Microdilution Assay Research Articles

Mixture Containing 5% Polysaccharide Extract of Cerioporus squamosus (Huds.) Quélet, 5% Dexpanthenol, and 0.2% Hyaluronic Acid Shows In Vitro and In Vivo Wound Healing Properties

Background: This study explores wound healing and the antimicrobial potential of a natural formulation containing a polysaccharide extract from Cerioporus squamosus, hyaluronic acid, and dexpanthenol. Methods: Wound healing effects were assessed using HaCaT keratinocytes, while antimicrobial activity was evaluated against human skin pathogens using a microdilution assay. In vitro cytotoxicity tests ensured formulation safety, whereas in vivo wound healing was further investigated using an animal model. Gene expression analysis was performed to assess the molecular mechanisms involved. Results: The unique glucan composition of C. squamosus (15.38% α-glucans and 7.91% β-glucans) deviated from typical mushroom polysaccharide profiles, warranting further exploration of its bioactivity. In vitro mushroom polysaccharides promoted 25.35% wound closure after 24 hours, while the three-component formulation achieved 35.81% closure. Antibacterial activity showed a minimum inhibitory concentration (MIC) of 0.44–1.75 mg/mL and minimum bactericidal concentration (MBCs) of 0.88–3.50 mg/mL, while antifungal activity ranged from 0.22 to 0.44 mg/mL (MICs) and 0.44 to 0.88 mg/mL (minimum fungicidal concentration—MFC). In vivo data showed that 60% of treated wounds fully closed by day 11, despite no statistically significant difference from the control. However, gene expression analysis highlighted VEGF and collagen upregulation, indicating an enhancement of wound healing on a molecular level. Conclusions: The novel three-component formulation demonstrated consistent wound healing and antimicrobial properties, supporting its potential as a safe and effective treatment for chronic and acute wounds.

Tenfold multiplex PCR method for simultaneous detection of mcr-1 to mcr-10 genes and application for retrospective investigations of Salmonella and Escherichia coli isolates in China.

Tenfold multiplex PCR method for simultaneous detection of mcr-1 to mcr-10 genes and application for retrospective investigations of Salmonella and Escherichia coli isolates in China.

Molecules Targeting EriCF1 Increase Streptococcus mutans Fluoride Sensitivity.

Dental caries, as one of the prevalent oral infectious diseases worldwide, constitutes a considerable disease burden. Fluoride has been widely used to prevent dental caries for decades. However, fluoride alone may not always be sufficient. The major cariogenic bacterial species, Streptococcus mutans, has not been effectively controlled by daily fluoride exposure, possibly because it has a detoxification mechanism. Studies have shown that most microorganisms have fluoride exporters dedicated to exporting fluoride ions (F-). S. mutans possesses 2 homologous genes, eriCF1 and eriCF2, which encode fluoride exporters, but their function has not been fully clarified. In this work, we constructed the markerless gene deletion mutants, overexpression, and complemented strains of S. mutans UA159. Assessing fluoride sensitivity, intracellular F- levels, and cell membrane permeability revealed that EriCF1 was the major functional unit of the fluoride exporter in S. mutans. To further enhance the antibacterial efficiency of fluoride, we identified 3 diphenylurea derivatives that might target EriCF1 by molecular docking, which significantly enhanced the antibacterial effect of sodium fluoride (NaF) by synergistically impeding fluoride efflux, as demonstrated by chequerboard broth microdilution assays. Moreover, these compounds combined with 1 mM NaF impaired the cariogenicity of S. mutans significantly in vivo and with good biocompatibility, especially compounds 9 and 15. Collectively, these findings suggest that fluoride exporters in S. mutans could serve as a potential target for caries prevention, and the diphenylurea derivatives identified for targeting EriCF1 could be a valuable therapeutic approach when combined with fluoride, providing promising measures for dental caries prevention.

