Lowest MBC Research Articles

Antimicrobial potential of Hippocratea Indica Willd. Acetone Leaf fractions against Salmonella Typhi: an in vitro and in silico study

Salmonella Typhi is a major global concern in many low- and middle-income countries. In addition, the emergence and persistence of drug resistant strains has increased the impact of this disease. Plant metabolites have been explored traditionally and scientifically as antimicrobial agents. Thus, this study was designed to investigate the antimicrobial potential of acetone leaf fractions of H. indica against S. Typhi. Dried pulverized leaves of H. indica were extracted using cold maceration with acetone after defatting with n-hexane. The leaf extract was concentrated and subjected to column chromatography and eight bioactive fractions were identified. The fractions were characterized using gas chromatography-mass spectrometry. The fractions were evaluated for antibacterial activity against Salmonella Typhi in-vitro and in-silico. The lowest MIC was observed in fractions 20 and 21 (0.375 mg/mL) while the lowest MBC was observed in all fractions except 7, 17 and 18 (0.375 mg/mL). A ligand from fraction 8 had the highest binding affinity to Type I dehydroquinase (-3.4) and a ligand from fraction 7 had the highest binding affinity to Gyrase B (-11.2). This study concludes that the overall antimicrobial activity of the acetone leaf extract of H. indica provided evidence that it contains drug-like compounds that can be further explored as a drug candidate against S. Typhi.

Advancing Antimicrobial Efficacy of Cucumis Momordica Seeds: Nanoemulsion Application in Eurotium cristatum-Mediated Solid-State Fermentation

This study explores the enhancement of Cucumis Momordica seed powder's properties through Eurotium cristatum-mediated solid-state fermentation (SSF) and its application in nanoemulsions, emphasizing protein content, functional properties, stability, and antimicrobial activity. The protein content increased significantly from 23.28±0.23% in the control to 29.83±0.12% after 144h of fermentation. The Cucumis Momordica seed powder fermented for 96h was further analyzed for its functional properties and characterization. The water absorption capacity was increased from 0.91 to 2.56g/g, and oil absorption capacity from 0.79 to 1.16g/g. SEM and FTIR analyses revealed morphological changes and chemical profile alterations, indicating enzymatic degradation and enhanced functional properties. Nanoemulsions from fermented powder showed reduced droplet sizes (148±0.34nm to 126±0.37nm) and more negative zeta potentials (-24.5±0.12mV to -25.79±0.18mV), suggesting improved stability. Temperature stability was superior in fermented seed powder nanoemulsions, demonstrating enhanced thermal resistance. Antimicrobial tests against E. coli and S. aureus showed significantly lower MIC and MBC values for fermented powder nanoemulsions (E. coli MIC: 2.189mg/mL, MBC: 1.089mg/mL; S. aureus MIC: 1.196mg/mL, MBC: 0.459mg/mL), indicating increased antimicrobial efficacy. These results highlight the potential of SSF and nanoemulsion technology in advancing the functionality and application of Cucumis Momordica seeds as natural antimicrobial agents.

Alpinia Officinarum Hance Essential Oil as Potent Antipseudomonal Agent: Chemical Profile, Antibacterial Activity, and Computational Study.

Alpinia officinarum Hance, is an aromatic and medicinal herb with a very interesting history and prominent chemical and biological prospects. We aimed to investigate the antibacterial activity of Alpinia officinarum essential oil and the preferred molecular targets of its constituents together with their pharmacokinetic properties and toxicity profile. According to GC-MS analysis, eucalyptol was the main compound (27.52%) identified in Alpinia officinarum essential oil, followed by α-terpineol, and β-sesquiphellandrene. As opposed to the weak antiradical activity estimated by DPPH and ABTS tests, the essential oil caused inhibition of all the bacteria following well-diffusion and microdilution methods, especially the gram-negative Pseudomonas aeruginosa and Escherichia coli. It displayed exceptionally remarkable activity against Pseudomonas aeruginosa by totally inhibiting its growth on the agar plate exceeding the effect of chloramphenicol standard. This bactericidal effect was confirmed by very low MIC and MBC values of 0.82 and 6.562 µg/mL, respectively. The molecular docking showed interesting binding affinity between the major compounds and various drug targets in Pseudomonas aeruginosa, also good pharmacokinetic and toxicity behavior. These encouraging findings are particularly relevant in light of the increasingly pressing challenge to find alternative substances with antibacterial aptitude to address the issue of antibiotic resistance among infectious bacteria.

