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The goal of this study was to evaluate if a magnetic water treatment device could be used to mitigate biofilms in water systems. Magnetic treatment was applied to water upstream of a modified Robbins device in which Pseudomonas fluorescence biofilms were formed. Duration of magnetic treatment, system flow rate, and field strength were varied to assess the impacts on the biofilm. A control system was concurrently established in which no magnetic treatment was applied. After treatment, the number of viable cells in the biofilm was reduced by up to 2.46 log10 CFU cm−2 depending on the operational conditions. Increased cell stress, and ultimately death, was observed during treatment as indicated by an elevated AMPi stress index. These results indicate that magnetic water treatment may be an effective technology to decrease the extent of biofilms in water systems and a reduced need for chemical treatment. A mechanism is proposed in which metabolic processes are hindered due to the magnetic field effects on ions in the water. However, a mechanistic investigation remains outside the scope of this study. Future studies should aim to characterize both the impacts of treatment on the matrix and cellular processes to determine a mechanism for the observed effects. HIGHLIGHTS: Magnetic water treatment reduced the number of viable bacterial cells present in biofilms by 2.46 log10 CFU/cm2 after 15 days of treatment. Magnetically treated water results in increased cellular stress as indicated by the ratio of AMP/ATP in bacteria. Removal of sessile cells from biofilms occurred without the direct interaction between the magnetic field and the biofilms. [ABSTRACT FROM AUTHOR]

Four novel selenite-reducing bacterial strains Achromobacter agilis, Lysinibacillus xylanticus, Lysinibacillus macroides, and Citrobacter freundi were isolated from industrial waste-contaminated soils in the coastal region of Chennai, India. The isolates reduced selenite and synthesized biogenic selenium nanoparticles (BioSeNPs) using extracellular metabolites. Nuclear magnetic resonance (NMR) and High-performance liquid chromatography (HPLC) data of the extracellular metabolites indicated that Nicotinamide adenine dinucleotide (NADH) and phenazine carboxylic acid (PCA) were involved in the synthesis. Culture ages, pH, initial selenite concentration with extracellular cell-free extracts mixing ratio, and reaction times were optimized using the classical method to synthesize BioSeNPs. Transmittance electron microscopy (TEM), High-resolution scanning electron microscopy (HR-SEM), Fourier transformed infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) analysis confirmed the synthesized BioSeNPs are spherical and homogenous, with a 2–14 nm size range. BioSeNPs from Lysinibacillus xylanticus and Achromobacter agilis showed strong antibacterial effects against the pathogens Escherichia coli and Staphylococcus aureus even at low concentrations (40 µg/mL). BioSeNPs from Lysinibacillus macroides removed the pathogen’s biofilm at 20 µg/mL. This study demonstrated that the findings could aid in investigating cost-effective BioSeNPs-based wastewater treatment technologies for removing pathogenic drug-resistant bacteria.Highlights: BioSeNPs synthesized from Achromobacter agilis, Lysinibacillus xylanticus, Lysinibacillus macrolides, and Citrobacter freundi reduced selenite by 94% in 24 hours. The extracellular cell-free extract of the isolates, containing NADH and PCA, successfully synthesized spherical and homogeneous selenium nanoparticles under the optimized conditions. BioSeNPs removed 85% of the biofilm at 20 μg/mL with 99% antibacterial efficacy against Staphylococcus aureus and Escherichia coli. [ABSTRACT FROM AUTHOR]

Abstract Purpose The major struggle in peri-implantitis therapy is the availability of successful decontamination of the infected implant surface. The main hypothesis of this study was the Er,Cr: YSGG laser decontamination efficacy investigation on the infected implant surfaces with various peri-implantitis defects. The primary objective of this study was to decide the efficacy of Er,Cr:YSGG laser as a decontamination tool at various peri-implantitis simulating defects. The secondary objective was to compare the efficacy of the Er,Cr: YSGG laser on oral biofilm removal between two protocols the first protocol (4 cycles at 2.5 min) and the second protocol (5 cycles at 5 min) at various peri-implantitis simulating defects. Materials and methods A total of 3 subjects whose plaque biofilms formed in-vivo on twenty-four tested implants were divided into four tested groups. Two native implants were tested as controls.The in vitro defect model was computer‐aided designed and printed into a 3D-printed model with various anulations in peri-implant infrabony defects, which were 15,30,60,and 90 degrees. Results Both Er, Cr: YSGG decontamination protocols at 50 mJ (1.5 W/30 Hz), 50% air, and 40% water were effective at reducing the total implant surface area/ biofilm ratio (%), but the second protocol had a markedly greater reduction in the duration of application (5 cycles at 5 min) than did the first protocol (4 cycles at 2.5 min). Conclusion The Er, Cr: YSGG laser is an effective decontamination device in various peri-implantitis defects. The second protocol(5 cycles at 5 min) with greater application time and circles is more effective than the first one. The defect angulation influence the decontamination capability in peri-implantitis therapy. Clinical relevance (Scientific rationale for study) Clinicians anticipate that the exploration of suitable therapeutic modalities for peri-implantitis therapy is limited by the obvious heterogeneity of the available evidence in the literature and need for a pre-clinical theoretical basis setup. The major challenges associated with peri-implantitis therapy include the successful decontamination of the infected implant surface, the absence of any damage to the treated implant surface with adequate surface roughness, and the biocompatibility of the implant surface, which allows osteoblastic cells to grow on the treated surface and is the key for successful re-osseointegration. Therefore, these are the expected empirical triads that need to be respected for successful peri-implantitis therapy. Failure of one of the triads represents a peri-implantitis therapeutic failure. The Er, Cr: YSGG laser is regarded as one of the expected devices for achieving the required triad. Trial registration "Efficacy of Er,Cr YSGG Laser in Treatment of Peri-implantitis". ClinicalTrials.gov ID NCT05137821. First Posted date: 30 -11–2021.

Biofilm formation and growth is a significant concern for water treatment professionals, as it can lead to the contamination of water systems and pose a threat to public health. Biofilms are complex communities of microorganisms that adhere to surfaces and are embedded in an extracellular matrix of polysaccharides and proteins. They are notoriously difficult to control, as they provide a protective environment for bacteria, viruses, and other harmful organisms to grow and proliferate. This review article highlights some of the factors that favor biofilm growth, as well as various strategies for controlling biofilm in water systems. Adopting the best available technologies, such as wellhead protection programs, proper distribution system maintenance, and filtration and disinfection, can prevent the formation and growth of biofilms in water systems. A comprehensive and multi-faceted approach to biofilm control can reduce the occurrence of biofilms and ensure the delivery of high-quality water to consumers. [ABSTRACT FROM AUTHOR]

Objectives: To compare ultrasonic scaler prototypes based on a planar piezoelectric transducer with different working frequencies featuring a titanium (Ti-20, Ti-28, and Ti-40) or stainless steel (SS-28) instrument, with a commercially available scaler (com-29) in terms of biofilm removal and reformation, dentine surface roughness and adhesion of periodontal fibroblasts. Materials and methods: A periodontal multi-species biofilm was formed on specimens with dentine slices. Thereafter specimens were instrumented with scalers in a periodontal pocket model or left untreated (control). The remaining biofilms were quantified and allowed to reform on instrumented dentine slices. In addition, fibroblasts were seeded for attachment evaluation after 72 h of incubation. Dentine surface roughness was analyzed before and after instrumentation. Results: All tested instruments reduced the colony-forming unit (cfu) counts by about 3 to 4 log10 and the biofilm quantity (each p < 0.01 vs. control), but with no statistically significant difference between the instrumented groups. After 24-hour biofilm reformation, no differences in cfu counts were observed between any groups, but the biofilm quantity was about 50% in all instrumented groups compared to the control. The attachment of fibroblasts on instrumented dentine was significantly higher than on untreated dentine (p < 0.05), with the exception of Ti-20. The dentine surface roughness was not affected by any instrumentation. Conclusions: The planar piezoelectric scaler prototypes are able to efficiently remove biofilm without dentine surface alterations, regardless of the operating frequency or instrument material. Clinical relevance: Ultrasonic scalers based on a planar piezoelectric transducer might be an alternative to currently available ultrasonic scalers. [ABSTRACT FROM AUTHOR]