Antimicrobial Activity and the Synergy Potential of Cinnamomum aromaticum Nees and Syzygium aromaticum (L.) Merr. et Perry Essential Oils with Antimicrobial Drugs

Antimicrobial resistance is a growing global challenge, rendering many standard treatments ineffective. Essential oils (EOs) of cinnamon (Cinnamomum aromaticum Nees) and clove (Syzygium aromaticum (L.) Merr. et Perry) may offer an alternative solution due to their high antimicrobial properties and their abilities to fight resistant pathogens. This study evaluates the antimicrobial activity of these two EOs, and their synergistic potential when combined with two antibiotics (ciprofloxacin and vancomycin) and two antifungals (fluconazole and amphotericin B) against various bacterial and yeasts strains. The antimicrobial activities of each EO were evaluated by agar diffusion and broth microdilution assays, while the synergetic effects with antimicrobials were determined by calculating the fractional inhibitory concentration index (FICI) using the checkerboard method. The chemical composition of the EOs was analyzed using Gas Chromatography-Mass Spectrometry (GC-MS). The identification of individual components in the EOs was achieved by comparing their mass spectra with the NIST MS Search database and by correlating their retention times with those of known standards. GC-MS analysis revealed that the main constituents of S. aromaticum EO were eugenol (71.49%) and β-caryophyllene (23.43%), while C. aromaticum EO were dominated by cinnamaldehyde (47,04%) and cinnamyl acetate (18.93%). Antimicrobial activity showed that cinnamon EO exhibits highest effectiveness against all tested strains, with inhibition zones (IZ) ranging from 16.99 mm to 53.16 mm, and minimum inhibitory concentrations (MIC) and minimum microbicidal concentrations (MMC) ranging from 0.039 mg/mL to 0.156 mg/mL. However, for clove EO, the IZ ranged from 9.31 mm to 29.91 mm, with MIC and MMC values from 0.313 mg/mL to 1.25 mg/mL. In combination with antibiotics (ciprofloxacin and vancomycin), the studied EOs showed promising synergistic effects with reduction up to 128-fold. As regards antifungals (amphotericin B, and fluconazole), the synergistic effects were recorded with MIC gains up to 32-fold. Our findings demonstrate that the EOs from C. aromaticum and S. aromaticum exhibit significant broad-spectrum antimicrobial activity against diverse yeast and bacterial strains. This highlights their potential as bases for the development of novel plant-based antimicrobial agents. Importantly, the observed synergistic effects of these EOs with conventional antibiotics support their integration into medical treatments as a strategy to address microbial resistance. Future research should aim to elucidate the mechanisms underlying these synergistic actions, optimize their application, and enhance their therapeutic efficacy.

Antimicrobial activity of ear cleanser products against biofilm and planktonic phases of Staphylococcus spp. and Pseudomonas spp. isolated from canine skin and ear infections

BackgroundStaphylococcus spp., and Pseudomonas spp., including multidrug resistant staphylococci are frequent isolates from canine otitis externa and atopic dermatitis. The ability of these bacteria to form biofilms significantly contributes to the chronic nature of otitis. To manage microbial overgrowth, ear cleanser products are commonly used. It is important therefore, to measure their antibiofilm effects. In this study, six ear cleansers (EpioticⓇ SIS, EpioticⓇ Advanced, CleanauralⓇ, OtifreeⓇ, PeptivetⓇ and SonotixⓇ) were evaluated against clinical isolates of Pseudomonas aeruginosa, methicillin resistant and sensitive Staphylococcus aureus and Staphylococcus pseudintermedius. Antibiofilm activity was measured using a colorimetric assay that detects viable cells through the reduction of thiazolyl blue tetrazolium bromide (MTT). Additionally, minimum inhibitory concentration (MIC) of Epiotic SIS and Epiotic Advanced were determined using a broth micro-dilution assay to assess their ability to inhibit bacteria in the planktonic state.ResultsEpiotic (SIS and Advanced), Cleanaural and Peptivet showed high antibiofilm activity, with Otifree and Sonotix showing moderate to low antibiofilm activity. Notably, Otifree was significantly less effective at inhibiting methicillin-resistant S. aureus compared to methicillin-sensitive strains. P. aeruginosa biofilms were less effectively disrupted by some ear cleansers, and the MIC results indicated that less diluted solutions were required to inhibit this isolate compared to the staphylococcal species. Differences in the antibacterial effects between Epiotic SIS and Epiotic Advanced solutions could also be detected from the MIC assays suggesting differences in formulations can affect antimicrobial efficacy.ConclusionsCommonly used canine ear cleanser products showed variable activity against multidrug resistant and sensitive Staphylococcus spp. and P. aeruginosa isolates in both biofilm and planktonic phases. The observed differences between bacterial strains and cleanser formulations highlight the importance of selecting appropriate products for targeted microbial control, which can lead to more effective management of chronic otitis externa and atopic dermatitis in dogs.

