Inhibition Zone Diameter Research Articles

Poly acrylonitrile Schiff-bases nanofibers: Antibacterial and dye removal potency

Polymer nanofibers exhibit a diverse range of applications in both biological and environmental contexts owing to their unique surface structure and porosity. This study investigates the synthesis of polyacrylonitrile (PAN) Schiff base nanofibers utilizing an electrospinning protocol and their antibacterial potency as well as their dye-removing capability. Schiff bases were created from the reaction of modified PAN with vanillin PANVan and cinnamaldehyde PANCinn. X-ray diffraction analysis (XRD), Fourier transform infrared (FTIR), Thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) were employed to elucidate the structure of the resultant Schiff bases. Each compound's capability to inhibit bacterial growth and eliminate methylene blue dye (MB) from aqueous solutions was assessed. The fabricated PAN Schiff bases were able to inhibit the bacterial growth of both Gram-negative bacteria with inhibitory zone diameters ranging from 8.5 to 12.3 mm and Gram-positive bacteria with inhibitory zone diameters ranging from 9 to 15.6 mm. Furthermore, 77.8 % of the MB dye was found to be removed by PANVan nanofibers. This dye removal process was discovered to be endothermic, following the Langmuir isotherm model and having pseudo-second-order kinetics as a description. It has been discovered that PANVan nanofibers can be reused for dye removal. Simulated adsorption and docking studies were found to agree with dye removal and antibacterial studies. These synthesized Schiff bases could demonstrate their promise as bactericidal agents and useful materials for environmental applications involving the removal of dyes.

Isolation, characterization, and screening of secondary metabolites from endophytic fungi isolated from Nigerian Piliostigma thonningii for antimicrobial activities

Piliostigma thonningii leaves are used in Nigeria folk medicine for the treatment and management of diverse ailments. This study was carried out to investigate the antimicrobial activity of the secondary metabolites produced from endophytic fungi isolated from the leaves of Piliostigma thonningii. The isolation of endophytic fungi was carried out according to the standard procedures. The fungi were subjected to solid-state fermentation on rice medium and the secondary metabolites extracted using ethyl acetate. The fungal crude extracts were screened for antimicrobial activity against selected clinically important microbes using the agar well diffusion method. The fungus with the best antimicrobial activity was molecularly characterized and its secondary metabolites profiled using Gas Chromatography - Mass Spectroscopy to establish the correlation between the observed activity and its phytochemical composition. The fungal extracts showed antimicrobial activity with inhibitory zone diameter ranging from 2.00 to 9.00 mm. The secondary metabolites of Aspergillus fumigatus (the most bioactive endophyte) contain 50 compounds with several of them having established antimicrobial activity. The results of this study suggest that Aspergillus fumigatus an endophytic fungus associated with P. thonningii could be a promising source of novel bioactive compounds with pharmaceutical, agricultural and industrial importance. Keywords: Antimicrobial, Endophytic fungi, GC-MS, Piliostigma thonningii

Synthesis, characterization, computer-aided docking studies, and anti-fungal activity of two-armed quinazolin-2,4‑dione derivatives

A new series of two-armed quinazolin-2,4-diones incorporating N- heterocyclic moieties such as β-lactam, piperidine and/or morpholine, 2-thioxo imidazolidin-4-one and 2-iminothiazolidin-4-one 2–7 were designed and synthesized as attractive anti-fungal scaffolds. The structural elucidation of newly compounds was performed by means of FT-IR, 1H NMR, 13C NMR and MS techniques. Subsequently, the newly synthesized compounds were screened for their antifungal activity against Candida albicans via measuring the inhibition zone diameter around the fungal growth. The results obtained revealed varied response activity toward the tested fungal pathogen. Three most potent compounds 1, 3, and 4 exhibited noted inhibitory effects. Since, there was found superiority of the compound 1 in terms of inhibition zone diameter (mm) about the standard drug (i.e. Amphotericin B). Additionally, the MIC value was assessed for the potent compounds using different concentrations (5–400 μg/mL). A significant MIC value (20 μg/mL) was recorded for compound 1. Moreover, the molecular docking simulation was performed against sterol 14-alpha demethylase. In particular, compound 1 exhibited the best binding profile among the synthesized compounds (- 13.6 kcal/mol), followed by compounds 3 (-12.7 kcal/mol) and 4 (-11.9 kcal/mol). The structure activity relationship revealed the importance of electron withdrawing groups (chlorine atoms) on biological activity of compounds. Further, the eight compounds exhibited good ADMET profile and satisfied the Lipinski rule of drug likeness.