The aim of this in vitro study was to investigate the effect of different toothpaste ingredients on biofilm volume and vitality in an established non-contact biofilm removal model. A multi-species biofilm comprising Porphyromonas gingivalis, Streptococcus sanguinis, and Fusobacterium nucleatum was grown on protein-coated titanium disks. Six disks per group were exposed to 4 seconds non-contact brushing using a sonic toothbrush. Four groups assessed slurries containing different ingredients, i.e., dexpanthenol (DP), peppermint oil (PO), cocamidopropyl betaine (CB), and sodium hydroxide (NaOH), one positive control group with the slurry of a toothpaste (POS), and a negative control group with physiological saline (NEG). Biofilm volume and vitality were measured using live-dead staining and confocal laser scanning microscopy. Statistical analysis comprised descriptive statistics and inter-group differences. In the test groups, lowest vitality and volume were found for CB (50.2 ± 11.9%) and PO (3.6 × 105 ± 1.8 × 105 µm3), respectively. Significant differences regarding biofilm vitality were found comparing CB and PO (p = 0.033), CB and NEG (p = 0.014), NaOH and NEG (p = 0.033), and POS and NEG (p = 0.037). However, no significant inter-group differences for biofilm volume were observed. These findings suggest that CB as a toothpaste ingredient had a considerable impact on biofilm vitality even in a non-contact brushing setting, while no considerable impact on biofilm volume was found. [ABSTRACT FROM AUTHOR]

Abstract Background Achieving sufficient professional mechanical biofilm removal (PMPR) can be challenging in supportive periodontal therapy (SPT), particularly in patients with prosthetic restorations. This experimental study aimed to simulate five years of SPT with periodic PMPR near the luting gap of ceramic restorations using a rubber cup with polishing paste (RCP), air polishing with two different low-abrasive powders (LAPA-1: glycine powder, LAPA-2: erythritol powder), and non-professional mechanical cleaning (control group) to measure the extent of volume loss in the luting gap after baseline (∆V = Vbaseline-V1-5; in µm3). Methods Two operators randomly performed PMPR ten times for thirty seconds on one of four sides of 30 crown replicas fixed with glass-ionomer cement (CGIZ: n = 15) or adhesive bonding (CAB: n = 15). The replicas were separated in a template during PMPR, and afterward, cleaned for five seconds per side with a sonic brush under flowing water. The artificial aging process between two PMPRs simulated a 5-year SPT with two PMPRs per year. Profilometric measurements were performed at baseline and after each second PMPR to obtain the mean change of ∆V. The statistical evaluation of the data was carried out using nonparametric tests with Bonferroni correction applied for multiple tests. Results Ninety-six out of 120 sides could be included in the analysis. PMPR methods showed a loss of substance in the luting gap with a ∆V (mean(standard deviation)) of -4.35 × 106(4.8 × 106)µm3 versus 8.79 × 104(1.05 × 106)µm3 for control at V5 (p ≤ 0.001). No significant differences of ∆V1-5 values could be identified in the control (p > 0.05), whereat all PMPRs showed a significant increasing loss of substance per simulated year (p ≤ 0.001). Intergroup comparison identified LAPA-1 as having the highest significant loss of substance determined on CAB (∆V: -1.05 × 107 (7,2 × 106) µm3), followed by LAPA-2 on CAB (∆V: -6.29 × 106 (4,24 × 106) µm3), LAPA-1 on CGIZ (∆V: -4.15 × 106 (3,25 × 106) µm3), LAPA-2 on CGIZ (∆V: -3.0 × 106 (2,23 × 106) µm3), RCP on CAB (∆V: -1.86 × 106 (2,23 × 106) µm3) and CGIZ (∆V: -1.2 × 106 (1,31 × 106) µm3; p ≤ 0.001)). Conclusions Within study limitations, all PMPRs caused a significantly higher loss of substance in the luting gap versus control without professional intervention, with the highest values in the CAB group for LAPA-1, LAPA-2 and RCP. Similar findings were observed for CGIZ, although the loss values were lower.

Microrobotics can address current limitations to control biofilm infections, and advance diagnostic and therapeutic modalities, in the face of increased antimicrobial resistance. Versatility in design and control of microrobots combined with targeting and detection capabilities, physical disruption and in situ drug delivery provides ample opportunities to improve the standard of care against biofilm infections. Opportunities for clinical translation and feasibility in complex physiological environments and different anatomical niches without harmful effects, mitigating the need for invasive surgical intervention. Biocompatibility and biodegradability of materials used in microrobotics is critical toward regulatory approval and clinical implementation. Potential solutions for microrobotics to overcome technical and regulatory hurdles for practical development and commercialization. The eradication of drug-resistant microbial biofilms remains an unresolved global health challenge. Small-scale robotics are providing innovative therapeutic and diagnostic approaches with high precision and efficacy. These approaches are rapidly moving from proof-of-concept studies to translational biomedical applications using ex vivo , animal, and clinical models. Here, we discuss the fundamental and translational aspects of how microrobots target the infection sites to disrupt the structural and functional traits of biofilms and their antimicrobial resistance mechanisms. We emphasize current approaches of mechanochemical disruption and on-site drug delivery that are supported by in vivo models and preclinical testing, while also highlighting diagnostics potential. We also discuss clinical translation challenges and provide perspectives for development of microrobotics approaches to combat biofilm infections and biofouling in humans. [ABSTRACT FROM AUTHOR]

Biofilms are responsible for most bacterial infections and significantly threaten human health. Designing effective and less harmful materials to inhibit and remove biofilms remains a significant challenge. Complex biofilm structures make conventional antibiotic treatments ineffective, and in recent years, photothermal therapy (PTT) and photodynamic therapy (PDT) have attracted attention for their ability to treat drug-resistant bacterial infections effectively. Therefore, a synergistic nanoantimicrobial system (PFH/TCPP@SL@PDA) enhances the effect through PTT and PDT. It is synthesized by loading meso-tetra-(4-carboxyphenyl) porphine (TCPP) on soybean lecithin (SL), further coating perfluorohexane (PFH) and finally coating polydopamine (PDA) on the outer layer. The designed nanoantimicrobial system alleviates the hypoxic properties of the biofilm microenvironment by loading oxygen and enhances the effect of PDT to generate more reactive oxygen species. It significantly enhanced biofilm permeability and improved antimicrobial properties, with over 95% inhibition of multidrug-resistant (MDR) Escherichia coli and MDR Staphylococcus aureus while inhibiting and removing over 90% of biofilms. PDA not only acts as a good nanoshell but also induces relatively mild PTT and can facilitate the reaction of PDT. PFH/TCPP@SL@PDA has good biocompatibility, and the hemolysis test showed less than 5% hemolysis of erythrocytes, effectively relieving inflammatory symptoms and accelerating wound healing in mice model. In conclusion, this study provides an efficient and safe combined therapeutic strategy for the bacterial inhibition, suppression, and removal of biofilms. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to quantitatively investigate the accumulation of Streptococcus mutans biofilm on enamel and root surfaces and assess the amount of biofilm removal using (1) experimental toothpaste and (2) water, in a closed system of flow chamber. Methods: Eight sound premolars were embedded in epoxy resin and polished with silicon carbide grinding papers to display enamel and root surfaces. To mimic biofilm, cultures of Streptococcus mutans were prepared and grown on the tooth surfaces over night before they were exposed to either 2 liters of Milli Q water or 2 liters of 40% experimental toothpaste in the flow chamber. The amount of biofilm was measured and quantified in Fluorescence microscopy. Mean fluorescence values were recorded and analysed using Microsoft® Excel® (MS Excel 2016). Results: The ability to grow biofilm was equally present at both the enamel and root surfaces. The use of water and 40% experimental toothpaste showed a significant reduction of areas covered with biofilm on both enamel and root dentin in comparison to untreated surfaces (p < 0.01). Significantly more biofilm was removed from enamel compared to root surfaces when treated with either water and toothpaste (p < 0.01). Slightly less biofilm was removed by the use of water compared to toothpaste on both enamel and root dentin surfaces, although the differences were not statistically significant. Conclusion: The results indicate that less biofilm is removed from the root surfaces than enamel by the use of water and 40% experimental toothpaste in flow chamber. Assessing oral biofilm accumulation and monitoring biofilm formation on enamel and root dentin surfaces give oral health professionals important directions that could strenghten the significance of dental caries prevention. Improving older individuals’ oral hygiene practices should therefore be considered an important measure to prevent root caries.