Efficient control of newly emerging bacterial pathogens in wastewater effluents of livestock farms and abattoirs using terminator disinfectant-based copper oxide nanoparticles.

The development of highly operational, reusable, multifunctional antibacterial agents has become an urgent need of the hour in terms of environmental safety and sustenance. This study was aimed at determining newly emerging bacterial pathogens in the wastewater effluent of broiler chicken and dairy cattle farms, beside their slaughterhouses. Also, the study assesses the biocidal effect of chitosan (CS), terminator disinfectant (TD), copper oxide nanoparticles (CuO-NPs), and terminator-based copper oxide nanoparticles (TD/CuO-NPs) against isolated emerging bacterial pathogens from wastewater effluents. Eighty wastewater samples were collected from the local sewage systems of these farms and slaughterhouses for the isolation and identification of bacterial pathogens. The biocidal activity of compounds was tested against fifty strains of isolated bacterial pathogens using an agar well diffusion and broth micro-dilution assay. CuO-NPs and TD/CuO-NPs composites were characterized using the Fourier transform infrared spectrum (FT-IR), high-resolution transmission electron microscopy (HR-TEM), energy dispersive X-ray spectroscopy (EDX), and zeta potential distribution. The wastewater effluents of broiler chicken and dairy cattle farms reported the highest rates of bacterial pathogens (95.0% and 90.0%, respectively), followed by animal abattoirs (80.0%). The effectiveness of TD/CuO-NPs composites against all emerging bacteria was found to be highly efficient (100%) compared to the efficiency of CuO-NPs, TD, and CS (90, 70, and 60%, respectively), at the highest concentration (2.0 µg/ml, 1.0 mg/l, and 1.5 µg/ml, respectively). In conclusion, the TD/CuO-NPs composite proved its biocidal effect (100%) against all isolated bacterial pathogens at 1.0 µg/ml. The synthetic nanocomposite could be implemented in any disinfection program and/or as an effective control strategy for the bacterial pathogens in wastewater effluents in various investigated areas.

Improving the antimicrobial potential of the peptide CIDEM-501 through acylation: A computational approach.

Improving the antimicrobial potential of the peptide CIDEM-501 through acylation: A computational approach.

Antimicrobial susceptibility and epidemiological types of Legionella pneumophila human isolates from Italy (1987-2020).

Antimicrobial susceptibility and epidemiological types of Legionella pneumophila human isolates from Italy (1987-2020).

Antimicrobial and antiparasitic potential of lupeol: antifungal effect on the Candida parapsilosis species complex and nematicidal activity against Caenorhabditis elegans.

Introduction. There is growing concern about infections caused by non-albicans Candida species, including species of the Candida parapsilosis complex - which have seen a considerable increase in cases during the COVID-19 pandemic - in addition to concern about nematode resistance to currently used anthelmintics.Gap Statement. Lupeol is a triterpenoid phytosterol that has a wide range of biological activities, although its antifungal and antiparasitic potential is still poorly explored. Additionally, its effect on the biofilm of the C. parapsilosis species complex has not yet been studied.Aim. This study aimed to investigate the antifungal effect of lupeol against C. parapsilosis complex species, in planktonic cells and mature biofilms, as well as its nematicidal potential against Caenorhabditis elegans. In addition, molecular docking was performed to identify potential target molecules for lupeol's antifungal effect.Methodology. Twelve strains of C. parapsilosis species complex were used. Planktonic susceptibility was performed through the broth microdilution assay, while the antibiofilm effect was investigated by measuring the biomass and metabolic activity. The antifungal mechanism of action of lupeol was investigated by target fishing. The evaluation of the nematicidal effect was performed using the C. elegans infection model.Results. Lupeol demonstrated antifungal activity against planktonic cells with a MIC between 64 and 512 µg ml-1. In mature biofilms, lupeol was able to reduce biomass starting from a concentration of 1024 µg ml-1 and reduce metabolic activity from a concentration of 64 µg ml-1. It was observed that there was interaction of lupeol with the enzyme 14α-demethylase. Furthermore, lupeol had a nematicidal effect from a concentration of 64 µg ml-1.Conclusion. Lupeol exhibits an antifungal effect on the C. parapsilosis species complex, in the planktonic and mature biofilm forms, possibly by affecting the ergosterol synthesis. Lupeol further demonstrated a nematicidal potential.