The Synthesis of Y-zeolite-modified CaCO3-ZnO Nanocomposites as an Antibacterial Agent

The ability of inorganic antibacterial agents like metal oxides and nanoscale inorganic materials to inhibit bacterial growth rates has yet to receive much research attention. In this study, CaCO3-ZnO/Y-zeolite nanocomposites were created utilizing coprecipitation and impregnation techniques with Ca(CH3COO)2, Zn(CH3COO)2 2H2O, Y-zeolite precursors. Physical and chemical characteristics of nanocomposites have been investigated using XRD, FTIR, and SEM-EDX characterizations. The agar-well diffusion method tested the substance for antibacterial activity against gram-positive and gram-negative bacteria. Nanocomposites have a crystal size range of 35.46-36.53 nm and a crystallinity of 35-37 %, according to the results of XRD analysis. The carbonate groups are visible in FTIR data at wave numbers 1433, 875, and 712 cm-1. The Zn-O absorption band was verified at wave numbers 600-400 cm-1. The Y-zeolite absorption bands at wave numbers 1012-997 cm-1 and 745-746 cm-1 were confirmed. The particle morphology is cube-shaped with irregular sizes. The EDX result showed that the composition consists of 35.92 % calcium, 1.68 % zinc, 44.81 % oxygen, and 13.79 % carbon as elements. With the addition of 2.5 % Y-zeolite, the antibacterial activity of nanocomposites showed the best results, with an inhibition zone diameter of 7.62 mm against Escherichia coli and 6.56 mm against Staphylococcus aureus bacteria.

Antibacterial Activity Of Toothpaste Formulation Containing Spirulina platensis Extract Against Streptococcus mutans

Background: The main bacteria involved in the formation of dental caries is Streptococcus mutans (S. mutans). One approach to reduce the growth of S. mutans bacterial colonies is by brushing teeth with toothpaste containing antibacterial agent. The commonly used antibacterial agent is chlorhexidine, which is the gold standard chemical in reducing the colonization of S. mutans bacteria and other oral biofilms. However, over time, it causes various side effects, thus necessitating the search for alternative natural ingredients. One of potential ingredient with antibacterial agent is the Spirulina platensis, which contains secondary metabolites known to inhibit the growth of pathogenic bacteria. Thus, Spirulina platensis can be added to toothpaste as an antibacterial agent. Method: This study employed an experimental laboratory design with a post-test-only control group design. The study consisted of 7 treatments with 5 replications. Antibacterial activity was tested using the agar diffusion method by observing the average diameter of the inhibition zone formed. Data were analyzed using parametric one-way ANOVA. Discussion and Results: In this study, toothpaste with Spirulina platensis extract at concentrations of 0.25%, 0.5%, 1%, 2%, and 3% can inhibited the growth of S. mutans with average inhibition zone diameters of 20.4 mm, 20.8 mm, 21.8 mm, 22.3 mm, and 22.7 mm. The one-way ANOVA parametric test results showed a value of p0.05, indicating a significant difference in the antibacterial activity of S. mutans in all treatment groups. Conclusion: Toothpaste formulations with Spirulina platensis extract have antibacterial activity against S. mutans bacteria.

Effect of Essential oil and Extracts of Artemisia Herba – Alba Plant Against Some E Pathogenic Bacteria

Artemisia Herba – Alba is the one of the most important genus of Asteraceae family. It has numerous values because of medicine properties. Artemisia Herba – Alba has numerous application in traditional medicine from ancient times. In this research, antimicrobial effects of leaf aqueous, alcoholic extracts and essential oil of Artemisia Herba – Alba against Staphylococcus aureus PTCC 1431 and Escherichia coli PTCC 1399 were studied, using agar disc diffusion method. Methanol and ethanol extracts obtained from leaves of A. Herba – Alba exhibited antimicrobial activity against test microorganisms. In addition Artemisia herba-alba essential oil was inhibitory effects against all studied pathogenic bacteria. The results showed that essential oil of Artemisia herba-alba had the most inhibition diameter zone in Staphylococcus aureusthan E.coli (25-17mm successively). Therefore in this research we showed that the positive gram bacteria are more sensitive than negative gram bacteria. our results indicate the possibility of using essential oil in the treatment of bacterial infections, and the results of this study was encouraging, despite the need for clinical studies to determine of the real effectiveness and potential toxic effects in vivo