Chia gum-gelatin-based encapsulation of chia sprouts phenolic compounds enhanced storage stability, bioavailability, antioxidant, antidiabetic, and antibacterial properties

Chia seeds are currently gaining popularity as functional and healthy foods. The developed chia 7-day sprout phenolic extract (CSP) is an abundant supply of highly concentrated antioxidant phenolic compounds with health-promoting and antibacterial properties. The easy destruction against different environmental changes and low bioavailability of these phenolic compounds are the main limitations of their applications/utilization. This study aims to microencapsulate the phenolic compounds of developed CSP for use as valuable functional food additives. Three microcapsules were prepared using coating materials, chia gum (CG), gelatin (G), and their mixture (CG/G) via the freeze-drying technique. The prepared CG-, CG/G-, and G-microcapsules demonstrated high encapsulation efficiency percentages of 97.0, 98.1, and 94.5%, respectively. They retained most of the CSP-phenolics (91.4–97.2%) and increased total antioxidant activity (108–127.1%). The prepared microcapsules released more CSP-phenolic compounds into the simulated intestinal stage (70–82%) than the gastric stage (15–24%), demonstrating that the coating materials enhance protection during the gastric stage. The produced microcapsules exhibited higher storage stability at 40 °C for 60 days than the non-capsulated CSP, indicating that the encapsulation provided enhanced stability. The prepared microcapsules microstructures showed uniform, smoother surfaces, and hidden micropores compared to their coating material microstructures. In addition, the connection between the functional groups of coating materials and CSP-phenolic compounds was demonstrated by FTIR analysis. The prepared CG-, CG/G-, and G-microcapsules can perfectly inhibit the α-amylase and α-glucosidase activities by 65, 68, 60 and 74, 78, and 70%, respectively, compared to CSP (54, and 66%). The three prepared microcapsules displayed better antibacterial with low MBC values (0.36–0.68 mg ml−1) compared to CSP (0.53–0.74 mg ml−1). The prepared CSP microcapsules can be incorporated into various food products to enhance their antioxidant, antidiabetic, and antibacterial properties.

A meta-analysis analyzing the efficacy of trastuzumab-deruxtecan (T-DXd) on central nervous system (CNS) disease in patients with metastatic breast cancer (mBC).

e14012 Background: CNS metastasis from mBC portends a poor prognosis. We sought to analyze CNS activity of T-DXd through a meta-analysis. Methods: A systematic search with terms encompassing BC and T-DXd was conducted in PubMed, Embase, Scopus, and Cochrane on November 23 2023. There were no search restrictions. A total of 2318 records were identified, and duplicates were removed using Mendeley. 1189 records that remained were imported into Rayyan, and the titles were screened independently by 2 reviewers. 47/75 full texts were relevant, of which 12 [7 clinical trials and 5 retrospective study] were included for analysis. Only studies that provided stratified CNS response data for mBC were included. RevMan was used to analyze the Risk Ratio (RR) and Odds Ratio (OR) with 95% Confidence Interval (CI), derived from Random Effects (RE) model with Mantel-Haenszel (MH) method. Binary RE Pooled Proportions (PP) using DerSimonian-Laird method were determined using OpenMeta. Visual inspection of our funnel plots revealed no bias. Results: The T-DXd cohort had a total of 377 patients with a median age of 54.2 years (42.5-69). Control group (T-DM1-1, Chemotherapy-2 studies) had 86 patients with a median age of 54.5 years (54.2-54.7). All studies had previously treated patients and most of the patients received local therapy. PP with T-DXd for CNS Complete Response (CR) was 4.8% (2-7.6%). Partial Response (PR) was 50.1% (32.4-67.7%) and Stable Disease (SD) was 28.9 (20.5-37.3%). PP of Objective Response Rate (ORR) (CR+PR) was 60.9% (48.3-73.5%). Drug discontinuation rate was 18% (12.2-23.9%) and pneumonitis rate was 14.5% (9.4-19.6%). RR for Event/Progressive Disease (PD) comparing T-DXd and control group was not significant [0.96 (0.77,1.2) p=0.74, I²=0%], nor was OR for Disease Control Rate (DCR) (CR+PR+SD) [1.11 (0.63,1.96) p=0.64, I²=0%] (Table). The median Progression Free Survival (PFS) was 14.1 (8.5-18.1) months for the T-DXd and 4.3 (3-5.6) months for the control group. Conclusions: Although direct comparison between the pooled T-DXd and control group failed to reveal a difference, the pooled ORR from 10/12 studies was clinically significant at 60.9%. The median PFS for T-DXd was also longer. T-DXd could be a viable treatment option for pretreated HER2+ and low mBC with CNS metastasis. Limitation of our study is the heterogeneity between the studies, entailing the need for future clinical trials in this setting. [Table: see text]