In vivo antibacterial activity and biochemical effects of methanol extract of Annona muricata leaves against multidrug- resistant Salmonella Typhimurium in Wistar rats

Background: The increasing antibiotic resistance and paucity of new antibiotics has contributed greatly to the high morbidity and mortality of salmonellosis necessitating the search for alternative treatments. Annona muricata has shown promising activity against multidrug-resistant (MDR) Salmonella in vitro but in vivo studies are rare. This study evaluated the activity of A. muricata, against MDR Salmonella Typhimurium in vivo. Methods: The minimum inhibitory concentration (MIC) of a methanol crude extract of A. muricata was determined by micro-dilution assay against a characterized MDR clinical S. Typhimurium strain. Wistar rats infected with 3 x 108 CFUs/mL of the MDR strain were treated with 50-200 mg/kg body weight of extract for 10 days. Faecal load of S. Typhimurium colonies was determined by the direct plate count technique on days 1, 5 and 10. Animals were sacrificed and blood was collected for biochemical analyses. Data were analysed using GraphPad Prism Software. Results: The S. Typhimurium strain was multidrug-resistant and the extract recorded a MIC of 2 mg/ml The extract produced a significant (p<0.001) dose-dependent reduction in Salmonella colonies in faeces of treated rats with a 100% inhibition recorded at 200 mg/kg body weight on day 10. Liver and renal function tests did not indicate any abnormalities (p<0.05). Conclusions: This is the first report of in vivo activity of A. muricata leaves against multidrug-resistant Salmonella. The high activity and lack of adverse toxicity supports it use in traditional medicine and hence is a potential treatment for resistant Salmonella infections.

Evaluation of the Efflux Pump Inhibition Activity of Thiadiazine-Derived Compounds Against the Staphylococcus aureus 1199B Strain

Background: Substances with antibacterial properties have become crucial in light of the continuous increase in infections caused by multidrug-resistant bacteria. In this context, thiadiazines have emerged as heterocyclic compounds already known for their pharmacological activities. However, their potential as antibacterial agents and inhibitors of the efflux system found in resistant bacteria remains poorly understood. From this perspective, the present study highlights the synthesis of thiadiazine-derived compounds and evaluates their antibacterial activity and efflux pump inhibition against the Staphylococcus aureus 1199B strain. Methods: To this end, Minimum Inhibitory Concentration (MIC) tests were conducted, along with the analysis of antibacterial activity through the inhibition of the NorA efflux system using 96-well microdilution assays. Additionally, to assess efflux system inhibition, ethidium bromide (EtBr) fluorescence emission tests were performed, alongside in silico molecular docking studies. Results: Based on the results obtained, it was observed that compound IJ28 exhibited direct activity against the tested SA 1199B strains, with an MIC of 512 µg/mL. It also demonstrated antibacterial activity through efflux pump inhibition, resulting in increased fluorescence rates emitted by EtBr. Compound IJ28 showed a more significant reduction in the Minimum Inhibitory Concentration (MIC) of ethidium bromide, decreasing from 26.6 µg/mL to 0.5 µg/mL, compared to the other compounds. Conclusions: Therefore, it is essential to conduct further studies to investigate the mechanism of action and clarify the feasibility and effects of compound IJ28 as a potential antibacterial agent.

