Significant Antibacterial Activity Research Articles

Synthesis and Antimicrobial Activities of Salicylaldehyde Schiff Base-Cu(II) Complex and Its Catalytic Activity in N-Arylation Reactions

Salicylaldehyde Schiff base-Cu complex (1:1 [M:L] chelate) was synthesized using salicylaldehyde, urea, and CuCl2. Its catalytic activity was then assessed in N-arylation of aromatic amines (1H-indole, 1H- pyrazole, 1H-imidazole, 1H-benzo[d][1,2,3]triazole, and aniline) with aryl halides. This reaction does not need aryl boronic acids as the active aryl source or palladium-based catalyst. Cu is cheaper than many other catalysts, and required ligands usually having quite simple structure and being inexpensive. On the other hand, with a proper ligand selection we can have a modified solubility, reactivity, and reaction efficiency. The structure and composition of this novel complex were approved by FT-IR, UV-Vis, atomic absorption spectroscopy, elemental analysis, and TGA/DTA. Investigating the antibacterial activity of the Cu complex suggests a significant antibacterial activity against standard species Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus subtilis.

Haneummycin, a new 22-membered macrolide lactam antibiotic, produced by marine-derived Streptomyces sp. KM77-8.

A new antibiotic named haneummycin (1) was isolated from a culture broth of marine-derived Streptomyces sp. KM77-8 by solvent extraction and HPLC using a C4 column. The structure of 1 was elucidated including relative stereochemistry as a new 22-membered macrolide lactam associated with a cyclopentanone and three sugars by various spectroscopic analyses, such as MS and NMR. Compound 1 displayed significant antibacterial activities against Gram-positive bacteria including vancomycin-resistant Enterococcus faecium (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) with both MIC values of 8.0 µg ml-1.

Synergistic anti-bacterial effects of green synthesized zinc oxide nanoparticles with levofloxacin

Nowadays, the emergence of drug resistance is a major problem due to the limited bioavailability and unintended toxicity of antibiotics because of their non-specific targeting, which makes it difficult to eradicate pathogenic infections. Zinc oxide nanoparticles gain much attention as nanocarriers due to their non-toxic, eco-friendly, and economical cost to treat severe pathogenic infections. The purpose of this research was to produce and analyze zinc oxide nanoparticles (ZnONPs) functions using a green synthesis process to evaluate their anti-bacterial and biofilm inhibitory activities against gram-positive and gram-negative microorganisms. ZnONPs were formed via a green synthetic approach using a seed extract of soybean (Glycine max) and nanoparticle characterization was done using FESEM, X-ray diffraction, UV–VIS spectroscopy, and EDAX. The anti-bacterial and biofilm inhibitory activities of ZnONPs, levofloxacin, and levofloxacin-loaded ZnONPs were determined using an agar disc diffusion assay and a microtiter plate assay, respectively. Levofloaxcin-loaded ZnONPs showed more potent and statistically significant antibacterial activity than ZnONPs alone against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Enterococcus faecalis. The bacterial inhibition zone of levofloxacin-loaded ZnONPs at 80 µg/ml concentrations was higher in comparison to the standard levofloxacin and ZnONPs alone, which showed levofloxacin-loaded ZnONPs possess effective antibacterial activity that prevents the growth of diverse microorganisms. Our findings revealed that levofloxacin-loaded ZnONPs have an effective range of antimicrobial effects and could be used for the eradication of pathogenic infections.

