Disinfectant Solutions Research Articles

Phytotherapeutic potential against MRSA: mechanisms, synergy, and therapeutic prospects

BackgroundRising resistance to antimicrobials, particularly in the case of methicillin-resistant Staphylococcus aureus (MRSA), represents a formidable global health challenge. Consequently, it is imperative to develop new antimicrobial solutions. This study evaluated 68 Chinese medicinal plants renowned for their historical applications in treating infectious diseases.MethodsThe antimicrobial efficacy of medicinal plants were evaluated by determining their minimum inhibitory concentration (MIC) against MRSA. Safety profiles were assessed on human colorectal adenocarcinoma (Caco-2) and hepatocellular carcinoma (HepG2) cells. Mechanistic insights were obtained through fluorescence and transmission electron microscopy (FM and TEM). Synergistic effects with vancomycin were investigated using the Fractional Inhibitory Concentration Index (FICI).ResultsRheum palmatum L., Arctium lappa L. and Paeonia suffructicosaas Andr. have emerged as potential candidates with potent anti-MRSA properties, with an impressive low MIC of 7.8 µg/mL, comparable to the 2 µg/mL MIC of vancomycin served as the antibiotic control. Crucially, these candidates demonstrated significant safety profiles when evaluated on Caco-2 and HepG2 cells. Even at 16 times the MIC, the cell viability ranged from 83.3% to 95.7%, highlighting their potential safety. FM and TEM revealed a diverse array of actions against MRSA, such as disrupting the cell wall and membrane, interference with nucleoids, and inducing morphological alterations resembling pseudo-multicellular structures in MRSA. Additionally, the synergy between vancomycin and these three plant extracts was evident against MRSA (FICI < 0.5). Notably, aqueous extract of R. palmatum at 1/4 MIC significantly reduced the vancomycin MIC from 2 µg/mL to 0.03 µg/mL, making a remarkable 67-fold decrease.ConclusionsThis study unveil new insights into the mechanistic actions and pleiotropic antibacterial effectiveness of these medicinal plants against resistant bacteria, providing robust evidence for their potential use as standalone or in conjunction with antibiotics, to effectively combat antimicrobial resistance, particularly against MRSA.

The Effectiveness of Belimbing Wuluh Fruit Extract (Averrhoa bilimbi L) as A Smear Layer Cleanser

Background: Root canal treatment is an effort to maintain the function and aesthetics of teeth. The smear layer is formed from the remains of instrumentation composed of organic and inorganic components. A smear layer in the tooth root canal will benefit the adhesion and colonization of microorganisms, block the action of disinfectant solutions, and prevent medicaments in the tooth root canal from penetrating the dentin tubules in the tooth root canal walls. Irrigation can be used for cleaning and disinfection in areas of the root canal that cannot be reached using instruments. Starfruit contains alkoloids, saponins, tannins, flavonoids, phenols, and triterpenoids. Objective: To determine the effectiveness of star fruit extract (Averrhoa bilimbi L) as a smear layer cleaning agent. Materials and Methods: This researcher used laboratory or experimental testing called Post Test Only Control Design. Samples were taken using the purposive sampling technique involving four treatments and six repetitions. The statistical test used is the Mann-Whiteney test. Results: Based on the Mann-Whiteney test, the test results obtained a p-value of 0.093 which is more significant than 0.05 (p-value 0.05). The results showed no significant difference between the 17% EDTA and 35% extract treatment groups regarding smear layer cleanliness. The 35% extract group is as good as the 17% EDTA group. Conclusion: star fruit extract (Averrhoa bilimbi L) is 35% effective in cleaning the smear layer.

Chemical-mediated virulence: the effects of host chemicals on microbial virulence and potential new antivirulence strategies.