Preventive Activity of an Arginine-Based Surfactant on the Formation of Mixed Biofilms of Fluconazole-Resistant Candida albicans and Extended-Spectrum-Beta-Lactamase-Producing Escherichia coli on Central Venous Catheters

Background/Objectives: Mixed bloodstream infections associated with central venous catheter (CVC) use are a growing problem. The aim of this study was to evaluate the activity of a cationic arginine-based gemini surfactant, C9(LA)2, against mixed biofilms of fluconazole-resistant Candida albicans and extended-spectrum beta-lactamase (ESBL)-producing E. coli, and the preventive effect of this surfactant impregnated in CVCs on the formation of inter-kingdom biofilms. Methods: Broth microdilution assays were performed along with evaluation of the effect against mixed biofilms in formation. The impregnation of CVCs with the surfactant and with a hydrogel containing the cationic surfactant was investigated to assess their potential to prevent the formation of mixed biofilms. Scanning electron microscopy (SEM) was also utilized. Results: Minimum inhibitory concentrations (MICs) for resistant C. albicans ranged from 4–5.3 µg/mL, while for E. coli, the MICs varied from 85.3 to 298.7 µg/mL. Fungicidal and bactericidal action patterns were obtained. In mixed biofilm formation in 96-well plates, there was a significant reduction in the colony-forming unit (CFU) count. The impregnation of the CVC with C9(LA)2 alone resulted in a biofilm reduction of 62% versus C. albicans and 48.7% against E. coli in terms of CFUs. When the CVC was impregnated with the surfactant hydrogel, the effect was improved with an inhibition of 71.7% for C. albicans and 86.7% for E. coli. The images obtained by SEM corroborated the results. Conclusions: C9(LA)2 has potential for use in CVC impregnation to prevent the formation of mixed biofilms of fluconazole-resistant C. albicans and ESBL-producing E. coli.

Determining the Antimycobacterial Action of Rottlerin Against Mycobacterium Species and Toxicity, Antioxidant Properties, and Therapeutic Target Affinity of Rottlerin.

Infections by Mycobacterium spp. are responsible for thousands of deaths every year worldwide. Microbial resistance, toxic effects, and adverse consequences of conventional therapies bring forth the need to search for new therapeutic agents. The aim of this study was to determine the antimicrobial action of the molecule Rottlerin against Mycobacterium spp. The broth microdilution assay showed that Rottlerin inhibited the mycobacterial growth at concentrations ≤ 50µg/mL (≤ 96.81µM), and the lowest bactericidal concentration was observed against M. tuberculosis (25µg/mL-48.40µM). The cytotoxicity of Rottlerin was conducted in a epithelial cell culture and evaluated through 2,3-Bis-(2-Methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) colorimetric assay, revealing an IC50 equivalent to 81.89 ± 4.64µM. The antioxidant action determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay demonstrated that Rottlerin reduced at least 50% of free radicals at 109.2µM. To gain insights into the antimycobacterial activity of Rottlerin, we performed molecular docking simulations with therapeutic targets of M. tuberculosis and observed that Rottlerin binds into the inhibitory site of the anti-infective target diterpene synthase (Rv3378c). Our findings indicate that Rottlerin presents antimicrobial effects with antioxidant action and prominent therapeutic targets, showing its biotechnological potential for the development of new agent against Mycobacterium spp. infection.

Synergistic antibacterial activity of chitosan-polyethylene glycol nanocomposites films containing ZIF-8 and doxycycline