IN VITRO ANTIBACTERIAL AND ANTIBIOFILM ACTIVITIES OF ULTRAFILTRATED-BROMELAIN AGAINST DENTAL CARIES PATHOGENS

Dental plaque on tooth surfaces significantly contributes to dental caries leading to acidic demineralization of the tooth enamel and dentin. This is mainly caused by the formation of pathogenic bacterial biofilm. Dental caries affects approximately 3.5 million people around the world. Compared to synthetic anticariogenic agents such as chlorohexidine, plant-based compounds were found to have fewer side effects and higher economic value. Pineapple (Ananas comosus) is one of the largely commercialized plants in Malaysia with beneficial attributes such as its Bromelain enzyme. This study aimed to purify Bromelain enzyme from MD2 pineapple core and to evaluate their antibacterial properties against dental caries-associate pathogens in vitro. This study evaluated the effect of Bromelain enzyme isolated from MD2 pineapple core using 50% Ammonium Sulphate precipitation incorporated with centrifugal ultrafiltration against Streptococcus mutans, Staphylococcus aureus, Lactobacillus acidophilus, and Lactobacillus casei. Bromelain enzyme showed effectivity of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) for all cariogenic organisms. Ultrafiltrate Bromelain (UFB) enzyme had significant antibacterial activity against S.mutans with a MIC value of 250 μg/ml and complete susceptibility at an MBC value of 1000 μg/ml. Biofilm inhibition against S.mutans increased from 45.98% to 57.48% with ultrafiltration. A 3.25 purification fold increase was observed in the ultrafiltrate sample. In conclusion, the ultrafiltration technique is efficient in purifying Bromelain enzyme and effectively inhibits S. mutans biofilm formation and thus possesses a potential inhibitory effect on dental caries in vitro.

Evaluation of Antibacterial, Antibiofilm, Antioxidant, and Anti-Inflammatory Activities of Kratom Leaves (Mitragyna speciosa) Fermentation Supernatant Containing Lactobacillus rhamnosus GG.

Kratom (Mitragyna speciosa) leaves are commonly used to enhance endurance and treat various diseases. This study evaluated the effect of kratom leaf fermentation with Lactobacillus rhamnosus. Antibacterial activity was investigated against Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Escherichia coli, and E. coli O157:H7. Biofilm inhibition and eradication assays were also performed. Antioxidant properties were determined by measuring the total phenolic and flavonoid content and DPPH and ABTS scavenging activities. Nitric oxide and TNF-α, IL-1β, and IL-6 expressions in LPS-stimulated RAW 264.7 macrophage cells were also measured. Aqueous kratom extract exhibited promising effects against free radicals and pro-inflammatory cytokines. Notably, all fermented kratoms showed significant antibacterial activity against the tested pathogens and antibiofilm formation by S. aureus and MRSA. Furthermore, the eradication of established biofilms of fermented kratoms was observed in S. aureus (day 2, 50mg/mL) and E. coli (day 2, 100mg/mL and day 4, 50mg/mL). To the best of our knowledge, this study is the first to report that fermented and non-fermented kratoms could be nutraceutical sources of antibacterial, antibiofilm, antioxidant, and anti-inflammatory substances against related diseases and can be applied further in dietary or cosmetic products with health-promoting effects.

Green synthesis of Multifunctional Zinc oxide Nanoparticles from Cordia myxa gum; and their Catalytic Reduction of Nitrophenol, Anticancer and Antimicrobial Activity

In situ exfoliated natural polysaccharide Cordia myxa (CMX) is used to promote the utilization of zinc-oxide nanoparticles for eco-friendly catalytic hydrogenation of p-nitrophenol (p-NP) and microbial growth inhibition. Polysaccharide-mediated biosynthetic nanocomposite materials are interesting because they are cheap, green, and environmentally friendly. This study uses CMX gum as a bioreduction to produce multifunctional, environmentally friendly zinc-oxide nanocomposites (ZnO NPs). The process involves a low reaction time and temperature and utilizes CMX as a reducing and stabilizing agent. The structural, morphological, and optical properties of the CMX-ZnO nanocomposite were characterized. The biosynthetic CMX-ZnO NPs exhibited robust catalytic activity and recycling capacity for rapidly oxidizing hazardous p-NPs. The complete reduction of 4-NP to CMX-ZnO NPs in excess NaBH4 was achieved within 15 min, with recyclability and pseudo-first-order kinetics with a rate constant of 0.2571 min−1. Additionally, human colon cancer (HCT116) and 3T3L1 cell lines were remarkably sensitive to the cytotoxic effects of ZnO nanoparticles. CMX-ZnO NPs exhibited potent antibacterial properties against human pathogenic gram-positive and gram-negative bacteria (Bacillus, Salmonella, E. coli, and Pseudomonas aeruginosa) based on the zone of inhibition measured by the disc-diffusion method. The significant antibacterial activity of CMX-ZnO NPs can overcome the current limitations associated with removing water-soluble organic pollutants and microbiological contaminants for long-term environmental sustainability.