Antibacterial and antibiofilm activity of mint leaves (Mentha piperita L) extracts against Streptococcus mutans UA159: a laboratory experiment

Introduction: Oral health is a major concern in healthcare worldwide, with dental caries being a prevalent issue among children and adults. Streptococcus mutans is a primary bacterium implicated in the development of dental caries due to its acidogenic nature. Mint leaf (Mentha piperita L.) is a unique herbal plant that has antibacterial and antibiofilm properties against S. mutans and minimal side effects. The purpose of this study was to analyze the antibacterial effectiveness of mint leaf against the growth of S. mutans UA159 and its antibiofilm effects. Methods: This study was conducted experimentally with the posttest-only control group design, using the broth microdilution method in 6 test groups, namely mint leaf extract with a concentration of 3.125, 6.25, 12.5, 25, 50, and 100% and also two control groups, namely the negative control using aquadest and the positive control using 0.2% chlorhexidine. Biofilm growth is determined by comparing Optical Density (OD) values and then calculating the percentage of eradication of S. mutans biofilm formation. Results: The results indicated that the mint leaf extract exhibited antibacterial effects against S. mutans, with the largest inhibition zone diameter observed at a 100% concentration. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)90 values using the broth microdilution method in this study were 12.5% and 100% concentrations, respectively. Mint leaf extract has been shown to significantly inhibit the growth of S. mutans (p<0.05). The results of the inhibition test on biofilm formation at a concentration of 100% averaged 87.39%. Conclusion: Mint leaf extract has an antibacterial and antibiofilm effect on the growth of S. mutans. The level of inhibition of mint leaf extract on the growth of S. mutans is proportional to its concentration; the higher the concentration of the extract, the stronger the inhibitory ability.KeywordAnti-Bacterial agents, biofilms, Mentha piperita, oral health, Streptococcus mutans.

Enhanced effect of ultrasound and gelatin on physical and antibacterial properties of thymol/hollow mesoporous silicon spheres doped zein film

A new antibacterial film, Thy-HMSS/zein film, was prepared from hollow mesoporous silicon spheres loaded with thymol (Thy-HMSS) by ultrasonic optimization casting method (150 W power ultrasonic treatment solution for 3 min). To further enhance the film quality, a composite film, Thy-HMSS/Zein-gelatin film (Thy-HMSS/ZG film), was created by incorporating gelatin into zein. Compared to film containing the same amount of Thy, the effective protection and slow-release effect of HMSS on Thy resulted in a lower release rate of Thy in Thy-HMSS/zein films in the first 2 h, while the total amount of Thy released increased by 10 %. The appearance and structure of the films were optimized by ultrasonic treatment, which reduced the surface bubbles, cross section pores and particle agglomeration. The addition of gelatin enhanced the antibacterial effect of the film, the inhibition zone diameters of Escherichia coli and Staphylococcus aureus can be increased by up to 123.53 % and 159.37 %, respectively. Both Thy-HMSS/zein film and Thy-HMSS/ZG film showed no toxicity in cytotoxicity tests and exhibited good anti-corrosion ability when applied to blueberry preservation. Therefore, the combination of HMSS encapsulation with ultrasonic treatment and gelatin addition represents a suitable and straightforward approach for producing excellent antimicrobial films with superior appearance, structure, and antibacterial properties. This method holds significant potential in the food industry for producing sustainable active packaging materials while also offering new avenues for employing various techniques in films preparation.