The rising antimicrobial resistance rates and declining antimicrobial discovery necessitate alternative strategies to combat multidrug-resistant pathogens. Targeting microbial virulence is an emerging area of interest. Traditionally, virulence factors were largely restricted to bacteria-derived toxins, adhesins, capsules, quorum sensing systems, secretion systems, factors required to sense, respond to, acquire, or synthesize, and utilize trace elements (such as iron and other metals) and micronutrients (such as vitamins), and other factors bacteria use to establish infection, form biofilms, or damage the host tissues and regulatory elements thereof. However, this traditional definition overlooks bacterial virulence that may be induced or influenced by host-produced metabolites or other chemicals that bacteria may encounter at the infection site. This review will discuss virulence from a non-traditional perspective, shedding light on chemical-mediated host-pathogen interactions and outlining currently available mechanistic insight into increased bacterial virulence in response to host factors. This review aims to define a possibly underestimated theme of chemically mediated host-pathogen interactions and encourage future validation and characterization of the contribution of host chemicals to microbial virulence in vivo. From this perspective, we discuss proposed antivirulence compounds and suggest new potential targets for antimicrobials that prevent chemical-mediated virulence. We also explore proposed host-targeting therapeutics reducing the level of host chemicals that induce microbial virulence, serving as virulence attenuators. Understanding the host chemical-mediated virulence may enable new antimicrobial solutions to fight multidrug-resistant pathogens.

Development of apple pectin/soy protein isolate-based edible films containing punicalagin for strawberry preservation

In this study, we developed punicalagin-loaded antimicrobial films based on soy protein isolate (SPI) and apple pectin (AP). The AP was derived from apple pomace waste while the punicalagin was obtained from pomegranate peel. Punicalagin was identified to exist in both α- and β-isomers, with the β-type being predominant. The composite films were characterized using scanning electron microscopy, Fourier transformed infrared spectroscopy, X-ray diffraction, and thermogravimetric analysis. Our results demonstrated that the incorporation of AP significantly enhanced the mechanical strength, heat resistance, and barrier properties of the films. Moreover, the composite films integrated with punicalagin exhibited excellent antimicrobial activities against Staphylococcus aureus (with a minimum bactericidal concentration value of 0.25 %), Escherichia coli (with a minimum bactericidal concentration value of 0.50 %), and Aspergillus niger. Finally, these antimicrobial film solutions were tested as coatings on strawberries and found to have significantly better effects on reducing weight loss, improving shelf-life, and maintaining the freshness of strawberries compared to coatings without punicalagin. The results indicate that antimicrobial coatings loaded with punicalagin hold great promise as multifunctional active packaging materials for fruit preservation.

Employing Metal-Enriched Polymeric Composites: An Innovative Approach for Combatting Microbes and Bacteria in Building Components in Public Places

The escalating occurrence of hospital-associated infections globally, compounded by the ongoing pandemic, has spurred researchers to delve into innovative approaches for combating pathogens and overcoming their resistance to commonly used materials. One of the most important concerns is frequently touched building components in public places and hospitals, which serve as potential sources of infection transmission, prompting a pressing need for effective antimicrobial solutions. This research developed antimicrobial polymeric composites comprising Copper (Cu), Aluminum (Al), and Stainless Steel (SS) particles incorporated into Polylactic Acid (PLA) via injection molding as a commercial method for the production of building components, to investigate the antimicrobial properties. The study aims at increasing the antimicrobial efficiency of polymeric composites with different metallic particles and tests the prepared polymeric composites (two sets of Cu-enriched composites, i.e., Cu–PLA–SS, by mixing Al–PLA with Cu–PLA, and Cu–PLA–Al, by mixing SS–PLA with Cu–PLA) against various bacteria. The results demonstrate that the samples prepared with Cu-PLA mixed with SS and Al exhibited the best antibacterial activity (98.6%) after 20 min of exposure to all bacteria, notably against Staphylococcus aureus and Enterococci. In addition, the hybrid composites Cu–PLA–SS and Cu–PLA–Al, prepared using injection molding, showed similar antimicrobial activity against all bacteria compared to those prepared using 3D printing. Therefore, polymeric composites enriched with metallic particles such as Cu, Al, and SS prepared via injection molding show potential in biomedical applications, food packaging, tissue engineering, and various technological industries, offering viable solutions for environments where risks from contact with infected surfaces are a concern.