Biofilm removal from the apical region of the periodontal or peri-implant pocket, which is very difficult to achieve with mechanical instruments, is a major unresolved issue in dentistry. Here, we propose the use of photoacoustically induced streaming and secondary cavitation to achieve superior cleaning efficacy in the apical region of the periodontal and peri-implant pocket. We have used a prefabricated narrow wedge system that mimics the consistency of periodontal and peri-implant pockets of both healthy and severely inflamed tissue. We studied the effect of single-pulse modality Er:YAG on Pseudomonas aeruginosa biofilm removal. We used different laser energies, fiber-tip positions, and laser treatment durations. The cleaning process was monitored in real-time with a high-speed camera after each individual laser pulse application. The obtained results suggest that biofilm cleaning efficacy in a difficult-to-reach place in healthy model tissue is directly related to the onset of secondary cavitation bubble formation, which correlates with a significant improvement of biofilm removal from the apical region of the periodontal or peri-implant pocket. In comparison to the healthy tissue model, the laser energy in inflamed tissue model had to be increased to obtain comparable biofilm cleaning efficacy. The advantage of photoacoustic cavitation compared to other methods is that laser-induced cavitation can trigger secondary cavitation at large distances from the point of laser application, which in principle allows biofilm removal at distant locations not reachable with a laser fiber tip or other mechanical instruments.

Objectives: Low-frequency, low-intensity ultrasound is commonly utilized in various dental research fields to remove biofilms from surfaces, but no clear recommendation exists in dental studies so far. Therefore, this study aims to optimize the sonication procedure for the dental field to efficiently detach bacteria while preserving viability. Materials and methods: Initial biofilm was formed in vivo on bovine enamel slabs (n = 6) which were worn by four healthy participants for 4 h and 24 h. The enamel slabs covered with biofilm were then ultrasonicated ex vivo for various time periods (0, 1, 2, 4, 6 min). Colony-forming units were determined for quantification, and bacteria were identified using MALDI-TOF. Scanning electron microscopic images were taken to also examine the efficiency of ultrasonications for different time periods. Results: Ultrasonication for 1 min resulted in the highest bacterial counts, with at least 4.5-fold number compared to the non-sonicated control (p < 0.05). Most bacteria were detached within the first 2 min of sonication, but there were still bacteria detached afterwards, although significantly fewer (p < 0.0001). The highest bacterial diversity was observed after 1 and 2 min of sonication (p < 0.03). Longer sonication periods negatively affected bacterial counts of anaerobes, Gram-negative bacteria, and bacilli. Scanning electron microscopic images demonstrated the ability of ultrasound to desorb microorganisms, as well as revealing cell damage and remaining bacteria. Conclusions: With the use of low-frequency, low-intensity ultrasound, significantly higher bacterial counts and diversity can be reached. A shorter sonication time of 1 min shows the best results overall. Clinical relevance: This standardization is recommended to study initial oral biofilms aged up to 24 h to maximize the outcome of experiments and lead to better comparability of studies. [ABSTRACT FROM AUTHOR]

The emergence of antimicrobial resistance remains one of the greatest public health concerns. Biofilm formation has been postulated as a mechanism of microbial pathogens to resist antimicrobial agents. Lactic Acid Bacteria (LAB) and their metabolites have been proposed to combat bacterial biofilms due to their antimicrobial activity. In this vein, the aim of the present study was to investigate the biofilm removal potential of cell-free supernatants (CFSs) of five wild-type Lacticaseibacillus rhamnosus strains, isolated from Greek natural products, in comparison to the commercially available L. rhamnosus GG strain, against biofilms formed by common foodborne pathogens (Salmonella Enteritidis, Salmonella Typhimurium, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus). The biofilm removal activity of LAB was assessed on a two-day-old mature biofilm using a microtiter plate-based procedure. Both non-neutralized and neutralized CFSs removed biofilms in a concentration-dependent manner. The biofilm removal activity of the non-neutralized CFSs was significantly higher compared to the neutralized CFSs, as expected, with ranges of 60–89% and 30–80%, respectively. The biofilm removal efficiency of L. rhamnosus OLXAL-3 was significantly higher among the wild-type L. rhamnosus strains tested (20–100% v/v). In conclusion, our results suggest the great potential of the application of wild-type L. rhamnosus strain' CFSs as effective natural agents against pathogenic bacterial biofilms. [ABSTRACT FROM AUTHOR]

Aims: Isolation and characterization of Enterococcus phages and application of phage cocktail to control E. faecalis in milk. Methods and Results: For phage isolations, double layer agar method was used. Host range of the phages were determined by the spot test. Twelve phages with varying host ranges were isolated. Phages PEF1, PEF7b, and PEF9 with different host ranges and lytic activities were selected for phage cocktails. Compared to two-phages cocktails tested, the cocktail containing all the three phages displayed stronger antibacterial and biofilm removal activities. The cocktail treatment reduced viable E. faecalis in biofilm by 6 log within 6 h at both 30◦C and 4◦C. In milk, the cocktail gradually reduced the viable count of E. faecalis and the count reached below the lower limit of detection at 48 h at 4◦C. Conclusion: The strong bactericidal and biofilm removal activities of the phage cocktail suggest the potential of this cocktail as a natural biocontrol agent for combating E. faecalis in milk. [ABSTRACT FROM AUTHOR]

The aim of this in vitro study was to investigate the effect of different toothpaste ingredients on biofilm volume and vitality in an established non-contact biofilm removal model. A multi-species biofilm comprising Porphyromonas gingivalis, Streptococcus sanguinis, and Fusobacterium nucleatum was grown on protein-coated titanium disks. Six disks per group were exposed to 4 seconds non-contact brushing using a sonic toothbrush. Four groups assessed slurries containing different ingredients, i.e., dexpanthenol (DP), peppermint oil (PO), cocamidopropyl betaine (CB), and sodium hydroxide (NaOH), one positive control group with the slurry of a toothpaste (POS), and a negative control group with physiological saline (NEG). Biofilm volume and vitality were measured using live-dead staining and confocal laser scanning microscopy. Statistical analysis comprised descriptive statistics and inter-group differences. In the test groups, lowest vitality and volume were found for CB (50.2 ± 11.9%) and PO (3.6 × 105 ± 1.8 × 105 µm3), respectively. Significant differences regarding biofilm vitality were found comparing CB and PO (p = 0.033), CB and NEG (p = 0.014), NaOH and NEG (p = 0.033), and POS and NEG (p = 0.037). However, no significant inter-group differences for biofilm volume were observed. These findings suggest that CB as a toothpaste ingredient had a considerable impact on biofilm vitality even in a non-contact brushing setting, while no considerable impact on biofilm volume was found.