Antimicrobial Assessment of Hand Sanitizers Formulated from Neem Leaf Extract (Azadirachta indica) and Coconut Shell Liquid Smoke

Abstract The widespread use of alcohol/ethanol-based hand sanitizers has raised concerns due to the concurrent issues of skin irritation, allergies, childhood poisoning risks, and the potential for bacterial resistance to antibiotics, which may disrupt the human digestive system. This study explores the potential of Neem leaves (Azadirachta indica) and liquid smoke as natural alternatives to alcohol-based antiseptics. The objective is to assess the antimicrobial efficacy of hand sanitizers containing Neem leaf extract and coconut shell liquid smoke against Escherichia coli and Salmonella typhimurium. Hand sanitizers were prepared by mixing 4g of Neem leaf extract with varying quantities of coconut shell liquid smoke (labeled as A1, A2, A3, A4, and A5, corresponding to 0g, 1g, 3g, 5g, and 7g, respectively). distilled water was then added until the total volume reached 100 ml. The solution was then stabilized with 0.5g of Carboxyl Methyl Cellulose (CMC) and 10g of glycerin. Results indicate that formulations A1, A2, A3, and A5 exhibit moderate inhibitory activity against Escherichia coli, with inhibition zone diameters of 6.02 mm, 8.17 mm, 9.67 mm, and 9.11 mm, respectively. Notably, formulation A4 displays strong inhibitory activity (11.15 mm). For Salmonella typhimurium, formulations A4 and A5 demonstrate very strong antimicrobial properties with inhibition zones measuring 11.68 mm and 12.59 mm, respectively. These findings suggest that hand sanitizers comprising Neem leaf extract and liquid smoke possess the potential as environmentally friendly, natural antiseptics.

Anthocyanins from pomegranate peel (Punica granatum), chili pepper fruit (Capsicum annuum), and bougainvillea flowers (Bougainvillea spectabilis) with multiple biofunctions: Antibacterial, antioxidant, and anticancer

BackgroundNatural colorants, including natural pigments, e.g., anthocyanins, carotenoids, and chlorophylls, in novel and attractive food matrixes have become a popular trend. They impart favorite colors to food products and provide significant therapeutic effects. This study is aimed at extracting and identifying some natural pigments from different plant sources and evaluating their ability as antibacterial, antioxidant, and anticancer activities. MethodsThe anthocyanin-rich extract (ARE) is derived from three natural plant sources: pomegranate peel (Punica granatum), chili pepper fruit (Capsicum annuum), and Bougainvillea flowers. Bougainvillea spectabilis are analyzed for biochemical composition, as well as antioxidant, antibacterial, and anticancer activity, HPLC, DPPH, FRAP, disc diffusion assay, MIC, MTT, VEGFR‐2, and caspase-9 assays. ResultsAll three extracts had varying total phenolic contents, ranging from 14 to 466 mg GAE/g extract, where Punica granatum was the highest (466 mg GAE/g extract), followed by Bougainvillea spectabilis (180 mg GAE/g extract), and then Capsicum annuum (14 mg GAE/g extract). The antioxidant activity rose steadily with raising concentration. The ARE of pomegranate peels recorded highest value, followed by Bougainvillea flowers and chili pepper fruit. The MTT assay revealed an inhibitory action of the tested extracts on the proliferation of HCT-116, MCF-7, and HepG2 in a concentration-based manner. Gene expression of caspase-9 transcripts was considerably multiplied by the application of ARE of pomegranate peels. All the tested extracts inhibited VEGFR-2, and the inhibition (%) expanded gradually with increasing concentrations, achieving the highest value (80 %) at 10 μg/mL. The ARE of pomegranate peels scored highest antibacterial activity, followed by ARE of chili pepper fruit and Bougainvillea flowers. The inhibition zone diameter escalated gradually with rising concentrations of the tested samples. ConclusionThe AREs of the three studied plant sources can be used as multifunctional products with antioxidant, anticancer, and antibacterial activities that are natural, safe, and cheap.

Synthesis, structural investigations, in vitro cytotoxicity, apoptotic activity, cell cycle analysis, and molecular modeling studies of nano‐sized Zn(II) Schiff base complex