Evaluation of commercial, customized microdilution plates for Ureaplasma parvum, Ureaplasma urealyticum, and Mycoplasma hominis antimicrobial susceptibility testing and determination of antimicrobial resistance prevalence in France.

Antimicrobial susceptibility testing of human urogenital mycoplasmas using the CLSI reference broth microdilution method is time-consuming and requires the laborious preparation of antimicrobial stock solutions. Here, we validated the use of reliable, convenient plates designed for antimicrobial susceptibility testing that allows the simultaneous determination of the MICs of eight antibiotics of interest. We then investigated the prevalence and mechanisms of resistance of each of these bacteria to tetracyclines, fluoroquinolones, and macrolides in France in 2020 and 2021. We showed that the prevalence of levofloxacin and moxifloxacin resistance has increased significantly in Ureaplasma spp. from 2010 to 2015 and requires ongoing monitoring.

In situ study of the effect of endogenous and exogenous agents on color stability, hardness, and surface roughness of an elastomer for facial prostheses.

To evaluate in situ the influence of sweat, oil, sunscreen, and disinfectant solution on the color stability, hardness, and roughness of elastomer for facial prostheses. Standardized and intrinsically pigmented specimens remained in contact with human skin from the same person for 30days, considering exposures (n=36 per group), absent of exposition (Control, C); sweat and oiliness contact (SO); sweat and oiliness associated with sunscreen (SOS); 0.12% chlorhexidine digluconate immersion (CD0.12%); and all agents exposed (SOSCD). The main variables were color change (CIELab and National Standard Bureau system, NBS), Shore A hardness, and surface roughness, measured at baseline and 30days. Qualitative analyses were performed by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The data were analyzed by Kruskal-Wallis tests (color) and two-way ANOVA (hardness and roughness) with Sidak post-test (α=0.05). CD0.12% (1.54±0.49) and SOSCD (2.10±1.03) had similar effects and caused the smallest color changes, considered mild and noticeable (NBS), respectively. SOS promoted the greatest color change (6.99±1.43, NBS: large) and hardness (17.97±0.56); SOS promoted intermediate roughness (3.48±1.05) between SOSCD (2.25±0.53), and two similar groups: C (4.46±0.95), and CD0.12% (4.39±1.26). The qualitative analysis showed an irregular, dense, dry, and whitish layer on the surface of the specimens exposed to sunscreen, which was reduced when in contact with 0.12% chlorhexidine digluconate. Endogenous and exogenous factors are capable of altering elastomer properties. The 0.12% chlorhexidine digluconate minimized the changes caused by sweat, oil, and sunscreen.

Revolutionizing Antimicrobial Solutions Nanotechnology, CRISPR-Cas9 and Innovative Approaches to Combat Drug Resistance in ESKAPE Pathogens

Antimicrobial drug resistance within ESKAPE pathogens is a formidable global challenge, necessitating innovative solutions. This review explores a multifaceted strategy incorporating nanotechnology, CRISPR/Cas9, and other cutting-edge approaches to effectively combat multidrug resistance in ESKAPE bacteria. Nanotechnology presents a promising avenue through targeted drug delivery systems like antibiotic nanoparticles and antibiotic–antibody conjugates (AACs). While these nanostructures aim to enhance therapeutic efficacy and mitigate resistance spread, challenges such as anti-PEG antibodies and optimal drug release must be considered. Inspired by successful anticancer nanomedicines, nanotechnology seeks to optimize drug penetration and retention within infected tissues. The revolutionary CRISPR/Cas9 gene-editing technology offers a precise and tailored approach by selectively targeting and modifying bacterial resistance genes. This holds the potential to reverse or eliminate drug resistance in ESKAPE pathogens, though challenges like off-target effects and efficient delivery mechanisms require attention for clinical translation. Additionally, alternative approaches such as fecal microbial transplantation, bacteriophage therapy, and probiotic bacterial replacement are actively explored in clinical trials. These strategies diversify the arsenal against antibiotic resistance by targeting unique vulnerabilities in ESKAPE pathogens. A comprehensive and multidisciplinary strategy is imperative to effectively address antimicrobial drug resistance in ESKAPE pathogens. Integration of nanotechnology, CRISPR/Cas9, and emerging approaches offers a synergistic solution, holding promise in overcoming the challenges posed by these resilient multidrug-resistant bacteria. This review provides insights into current research, challenges, and potential breakthroughs, emphasizing the urgency for collaborative efforts to safeguard global health.