Purification of bacteriophage-expressed proteins poses methodological difficulties associated with the need to process entire culture medium volume upon bacteriophage-induced bacterial cell lysis. We have used novel capsule glycosylase-depolymerase (TP84_26 GD) from bacteriophage TP-84, infecting thermophilic Geobacillus stearothermophilus bacteria, as a representative enzyme to develop a method for rapid concentration and purification of the enzyme present in diluted crude host cell lysate. A novel variant of the polyethyleneimine (PEI)-based purification method was devised that offers a fast and effective approach for handling PEI-facilitated purification of bacteriophage-expressed native proteins. Due to the very basic nature of PEI, the method is suitable for proteins interacting with nucleic acids or acidic proteins, where either mixed PEI-DNA or RNA–protein complexes or PEI–acidic protein complexes are reversibly precipitated. (i) The method is of general use, applicable with minor modifications to a variety of bacteriophage cell lysates and proteins. (ii) In the example application, TP84_26 GD was highly purified (over 50%) in a single PEI step; subsequent chromatography yielded a homogeneous enzyme. (iii) The enzyme's properties were examined, revealing the presence of three distinct forms of the TP84_26 GD. These forms included soluble, unbound proteins found in host cell lysate, as well as an integrated form within the TP-84 virion. [ABSTRACT FROM AUTHOR]

The persistence of organisms as biofilms and the increase in antimicrobial resistance has raised the need for alternative strategies. The study objective was to compare the ability of isolated bacteriophages to remove in vitro biofilms formed by Pseudomonas aeruginosa isolated from the environment with those isolated from diabetic and non-diabetic wounds. P. aeruginosa were isolated from clinical and environmental sites, and antimicrobial susceptibility was tested. Bacteriophages were isolated and characterized based on plaque morphology and host range. A reduction in the viable count assayed the lytic ability of candidate phages. The crystal violet method was used to determine the residual biofilm after 24 h of phage treatment on 72-h-old biofilms. The statistical significance of phage treatment was tested by one-way ANOVA. Of 35 clinical isolates, 17 showed resistance to 1 antibiotic at least, and 7 were multidrug resistant. Nineteen environmental isolates and 11 clinical isolates were drug-sensitive. Nine phages showed 91.2% host coverage, including multidrug-resistant isolates. Phages eradicated 85% of biofilms formed by environmental isolates compared to 58% of biofilms of diabetic isolates and 56% of biofilms of non-diabetic isolates. Clinical isolates are susceptible to phage infection in planktonic form. Biofilms of P. aeruginosa isolated from diabetic wounds and non-diabetic wounds resist removal by phages compared to biofilms formed by environmental isolates. All phages were efficient in dispersing PAO1 biofilms. However, there was a significant difference in their ability to disperse PAO1 biofilms across the different surfaces tested. Partial eradication of biofilm by phages can aid in complementing antibiotics that are unable to penetrate biofilms in a clinical set-up. [ABSTRACT FROM AUTHOR]

The disinfection and removal of biofilm from titanium dental implants remains a great challenge in oral medicine. Here we present results of novel photoacoustic irrigation laser modalities for biofilm removal in model geometries mimicking the peri-implant pocket. The efficacy of single pulse (Er:YAG-SSP) and dual pulse (Er:YAG-AutoSWEEPS) photoacoustic irrigation modalities were determined for Enterococcus faecalis biofilm decontamination from titanium surfaces in narrow cylindrical and square gap geometries. The density of bacteria as well as the number of live bacteria were determined prior and after different photoacoustic treatments. Both SSP and AutoSWEEPS photoacoustic irrigation techniques removed at least 92% of biofilm bacteria during the 10 s photoacoustic treatment. The effectiveness of cleaning was better in the narrow square gap geometry compared to the cylindrical geometry. The dual pulse Er:YAG-AutoSWEEPS photoacoustic irrigation showed better results compared to SSP modality. No chemical adjuvants were needed to boost the effectiveness of the photoacoustic irrigation in the saline solution. The results imply that photoacoustic irrigation is an efficient cleaning method for debridement and decontamination in narrow geometries and should be considered as a new therapeutic option for the treatment of peri-implant diseases. [ABSTRACT FROM AUTHOR]

Food degradation made by mycotoxigenic molds represents a significant challenge too food security. Postbiotics are associated with soluble compounds liberated by living bacterial cells or their construction release after lysis, and these metabolites offer the host biological action and specific physiological benefits. In this work, the postbiotics from tree strains of Lactobacillus spp. (Limosilactobacillus reuteri ATCC 367, Lacticaseibacillus casei431 and Levilactobacillus brevisATCC) were lyophilized, filtered, and tested to evaluate the antimicrobial and anti-biofilm activity in vitro and milk against P. expansoum. Also, to assess the antioxidant efficacy and the free radical scavenging possibility of the postbiotic, DPPH, and ABTS + methods were used. Antimicrobial activity and biofilm removal activity of postbiotics depended on the Lactobacillus strains used. The minimum inhibitory concentration (MIC) of the prepared postbiotic was determined to be 70ug/ml. The lowest minimum effective concentration (MEC) of postbiotics were significantly differed, in the food matrix, and a low MEC index (100 mg/ml) was detected for postbiotic of L. brevis. Postbiotics derived from L. brevis showed the highest antimicrobial activity compared to L. casei and L. reuteri. The postbiotic extracted from Lactobacillus strain may have functional properties (potential antimicrobial and anti-biofilm) in vitro and food models. [ABSTRACT FROM AUTHOR]

Combatting the rapidly growing threat of antimicrobial resistance and reducing prevalence and transmission of ESKAPEE pathogens in healthcare settings requires innovative strategies, one of which is displacing these pathogens using beneficial microorganisms. Our review comprehensively examines the evidence of probiotic bacteria displacing ESKAPEE pathogens, with a focus on inanimate surfaces. A systematic search was conducted using the PubMed and Web of Science databases on 21 December 2021, and 143 studies were identified examining the effects of Lactobacillaceae and Bacillus spp. cells and products on the growth, colonization, and survival of ESKAPEE pathogens. While the diversity of study methods limits evidence analysis, results presented by narrative synthesis demonstrate that several species have the potential as cells or their products or supernatants to displace nosocomial infection-causing organisms in a variety of in vitro and in vivo settings. Our review aims to aid the development of new promising approaches to control pathogen biofilms in medical settings by informing researchers and policymakers about the potential of probiotics to combat nosocomial infections. More targeted studies are needed to assess safety and efficacy of different probiotic formulations, followed by large-scale studies to assess utility in infection control and medical practice. [ABSTRACT FROM AUTHOR]

Novel strategies to combat dental biofilms aim at reducing biofilm stability with the ultimate goal of facilitating mechanical cleaning. To test the stability of dental biofilms, they need to be subjected to a defined mechanical stress. Here, we employed an oral care device (Airfloss) that emits microbursts of compressed air and water to apply a defined mechanical shear to 14-day-old dental plaque in 20 healthy participants with no signs of oral diseases (clinical trial no. NCT05082103). Exclusion criteria included pregnant or nursing women, users of oral prostheses, retainers or orthodontic appliances, and recent antimicrobial or anti-inflammatory therapy. Plaque accumulation, before and after treatment, was assessed using fluorescence images of disclosed dental plaque on the central incisor, first premolar, and first molar in the third quadrant (120 images). For each tooth, the pre- and post-treatment plaque percentage index (PPI) and Turesky modification of the Quigley-Hein plaque index (TM-QHPI) were recorded. The mean TM-QHPI significantly decreased after treatment (p = 0.03; one-sample sign test), but no significant difference between the mean pre- and post-treatment PPI was observed (p = 0.09; one-sample t-test). These data are of value for researchers that seek to apply a defined mechanical shear to remove and/or disrupt dental biofilms. Dataset: The dataset is submitted as a supplementDataset License: CC-BY-NC [ABSTRACT FROM AUTHOR]