A meta-analysis of the difference in response to trastuzumab-deruxtecan (T-DXd) based on HER2 immunohistochemistry (IHC) in HER2 low metastatic breast cancer (mBC).

e13164 Background: HER2 low BC have an IHC staining of 1+ or 2+ with negative fluorescence in situ hybridization (ISH). Although T-DXd is approved for this, difference in activity between 1+ and 2+ is uncertain. Methods: A systematic search with controlled vocabulary encompassing BC and T-DXd was conducted in PubMed, Embase, Scopus, and Cochrane on November 11 2023 with no search restrictions. 2318 records were identified and duplicates were removed using Mendeley. The remaining 1189 records were imported into Rayyan, and the titles were screened independently by 2 reviewers. 47/75 full texts were relevant, of which 4 [3 clinical trials, 1 retrospective study] were included for analysis. Only studies that provided outcome data for HER2 1+ and 2+ ISH- were included. RevMan was used to analyze the Risk Ratio (RR) and Odds Ratio (OR) with 95% Confidence Interval (CI), derived from Random Effects (RE) model with Mantel-Haenszel (MH) method. Pooled proportions (PP) were determined using OpenMeta. Results: There were a total of 264 patients in 1+ and 204 in 2+ISH-. Median age was 57 years. All studies had pre-treated mBC. T-DXd dose was at least 5.4 mg/kg every 3 weeks. Visual inspection of our funnel plots revealed no bias. PP (3/4 studies) for patients achieving an Objective Response Rate (ORR) [Complete Response (CR)+Partial Response (PR)] was 42.9% (31.6-54.2%) in 1+ and 38% (26.3-49.7%) in 2+. The median Progression free survival (2/4 studies) was 8.6 (1+) and 7.95 (2+) months respectively. RE RR (3/4 studies) for Progressive Disease (PD) showed no difference between 1+ and 2+ [0.93 (0.80, 1.10), p=0.4, I²=0%]. Similarly, RE OR (3/4 studies) for Disease Control Rate (DCR) [CR+PR+Stable disease (SD)] [1.20 (0.78, 1.85), p=0.41, I²=0%], ORR [1.17 (0.58, 2.34), p=0.66, I²=0%], and PR [1.05 (0.52, 2.11), p=0.89, I²=0%] showed no significant difference between 1+ and 2+ (Table). Conclusions: Our results indicate no difference in response to T-DXd between 1+ and 2+, solidifying its role as a treatment option in HER2 low mBC. Limited number and heterogeneity between studies are limitations of our study, which ought to be addressed in future trials through clear subgroup stratification between 1+ and 2+. [Table: see text]

Exploring the multifaceted bioactivities of Lavandula pinnata L. essential oil: promising pharmacological activities.

Introduction: This study investigates the biological activities of Lavandula pinnata essential oil (LPEO), an endemic lavender species from the Canary Islands, traditionally used in treating various ailments. Methods: LPEO was extracted by hydrodistillation and analyzed using GC-MS. Antioxidant activity was assessed by DPPH radical scavenging and total antioxidant capacity assays. Antimicrobial activity was evaluated by disc diffusion, MIC, MBC, and MFC determination against bacterial (Staphylococcus aureus, Micrococcus luteus, Escherichia coli, Pseudomonas aeruginosa) and fungal (Candida glabrata, Rhodotorula glutinis, Aspergillus niger, Penicillium digitatum) strains. Antidiabetic and anti-gout potential were investigated through α-amylase, α-glucosidase, and xanthine oxidase inhibition assays. Antityrosinase activity was determined using a modified dopachrome method. Cytotoxicity was assessed by MTT assay against breast (MCF-7, MDA-MB-468), liver (HepG2), colon (HCT-15) cancer cells, and normal cells (PBMCs). Results and discussion: LPEO exhibits potent antiradical activity (IC50 = 148.33 ± 2.48μg/mL) and significant antioxidant capacity (TAC = 171.56 ± 2.34μg AA/mg of EO). It demonstrates notable antibacterial activity against four strains (Staphylococcus aureus, Micrococcus luteus, Escherichia coli, and Pseudomonas aeruginosa) with inhibition zones ranging from 18.70 ± 0.30mm to 29.20 ± 0.30mm, along with relatively low MIC and MBC values. LPEO displays significant antifungal activity against four strains (Candida glabrata, Rhodotorula glutinis, Aspergillus niger, and Penicillium digitatum) with a fungicidal effect at 1mg/mL, surpassing the positive control (cycloheximide), and MIC and MFC values indicating a fungicidal effect. It exhibits substantial inhibition of xanthine oxidase enzyme (IC50 = 26.48 ± 0.90μg/mL), comparable to allopurinol, and marked inhibitory effects on α-amylase (IC50 = 31.56 ± 0.46μg/mL) and α-glucosidase (IC50 = 58.47 ± 2.35μg/mL) enzymes.The enzyme tyrosinase is inhibited by LPEO (IC50 = 29.11 ± 0.08mg/mL). LPEO displays moderate cytotoxic activity against breast, liver, and colon cancer cells, with low toxicity towards normal cells (PBMC). LPEO exhibits greater selectivity than cisplatin for breast (MCF-7) and colon (HCT-15) cancer cells but lower selectivity for liver (HepG2) and metastatic breast (MDA-MB-468) cancer cells. These findings suggest the potential of LPEO as an antioxidant, antimicrobial, anti-gout, antidiabetic, and anticancer agent.