Assessment of dimensional stability of novel VPES impression material at different time intervals with standard disinfectants

BackgroundVinyl polyether silicone (VPES) is a novel impression biomaterial made of a combination of vinyl polysiloxane (VPS) and polyether (PE). Thus, it is significant to assess its properties and behaviour under varied disinfectant test conditions. This study aimed to assess the dimensional stability of novel VPES impression material after immersion in standard disinfectants for different time intervals.MethodsElastomeric impression material used –medium body regular set (Monophase) [Exa’lence GC America]. A total of 84 Specimens were fabricated using stainless steel die and ring (ADA specification 19). These samples were distributed into a control group (n=12) and a test group (n=72). The test group was divided into 3 groups, based on the type of disinfectant used - Group-A- 2% Glutaraldehyde, Group-B- 0. 5% Sodium hypochlorite and Group-C- 2% Chlorhexidine each test group was further divided into 2 subgroups (n=12/subgroup) based on time intervals for which each sample was immersed in the disinfectants – subgroup-1- 10 mins and Subgroup 2- 30 mins. After the impression material was set, it was removed from the ring and then it was washed in water for 15 seconds. Control group measurements were made immediately on a stereomicroscope and other samples were immersed in the three disinfection solutions for 10 mins and 30 mins to check the dimensional stability by measuring the distance between the lines generated by the stainless steel die on the samples using a stereomicroscope at x40 magnification.ResultsThe distance measured in the control group was 4397.2078 µm and 4396.1571 µm; for the test group Group-A- 2% Glutaraldehyde was 4396.4075 µm and 4394.5992 µm; Group-B- 0. 5% Sodium hypochlorite was 4394.5453 µm and 4389.4711 µm Group-C- 2% Chlorhexidine was 4395.2953 µm and 4387.1703 µm respectively for 10 mins and 30 mins. Percentage dimensional change was in the range of 0.02 – 0.25 for all the groups for 10 mins and 30 mins.Conclusions2 % Glutaraldehyde is the most suitable disinfectant for VPES elastomeric impression material in terms of dimensional stability and shows minimum dimensional changes as compared to that of 2% Chlorhexidine and 0.5% Sodium hypochlorite.

Synthesis, characterization, and antibacterial effectiveness of gemifloxacin C-3 modified amide analogs: A theoretical and experimental approach