Metabolite Profiling and Bioactivity Assessment of Beet Juice fermented by Lactobacillus spp.

Probiotic drink from fermented beet juice (Beta vulgaris) using Lactobacillus acidophilus and Lactobacillus plantarum was studied for its bioactive properties. The samples were assessed after 24h and 48h of fermentation for their physico-chemical changes and cell viability. Fermented juice showed a significant antibacterial activity against Listeria monocytogenes. Fermented beet juice exhibited a prominent anti-oxidant activity. When compared to fresh beet juice, more amount of total polyphenol content was detected in the fermented beet juice. The probiotic drink also exhibited anti-inflammatory and anti-hemolytic activity which exposed the potential usage of this probiotic drink in the pharmaceutical industry. The antibacterial activity observed against Listeria monocytogenes demonstrated that the fermented beet juice can be used to treat Listeriosis. The FTIR analysis and GC-MS results confirmed the presence of bioactive compounds in the fermented beet juice.

Eugenol works synergistically with colistin against colistin-resistant Pseudomonas aeruginosa and Klebsiella pneumoniae isolates by enhancing membrane permeability.

Colistin is a potent antibiotic for the treatment of carbapenem-resistant Gram-negative bacteria and is considered a last-resort drug. Unfortunately, the incidence of colistin-resistant bacteria isolated from patients is continuously growing due to clinical reuse of colistin. In this study, we found that the combination of colistin and eugenol has a significant synergistic antibacterial effect and reverses the sensitivity of colistin-resistant Pseudomonas aeruginosa and Klebsiella pneumoniae against colistin, as confirmed by checkerboard and time-kill assays. Crystal violet staining and scanning electron microscopy revealed colistin and eugenol's synergistic antibiofilm action. Concerning the synergy mechanism, the results revealed that the combination of eugenol and colistin increases membrane permeability and causes considerable membrane damage, further inhibiting bacteria synergistically. Meanwhile, up to 500 µg/mL of eugenol is non-toxic to RAW 264.7 cells, and the colistin/eugenol combination is also efficacious in vivo, as demonstrated by the Galleria mellonella infection model. Our findings indicate that the colistin/eugenol combination is a viable treatment option for colistin-resistant P. aeruginosa and K. pneumoniae clinical infections. IMPORTANCE Colistin is used as a last resort for severe infections caused by multidrug-resistant Gram-negative bacteria, however, colistin resistance is increasing. As a result, we investigated the synergistic effect of eugenol/colistin combination, and the results revealed significant antibacterial and antibiofilm action. Eugenol may help clinical colistin-resistant Pseudomonas aeruginosa and Klebsiella pneumoniae recover their susceptibility. These findings suggest that combining eugenol and colistin may be a viable treatment option for colistin-resistant pathogen clinical infections.

Novel Thiosemicarbazone Derivatives from Furan-2-Carbaldehyde: Synthesis, Characterization, Crystal Structures, and Antibacterial, Antifungal, Antioxidant, and Antitumor Activities