Antibiofilm Efficacy and Mode of Action of Etlingera elatior Extracts Against Staphylococcus aureus

Staphylococcus aureus represents a major bacterial human pathogen that causes a wide variety of clinical manifestations. Various medicinal plants have been used to control its infection, however, the effect of Etlingera elatior on S. aureus biofilm is still uncertain. Thus, the objective of this study was to evaluate the antibacterial and antibiofilm efficacy of E. elatior extracts against S. aureus. Phytochemical screening was carried out to determine the presence of phenols, tannins, saponins, and alkaloids in different extracts (acetone, methanol, ethanol, and aqueous) of E. elatior. Antibacterial activities were determined by disk diffusion assay, minimum inhibitory concentration assay (MIC), and minimum bactericidal concentration assay (MBC) while antibiofilm activities were determined by crystal violet assay and Fourier-transform infrared (FTIR) spectroscopy. All the extracts were found to contain phenols, tannins, saponins, and alkaloids. Only acetone extract showed a high amount of saponins. Among all the extracts, acetone extract showed the widest inhibition zone (21.23±0.2 mm), lowest MIC (20 mg/mL), and lowest MBC (50 mg/mL) values. The acetone extract also showed the highest antibiofilm activities at all biofilm stages (6 hr: 12%-31%; 12 hr: 20%-36%; 18 hr: 27%-32%; 24 hr: 5%-46%). Further analysis with FTIR spectroscopy revealed spectral changes associated with proteins (1700–1400 cm-1), phospholipids, and polysaccharides (1300–700 cm-1) in S. aureus biofilm following the treatment with 200 mg/mL of E. elatior extracts. In conclusion, E. elatior is a potential source of antibacterial and antibiofilm agents to control S. aureus infections. Changes in the composition of proteins, phospholipids, and polysaccharides may mediate the biofilm inhibition by E. elatior extracts. The acetone extract of E. elatior may be useful for various applications such as antimicrobial topical cream and wound dressing.

Assessment of antibacterial efficacy and toxicological implications of emperor scorpion (Pandinus imperator) venom using animal model

This research work was carried out by collecting 50 Pandinus imperator Scorpions and ascetically extracting venom locally from them and testing the venom on some selected bacteria. The extracted venom used was both in the lyophilized and crude (non-lyophilized) state to determine their different efficacy and was passed through a membrane filter to ensure sterility. Bacterial (Pseudomonas aeruginosa, Escherichia coli, and Acetinibacter baumannii) were isolated from drinking water sources of the University of Abuja after which it was preserved in slant for further use. Serotyped bacteria were also obtained and used in this study. Appropriate differential and selective agar were used to culture and sub-culture the isolates and serotyped while Analytical Profile Index (API) kits were used to confirm the isolated bacteria. A sensitivity test was carried out on each bacterium with the venom at concentrations of 25%, 50%, 75%, and 100% for crude venom while 10, 20, 30, and 40 mg/ml for the lyophilized venom, minimum inhibitory concentration, and minimum bactericidal concentration were also determined. The result shows lowest zone for crude venom against isolated bacteria was 3mm at 25% against Acinetobacter baumanni while the highest was 11.5 mm at 100% against Pseudomonas aeruginosa, the lowest for crude venom against serotyped was 4 mm at 25% against Acinetobacter baumanni and highest was 12.2 mm at 100% against Pseudomonas aeruginosa, lowest zone for lyophilized venom against isolated bacteria was 2.8 mm at 10 mg/ml against Acinetobacter baumanni while highest was 10.8 mm at 40 mg/ml against Pseudomonas aeruginosa, also the lowest for lyophilized venom serotyped was 3.8 mm at 10 mg/ml against Acinetobacter baumanni and highest was 11.5 mm at 40 mg/ml against Pseudomonas aeruginosa. The lowest MIC was 25% and 20 mg/ml while the highest was 50% and 30 mg/ml, the lowest MBC was 50% and 30 mg/ml while the lowest was 75% and 40 mg/ml. The toxicity of the venom was carried out by testing the venom on mice which shows no harmful effect on them. ANOVA statistical analysis carried out showed no significant difference in the activities of both venom states.