In search of a newer, efficient, and adaptable antimicrobial solution to combat the resistance that has developed due to the widespread extensive and in appropriate use of antibiotics. Seven new amide analogs of Gemifloxacin (G-D01-G-D07), an important member of the fluoroquinolone (FQ's) was synthesized by modifying the C-3 position in a quick and facile way, using Schotten Baumann reaction approach exhibiting highly efficient yields and short reaction times. Their in-silico pharmacokinetic and toxicity studies were determined by SwissADME and Protox-II webserver, and found that all the compounds obeys the lipinski's rule and didn't exhibit any vital organ toxicity. The introduction of selected amines to form amide analogs (G-D01-G-D07) was assured by their spectroscopic characterization, structural stability studies by DFT parameters and Microbiological assay evaluates these synthesized analogs as potent antibacterial and antifungal agents against studied species. At the B3LYP/6–311 G level of theory, the molecular structures, reactivity, and electronic characteristics of candidate compounds exhibiting the most promising antibacterial actions were examined, and their quantum mechanical parameters were calculated. The energy gaps of all the synthesized compounds were found in ranges between 0.1088 and 0.1091 eV, indicating good softness, thermal and kinetic stability. This can be correlated by the activity of these analogs against Klebsiella pneumonia, and Citrobacter freundii, where synthesized derivatives G-D06 and G-D03, G-D04, and G-D07 exhibit activities more than the parent drug. The binding affinity of complexes revealed by docking was found in the range between -14.31 and -16.20 kcal/ mol, which indicates their high antibacterial potential against one of the major targets Klebsiella pneumoniae cytidine deaminase CDA protein by using AutoDock Vina and MD simulations by GROMACS, confirming them as potential antibacterial agents.

Inactivation of Desiccation-Resistant Salmonella on Apple Slices Following Treatment with ε-Polylysine, Sodium Bisulfate, or Peracetic Acid and Subsequent Dehydration

Salmonella is capable of surviving dehydration within various foods, such as dried fruit. Dried fruit, including apple slices, have been the subject of product recalls due to contamination with Salmonella. A study was conducted to determine the fate of Salmonella on apple slices, following immersion in three antimicrobial solutions (viz., ε-polylysine [epsilon-polylysine or EP], sodium bisulfate [SBS], or peracetic acid [PAA]), and subsequent hot air dehydration. Gala apples were aseptically cored and sliced into 0.4 cm thick rings, bisected, and inoculated with a five-strain composite of desiccation-resistant Salmonella, to a population of 8.28 log CFU/slice. Slices were then immersed for 2 min in various concentrations of antimicrobial solutions, including EP (0.005, 0.02, 0.05, and 0.1%), SBS (0.05, 0.1, 0.2, and 0.3%), PAA (18 or 42 ppm), or varying concentrations of PAA + EP, and then dehydrated at 60°C for 5 h. Salmonella populations in positive control samples (inoculated apple slices washed in sterile water) declined by 2.64 log after drying. In the present study, the inactivation of Salmonella, following EP and SBS treatments, increased with increasing concentrations, with maximum reductions of 3.87 and 6.20 log (with 0.1 and 0.3% of the two compounds, respectively). Based on preliminary studies, EP concentrations greater than 0.1% did not result in lower populations of Salmonella. Pretreatment washes with either 18 or 42 ppm of PAA inactivated Salmonella populations by 4.62 and 5.63 log, respectively, following desiccation. Combining PAA with up to 0.1% EP induced no greater population reductions of Salmonella than washing with PAA alone. The addition of EP to PAA solutions appeared to destabilize PAA concentrations, reducing its biocidal efficacy. These results may provide antimicrobial predrying treatment alternatives to promote the reduction of Salmonella during commercial or consumer hot air drying of apple slices.

Carbapenem-Resistant Klebsiella pneumoniae Bacteremia: Counterbalance between the Endemic Load and the Infection Control Program in a Hospital

Carbapenem-resistant Klebsiella pneumoniae (CRKP) remains a significant public health threat, given the associated increased healthcare burden and mortality rate. The objective of the current study was to investigate the association between the incidence of CRKP bacteremia, antibiotic consumption, and infection control measures in a tertiary-care hospital spanning the years 2013–2018. The analyzed indices included the incidence of CRKP bacteremia, antibiotic consumption, the use of hand hygiene solutions, and isolation rates of multidrug-resistant (MDR) carriers. In the total hospital, the incidence of CRKP bacteremia exhibited an absolute decrease during the study period, although this decrease did not reach statistical significance. Antibiotics used to treat CRKP infections, including carbapenems, colistin, tigecycline, and fosfomycin, as well as all classes of antibiotics, correlated positively with an increased incidence of CRKP bacteremia. On the contrary, increased use of scrub disinfectant solutions correlated negatively with a decreased incidence of CRKP bacteremia (IRR: 0.74, 95%CI: 0.59–0.93, p-value: 0.008) in the Adults ICU. Additionally, increased isolation rates of MDR carrier patients correlated negatively with a decreased incidence of CRKP bacteremia (IRR: 0.35, 95%CI: 0.13–0.97, p-value: 0.044). In conclusion, the implementation of multimodal infection control measures in our hospital contributed to the containment of CRKP, particularly in specific hospital sectors. However, the study suggests the need for additional strategies to overcome the endemic plateau.