A new novel tetradentate ligand, [(1E,1′E)‐N,N′‐(1,2‐phenylene)bis(1‐(5‐(2‐fluorophenyl)furan‐2‐yl)methanimine) (PFPFMI), and its nano‐sized [Zn(PFPFMI)Cl2].3H2O complex were synthesized. The geometry of PFPFMI and its Zn(II) complex was described through CHN analyses, Fourier‐transform infrared spectroscopy (FTIR), UV–visible, X‐ray diffraction (XRD), thermal gravimetric analysis (TGA), and mass spectral data tests. The spectral data of the nano‐sized [Zn(PFPFMI)Cl2].3H2O complex indicates that the PFPFMI ligand functions as a tetradentate (N2O2) coordination through two azomethine nitrogen groups (N) and two furan ring oxygen (O) atoms. Density functional theory (DFT) calculations were performed using the molecular studio software to investigate the optimal geometry of PFPFMI and its [Zn(PFPFMI)Cl2].3H2O complex. The SEM, TEM, XRD, AFM, and energy dispersive X‐ray analysis (EDX) analyses of the studied complex unveil distinct and strong diffraction peaks, indicating its crystalline nature and providing evidence of its nano‐sized particle sizes. Additionally, the inhibition zone diameter was used to assess the in vitro antimicrobial action of PFPFMI and the particular complex against Gram‐positive bacteria Streptococcus pneumonia and Bacillus subtilis, Gram‐negative bacteria Pseudomonas aeruginosa, Salmonella typhi, and Escherichia coli, as well as fungi Aspergillus fumigatus, Geotricum candidum, Syncephalastrum racemosum, and Candida tropicalis. The [Zn(PFPFMI)Cl2].3H2O complex exhibits higher activity than the ligand PFPFMI. In vitro cytotoxicity of the synthesized [Zn(PFPFMI)Cl2].3H2O complex was explored using MCF7 (breast cancer), HCT116 (colon cancer), A549 (lung cancer), HePG‐2 (liver cancer), A375 (melanoma cancer), and normal lung fibroblast (WI38) cell lines. Based on IC50 and selective index (SI) values, it was shown that the complex exhibited higher potency against MCF7 cell lines. Moreover, the Zn(II) complex exhibited the ability to induce DNA damage in MCF7 cells, resulting in dose‐dependent cell apoptosis. Subsequent investigations revealed that complex 2 also induced cell cycle arrest in the G2 and S phases.

A pilot study on the antimicrobial efficacy of Coleus Aromaticus on Lactobacillus acidophilus – Comparative In-Vitro analysis of five samples on a single plate

Objectives: Coleus aromaticus, also known as Indian borage, is a plant recognized for its medicinal uses, including potential antimicrobial properties. Lactobacillus acidophilus, a bacterium commonly found in the oral cavity and gastrointestinal tract, plays a crucial role in maintaining microbial balance but can lead to dental caries if imbalanced. The aim of this study is to assess the in vitro antimicrobial efficacy of C. aromaticus against L. acidophilus. Material and Methods: The study was performed by the utilization of homeopathic ethanolic and dry leaf extracts of C. aromaticus on Lactobacillus bacteria, with a control group treated with 0.2% chlorhexidine. For the preparation of the C. aromaticus extract, leaves were cleaned, dried, and ground into a paste. A 20 g portion of this paste was then weighed and used for extraction. In the assessment of inhibitory effects, the disc diffusion method was employed, and nutrient agar served as the growth medium. Discs loaded with the respective extracts were positioned on the agar, and the Petri dishes were subsequently incubated at 37°C for 24 h. Following the incubation period, the inhibitory zones surrounding the discs were measured using a measuring scale. Results: The study’s findings were determined by measuring the diameter of inhibition zones and assessing the mean values. It was observed that the aqueous extract derived from dried C. aromaticus leaves possesses antimicrobial activity against Lactobacillus. Specifically, it exhibited inhibition zones with diameters of 24 mm and 27 mm when using 100 µL/disc and 200 µL/disc, respectively. In comparison, the control group (0.2% chlorhexidine) displayed an inhibitory zone with a 23 mm diameter. Conclusion: The reason for these findings could be attributed to the existence of phytochemicals and essential volatile oils within C. aromaticus, which possess antimicrobial properties against Lactobacillus. This natural component appears to be effective in reducing Lactobacillus growth when used as an oral rinse containing phytochemicals.