Bioactivity assay of Arundina graminifolia (D.Don) Hochr. extracts from diverse plant parts in Thailand: An assay-based investigation

This research involved surveying and collecting 16 samples of Arundina graminifolia from 8 different subpopulation areas. The main objectives were to analyze the preliminary phytochemical fingerprints and biological activity of the crude extracts obtained from various parts of the plant (roots, rhizomes, stems, and leaves). The findings indicated that rhizome extracts generally yielded a higher percentage of crude extract compared to the dry plant weight in comparison to other plant parts. Moreover, the Thin layer chromatography (TLC) fingerprint data revealed distinct compositions for each part of the plant, with rhizomes exhibiting more prevalent bands of compounds than other parts. Regarding antioxidant activity, the root and rhizome crude extracts from various populations displayed stronger inhibitory activity against DPPH, ABTS, and FRAP methods compared to stems and leaves. High total phenolic content was also found to effectively inhibit free radicals. The lipoxygenase inhibition test, which serves as an in vitro anti-inflammatory activity evaluation, demonstrated that most root extracts exhibited higher lipoxygenase inhibitory activity than the rhizome extracts at a concentration of 0.1 mg/mL. The antibacterial activity demonstrated that rhizome extracts from different regions exerted lower MIC and MBC values against all tested bacteria compared to the root extracts. The findings offer valuable information for selecting specific populations of A. graminifolia as potential sources of bioactive compounds for future nutraceutical applications.

Investigation of New Potential Uses of Pistacia terebinthus for Various Industries

Investigation of New Potential Uses of Pistacia terebinthus for Various Industries
 ABSTRACT: Pistacia terebinthus has been used extensively in alternative medicine. Inhibitory activity of ethanol fruit extract from P. terebinthus fruit on food-borne and clinical test microorganisms was obtained to determine the potential use of the extract for food and pharmaceutical industries as a natural antimicrobial source. Antibacterial activity of the ethanol extract on fish originated pathogen bacteria was also determined for its potential use in the feed industry. In addition, the effect of the extract on the probiotic bacteria originated from breast milk were tested to obtain the potential use of the extract together with probiotic bacteria for pharmaceutical and food industries. Antimicrobial activity was obtained by performing micro-dilution and macro-dilution assays as well as disc diffusion. Among the food-borne and clinical test microorganisms, the highest inhibition zone diameter (22.39±1.92 mm) was detected on Listeria monocytogenes. The highest antibacterial activity on the fish pathogens was recorded as 17.67±0 mm against Vibrio anguillarum A4. It was determined that P. terebinthus fruit extract had higher antimicrobial activity against some test microorganisms than Amikacin and Gentamicin antibiotics. Antifungal activity on Candida glabrata was also investigated by counting viable cell. At a concentration of 20 mg/mL, no viable cells were determined after 24 hours. The extract inhibited all the tested LAB, however, with low MIC and MBC values. The sun protection factor (SPF) of the extract and the extract+cream mixture at 10 mL concentration was recorded as 9.36 and 7.51. The results of the study indicated that P. terebinthus fruit ethanol extract can be an alternative as a natural additive in various industries such as feed, food, pharmaceutical and cosmetic industries.
 Keywords: Menengiç, Antimicrobial activity, Extract, Lactic acid bacteria, Solar protection

Exploring the synergistic potential of wild nettle and olive oil: bioactive compounds, antioxidant capacity, and antibacterial properties

ABSTRACT This study delved into the incorporation of wild nettle (Urtica dioica L.) leaves powder with virgin olive oil, exploring its potential to enhance nutritional value and health benefits. The antioxidant, antibacterial, and mineral-enrichment attributes of the resultant nettle-infused olive oil were investigated. Phenolic composition analysis revealed that an optimal maceration time of 30–40 minutes leads to maximal phenolic and flavonoid contents (57.66 mg GAE/100 g and 67.18 mg QE/100 g, respectively). The infused oil demonstrated superior radical scavenging activity (DPPH and ABTS assays) compared to virgin olive oil. Notably, nettle infusion significantly elevates zinc (10.12 mg/kg) and iron (13.85 mg/kg) contents. Antibacterial assays exhibited enhanced inhibition diameters and lower MIC and MBC values for nettle-infused oil against various bacterial strains. The study’s findings underscore the potential of nettle infusion to enhance the nutritional and functional attributes of olive oil, holding promise for novel culinary and health applications.