Ten new thiosemicarbazone derivatives, furan-2-carbaldehyde thiosemicarbazone (1), 3-methyl-furan-2-carbaldehyde thiosemicarbazone (2), 5-hydroxymethyl-furan-2-carbaldehyde thiosemicarbazone (3), 5-trifluoromethyl-furan-2-carbaldehyde thiosemicarbazone (4), 5-nitro-furan-2-carbaldehyde thiosemicarbazone (5), 5-phenyl-furan-2-carbaldehyde thiosemicarbazone (6), 5-(2-fluorophenyl)-furan-2-carbaldehyde thiosemicarbazone (7), 5-(4-methoxyphenyl)-furan-2-carbaldehyde thiosemicarbazone (8), 5-(1-naphthyl)-furan-2-carbaldehyde thiosemicarbazone (9), and 5-(1H-Pyrazol-5-yl)-furan-2-carbaldehyde thiosemicarbazone (10) were synthesized by condensing thiosemicarbazide with the respective furan-2-carbaldehyde in methanol. The prepared compounds were characterized by spectroscopic studies (FT-IR and NMR) and electrospray mass spectrometry. The molecular structures of 2, 6, 7, and 8 have also been determined by X-ray crystallography. Compounds 2, 6, and 7 crystallize in the E conformation about the N1-C6, N1-C11, and N1-C11 bonds, respectively, while 8 adopts the Z conformation about the N1-C12 bond with the presence of an intramolecular N2-H…O2 hydrogen bond. All prepared thiosemicarbazone derivatives were evaluated for their in vitro antibacterial, antifungal, and antitumor activities against Staphylococcus aureus strains, Candida albicans/Candida tropicalis fungi, and seven human tumor cell lines (HuTu80, H460, DU145, M-14, HT-29, MCF-7, and LNCaP), respectively. The antioxidant activity was also studied by the DPPH assay. Compound 5 exhibited significant antibacterial activity against Staphylococcus aureus ATCC700699 (MIC = 1 μg/mL) compared to the nitrofurantoin and gentamicin reference drugs (MIC = 1–25 and 10->100 μg/mL, respectively). Compound 4 was ten times less active than amphotericin B (MIC = 5 μg/mL) against Candida albicans (ATCC90028 and ATCC10231), while 1 exhibited a moderate effect of scavenging of DPPH radical (IC50 = 40.9 μg/mL) in comparison to ascorbic acid reference compound (IC50 = 22.0 μg/mL). Among all the studied thiosemicarbazones, 5 showed a higher cytotoxic activity (IC50 = 13.36–27.73 μΜ) in relation to the other tested compounds (IC50 = 34.84—>372.34 μΜ) against all tested cell lines, except the LNCaP cell line, exhibiting its highest antiproliferative activity (IC50 = 13.36 μΜ) on the HuTu80 cell line. Besides, 8 and 9 exhibited high antitumor activity (IC50 = 13.31 and 7.69 μΜ, respectively) against the LNCaP cells.

Green synthesis of silver nanoparticles using Morinda citrifolia Linn leaf extract and its antioxidant, antibacterial and anticancer potential.

Nanomedicine has emerged as a revolutionary regimen for moderating communicable as well as non-communicable diseases. This study demonstrated the phytosynthesis of silver nanoparticles using M. citrifolia leaf extract (MC-AgNPs) and their in vitro antioxidant, antibacterial and anticancer potential. The Biosynthesis of MC-AgNPs was studied by spectroscopy and characterized by SEM, TEM, XRD and FTIR analysis. The antibacterial activity was checked by minimum inhibition concentration assay. The HeLa and MCF-7 cancer cell lines were used to explore the cytotoxicity and genotoxicity activity of biogenic MC-AgNPs. The free radical scavenging potential of MC-AgNPs was studied by in vitro DPPH and ABTS assays, which confirmed significant radical scavenging activity in a dose-dependent manner with IC50 of 17.70 ± 0.36 µg/mL for DPPH and 13.37 ± 3.15 µg/mL for ABTS radicals. The bactericidal effects of MC-AgNPs confirmed by MIC showed 0.1 mg/mL concentration of MC-AgNPs with greater sensitivity for E.coli (93.33 ± 0.89), followed by K. pneumoniae (90.99 ± 0.57), S. aureus (87.26 ± 2.80) and P. aeruginosa strains (44.68 ± 0.73). The cytotoxicity results depicted strong dose and time-dependent toxicity of biogenic MC-AgNPs against cancer cell lines fifty percent inhibitory concentration MC-AgNPs against HeLa cells were 13.56 ± 1.22 µg/mL after 24h and 5.57 ± 0.12 µg/mL after 48 h exposure, likewise 16.86 ± 0.88 µg/mL and 11.60 ± 0.97 µg/mL respectively for MCF-7 cells. The present study revealed the green synthesis of silver nanoparticles using M. citrifolia and their significant antioxidant, antibacterial and anticancer activities.

