 28°C for 7 days. The biofilms were treated with 2% acetic or lactic acid and manufacturer-recommended concentrations of acidic or alkaline sanitizers, and residual biofilms were quantified. Treatments with the acidic and alkaline sanitizers were more effective than those with the organic acids for removing the biofilms. Compared with their counterparts, cells expressing a greater amount of cellulose or curli formed more biofilm mass and had greater residual mass after sanitizing treatments on polystyrene than on stainless steel. Research suggests that the organic acids and sanitizers used in the present study differed in their ability to control biofilms. Bacterial surface components and cell contact surfaces can influence both biofilm formation and the efficacy of sanitizing treatments. These results provide additional information on control of biofilms formed by STEC.

Integrated Computer-Aided Approach for Supporting Development of Biomedical Devices

2013 ◽  
Author(s):  
Ahmed Sherif El-Gizawy
Keyword(s):  
Quality Function Deployment ◽  
Orthopaedic Surgery ◽  
Orthopedic Implants ◽  
Medical Community ◽  
Biomedical Devices ◽  
System Behavior ◽  
Road Map ◽  
Computer Aided ◽  
Important System ◽  
Case Based

Both medicine and engineering disciplines use problem-solving techniques to address different needs. The solutions often require an understanding of complex system behavior, identification of important system factors, and prediction of the outcome prior to application. This paper presents an introduction to integrated computer-aided approach to support developments in the field of biomedical devices, particularly for those used with orthopaedic surgery applications. The modern design process is first introduced as a road map to establish design that is robust, cost and time effective in order to satisfy the needs of the medical community. The coverage includes methods such as: function abstraction and decomposition, quality function deployment (QFD), case-based design (CBD) methodology, and risk management in design of orthopedic implants.

Experimental study of iron and silica immobilization by bacteria in mixed Fe-Si systems: implications for microbial silicification in hot springs

2003 ◽  
Vol 40 (11) ◽  
pp. 1669-1678 ◽  
Author(s):  
Vernon R Phoenix ◽  
Kurt O Konhauser ◽  
F Grant Ferris
Keyword(s):  
Hot Springs ◽  
Iron Concentration ◽  
Salt Bridge ◽  
Bacterial Cells ◽  
Bacterial Concentration ◽  
Bacterial Surface ◽  
Molar Ratios ◽  
Silica Concentration ◽  
The Difference ◽  
Iron Concentrations

The immobilization of silica and iron by the bacteria Bacillus subtilis was monitored in controlled microcosms to elucidate the role iron may play in aiding bacterial silicification in hot springs. Silica and iron immobilization was monitored as a function of bacterial concentration, iron concentration, and silica concentration (both undersaturated and oversaturated with respect to amorphous silica). Results demonstrate that bacterial cells do immobilize more Fe than bacteria-free systems in solutions with iron concentrations [Formula: see text]50 ppm Fe. However, as iron concentrations increase, the difference between Fe immobilization in bacterial and bacteria-free systems decreases as non-bacterially mediated precipitation processes dominate. Additionally, bacterial systems that had immobilized more Fe compared with bacteria-free systems did not immobilize more silica than bacteria-free systems. By comparing molar ratios of (silica in solution)/(bacterially bound Fe), it is evident that insufficient iron is bound to the bacterial surface to act as an effective salt bridge for silica sorption. This appears to be because much of the iron is immobilized by non-bacterially mediated precipitation of phases such as Fe(OH)3 and poorly ordered hydrous iron silicates. It follows that in silica-enriched hot springs, silica and iron immobilization processes are significantly dominated by non-bacterially mediated precipitation. Any bacterially mediated processes are exceedingly small and outside the resolution of these experiments.

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