A Perusal of Phenolics Within Polar Peel Fractions of Malus domestica var Maharaji via Hyphenated Techniques Cum Anti-microbial with REMA and Tyrosinase Inhibitory Potential thereof

This study aims to scrutinize the phenolic secondary metabolites in the polar peel decocture of Malus domestica var Maharaji via hyphenated techniques along with the study of the antibacterial, anti-candida, and tyrosinase inhibitory potential of bioactive compound-rich fractions. Preliminary phenolics go over was performed together with thin layer chromatography before the polar decocture was subjected to hyphenated techniques. FTIR investigation revealed the C-O bonds as in phenols, O-H bond stretch, and vibrations of alcohols and carboxylic acids as well as portrayed the C-H and >C=O stretches among other functional groups all of which are representative of phenolic and polyphenolic compounds. GC-MS perusal demonstrated the presence of bioactive compounds like Quercetin (13.04%), Ascorbic acid (6.48%), p-Coumaric acid (6.17%), Caffeic acid (5.69 %), Mallic acid (5.44%), Apigenin (5.28%), Citric acid (5.15%), Gallic acid (4.38%), Cyanidin (3.52%), and Ferulic acid (3.51%). Kirby-Bauer method followed by the resazurin microtiter assay technique (REMA) for MIC/MBC against six MTCC bacterial strains and one yeast, all producing stubborn opportunistic infection in humans, was used to assess the antibacterial property of all the bioactive rich fractions. Some fractions comparatively revealed a good activity index (AI) against tested microbes. MIC concentrations for bacteria ranged from 15-24 mg/ml while a lower MBC value recorded was 18 mg/ml. Methanol fraction revealed significant tyrosinase inhibitory activity by revealing IC50 of 980.98 µg/ml when L-Tyrosine was substrate and IC50 of 830.68 µg/ml when L-DOPA was substrate when juxtaposed to standard kojic acid that revealed IC50 of 128.822 µg/ml when L-Tyrosine was substrate and IC50 of 149.43 µg/ml when L-DOPA was substrate. The bioactive compounds possessed by the fractions, may be synergistically, turned out to be more effective in the diphenolase reaction and kojic acid acts more effectively in the monophenolase one. It was inferred that peel phenolics of this malus variety have a lot of therapeutic potential in the context of bacterial infections and pigmentation disorders.

Increased antibiofilm and growth inhibitory effect of Imipenem/Cilastatin nanoliposomes against clinical Pseudomonas aeruginosa isolates

Numerous infections are linked to Pseudomonas aeruginosa. It is one of the major medical concerns because of virulence and antibiotic resistance. Antibiotic encapsulation in liposomes is a good strategy for controlling infections caused by this microorganism. Evaluation of anti-Pseudomonas aeruginosa effect of liposomal form of Imipenem/Cilastatin in vitro condition. By using the disk agar diffusion technique, the isolates’ pattern of antibiotic resistance was identified. The antibiotic was placed into the nanoliposome after it had been made using the thin layer and ethanol injection techniques. SEM and DLS were used to determine the size, shape, and zeta potential of the encapsulated drug form and the empty nanoliposome. Additionally, Imipenem/Cilastatin encapsulation in nanoliposomes was studied using FT-IR spectroscopy. In the microbial assay experiments the MIC, MBC and MBEC of liposomal and free drug forms were determined. The nanoparticles were spherical, with a diameter ranging from 30 to 39 nm, and the EE% in the thin layer and ethanol injection procedures were 97 and 98, respectively. Imipenem/Cilastatin nanoliposomes showed peaks at 3009 cm−1 and 1650 cm−1, demonstrating the thermodynamic stability for the chemical structure of the drug enclosed and validating the encapsulation of antibiotic in the nanoliposomes. When compared to free drug forms, nanoliposomes had lower MIC and MBC values in the majority of the isolates and had a greater ability to eradicate the biofilm formation. It was shown that the two nanoliposome preparation techniques were more efficient in 80% of the isolates, which had outcomes that were consistent with those of numerous other investigations. Overall, we demonstrated that the antibacterial activity of nanoliposomes was higher than that of the free drug form based on the evaluation of their MIC and MBC. Pharmaceutical nanoliposome techniques provide an excellent future perspective on how to manage microbial infections that are resistant to antibiotics.Graphical

Valorisation of the Invasive Macroalgae Undaria pinnatifida (Harvey) Suringar for the Green Synthesis of Gold and Silver Nanoparticles with Antimicrobial and Antioxidant Potential.