Biopharmaceutical properties of polyvalent bacteriophage capsules

Scientific relevance. Rational phage therapy is a highly effective way to combat bacterial infections, especially in conditions of steadily increasing antibiotic resistance. Most bacteriophage preparations are formulated as oral and topical solutions. However, oral administration of liquid phage preparations results in significant inactivation in the stomach. To shield active ingredients from the acidic environment, Sextaphag® Pyobacteriophage, polyvalent, has been formulated into capsules.Aim. This study evaluated the polyvalent bacteriophage preparation in capsules in terms of its potency and biopharmaceutical properties.Materials and methods. The study compared the polyvalent bacteriophage preparation formulated as capsules with the polyvalent bacteriophage preparation formulated as a solution. The potency was evaluated by the Appelmans method, and phage particles were quantified by the Gratia method. To evaluate the acid-neutralising capacity, the authors placed test samples of the bacteriophage preparation in 0.1 M hydrochloric acid and analysed their potency by the Appelmans method. Chinchilla rabbits were used to analyse anti-phage immune responses, and their antibody levels were measured using an enzyme immunoassay test system developed by the authors. The pharmacokinetic parameters were studied in outbred white mice after oral dosing.Results. The polyvalent bacteriophage preparation exhibited high lytic activity towards Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Proteus vulgaris, Pseudomonas aegidinosa, Staphylococcus aureus, and Streptococcus pneumoniae, which accounted for a dilution factor of 10-6. Following oral administration of the polyvalent bacteriophage preparation in capsules to mice, the level of absorption was 3.1–3.7 times higher than that observed with the solution. Repeated oral administration of therapeutic doses did not induce anti-phage antibodies in rabbits. The stability study showed that the polyvalent bacteriophage preparation retained high lytic activity for 18 months.Conclusions. According to the study results, the polyvalent bacteriophage preparation in capsules exerts significant antibacterial activity against the studied microorganisms, has a high level of absorption, retains its lytic activity for a long time, and does not induce anti-phage antibodies after oral dosing, which confirms its safety and efficacy.

Bacterial Examination in Spoiled Vegetables, Its Isolation, Identification and Antibacterial Activity of Turmeric, Pongamia and Betel Leaf

Microbial contamination is a major concern in the food and pharmaceutical industries, leading to economic losses and public health risks. Natural products such as turmeric, betel leaf, and Pongamia leaves have been traditionally used for their antimicrobial properties. This thesis aimed to examine, identify, and isolate bacteria from selected spoiled vegetable samples and to evaluate the antibacterial activity of turmeric, betel leaf and Pongamia leaves. Bacterial isolation was performed using standard microbiological techniques, and the identification was done based on cultural characteristics. The antibacterial activity was assessed using disc diffusion method. The results showed the presence of bacterial contaminants in the tested samples, including Staphylococcus sp. And Escherichia coli. The turmeric, betel leaf, and Pongamia leaves extracts exhibited significant antibacterial activity against the tested bacteria. The phytochemical analysis of the extracts revealed the presence of alkaloids, flavonoids, phenols, tannins, and saponins, which may contribute to their antibacterial properties. This research provides valuable insights into the microbial contamination of food and pharmaceutical samples and the potential of natural products as antimicrobial agents. The findings of this study can contribute to the development of new antimicrobial agents based on natural products and the improvement of food and pharmaceutical safety.