Green synthetic biomaterials: Synthesis, characterization and antimicrobial properties of lichen-derived nanomaterials

The green synthesis of nanoparticles using lichen extracts offers a safer and more environmentally friendly alternative to traditional methods. Known for their medicinal properties, lichens can effectively reduce and stabilise metallic salts, providing an eco-friendly approach to producing nanomaterials with potential antimicrobial applications. In this study, the lichen Rhizoplaca chrysoleuca was utilised in the green synthesis of nanoparticles, successfully creating lichen-derived silver-zinc oxide (Ag–ZnO), silver-strontium oxide (Ag–SrO), and silver-nickel oxide (Ag–NiO) nanoparticles. Ultraviolet–visible absorption spectroscopy revealed that the characteristic light absorption of the NCs occurred within the range of 300–400 nm for each synthesis, and dynamic light scattering measurements indicated that the hydrodynamic diameters of the nanoparticles were below 100 nm. Energy-dispersive X-ray spectroscopy confirmed the presence of the constituent elements. Imaging with field-emission scanning electron microscopy and scanning transmission electron microscopy showed that the nanoparticles had spherical shapes with dimensions measuring below 50 nm. X-ray diffraction analysis of the synthesised nanocomposite materials revealed the presence of Ag–ZnO (22 nm), Ag–SrO (48 nm), and Ag–NiO (21 nm) nanoparticles. Fourier-transform infrared spectroscopy identified functional groups in the nanoparticles, confirming their compositions, while thermogravimetric analysis determined the thermal decomposition temperatures of the NCs. The antibacterial efficacy of these materials was assessed, with Ag–ZnO (inhibition zone 11.0 mm) and Ag–NiO (inhibition zone 10.0 mm) showing significant effectiveness against both Gram-negative and Gram-positive bacteria. In contrast, Ag–SrO (inhibition zone 6.5 mm) exhibited comparatively lower antibacterial activity. Additionally, the study highlighted the antifungal properties of Ag–NiO (inhibition zone 19.0 mm) and Ag–ZnO (inhibition zone 8.5 mm) nanomaterials. This research advances the understanding of lichen-based nanotechnology and its potential for developing sustainable antimicrobial solutions.

An Overview of Research for the Application of a Novel Biofilm-Preventing Surgical Irrigation System for Total Joint Arthroplasty Procedures in Order to Reduce the Risk of Periprosthetic Infection.

Periprosthetic joint infection (PJI) is a serious postoperative complication in joint arthroplasty procedures that carries substantial morbidity and mortality associated with it. Several strategies have been developed both in the preoperative, perioperative, and postoperative periods to both combat and prevent the development of this devastating complication. Intraoperative irrigation is an important modality used during arthroplasty procedures prior to the implantation of final components that seeks to eradicate any biofilm formation. In this updated review, we discuss the XPERIENCE™ Advanced Surgical Irrigation solution (Next Science, Jacksonville, Florida) and the various completed, ongoing, and planned basic science and clinical investigations associated with it. Although there is already an impressive body of literature supporting its widespread utilization, future basic and clinical trials will continue to be performed to comprehensively characterize the effect this antimicrobial solution has on eliminating the risk of PJI following arthroplasty procedures.