Comparison the effect of plant extracts and antibiotics on gram negative bacteria isolated from patients with urinary tract infection in Tikrit city

Background: With increasing bacterial resistance for antibiotic, there is an increasing interest in medicinal herbal as a new source of an antimicrobial agents and with less side effects than conventional drugs. Objective: Was to evaluate the potential of Syzygium aromaticum and rosemarinus officinalis extract on Proteus mirabilis isolates in vitro. Methods: Six pathogenic gram negative bacilli belonging to three different genus (E.coli, Proteus mirabilis, and Enterobacter aerogenes) and two isolates from each species were used in this study and four concentration (100%, 75%, 50%, 25% mg/ml ) from each plant extracts (aqueous and ethanolic of Syzygium aromaticum and rosemarinus officinalis extracts ) were prepared to be antibacterial agent. antibacterial activity was measured by using wells method and five antibiotics using to compare with the activity of antibacterial agent. Results: The result of the study shown that the ethanolic extracts of Syzygium aromaticum is a strong antibacterial agent (with diameter of inhibition zone 25 mm) against Proteus mirabilis. Enterobacter aerogenes with (15mm) of inhibition zon, E.coli did not show any inhibition zone also the aqueous and ethanolic of rosemarinus officinalis extracts and aqueous of Syzygium aromaticum extracts did not show any activity towards any gram negative bacilli also the results of the study show resistance isolates of E.coli and Proteus mirabilis toward several antibiotic while Enterobacter aerogenes is sensitive for more antibiotics that used in this study. Conclusions: Our study concluded that the extract of Syzygium aromaticum has high potential as antibacterial agent against UTI that caused by Proteus mirabilis, clove (syzygium aromaticum) can be used in pharmaceutical for the production of new synthetic agents. There is an increasing interest in phytochemicals as new sources of natural antioxidant and antimicrobial agents. The natural compounds which have biological activities are interest to pharmaceutical industries especially for treatment of human disease of microbial origin and several pathological disorders such as cancergenesis, coronary atherosclerosis, as well as in ageing processes.

Phytofabrication of biocompatible chitosan-based ZnO nanocomposite aided by Cissus quadrangularis extract enriched with antimicrobial and antioxidant potential

A dynamic chitosan-based ZnO nanocomposite (NC) was fabricated via a cost-effective formulation and an eco-friendly procedure utilizing Cissus quadrangularis (CQ) plant extract. This study investigates the antimicrobial and antioxidant properties, together with the cytocompatibility aspects of chitosan-incorporated ZnO nanocomposite (CS-ZnO/CQE). The formation and structural morphology of the nanocomposites were examined using FTIR, UV–Vis, XRD, XPS, BET, TGA, SEM, and TEM techniques. The antibacterial test results demonstrated the greatest inhibitory zone diameter against S. aureus (19 ± 1.00 mm) and E. coli (17 ± 1.05 mm), assessed through agar well diffusion method. Also, the composite exhibited a DPPH inhibition rate of 78.7 ± 0.34 %, indicating its high effectiveness in neutralizing free radicals. In addition, the nanocomposite exhibited less toxicity towards human erythrocytes, HDF and HEK-293 cells as a result of the biocompatibility exhibited by CS, ZnO, and CQ plant extract. Likewise, it has exceptional cell migratory capacity and possesses biodegradability factors. These observations strongly suggest the potential of CS-ZnO/CQE as a cutting-edge antibacterial and antioxidant agent to be implemented in the medical sector.

Synthesis and characterization of lemon leaf extract-mediated silver nanoparticles: An environmentally friendly approach with enhanced antibacterial efficacy

In this study, silver nanoparticles were synthesized using lemon leaf extract, which served as both a reducing and stabilizing agent. The synthesis process proved to be rapid, cost-effective, and environmentally friendly. The effect of the mixing ratio of the reactants was investigated. Optimal yield, approximately 70 %, was achieved at 60 °C with a 0.25 M silver nitrate solution interacting for 40 min with lemon leaf extract in a 1:1 (v/v) ratio. Confirmation of nanoparticle formation was achieved through visible color change, UV–visible spectra (UV–Vis), X-ray diffraction analysis (XRD), Fourier transform infrared spectra (FT-IR), zeta potential, scanning electron microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), and transmission electron microscopy (TEM). The UV–Vis spectrum of the aqueous medium containing silver nanoparticles showed an absorption peak at around 412 nm. FT-IR spectra had shown that the biomolecule compounds were responsible for the reduction and capping material of silver nanoparticles. The XRD study showed the particles displayed an average crystallite size ranging from 9.4 to 36 nm. SEM and TEM showed a face-centered cubic (FCC) structure with an average size of 34 nm. The stability was detected using zeta potential analysis. These nanoparticles were used as antibacterial agents against Escherichia coli and Methicillin-resistant Staphylococcus aureus (MRSA), and the effect of silver nanoparticle concentration was investigated. The results indicated the synthesized silver nanoparticles demonstrated significant antibacterial activity against E. coli and MRSA, with average inhibition zone diameters exceeding 17 mm for E. coli and 15 mm for MRSA. Remarkably, antimicrobial activity was observed against two tested microbes at extremely low concentrations of 1–3 mM of silver nanoparticles.