Bacterial and fungal infections are a challenging global problem due to the reported increasing resistance of pathogenic microorganisms to conventional antimicrobials. Nanomaterials are a promising strategy to fight infections caused by multidrug-resistant microbes. In this work, gold (Au@UP) and silver (Ag@UP) nanoparticles were produced for the first time by green synthesis using an aqueous extract of the invasive macroalgae Undaria pinnatifida (UP). The nanoparticles were characterized by a wide range of physicochemical techniques. Au@UP and Ag@UP demonstrated to be spherical and crystalline with an average size of 6.8 ± 1.0 nm and 14.1 ± 2.8 nm, respectively. Carbohydrates and proteins of the UP extract may participate in the synthesis and capping of the nanoparticles. The UP extract, Ag@UP, and Au@UP were assessed for their antimicrobial activity against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, and Candida auris. Ag@UP showed the highest antimicrobial activity with very low MIC and MBC values for all the tested bacteria, and Au@UP demonstrated to be very effective against biofilm-producing bacteria. The antifungal properties of both Ag@UP and Au@UP were remarkable, inhibiting hyphae formation. This study points towards a very promising biomedical exploitation of this invasive brown algae.

Antibacterial and Biofilm Production Inhibition Activity of Thymus vulgaris L. Essential Oil against Salmonella spp. Isolates from Reptiles.

Salmonellosis is an infectious disease affecting both animals and humans. Antimicrobial resistant (AMR) and biofilm-producing Salmonella spp., frequently detected in reptiles (who can then act as asymptomatic carriers for warm-blooded animals), have developed resistance to biocides; this represents a warning for the emergence of biocide/antimicrobial cross-resistance. The aim of this study was to evaluate the efficacy of Thymus vulgaris L. essential oil (TEO) in inhibiting bacterial growth and biofilm production of Salmonella spp., which had been isolated from wild reptiles housed in a Zoo in Italy. The resistance profile against different classes of antibiotics showed that all the isolates were susceptible to the tested antibiotics, despite the presence of several AMR genes. All the isolates were also tested with aqueous solutions of TEO at different dilutions (5% to 0.039%). Interestingly, TEO proved effective both in inhibiting bacterial growth at low dilutions, with MIC and MBC values ranging between 0.078% and 0.312%, and in inhibiting biofilm production, with values ranging from 0.039% to 0.156%. TEO demonstrated effective bioactivity against the biofilm producer Salmonella spp., proving to be a valid disinfectant for the prevention of salmonellosis from reptiles, a possible source of infection for humans exposed to the reptiles' environment.

Design, synthesis, and antibacterial activity of a new series of ciprofloxacin-thiadiazole hybrid

This study synthesized novel ciprofloxacin analogs bearing the 2-amino-1,3,4-thiadiazole ring, including tryptophan and different sulfonamides, to act as antimicrobial agents. Then, the activities of the synthesized hybrids were screened against 18 tested bacterial isolates from 4 standard strains (Escherichia coli ATCC 8739, Staphylococcus aureus ATCC 25,923, Acinetobacter baumannii ATCC 19,606, and Pseudomonas aeruginosa PAO1) and 14 clinical strains (2 Enterobacter cloacae and 12 Klebsiella pneumonia isolates). Investigations revealed that compound 2 showed better antimicrobial activities among the synthesized compounds than the standard drug, ciprofloxacin, demonstrated by its lower MIC and MBC values. We also notably observed that compared to ciprofloxacin, compound 2 maintained its activity for a longer time without inducing resistance in the tested bacterium. Hence, we conducted a time-to-kill assay and compared the results with its parent drug, followed by a molecular modeling simulation study through the docking of compound 2 into E. coli DNA gyrase enzyme active site to elucidate its binding modes to the receptor. Then, we compared these results with ciprofloxacin and calculated the physicochemical descriptors, ADME parameters, pharmacokinetic properties, and drug-like nature profile of compound 2 as the most potent were also calculated. Based on our findings, we conclude that with further modifications of compound 2, the design of a new and optimized fluoroquinolone generation should be possible.

Determination of Chemical Composition and Investigation of Biological Activities of Ocimum basilicum L.