BackgroundAntibiotic resistance is a growing global threat due to antibiotic overuse and limited treatment options. Multidrug-resistant bacteria, like Staphylococcus aureus and Escherichia coli, increase infection complexity and mortality. This study explores nanocomposite films of ZIF-8 nanoparticles and Doxycycline (Dox) to enhance antibacterial efficacy. In this study, nanocomposite films composed of chitosan (CS) and polyethylene glycol (PEG), incorporating zeolitic imidazolate framework-8 (ZIF-8) nanoparticles and DOX, were developed. These films were characterized by their morphological, mechanical, antibacterial, and drug-release properties. Antibacterial efficacy was evaluated using disk diffusion, broth microdilution, and checkerboard assay methods to determine MICs and potential synergistic effects.ResultsThe nanocomposite films demonstrated flexibility, semi-transparency, and a yellowish-brown hue, with films containing ZIF-8 nanoparticles being thicker (79 ± 0.2 μm) than those without (54 ± 0.5 μm). The tensile strength was enhanced with the incorporation of ZIF-8, peaking at 53.12 MPa for the CS-PEG-G-10% DOX-4% ZIF-8 film. XRD analysis confirmed the crystallinity of the ZIF-8 and DOX, with distinct peaks observed for each material. The drug release studies revealed an initial burst followed by sustained release, with higher release rates in acidic environments compared to neutral and alkaline media. The CS-PEG-G-10% DOX-4% ZIF-8 nanocomposite film demonstrated significantly higher antibacterial activity, achieving the lowest MIC values, particularly against S. aureus (22.5 mm inhibition zone) compared to E. coli (14 mm inhibition zone). Additionally, a notable synergistic effect was observed between CS-PEG-G-10% DOX and CS-PEG-G-10% DOX, with FICI values below 0.5.ConclusionsThe CS-PEG-G-10% DOX-4% ZIF-8 nanocomposite exhibits enhanced antibacterial efficacy and optimal properties, positioning it as a strong candidate for developing effective treatments against multidrug-resistant pathogens.

Impeding Biofilm-Forming Mediated Methicillin-Resistant Staphylococcus aureus and Virulence Genes Using a Biosynthesized Silver Nanoparticles-Antibiotic Combination.

Methicillin-resistant Staphylococcus aureus (MRSA) continues to represent a significant clinical challenge, characterized by consistently elevated rates of morbidity and mortality. Care regimen success is still difficult and necessitates assessing new antibiotics as well as supplemental services, including source control and searching for alternative approaches to combating it. Hence, we propose to synthesize silver nanoparticles (Ag-NPs) by employing a cell-free filter (CFF) of Streptomyces sp. to augment antibiotic activity and combat biofilm-forming MRSA. Seven bacterial isolates from clinical samples were identified, antibiotics were profiled with Vitek-2, and the phenotypic detecting of biofilm with Congo red medium and microplate assay was carried out. The PCR technique was used for detecting genes (icaA and icaD) coded in biofilm forming. The characterization of Ag-NPs was performed using several analytical methods, such as UV spectroscopy, dynamic light scattering (DLS), zeta potential measurement, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The antibacterial properties of Ag-NPs and oxacillin-Ag-NPs were assessed against standard strains and clinical isolates by employing the agar well diffusion technique and the microdilution assay. The biogenic synthesis Ag-NPs resulted in uniformly spherical particles, with an average size of 20 nm. These Ag-NPs demonstrated significant activity against biofilm-forming MRSA, with minimum inhibitory concentrations (MICs) ranging from 12 to 15 μg/mL. Additionally, Ag-NPs completely impede biofilm formation by MRSA at sublethal doses of 0.75 MICs. The expression levels of the icaA and icaD genes were reduced by 1.9- to 2.2- and 2.4- to 2.8-fold, respectively. A significant synergistic effect was noted when Ag-NPs were used in combination with oxacillin, leading to reduced MICs of 1.87 μg/mL for oxacillin and 4.0 μg/mL for Ag-NPs against MRSA. The FICi of 0.375 further validated the synergistic relationship between oxacillin and Ag-NPs at the concentrations of 1.87 and 4 μg/mL. Findings from the time-kill test demonstrated the highest reduction in log10 (CFU)/mL of the initial MRSA inoculum after 12-hour exposure. The cytotoxicity analysis of Ag-NPs revealed no significant cytotoxic effects on the human skin cell line HFB-4 at low concentrations, with IC50 values of 61.40 µg/mL for HFB-4 and 34.2 µg/mL for HepG-2. Comparable with oxacillin-Ag-NPs, Ag-NPs showed no cytotoxic effects on HFB-4 at different concentrations and exhibited an IC50 value of 31.2 against HepG-2-cells. In conclusion, the biosynthesis of Ag-NPs has demonstrated effective antibacterial activity against MRSA and has completely hindered biofilm formation, suggesting a valuable alternative for clinical applications.