Synthesis of novel antibacterial nanocomposite CuO/Ag-modified zeolite for removal of MB dye

Novel CuO/Ag nanocomposites added zeolite (CAZ) were successfully fabricated, and their effectiveness as an antibacterial on S. aureus and MB removal was evaluated. EDX, XRD, and FTIR confirm the presence of the elemental compositions of CAZ. Friable CuO nanorods (10–70 nm in diameter) existed on the surface of the zeolite. Pure zeolite had a higher band gap (5.433 eV) and lower MB removal efficiency than CAZ. The adsorption method by CAZ was more effective at removing MB than photodegradation. 0.10 CAZ had the highest removal effectiveness (~ 99%) and adsorption capacity (~ 70.4 mg g−1) of MB. The inhibitory zone diameter for 0.005 CAZ against S. aureus was 20 mm, while 0.01 CAZ had a diameter of 17 mm. Azithromycin, ceftriaxone, and erythromycin antibiotics demonstrated lower or no efficacy against S. aureus than CAZ. Significant antibacterial activities and wastewater treatment were achieved by CAZ. The combination of photodegradation and adsorption enhanced pollutant removal. It will be interesting to study further the optimal molar ratio for MB removal (0.10 CAZ) in future investigations.

Discovery and druggability evaluation of pyrrolamide-type GyrB/ParE inhibitor against drug-resistant bacterial infection

The bacterial ATP-competitive GyrB/ParE subunits of type II topoisomerase are important anti-bacterial targets to treat super drug-resistant bacterial infections. Herein we discovered novel pyrrolamide-type GyrB/ParE inhibitors based on the structural modifications of the candidate AZD5099 that was withdrawn from the clinical trials due to safety liabilities such as mitochondrial toxicity. The hydroxyisopropyl pyridazine compound 28 had a significant inhibitory effect on Gyrase (GyrB, IC50 = 49 nmol/L) and a modest inhibitory effect on Topo IV (ParE, IC50 = 1.513 μmol/L) of Staphylococcus aureus. It also had significant antibacterial activities on susceptible and resistant Gram-positive bacteria with a minimum inhibitory concentration (MIC) of less than 0.03 μg/mL, which showed a time-dependent bactericidal effect and low frequencies of spontaneous resistance against S. aureus. Compound 28 had better protective effects than the positive control drugs such as DS-2969 (5) and AZD5099 (6) in mouse models of sepsis induced by methicillin-resistant Staphylococcus aureus (MRSA) infection. It also showed better bactericidal activities than clinically used vancomycin in the mouse thigh MRSA infection models. Moreover, compound 28 has much lower mitochondrial toxicity than AZD5099 (6) as well as excellent therapeutic indexes and pharmacokinetic properties. At present, compound 28 has been evaluated as a pre-clinical drug candidate for the treatment of drug-resistant Gram-positive bacterial infection. On the other hand, compound 28 also has good inhibitory activities against stubborn Gram-negative bacteria such as Escherichia coli (MIC = 1 μg/mL), which is comparable with the most potent pyrrolamide-type GyrB/ParE inhibitors reported recently. In addition, the structure–activity relationships of the compounds were also studied.

Unveiling the Potency and Harnessing the Antibacterial Activities of Plant Oils against Foodborne Pathogens

The rising concerns regarding antibiotic resistance and the harmful effects of synthetic preservatives have led to an increasing interest in exploring natural alternatives. Plant oils have been traditionally used for their antimicrobial properties, but systematic investigations into their efficacy against foodborne pathogens are necessary for potential applications in food preservation. This study aimed to evaluate the antibacterial potential of various plant oils (neem, coconut, castor, and olive oil) against common foodborne pathogens and analyze their chemical composition using gas chromatography–mass spectrometry (GC-MS). The oils were tested against foodborne pathogens using the disk diffusion method. Minimum inhibitory concentrations (MICs) were determined to assess the potency of the oils. GC-MS was employed to identify the compounds present in each oil. Neem oil exhibited significant antibacterial activity against all tested pathogens, with pronounced effects against Staphylococcus aureus and Bacillus cereus. Coconut oil showed notable activity against Listeria monocytogenes. Castor oil displayed moderate activity, while olive oil exhibited minimal antibacterial effects. The GC-MS analysis revealed a diverse array of compounds in neem oil, which is likely to contribute to its potent antibacterial properties. Neem and coconut oils, owing to their rich bioactive components, emerged as promising candidates for the development of natural antimicrobial agents. These brief findings support the potential application of plant oils in food preservation and emphasize the need for further research into understanding the underlying mechanisms and optimizing their use.