This study aimed to determine the chemical composition of the essential oils (EOs) of Ocimum basilicum L., as well as to evaluate the antibacterial, antidiabetic, dermatoprotective, and anti-inflammatory properties, and the EOs and aqueous extracts of O. basilicum. The antibacterial activity was evaluated against bacterial strains, Gram-positive and Gram-negative, using the well diffusion and microdilution methods, whereas the antidiabetic activity was assessed in vitro using two enzymes involved in carbohydrate digestion, α-amylase and α-glucosidase. On the other hand, the dermatoprotective and anti-inflammatory activities were studied by testing tyrosinase and lipoxygenase inhibition activity, respectively. The results showed that the chemical composition of O. basilicum EO (OBEO) is dominated by methyl chavicol (86%) and trans-anethol (8%). OBEO exhibited significant antibacterial effects against Gram-negative and Gram-positive strains, demonstrated by considerable diameters of the inhibition zones and lower MIC and MBC values. In addition, OBEO exhibited significant inhibition of α-amylase (IC50 = 50.51 ± 0.32 μg/mL) and α-glucosidase (IC50 = 39.84 ± 1.2 μg/mL). Concerning the anti-inflammatory activity, OBEO significantly inhibited lipoxygenase activity (IC50 = 18.28 ± 0.03 μg/mL) compared to the aqueous extract (IC50 = 24.8 ± 0.01 μg/mL). Moreover, tyrosinase was considerably inhibited by OBEO (IC50 = 68.58 ± 0.03 μg/mL) compared to the aqueous extract (IC50 = 118.37 ± 0.05 μg/mL). The toxicological investigations revealed the safety of O. basilicum in acute and chronic toxicity. The finding of in silico analysis showed that methyl chavicol and trans-anethole (main compounds of OBEO) validate the pharmacokinetics of these compounds and decipher some antibacterial targets.

Phosphorus availability and arbuscular mycorrhizal fungi limit soil C cycling and influence plant responses to elevated CO2 conditions

Soil organic matter (SOM) decomposition and organic phosphorus (P) cycling may help sustain plant productivity under elevated CO2 (eCO2) and low-P conditions. Arbuscular mycorrhizal (AM) fungi and their role in P-acquisition and SOM decomposition may become more relevant in these conditions. Yet, experimental evidence of AM fungi and P availability interactive effects on soil carbon (C) cycling under eCO2 is scarce with the potential mechanisms of this control being poorly understood. We performed a pot experiment with soil and a grass from a low-P ecosystem where plant biomass and soil C cycling have been mostly unresponsive to eCO2. We manipulated AM fungi, P, and CO2 levels and assessed their impacts on soil C cycling and plant growth using continuous 13C plant labelling to isolate and measure short-term changes in total and SOM-derived fractions of respired CO2, dissolved organic C (DOC) and microbial biomass (MBC), as relevant components of the soil C cycle. Increases in SOM decomposition and microbial C use were hypothesised to support plant growth under eCO2 and low-P with AM fungi intensifying this effect. However, we did not detect simultaneous significant impacts of the three experimental factors. We observed instead increased root biomass and nutrient uptake with eCO2 and AM presence and lower SOM-derived DOC and MBC with low-P, decreasing further with AM inoculation. Taken together, our findings in this model plant-soil system suggest that, AM fungi can support root biomass growth and nutrient uptake under eCO2 and protect the SOM pool against decomposition even in low-P conditions. Contrary to reports from N-limited ecosystems, our results allow us to conclude that C and P biogeochemical cycles may not become coupled to sustain an eCO2 fertilisation effect and that the role of AM fungi protecting the SOM pool is likely driven by competitive interactions with saprotrophic communities over nutrients.

Microplastic additions alter soil organic matter stability and bacterial community under varying temperature in two contrasting soils

Microplastics can accumulate in soils and strongly affect the biogeochemical cycle. Biodegradable plastic films show potential as sustainable alternatives that could reduce microplastic soil contamination and accumulation. However, the effects of traditional and biodegradable microplastics on soil organic matter (SOM) stability are not sufficiently understood, particularly under varying temperatures. The objective of this study was to examine the effects of polyethylene (PE) and biodegradable polylactic acid (PLA) microplastics on SOM stability and bacterial community in two contrasting soils (Black soil vs. Loess soil) under varying temperature conditions (15 °C vs. 25 °C). Results showed that microplastics addition significantly enhanced cumulative CO2 emissions and DOC contents, particularly 1 % PLA treatment accelerated CO2 emissions by 19 % – 74 %, DOC content by 3 % – 23 % at 25 °C. A higher temperature sensitivity (Q10) at the PLA treatment indicated that PLA is more susceptible to elevated temperature compared to PE. The presence of both PE and PLA microplastics significantly changed the DOC spectral characteristics, i.e., high temperature increased the value of the specific UV absorbance (SUVA) in soil without microplastics, while decreased it in soil with microplastics. In comparison to soil without microplastics, soil exposed to 1 % microplastics had lower MBC concentrations and greater metabolic quotient. 16S rRNA gene sequencing showed that the presence of PLA microplastic significantly alters soil bacterial community. PE and CK had similar Bray-Curtis distances between two temperatures, while PLA increased the dissimilarity between CK compared to PE. Compared to the two soils, loess soil is more sensitive to microplastics addition. Microplastics have a non-ignorable effect on soil organic matter stability, the interaction between microplastics and soil environment should be considered.