Synergistic Antibiofilm Effects of Chestnut and Linden Honey with Lavender Essential Oil Against Multidrug-Resistant Otitis Media Pathogens.

Bacterial resistance to antibiotics is a major problem in healthcare, complicated by the ability of bacteria to form biofilms. Complementary therapy for infectious diseases can rely on natural substances with antibacterial activity, e.g., essential oils and honeys. The aim of the study was to investigate the effects of linden and chestnut honeys, lavender essential oil, and their combinations against the multidrug-resistant otitis media pathogens Haemophilus influenzae, H. parainfluenzae, Moraxella catarrhalis, Pseudomonas aeruginosa, and Streptococcus pneumoniae. The efficacy of these natural substances was compared with each other and antibiotics used in clinical practice. Microscopic pollen analysis and physicochemical traits were used to confirm the botanical origin of honey samples. The antibiotic sensitivity of bacteria was tested with a disk diffusion assay. Minimum inhibitory concentrations were determined using a microdilution assay. A 24 h immature biofilm eradication test was performed with a crystal violet assay. The efficacy of combinations was tested with a checkerboard titration method. The DNA release of damaged bacterial cells was measured using a membrane degradation assay. Lavender essential oil displayed more potent antibacterial activity compared to the honey samples. However, honey-essential oil combinations showed higher inhibition rates for biofilm eradication, with P. aeruginosa being the most resistant bacterium. The combined use of chestnut honey and lavender oil resulted in a higher degree of membrane degradation in a shorter time, and their synergistic effect was proven with checkerboard titration. The combination of linden or chestnut honey with lavender essential oil was shown to be effective in the eradication of a 24 h immature biofilm formed by H. parainfluenzae, M. catarrhalis, and S. pneumoniae.

A phytotherapeutic approach to hinder the resistance against clindamycin by MRSA: in vitro and in silico studies.

This study investigates the potential effects of essential oils (EOs) in enhancing the efficacy of clindamycin against Methicillin-resistant Staphylococcus aureus (MRSA) using in vitro and computer simulations. The research seeks to identify essential oils that exhibit synergistic activity with clindamycin and determine their potential key active components. Essential oils commonly used in traditional medicine were tested for their antimicrobial activity against MRSA. The minimum inhibitory concentration (MIC) was determined using in vitro microdilution assays. A synergistic test with clindamycin was performed, and molecular docking studies evaluated the interaction between a key compound (trans-cinnamaldehyde) and MRSA protein. EOs from Cinnamomum verum, Rosmarinus officinalis, Salvia officinalis, and Thymus vulgaris demonstrated significant inhibitory and synergistic activities against MRSA, standard strain, and human clinical isolates. Gas Chromatography/Mass Spectroscopy identified trans-cinnamaldehyde, eucalyptol, and thymol as prominent antibacterial compounds. Molecular docking studies confirmed trans-cinnamaldehyde's strong binding to MRSA's AgrA protein, elucidating its enhanced efficacy. The study underscores the potential of plant-based therapies to augment the effectiveness of conventional antibiotics like clindamycin in combating MRSA and addressing antibiotic resistance by integrating traditional plant remedies with modern medical approaches.

Enhanced antimicrobial and biofilm disruption efficacy of the encapsulated Thymus pallidus and Lavandula stoechas essential oils and their mixture: A synergistic approach.

Enhanced antimicrobial and biofilm disruption efficacy of the encapsulated Thymus pallidus and Lavandula stoechas essential oils and their mixture: A synergistic approach.

Monitoring sewage and effluent water is an effective approach for the detection of the mobile colistin resistance genes (mcr) and associated bacterial hosts in the human population and environment in the USA.

Monitoring sewage and effluent water is an effective approach for the detection of the mobile colistin resistance genes (mcr) and associated bacterial hosts in the human population and environment in the USA.

FL058, a novel β-lactamase inhibitor, increases the anti-Mycobacterium abscessus activity of imipenem.

FL058, a novel β-lactamase inhibitor, increases the anti-Mycobacterium abscessus activity of imipenem.