The probiotic roles of Lactiplantibacillus plantarum E2 as a dietary supplement in growth promotion and disease resistance of juvenile large yellow croaker (Larimichthys crocea)

Bacterial diseases are the most important limiting factors for the development of large yellow croaker aquaculture. Probiotics are considered to be a promising alternative approach for the control of bacterial diseases in aquaculture. However, the studies on probiotics used in farmed large yellow croakers were very limited. In this study, we isolated and identified a Lactiplantibacillus plantarum E2 from the intestinal tract of large yellow croaker. L. plantarum E2 showed significant antibacterial activities against several aquaculture pathogenic bacteria, intestinal environmental tolerance, and biosafety. After 7 weeks of feeding, the E2 supplementation of dietary significantly improved the growth and the survival rates of large yellow croakers after Pseudomonas plecoglossicida PQLYC4 challenge. Further analysis showed that E2 effectively improved the intestinal integrity, and increased the intestinal α-amylase, trypsin and lipase activities. Moreover, the E2 supplementation also significantly suppressed the mRNA expression of IL-10 and increased the mRNA expression of IL-1β, IL-12α, IL-17D, IFN-γ, and TNF-α-R. Gut microbiota analysis showed that E2 significantly affected gut microbial community composition by decreasing the relative abundance of Sphingomonas and increasing the relative abundance of Lactobacillus and Pseudomonas. Finally, E2 could improve resistance of large yellow croaker against P. plecoglossicida PQLYC4 infection. Therefore, our findings showed that L. plantarum E2 has potential application as a probiotic in large yellow croaker, which may provide a new strategy of preventing and controlling bacterial diseases in this species.

Effect of Zn Doping on Antibacterial Efficacy of CuO Nanostructures

AbstractBacterial diseases are causing major health issues across the world. Recent research has revealed that the metal ion discharge of nanomaterials is extremely effective at eradicating bacterial outbreaks and resistance. Reactive oxygen species (ROS) for antibacterial functions have been produced using nanomaterials with high specific surface area, complex structural framework, and spectral properties. In this study, we thoroughly investigated the impact of Zn dopants on copper oxide (CuO) nanostructures and their nanomaterial‐based antibacterial processes. The method of production includes the formation of CuO and Zn‐doped CuO nanostructures via chemical coprecipitation. By using several characterization techniques, the as‐synthesized nanostructures were confirmed. Based on their specific surface area and surface‐active site, the different antibacterial activities of these dopants vary the antibacterial action. The antibacterial activity was evaluated using the agar well diffusion method. A significant antibacterial action was observed in the samples. In the pharmaceutical and food sectors, this CuO and its combined dopants can be a substitute for synthetic antibacterial agents.

Experimental and in silico evaluation of Carthamus tinctorius L. oil emulgel: a promising treatment for bacterial skin infections.