Electron Beam on Fermentation Medium as an Alternative Disinfection Method for Ethanol Distilleries: A Comprehensive Review

Corn and sugarcane are the primary feedstocks for ethanol production, but microbial contamination hinders yeast fermentation efficiency. Current control methods include antibiotics and sulfuric acid, but they have limitations, resulting in dependence on external inputs and the risk of antibiotic-resistant bacteria. This review examines electron beam technology as an industrial-scale disinfection solution for both corn- and sugarcane-based ethanol production, highlighting its advantages, limitations and opportunities for adoption in Brazil. A critical evaluation highlights the importance of optimal operating conditions for scalability, cost effectiveness and sustainable implementation. Through a practical example, we demonstrate the effectiveness of electron beam treatment in improving fermentation efficiency and reducing contamination-related losses. Notably, the ionizing radiation from this process does not affect wort sugar content or generate radioactive residues. While acknowledging the potentially high energy input requirements, cogeneration in sugarcane mills can address this, making it a viable option; however, further technical and economic evaluation should be made. In addition, electron beam technology is a promising approach for the production of high-value products such as neutral alcohol, amino acids, animal feed and pharmaceuticals. Therefore, this comprehensive review provides valuable insights for researchers, industry stakeholders and policymakers to promote sustainable and efficient ethanol production practices.

Guidelines in Practice: Manual High-Level Disinfection.

There are several steps involved when performing high-level disinfection (HLD) of semicritical devices. The recently updated AORN "Guideline for manual high-level disinfection" provides perioperative nurses with evidence-based best practices for performing safe and effective HLD of reusable semicritical items. The guideline also addresses preventing injury to patients and health care workers associated with the handling of high-level disinfectants. This article provides an overview of the guideline and discusses recommendations for selection of a processing method, sterile processing areas, preparation of items for HLD, preparation of high-level disinfectants, manual HLD, drying and storage of items after HLD, and processing records. It also includes a scenario that illustrates specific concerns related to performing quality tests on high-level disinfectant solutions. Perioperative nurses should review the guideline in its entirety and apply the recommendations when performing manual HLD.

L-Thyroxine and L-thyroxine-based antimicrobials against Streptococcus pneumoniae and other Gram-positive bacteria

ObjectivesThe rise of antibiotic-resistant Streptococcus pneumoniae (Sp) poses a significant global health threat, urging the quest for novel antimicrobial solutions. We have discovered that the human hormone l-thyroxine has antibacterial properties. In order to explore its drugability we perform here the characterization of a series of l-thyroxine analogues and describe the structural determinants influencing their antibacterial efficacy. MethodWe performed a high-throughput screening of a library of compounds approved for use in humans, complemented with ITC assays on purified Sp-flavodoxin, to pinpoint molecules binding to this protein. Antimicrobial in vitro susceptibility assays of the hit compound (l-thyroxine) as well as of 13 l-thyroxine analogues were done against a panel of Gram-positive and Gram-negative bacteria. Toxicity of compounds on HepG2 cells was also assessed. A combined structure-activity and computational docking analysis was carried out to uncover functional groups crucial for the antimicrobial potency of these compounds. ResultsHuman l-thyroxine binds to Sp-flavodoxin, forming a 1:1 complex of low micromolar Kd. While l-thyroxine specifically inhibited Sp growth, some derivatives displayed activity against other Gram-positive bacteria like Staphylococcus aureus and Enterococcus faecalis, while remaining inactive against Gram-negative pathogens. Neither l-thyroxine nor some selected derivatives exhibited toxicity to HepG2 cells. Conclusionsl-thyroxine derivatives targeting bacterial flavodoxins represent a new and promising class of antimicrobials.