Biofilms are often tolerant towards routine cleaning and disinfection processes. As they can grow on fabrics in household or healthcare settings, resulting in odors and serious health problems, it is necessary to contain biofilms through eradication strategies. The current study proposes a novel test model for the growth and removal of biofilms on textiles with Pseudomonas fluorescens and the opportunistic nosocomial pathogen Pseudomonas aeruginosa as model organisms. To assess the biofilm removal on fabrics, (1) a detergent-based, (2) enzyme-based, and (3) combined formulation of both detergent and enzymes (F1/2) were applied. Biofilms were analyzed microscopically (FE-SEM, SEM, 3D laser scanning- and epifluorescence microscopy), via a quartz crystal microbalance with mass dissipation monitoring (QCM-D) as well as plate counting of colonies. This study indicated that Pseudomonas spp. form robust biofilms on woven cellulose that can be efficiently removed via F1/2, proven by a significant reduction (p < 0.001) of viable bacteria in biofilms. Moreover, microscopic analysis indicated a disruption and almost complete removal of the biofilms after F1/2 treatment. QCM-D measurements further confirmed a maximal mass dissipation change after applying F1/2. The combination strategy applying both enzymes and detergent is a promising antibiofilm approach to remove bacteria from fabrics. [ABSTRACT FROM AUTHOR]

The emergence of antimicrobial resistance remains one of the greatest public health concerns. Biofilm formation has been postulated as a mechanism of microbial pathogens to resist antimicrobial agents. Lactic Acid Bacteria (LAB) and their metabolites have been proposed to combat bacterial biofilms due to their antimicrobial activity. In this vein, the aim of the present study was to investigate the biofilm removal potential of cell-free supernatants (CFSs) of five wild-type Lacticaseibacillus rhamnosus strains, isolated from Greek natural products, in comparison to the commercially available L. rhamnosus GG strain, against biofilms formed by common foodborne pathogens (Salmonella Enteritidis, Salmonella Typhimurium, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus). The biofilm removal activity of LAB was assessed on a two-day-old mature biofilm using a microtiter plate-based procedure. Both non-neutralized and neutralized CFSs removed biofilms in a concentration-dependent manner. The biofilm removal activity of the non-neutralized CFSs was significantly higher compared to the neutralized CFSs, as expected, with ranges of 60–89% and 30–80%, respectively. The biofilm removal efficiency of L. rhamnosus OLXAL-3 was significantly higher among the wild-type L. rhamnosus strains tested (20–100% v/v). In conclusion, our results suggest the great potential of the application of wild-type L. rhamnosus strain’ CFSs as effective natural agents against pathogenic bacterial biofilms.

Objective: The purpose of this study was to (i) synthesize and develop an alkynyloxy derivative of lawsone as an antifungal spray and (ii) assess the antifungal spray’s effectiveness in reducing the viability of Candida albicans (C. albicans) on polymethylmethacrylate (PMMA) specimens. Methods: Lawsone methyl ether (LME) and its derivative, 2-(prop-2-ynyloxy)naphthalene-1,4-dione (compound 1) were synthesized and characterized. The synthetic compounds were screened for antimicrobial activities against C. albicans using the microtiter broth dilution method to determine the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC). Compound 1 was further formulated as an antifungal spray in three concentrations (100, 200, and 400 μg/mL). C. albicans biofilms were developed for 48 h on PMMA specimens. The efficacy of using an antifungal spray for 1 and 3 min to remove biofilm was assessed using colony counting and scanning electron microscopy (SEM). Chlorhexidine gluconate (CHX), polident®, and distilled water were used as positive and negative control cleansing solutions, respectively. Results: LME and compound 1 showed comparable inhibition against C. albicans with a MIC of 25 μg/mL and MFC of 50 μg/mL. For immediate treatment, C. albicans was not detected on PMMA specimens when expose to 2% CHX and compound 1 (100, 200, and 400 μg/mL) antifungal spray for 3 min. However, after recolonization, a small number of viable cells were observed in denture soaked in compound 1 antifungal spray for 3 min group. Following recolonization, polident® and distilled water had comparable viable cell counts of C. albicans to the no treatment group. Scanning electron microscope (SEM) images revealed that CHX, polident®, and compound 1 caused cell damage in various forms. Conclusion: Denture spray containing synthetic alkynyloxy derivative of lawsone is a promising antifungal agent for C. albicans biofilm removal from the PMMA surface.

ABSTRACT Mechanical cleaning remains the standard of care for maintaining oral hygiene. However, mechanical cleaning is often augmented with active therapeutics that further promote oral health. A dentifrice, consisting of the “Dual Zinc plus Arginine” (DZA) technology, was found to be effective at controlling bacteria using in vitro laboratory studies, translating to clinical efficacy to deliver plaque and gingivitis reduction benefits. Here, we used biophysical analyses and confocal laser scanning microscopy to understand how a DZA dentifrice impacted the mechanical properties of dental plaque biofilms and determine if changes to biofilm rheology enhanced the removal of dental plaque. Using both uniaxial mechanical indentation and an adapted rotating-disc rheometry assay, it was found that DZA treatment compromised biofilm mechanical integrity, resulting in the biofilm being more susceptible to removal by shear forces compared to treatment with either arginine or zinc alone. Confocal laser scanning microscopy revealed that DZA treatment reduced the amount of extracellular polymeric slime within the biofilm, likely accounting for the reduced mechanical properties. We propose a model where arginine facilitates the entry of zinc into the biofilm, resulting in additive effects of the two activities toward dental plaque biofilms. Together, our results support the use of a dentifrice containing Dual Zinc plus Arginine as part of daily oral hygiene regimens. IMPORTANCE Mechanical removal of dental plaque is augmented with therapeutic compounds to promote oral health. A dentifrice containing the ingredients zinc and arginine has shown efficacy at reducing dental plaque both in vitro and in vivo. However, how these active compounds interact together to facilitate dental plaque removal is unclear. Here, we used a combination of biophysical analyses and microscopy to demonstrate that combined treatment with zinc and arginine targets the matrix of dental plaque biofilms, which destabilized the mechanical integrity of these microbial communities, making them more susceptible to removal by shear forces.

Prosthetic joint infection (PJI) presents several clinical challenges. This is in large part due to the formation of biofilm which can make infection eradication exceedingly difficult. Following an extensive literature search, this review surveys a variety of non-pharmacological methods of preventing and/or treating biofilm within the body and how they could be utilized in the treatment of PJI. Special attention has been paid to physical strategies such as heat, light, sound, and electromagnetic energy, and their uses in biofilm treatment. Though these methods are still under study, they offer a potential means to reduce the morbidity and financial burden related to multiple stage revisions and prolonged systemic antibiotic courses that make up the current gold standard in PJI treatment. Given that these options are still in the early stages of development and offer their own strengths and weaknesses, this review offers an assessment of each method, the progress made on each, and allows for comparison of methods with discussion of future challenges to their implementation in a clinical setting. [ABSTRACT FROM AUTHOR]

Background: The disinfection process represents an important activity closely linked to the removal of micro-organisms in common processing systems. Traditional disinfectants are often not sufficient to avoid the spread of food pathogens; therefore, innovative strategies for decontamination are crucial to countering microbial transmission. This study aims to assess the antimicrobial efficiency of tetrapotassium iminodisuccinic acid salt (IDSK) against the most common pathogens present on surfaces, especially in food-borne environments. Methods: IDSK was synthesized from maleic anhydride and characterized through nuclear magnetic resonance (NMR) spectroscopy (both 1H-NMR and 13C-NMR), thermogravimetric analysis (TGA) and Fourier Transform Infrared (FTIR) spectroscopy. The antibacterial activity was performed via the broth microdilution method and time-killing assays against Escherichia coli, Staphylococcus aureus, Salmonella enterica, Enterococcus faecalis and Pseudomonas aeruginosa (IDSK concentration range: 0.5–0.002 M). The biofilm biomass eradicating activity was assessed via a crystal violet (CV) assay. Results: The minimum inhibitory concentration (MIC) of IDSK was 0.25 M for all tested strains, exerting bacteriostatic action. IDSK also reduced biofilm biomass in a dose-dependent manner, reaching rates of about 50% eradication at a dose of 0.25 M. The advantages of using this innovative compound are not limited to disinfecting efficiency but also include its high biodegradability and its sustainable synthesis. Conclusions: IDSK could represent an innovative and advantageous disinfectant for food processing and workers' activities, leading to a better quality of food and safer working conditions for the operators. [ABSTRACT FROM AUTHOR]

Periodontitis is a highly prevalent and common condition in people of all ages, however, existing drugs to treat periodontitis have difficulty penetrating complex biofilms. Here, we report a biofilm-penetrating probiotic hybrid strategy for the treatment of periodontitis. It consists of therapeutic probiotics of E. coli Nissle 1917, which can produce antimicrobial peptides and hydrogen, and is coated with D-amino acids that can penetrate biofilms. After the fusion of D-amino acids with the biofilm, EcN entered the plaque biofilm and produced antimicrobial peptides to kill porphyromonas gingivalis and eliminate periodontitis under the action of hydrogen. The efficacy of EcN@DA-D in biofilm penetration and treatment of periodontitis was demonstrated in a rat model of periodontitis. In addition, the clinical combination to construct a rat periodontitis model by using clinical tissue has a significant therapeutic effect. In conclusion, EcN@DA-D offers a promising topical treatment for periodontitis without developing detectable pathogen resistance and side effects., (© 2024 Wiley‐VCH GmbH.)