The current study aimed to develop a topical herbal emulgel containing Carthamus tinctorius L. (CT) oil extract, which has been scientifically proven for its antibacterial and antioxidant activities for the ailment of bacterial skin infections. The CT emulgel was formulated by response surface methodology (RSM) and was evaluated by various parameters like extrudability, spreadability, pH, viscosity, and antibacterial and antioxidant activities. Molecular docking was also performed using AutoDock. Among all formulated CT emulgels, F9 and F8 were optimized. Optimized formulations had shown good spreadability and extrudability characteristics. Sample F8 had % inhibition of 42.131 ± 0.335, 56.720 ± 0.222, and 72.440 ± 0.335 at different concentrations. Sample F9 had % inhibition of 26.312 ± 0.280, 32.461 ± 0.328, and 42.762 ± 0.398 at concentrations of 250 µg/ml, 500 µg/ml, and 1,000 µg/ml, respectively, which shows that both samples F8 and F9 have significant antioxidant potential. Optimized CT emulgels F8 and F9 had significant antibacterial activity against Staphylococcus aureus and Escherichia coli at p-value = 0.00, the Emulgel-F8 shows zone of inhibition of 24 mm for E-coli and 19 mm for S-aureus. Emulgel-F9 shows zone of inhibition of 22 mm for E-coli and 15 mm for S-aureus while pure CT- Oil extract shows zone of inhibition of 25 mm for E-coli and 20 mm for S-aureus and ciprofloxacin used as standard shows 36mm zone of inhibition against both E-coli and S-aureus. The comparative investigation through molecular docking binding affinities and interactions of ligands with various target proteins provides insights into the molecular processes behind ligand binding and may have significance for drug discovery and design for the current study. The current study suggests that C. tinctorius L.-based emulgel has good antioxidant and antibacterial activities against E. coli for the treatment of bacterial skin infections.

Enhanced biological activities of coumarin-functionalized polysaccharide derivatives: Chemical modification and activity assessment

Natural polysaccharides are abundant and renewable resource, but their applications are hampered by limited biological activity. Chemical modification can overcome these drawbacks by altering their structure. Three series of polysaccharide derivatives with coumarins were synthesized to obtain polysaccharide derivatives with enhanced biological activity. The biological activities were tested, including antioxidant property, antifungal property, and antibacterial property. Based on the results, the inhibitory properties of the coumarin-polysaccharide derivatives were significantly improved over the raw polysaccharide. The IC50 of the inhibition of DPPH, ABTS•+, and superoxide (O2•−) radical-scavenging was 0.06–0.15 mg/mL, 2.3–15.9 μg/mL, and 0.03–0.25 mg/mL, respectively. Compared with the raw polysaccharides, coumarin- polysaccharide derivatives exhibited higher efficacy in inhibiting the growth of tested phytopathogens, showing inhibitory indices of 60.0–93.6 % at 1.0 mg/mL. Chitosan derivatives with methyl and chlorine (Compound 10B and 10C) exhibited significant antibacterial activity against S. aureus (MIC = 31.2 μg/mL), E. coli (MIC = 7.8 μg/mL), and V. harveyi (MIC = 15.6 μg/mL), respectively. The results of the cytotoxicity assay showed no observed cytotoxicity when the RAW 264.7 cells were incubated with the synthesized polysaccharide derivatives at the tested concentrations.

ANTIMICROBIAL AND HISTOLOGICAL EFFECTS OF NANO-NEOMYCIN SOLUTION AGAINST DIFFERENT MICROBIAL POPULATION

In the present study, pomegranate nanoparticles solution was synthesized by Sol gel method. Which show hexagonal morphology with size average (50±10) nm scanned by (SEM) and (TEM). The synergestic solution of (Neomycin and Nano-Pomegranate extract) scanned by Atomic Force Microscopy (AFM) analysis provided the information about the distribution of particles in new solution. Beside the phenolic compounds, flavonoids and tannin played crucial role in the significant antibacterial activity and the synergestic solution observed in F1 and F2 at range (9.5-12.5) mm against Staphylococcus aurous, E. coli between (5-11.5) mm, Bacillus sp. (3.9-5.5); Proteus vulgaris (4.1-5.1) mm; Salmonella typhimurium at ranges (5.8-6.5) mm, klebsiella pneumonia (3.8-4.8) mm and listeria monocytogenes (3.9-5.6) mm. the Synergistic effect of the solution increased the efficacy of their work compared to used them individually, this was shown through increasing the inhibition zone. These results were demonstrated through histopathological examination to organs examined, that identical to normal when given different concentrations of these solutions, and proof of their non-toxicity. Overall, the results elucidated a rapid, costeffective, environmentally friendly and convenient method for synthesis, which could be used as a potential antimicrobial agent against multidrug-resistant bacteria.