Investigation of Antimicrobial Activity and Cytotoxicity of Silver Nanoparticle Synthesized using Dopamine as a Reducing and Capping Agent

AbstractWe present a study focused on the controlled fabrication of silver nanoparticles (AgNPs) through colloidal synthesis, employing dopamine as a reducing and capping agent. By manipulating the concentration of silver nitrate, the production of spherical AgNPs with distinct particle diameters (16, 24, 48, and 74 nm) was achieved. The investigation extended to the evaluation of AgNPs′ impact on human embryonic kidney cells, revealing a concentration‐dependent response. At lower AgNPs concentrations, cell viability remained nearly 100 %, progressively declining with rising AgNPs concentrations. Importantly, the cytotoxic thresholds observed were notably elevated, underscoring the relatively mild to moderate toxicity profile of the nanoparticles. Furthermore, the antimicrobial efficacy of these synthesized AgNPs was probed against E. coli and S. aureus bacterial strains. Notably, the AgNPs exhibited robust antimicrobial activity, with superior performance exhibited by smaller‐sized particles compared to larger ones. Impressively, the minimum inhibitory concentration reached as low as 3.5 μg/mL, indicating their potent antimicrobial potential. The achieved distinct particle diameters, concentration‐dependent cytotoxic responses, and potent antimicrobial efficacy against bacterial strains underscore the multifaceted potential of these nanoparticles. These findings contribute valuable insights for their application in diverse fields, from biomedicine to antimicrobial solutions.

Effect of propolis on the mechanophysical properties of addition silicon dental impression material

Background Dental impressions should be disinfected to stop the transmission of germs among dental workers since they provide a risk of diseases. The aim of this study was to examine the effects of two disinfectants (16 mg/ml propolis and 5.25% sodium hypochlorite) on the detail reproduction, linear dimensional change, compatibility with gypsum products, wettability, and surface roughness of addition silicon material. Methods Ninety specimens were created using Addition silicon impression material, and they were then divided into three groups at random. Ten specimens from each test group were used in each test. Utilizing apparatus made in accordance with ISO 4823:2015, detail reproduction, linear dimensional change, and compatibility with gypsum products are assessed. A digital Profilometer was uutilized to evaluate surface roughness, and a Goniometer was utilized to evaluate wettability by taking the contact angle. Before testing, the specimens were immersed for 10 minutes each in two disinfection solutions: 16 mg/ml propolis and 5.25% NaOCL. The control group received no disinfection. One-way ANOVA tests and the Kruskal-Wallis test, which was statistically significant at a level of p 0.05, were used to examine the data. Results Comparing the linear dimensional change, surface roughness, and wettability of Addition silicon specimens immersed in 16 mg/ml propolis, 5.25% NaOCL, or the control group demonstrated statistically significant differences (p&lt; 0.05), while details reproduction and compatibility with gypsum revealed statistically no significant differences (p &gt; 0.05). Conclusion Within the parameters of this study, the addition silicon can be immersed in 16 mg/ml propolis for 10 min. to disinfect it without compromising its dimensional accuracy, detail reproduction, compatibility with gypsum products, surface roughness, or wettability.

Strategies for Preventing and Treating Oral Mucosal Infections Associated with Removable Dentures: A Scoping Review.

Oral infections occur due to contact between biofilm rich in Candida albicans formed on the inner surface of complete dentures and the mucosa. This study investigated historical advances in the prevention and treatment of oral mucosal infection and identified gaps in the literature. Bibliographic research was conducted, looking at PubMed, Embase, Web of Science, and Scopus, where 935 articles were found. After removing duplicates and excluding articles by reading the title and abstract, 131 articles were selected for full reading and 104 articles were included. Another 38 articles were added from the gray literature. This review followed the PRISMA-ScR guidelines. The historical period described ranges from 1969 to 2023, in which, during the 21st century, in vitro and in vivo studies became more common and, from 2010 to 2023, the number of randomized controlled trials increased. Among the various approaches tested are the incorporation of antimicrobial products into prosthetic materials, the improvement of oral and denture hygiene protocols, the development of synthetic and natural products for the chemical control of microorganisms, and intervention with local or systemic antimicrobial agents. Studies report good results with brushing combined with sodium hypochlorite, and new disinfectant solutions and products incorporated into prosthetic materials are promising.