The goal of this study was to evaluate if a magnetic water treatment device could be used to mitigate biofilms in water systems. Magnetic treatment was applied to water upstream of a modified Robbins device in which Pseudomonas fluorescence biofilms were formed. Duration of magnetic treatment, system flow rate, and field strength were varied to assess the impacts on the biofilm. A control system was concurrently established in which no magnetic treatment was applied. After treatment, the number of viable cells in the biofilm was reduced by up to 2.46 log 10 CFU cm -2 depending on the operational conditions. Increased cell stress, and ultimately death, was observed during treatment as indicated by an elevated AMPi stress index. These results indicate that magnetic water treatment may be an effective technology to decrease the extent of biofilms in water systems and a reduced need for chemical treatment. A mechanism is proposed in which metabolic processes are hindered due to the magnetic field effects on ions in the water. However, a mechanistic investigation remains outside the scope of this study. Future studies should aim to characterize both the impacts of treatment on the matrix and cellular processes to determine a mechanism for the observed effects.

Bacterial infection, which can trigger varieties of diseases and tens of thousands of deaths each year, poses serious threats to human health. Particularly, the new dilemma caused by biofilms is gradually becoming a severe and tough problem in the biomedical field. Thus, the strategies to address these problems are considered an urgent task at present. Micro/nanomotors (MNMs), also named micro/nanoscale robots, are mostly driven by chemical energy or external field, exhibiting strong diffusion and self-propulsion in the liquid media, which has the potential for antibacterial applications. In particular, when MNMs are assembled in swarms, they become robust and efficient for biofilm removal. However, there is a lack of comprehensive review discussing the progress in this aspect. Bearing it in mind and based on our own research experience in this regard, the studies on MNMs driven by different mechanisms orchestrated for antibacterial activity and biofilm removal are timely and concisely summarized and discussed in this work, aiming to show the advantages of MNMs brought to this field. In addition, an outlook was proposed, hoping to provide the fundamental guidance for future development in this area., (© 2024 Wiley-VCH GmbH.)

The persistence of organisms as biofilms and the increase in antimicrobial resistance has raised the need for alternative strategies. The study objective was to compare the ability of isolated bacteriophages to remove in vitro biofilms formed by Pseudomonas aeruginosa isolated from the environment with those isolated from diabetic and non-diabetic wounds. P. aeruginosa were isolated from clinical and environmental sites, and antimicrobial susceptibility was tested. Bacteriophages were isolated and characterized based on plaque morphology and host range. A reduction in the viable count assayed the lytic ability of candidate phages. The crystal violet method was used to determine the residual biofilm after 24 h of phage treatment on 72-h-old biofilms. The statistical significance of phage treatment was tested by one-way ANOVA. Of 35 clinical isolates, 17 showed resistance to 1 antibiotic at least, and 7 were multidrug resistant. Nineteen environmental isolates and 11 clinical isolates were drug-sensitive. Nine phages showed 91.2% host coverage, including multidrug-resistant isolates. Phages eradicated 85% of biofilms formed by environmental isolates compared to 58% of biofilms of diabetic isolates and 56% of biofilms of non-diabetic isolates. Clinical isolates are susceptible to phage infection in planktonic form. Biofilms of P. aeruginosa isolated from diabetic wounds and non-diabetic wounds resist removal by phages compared to biofilms formed by environmental isolates. All phages were efficient in dispersing PAO1 biofilms. However, there was a significant difference in their ability to disperse PAO1 biofilms across the different surfaces tested. Partial eradication of biofilm by phages can aid in complementing antibiotics that are unable to penetrate biofilms in a clinical set-up.

Purification of bacteriophage-expressed proteins poses methodological difficulties associated with the need to process entire culture medium volume upon bacteriophage-induced bacterial cell lysis. We have used novel capsule glycosylase-depolymerase (TP84_26 GD) from bacteriophage TP-84, infecting thermophilic Geobacillus stearothermophilus bacteria, as a representative enzyme to develop a method for rapid concentration and purification of the enzyme present in diluted crude host cell lysate. A novel variant of the polyethyleneimine (PEI)-based purification method was devised that offers a fast and effective approach for handling PEI-facilitated purification of bacteriophage-expressed native proteins. Due to the very basic nature of PEI, the method is suitable for proteins interacting with nucleic acids or acidic proteins, where either mixed PEI-DNA or RNA–protein complexes or PEI–acidic protein complexes are reversibly precipitated. (i) The method is of general use, applicable with minor modifications to a variety of bacteriophage cell lysates and proteins. (ii) In the example application, TP84_26 GD was highly purified (over 50%) in a single PEI step; subsequent chromatography yielded a homogeneous enzyme. (iii) The enzyme’s properties were examined, revealing the presence of three distinct forms of the TP84_26 GD. These forms included soluble, unbound proteins found in host cell lysate, as well as an integrated form within the TP-84 virion.

The disinfection and removal of biofilm from titanium dental implants remains a great challenge in oral medicine. Here we present results of novel photoacoustic irrigation laser modalities for biofilm removal in model geometries mimicking the peri-implant pocket. The efficacy of single pulse (Er:YAG-SSP) and dual pulse (Er:YAG-AutoSWEEPS) photoacoustic irrigation modalities were determined for Enterococcus faecalis biofilm decontamination from titanium surfaces in narrow cylindrical and square gap geometries. The density of bacteria as well as the number of live bacteria were determined prior and after different photoacoustic treatments. Both SSP and AutoSWEEPS photoacoustic irrigation techniques removed at least 92% of biofilm bacteria during the 10 s photoacoustic treatment. The effectiveness of cleaning was better in the narrow square gap geometry compared to the cylindrical geometry. The dual pulse Er:YAG-AutoSWEEPS photoacoustic irrigation showed better results compared to SSP modality. No chemical adjuvants were needed to boost the effectiveness of the photoacoustic irrigation in the saline solution. The results imply that photoacoustic irrigation is an efficient cleaning method for debridement and decontamination in narrow geometries and should be considered as a new therapeutic option for the treatment of peri-implant diseases.