Porous Chitosan/Hydroxyapatite Composite Microspheres for Vancomycin Loading and Releasing.

Porous chitosan/hydroxyapatite (Chi-HAp) composite microspheres were prepared in an aqueous solution containing chitosan, calcium nitrate, and ammonium dihydrogen phosphate by using a hydrothermal method at various temperatures. The investigation indicated that temperature significantly impacted the final product's appearance. Hydroxyapatite (HAp) coupled with dicalcium phosphate dihydrate (DCPD) flakes were obviously found at 65 and 70 °C, while the latter gradually disappeared at higher temperatures. Conversely, synthesis at 90 °C led to smaller particle sizes due to the broken chitosan chains. The microspheres synthesized at 75 °C were selected for further analysis, revealing porous structures with specific surface areas of 36.66 m2/g, pores ranging from 3 to 100 nm, and pore volumes of 0.58 cm3/g. Vancomycin (VCM), an antibiotic, was then absorbed on and released from the microspheres derived at 75 °C, with a drug entrapment efficiency of 20% and a release duration exceeding 20 days. The bacteriostatic activity of the VCM/composite microspheres against Staphylococcus aureus increased with the VCM concentration and immersion time, revealing a stable inhibition zone diameter of approximately 4.3 mm from 24 to 96 h, and this indicated the retained stability and efficacy of the VCM during the encapsulating process.

Assessment and Characterization of Lactic Acid Bacteria Isolated from Fermented African oil Bean Seed (Pentaclethra macrophylla) for Probiotic Application

Among the bacteria in fermented foods, lactic acid bacteria play a pivotal role and its main function is to convert carbohydrates and other related raw materials into lactic acid (organic acid). Therefore, the aim of this research was to assess and use lactic acid bacteria isolates obtained from fermented African oil bean seeds as probiotics. Lactic acid bacteria were isolated using MRS agar and screened for organic acid production and the ability to tolerate some environmental conditions such as temperature, pH, and osmotic pressure. The use of the isolates as probiotics was investigated by screening and determining the antimicrobial inhibitory zone diameter of the isolates obtained against the indicator microorganisms such as Staphylococcus aureus, Bacillus cereus, Escherichia coli and Listeria monocytogenes. Results show that isolate2, isolate3, isolate5, isolate6, isolate7 and isolate8 were able to produce organic acid. Out of the six bacterial isolates tested for antimicrobial activities against the indicator microorganisms, isolate2, isolate3, isolate6 and isolate8 were able to show antimicrobial activities against Staphylococcus aureus, Bacillus cereus, Escherichia coli and Listeria monocytogenes using different dilutions (10- 1 to 10- 3) of the isolates. The isolates were able to grow at temperatures of 37oCand 45oC; pH of 2.5, 3.0, 3.5 and 4.0; finally the osmotic pressure of 1.0, 1.5, 2.5 and 5.0 % w/v NaCl. The isolates were identified as Lactobacillus species and can be used as probiotics.

Phytochemical Profile and Antibacterial Activity of Nigella Sativa against Biofilm-producing Bacteria Uropathogens