[Display omitted] • Efficient disinfection of environmental surfaces by [C 16 MIM][Cl] and its formulations. • [C 16 MIM][Cl] completely eliminated viability of E. coli and S. aureus cells in 10 sec. • A 99% reduction in bacterial load from environmental surfaces by [C 16 MIM][Cl]. • Disinfection efficacy of [C 16 MIM][Cl] was increased by preparing in 70% ethanol. • Ionic liquid in ethanol (70%) caused more membrane damage in bacteria than individually. Surface disinfection is fundamental to good environmental hygiene and preventing infections. Development of newer formulations that can effectively kill and remove microorganisms from the surfaces is desired. Here, we assessed the efficacy of 1-hexadecyl-3-methylimidazolium chloride [C 16 MIM][Cl] ionic liquid (IL) and its formulation in ethanol for killing and removing bacteria from different environmental surfaces. Efficacy of IL and its formulation was determined on known monospecies bacterial cultures and unknown multispecies bacterial cultures on environmental surfaces. The surface disinfection efficacy of [C 16 MIM][Cl] was concentration dependent and achieved 41 to 100% reduction in total viable bacterial counts of Gram positive and Gram negative bacteria at varied concentrations. The treatment of wooden surface with 0.1% [C 16 MIM][Cl] caused 98% reduction in bacterial load within 20 s contact time as against mere 45% reduction (20 s) with 70% ethanol. Antibacterial and surface disinfection activities of [C 16 MIM][Cl] have increased markedly when prepared in 70% ethanol, suggesting synergistic activity. A formulation comprising of 0.01% [C 16 MIM][Cl] in 70% ethanol showed effective surface disinfection and achieved 95% to 98% reduction in bacterial load on different surfaces. Ionic liquids are potent candidates for disinfection of environmental surfaces. [ABSTRACT FROM AUTHOR]

Combatting the rapidly growing threat of antimicrobial resistance and reducing prevalence and transmission of ESKAPEE pathogens in healthcare settings requires innovative strategies, one of which is displacing these pathogens using beneficial microorganisms. Our review comprehensively examines the evidence of probiotic bacteria displacing ESKAPEE pathogens, with a focus on inanimate surfaces. A systematic search was conducted using the PubMed and Web of Science databases on 21 December 2021, and 143 studies were identified examining the effects of Lactobacillaceae and Bacillus spp. cells and products on the growth, colonization, and survival of ESKAPEE pathogens. While the diversity of study methods limits evidence analysis, results presented by narrative synthesis demonstrate that several species have the potential as cells or their products or supernatants to displace nosocomial infection-causing organisms in a variety of in vitro and in vivo settings. Our review aims to aid the development of new promising approaches to control pathogen biofilms in medical settings by informing researchers and policymakers about the potential of probiotics to combat nosocomial infections. More targeted studies are needed to assess safety and efficacy of different probiotic formulations, followed by large-scale studies to assess utility in infection control and medical practice.

[Display omitted] Diabetic wound treatment remains a major challenge due to the difficulties of eliminating bacterial biofilm and relieving wound hypoxia. To address these issues simultaneously, a multifunctional Dex-SA-AEMA/MnO 2 /PDA (DSAMP) hydrogel platform was developed with excellent biocompatibility and porous structure. The hydrogel could absorb the exudate, maintain humidity and permeate oxygen, which was prepared by encapsulating polydopamine (PDA) and manganese dioxide (MnO 2) into Dex-SA-AEMA (DSA) hydrogel by UV irradiation. With the addition of PDA, the DSAMP hydrogel was proved to eliminate the biofilm after NIR photodynamic therapy (PTT, 808 nm) irradiation at 54 °C. Furthermore, in order to mitigate hypoxia wound microenvironment, MnO 2 nanoparticles were added to convert the endogenous hydrogen peroxide (H 2 O 2) into oxygen (O 2 , 16 mg L−1). The diabetic wound in vivo treated by DSAMP hydrogel was completely healed on 14 days. It was revealed that the DSAMP hydrogel possessed a great potential as dressing for diabetic chronic wound healing. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the most effective chemotherapeutic agent for decontamination of infected dental implants. Material and methods: A systematic electronic literature search in MEDLINE (PubMed) and Google scholar between January 2010 to December 2021 was carried out by using the PRISMA guidelines. A total of five studies related to chemical decontamination of the dental implant were evaluated. The search strategy was based on the PICOS framework. Randomized controlled trials (RCT's) and cohort studies evaluating the effectiveness of different chemotherapeutic agents for the decontamination of dental implants were included in the study. The outcome variable examined was the most effective chemotherapeutic agent(s) for dental implant surface decontamination after comparing the chemotherapeutic agents used in the qualifying studies. Result: Out of the basic database of 1564 records, 1380 articles were excluded due to irrelevance, unavailability, and repetition. Furthermore, 134 articles were excluded from 184 studies for various reasons. After further filtration, 13 studies were shortlisted. Two investigators (SSA and SA) appraised the quality of the selected studies using the risk of bias assessment tool. After excluding eight studies, five articles were finally included in the present systematic review. Conclusion: The data reported for the efficacy of chemotherapeutic agents in cleaning contaminated titanium surfaces are scarce, thus it is not possible to draw a definite conclusion. However, chlorhexidine (CHX) (0.2%, 0.12%), citric acid (40%) and sodium hypochlorite (1%) are the most commonly used chemotherapeutic agents; amongst them, citric acid showed the highest potential for biofilm removal from the contaminated implant surface. All three agents [CHX (0.2%, 0.12%), citric acid (40%), and sodium hypochlorite (1%)] can be recommended as therapeutic agents along with their curbs. [ABSTRACT FROM AUTHOR]

Abstract Background The current study evaluated whether a new digitized scaling training program (DTP: n = 30; supervisor-student-ratio 1:10) improves the performance of undergraduate dental student during a preclinical course in regard to two different instruments [sonic scalers (AIR) and Gracey curettes (GRA)] compared to a conventional training program (CTP: n = 19; supervisor-student-ratio 1:4). Methods All the participants received a two-hour lecture on both instruments, followed by a 12-week period with a weekly training program lasting 45 min (10 sessions); one group was supported by DTP. At the end of the training phase, all the participants performed the subgingival scaling of six equivalent test teeth using GRA and AIR. Treatment time, proportion of removed simulated biofilm (relative cleaning efficacy, RCE-b) and hard deposits (RCE-d) were recorded. By using a pseudonymized questionnaire with a 5-point Likert scale, self-assessment of scaling effort, handling, root surface roughness/destruction and effectiveness were evaluated. In addition, personal data such as age, gender, handedness, regularity of playing computer games/consoles and previous dental/technical or medical education were elevated and correlated with cleaning efficacy. Results The DTP participants showed higher effectiveness in RCE-b compared to those who used the CTP with GRA (71.54% vs. 67.23%, p = 0.004) and AIR (71.75% vs. 62.63%, p ≤ 0.001), and the DTP students were faster with both instruments (p ≤ 0.001). For RCE-d, there was no significant difference between the DTP and CTP groups (GRA p = 0.471; AIR p = 0.158), whereas DTP showed better RCE-d results with GRA versus AIR (84.68% vs. 77.85%, p

Novel strategies to combat dental biofilms aim at reducing biofilm stability with the ultimate goal of facilitating mechanical cleaning. To test the stability of dental biofilms, they need to be subjected to a defined mechanical stress. Here, we employed an oral care device (Airfloss) that emits microbursts of compressed air and water to apply a defined mechanical shear to 14-day-old dental plaque in 20 healthy participants with no signs of oral diseases (clinical trial no. NCT05082103). Exclusion criteria included pregnant or nursing women, users of oral prostheses, retainers or orthodontic appliances, and recent antimicrobial or anti-inflammatory therapy. Plaque accumulation, before and after treatment, was assessed using fluorescence images of disclosed dental plaque on the central incisor, first premolar, and first molar in the third quadrant (120 images). For each tooth, the pre- and post-treatment plaque percentage index (PPI) and Turesky modification of the Quigley-Hein plaque index (TM-QHPI) were recorded. The mean TM-QHPI significantly decreased after treatment (p = 0.03; one-sample sign test), but no significant difference between the mean pre- and post-treatment PPI was observed (p = 0.09; one-sample t-test). These data are of value for researchers that seek to apply a defined mechanical shear to remove and/or disrupt dental biofilms.

Biofilms are often tolerant towards routine cleaning and disinfection processes. As they can grow on fabrics in household or healthcare settings, resulting in odors and serious health problems, it is necessary to contain biofilms through eradication strategies. The current study proposes a novel test model for the growth and removal of biofilms on textiles with Pseudomonas fluorescens and the opportunistic nosocomial pathogen Pseudomonas aeruginosa as model organisms. To assess the biofilm removal on fabrics, (1) a detergent-based, (2) enzyme-based, and (3) combined formulation of both detergent and enzymes (F1/2) were applied. Biofilms were analyzed microscopically (FE-SEM, SEM, 3D laser scanning- and epifluorescence microscopy), via a quartz crystal microbalance with mass dissipation monitoring (QCM-D) as well as plate counting of colonies. This study indicated that Pseudomonas spp. form robust biofilms on woven cellulose that can be efficiently removed via F1/2, proven by a significant reduction (p < 0.001) of viable bacteria in biofilms. Moreover, microscopic analysis indicated a disruption and almost complete removal of the biofilms after F1/2 treatment. QCM-D measurements further confirmed a maximal mass dissipation change after applying F1/2. The combination strategy applying both enzymes and detergent is a promising antibiofilm approach to remove bacteria from fabrics.

Tailoring the microstructure of magnetic microparticles is of vital importance for their applications. Spiky magnetic particles, such as those made from sunflower pollens, have shown promise in single cell treatment and biofilm removal. Synthetic methods that can replicate or extend the functionality of such spiky particles would be advantageous for their widespread utilization. In this work, a wet-chemical method is introduced for spiky magnetic particles that are templated from microrod-stabilized Pickering emulsions. The spiky morphology is generated by the upright attachment of silica microrods at the oil-water interface of oil droplets. Spiky magnetic microparticles with control over the length of the spikes are obtained by dispersing hydrophobic magnetic nanoparticles in the oil phase and photopolymerizing the monomer. The spiky morphology dramatically enhances colloidal stability of these particles in high ionic strength solutions and physiologic media such as human saliva and saline-based biofilm suspension. To demonstrate their utility, the spiky magnetic particles are applied for magnetically controlled removal of oral biofilms and retrieval of bacteria for diagnostic sampling. This method expands the toolbox for engineering microparticle morphology and could promote the fabrication of functional magnetic microrobots., (© 2024 The Author(s). Small published by Wiley‐VCH GmbH.)

Bioactive aminooxime ligands based on optically pure (R)-limonene have been synthesized in two steps. Their ruthenium (II) cationic water-soluble complex was prepared by a reaction between dichloro (para-cymene) ruthenium (II) dimers and aminooxime ligands in a 1:2 molar ratio. Antibacterial and antibiofilm activities of the synthetized complex were assessed against Escherichia coli , Staphylococcus aureus , Listeria monocytogenes , and Enterococcus faecalis. The results revealed that the ruthenium (II) complex has higher antibacterial and antibiofilm activities in comparison with free ligands or the enantiopure (R)-limonene. Moreover, microencapsulation of this complex reduced its cytotoxicity and improved their minimum inhibitory concentration and antibiofilm activity toward the considered bacteria. The ruthenium (II) complex targets the bacterial cell membrane, which leads to rapid leakage of intracellular potassium. Our study suggests that the developed ruthenium (II) complexes could be useful as an alternative to conventional disinfectants. [ABSTRACT FROM AUTHOR]

The growth of biofilm, which is caused by microorganism accumulation and growth on wetted surfaces, may damage industrial piping systems, increase maintenance and cleaning costs for the system sterilization, and even divulge the immune system into high risk. This article systematically analyzes the biofilm interactions with piping surface materials from the perspectives of physical convection, and biological and chemical adhesion. The thermodynamics of the flow, bacterial surface sensing, and bio-communication are the most critical factors for biofilm attachment. Furthermore, experimental analysis methods as well as biofilm control and removal approaches, are also included in this study. Finally, the resistance and growth of biofilm, as well as the practical and advanced methodology to control the biofilm and challenges associated with technology, are also discussed. Moreover, this paper may also offer a significant reference for the practice and strategic applications to address the biofilm resistance issues in industrial piping.

Background: The disinfection process represents an important activity closely linked to the removal of micro-organisms in common processing systems. Traditional disinfectants are often not sufficient to avoid the spread of food pathogens; therefore, innovative strategies for decontamination are crucial to countering microbial transmission. This study aims to assess the antimicrobial efficiency of tetrapotassium iminodisuccinic acid salt (IDSK) against the most common pathogens present on surfaces, especially in food-borne environments. Methods: IDSK was synthesized from maleic anhydride and characterized through nuclear magnetic resonance (NMR) spectroscopy (both 1H-NMR and 13C-NMR), thermogravimetric analysis (TGA) and Fourier Transform Infrared (FTIR) spectroscopy. The antibacterial activity was performed via the broth microdilution method and time-killing assays against Escherichia coli, Staphylococcus aureus, Salmonella enterica, Enterococcus faecalis and Pseudomonas aeruginosa (IDSK concentration range: 0.5–0.002 M). The biofilm biomass eradicating activity was assessed via a crystal violet (CV) assay. Results: The minimum inhibitory concentration (MIC) of IDSK was 0.25 M for all tested strains, exerting bacteriostatic action. IDSK also reduced biofilm biomass in a dose-dependent manner, reaching rates of about 50% eradication at a dose of 0.25 M. The advantages of using this innovative compound are not limited to disinfecting efficiency but also include its high biodegradability and its sustainable synthesis. Conclusions: IDSK could represent an innovative and advantageous disinfectant for food processing and workers’ activities, leading to a better quality of food and safer working conditions for the operators.

Prosthetic joint infection (PJI) presents several clinical challenges. This is in large part due to the formation of biofilm which can make infection eradication exceedingly difficult. Following an extensive literature search, this review surveys a variety of non-pharmacological methods of preventing and/or treating biofilm within the body and how they could be utilized in the treatment of PJI. Special attention has been paid to physical strategies such as heat, light, sound, and electromagnetic energy, and their uses in biofilm treatment. Though these methods are still under study, they offer a potential means to reduce the morbidity and financial burden related to multiple stage revisions and prolonged systemic antibiotic courses that make up the current gold standard in PJI treatment. Given that these options are still in the early stages of development and offer their own strengths and weaknesses, this review offers an assessment of each method, the progress made on each, and allows for comparison of methods with discussion of future challenges to their implementation in a clinical setting.

Minthostachys setosa (Briquet) (M. setosa) and Piper elongatum (Vahl) (P. elongatum), known as muña and matico, respectively, are plants originating from Peru. They are widely used in a variety of traditional uses, such as food preservatives, digestives, antispasmodics, carminatives, insecticides, and antibacterials. This study was conducted to determine the chemical composition of M. setosa and P. elongatum essential oils (EOs), as well as to evaluate their antistaphylococcal activity and effect on the removal of preformed biofilm by Staphylococcus aureus on stainless steel. Gas chromatography/mass spectrometry revealed pulegone (57.54%) and caryophyllene (7.29%) as the most abundant compounds of M. setosa essential oil (EO), while eucalyptol (10.84%) and methyl eugenol (9.29%) were the main compounds of P. elongatum EO. Both EOs showed antistaphylococcal activity and the ability to remove preformed S. aureus biofilm on stainless steel at two temperatures (25 and 37 °C). A reduction of up to 2.52 CFU log.cm−2 was observed in S. aureus viable cell counts in preformed biofilm, which was concentration- and isolate-dependent. Confocal laser scanning microscopy demonstrated that M. setosa and P. elongatum EOs presented activity on the preformed S. aureus biofilm. Significant reductions in the count of viable cells in the biofilm were observed as the concentrations of EOs increased. In conclusion, pulegone and eucalyptol, respectively, were the main compounds found in the EOs of M. setosa and P. elongatum. These EOs demonstrated antistaphylococcal activity and the potential to remove S. aureus biofilms on surfaces commonly found in the food industry. [Display omitted] • The essential oils extracted from Andean plants have antistaphylococcal activity. • Minthostachys setosa and Piper elongatum EOs showed pulegone and eucalyptol as the main compounds. • The CLSM technique showed that M. setosa and P. elongatum EOs removed preformed S. aureus biofilm on stainless steel. • The essential oils were able to reduce preformed S. aureus biofilm. [ABSTRACT FROM AUTHOR]