This study explores the antibacterial effects of Nigella sativa seeds on bacteria obtained from clinical samples. The aim was to assess the antibacterial properties of both aqueous and methanolic extracts of Nigella sativa seeds against E. coli, S. aureus, and P. aeruginosa. The three samples were collected from the Microbiology Laboratory of Modibbo Adamawa Medical Centre and were reconfirmed using culture, microscopy, and some biochemical tests. The seed samples of N. sativa were procured from herbal point Yola, Adamawa State, Nigeria. The phytochemical assay of the extracts revealed the presence of flavonoids, alkaloids, tannins, phenols, cardiac glycosides, steroids, saponins, and terpenoids in both extracts. The highest antibacterial activity against S. aureus, E. coli, and P. aeruginosa was demonstrated by the aqueous extract of N. sativa seeds, with inhibition zone diameters of 19.30 ±0.61 mm, 8.10 ±2.17 mm, and 12.00 ±0.29 mm, respectively. However, the methanol extract exhibited slightly greater activity against E. coli and P. aeruginosa, with inhibition zone diameters of 12.10 ±0.38 mm and 13.80 ±0.40 mm, respectively. Both methanol and aqueous extracts showed minimum inhibitory concentrations (MICs) of 25 mg/mL against S. aureus and E. coli. Similarly, for P. aeruginosa, the MIC was 25 mg/mL for methanol extract and 50 mg/mL for aqueous extract. The minimum bactericidal concentration (MBC) for both extracts against S. aureus and E. coli was determined to be 25 mg/mL. However, for P. aeruginosa, the MBC was 25 mg/mL for the aqueous extract and 50 mg/mL for the methanol extract. The study indicates that N. sativa seed extract possesses antibacterial properties against S. aureus and P. aeruginosa, underscoring its potential as an effective medicinal antibacterial agent.

Fabrication of gelatin-based antibacterial bilayer wound dressing using direct writing and electrospinning methods

Fabricating a fibrous well-ordered wound dressing for accelerating full-thickness wounds is a desirable treatment vector. Here, through modifications in the material extrusion device and adding a pneumatic-based injection, a material extrusion method for gelatin was introduced with the ability to fabricate 3D structure with repeat layers to support cell activity for the under layer. Furthermore, in the upper layer, the co-electrospinning of PU with gelatin was designed to simultaneously exploit the oxygen permeability and mechanical stability of PU with regenerative properties and collagen-like structure of gelatin. Moreover, zinc oxide nanoparticles (ZnO) was added into the 3D-printed under layer to synergistically benefit from the antibacterial properties of ZnO and the excellent biocompatibility of gelatin. The controllable porosity of the under layer, enabled through the additive manufacturing method, was adjusted to mimic the extracellular matrix of natural tissue with around (127.28 ± 20.70) μm pore size after swelling with smooth fibers. S. aureus, E. coli, Bacillus subtilis, and Pseudomonas with inhibition zone diameters at ∼ 2.14 cm and ∼ 1.96 cm, ∼ 4.01 cm, and ∼ 2.24 cm, respectively. Moreover, the scaffold showed great biocompatibility toward fibroblast cells after 7 days of cell culture with ∼ 89 % cell viability.

Helicobacter pylori Growth and Urease Inhibition by Cranberry (Vaccinium macrocarpon) Extract: a Pilot Study

The aim of the study was to evaluate the activity of three cranberry (Vaccinium macrocarpon) ethanol solutions on Helicobacter pylori growth and urease activity. We included numerous clinical Helicobacter pylori isolates and three methods: agar well diffusion method (AWDM), disk diffusion method (DDM) and urease inhibition test (UIT). The results were expressed as differences in inhibitory zone diameters (AWDM and DDM) or urease inhibition duration (UIT) by cranberry solutions compared to the ethanol control. AWDM showed that 400, 40 and 4 mg/l cranberry extracts inhibited the growth of 82.1, 57.1 and 42.8% of the isolates, respectively, while DDM at the highest cranberry concentration suppressed only 39.3% of the isolates. At 400, 40 and 4 mg/l, cranberry extracts also inhibited urease activity of 63.6, 54.5 and 40.9% isolates within 10 min, but of fewer isolates (18.2, 13.6 and 9.1%, respectively) at the 45th min. Although cranberry activity was dose- and strain-dependent, it affected more than half of the isolates at the two highest concentrations. DDM was less effective in detecting this activity. The cranberry extracts also inhibited the urease activity of H. pylori; however, in most cases, the inhibition was only temporary. Briefly, the high cranberry activity against H. pylori, together with its anti-adhesive, antioxidant, anti-biofilm and anti-cancer properties, justifies its use for prophylaxis or adjunctive treatment of chronic H. pylori infection. Importantly, UIT results suggest the benefit of regular cranberry intake over random intake.