Formation Of Inhibition Zones Research Articles

Next-generation membranes for verapamil removal: Graphene oxide quantum dot-modified polyethersulfone membranes

The presence of verapamil in water sources has gained attention due to its potential risks to ecosystems and human health. Because of its great separation performance and simplicity of integration into existing treatment processes, membrane filtration could be a viable alternative. Polyethersulfone (PES) membrane is usually employed for filtration processes due to its good mechanical and thermal stability. However, pristine PES membrane exhibits low flux and lower fouling properties due to its poor antibacterial properties. Thus, the phase inversion approach was used in the current study to develop graphene oxide quantum dots (GOQDs)-modified PES ultrafiltration (UF) membranes with varying quantities of GOQDs loading (0.01–0.07 wt%). With 0.03 wt% GOQDs, the PES composite membrane exhibited a water flux of 75.23 ±10.43 L/m2 h with a verapamil retention capability of 80.36%. All the modified PES membranes containing GOQDs exhibited the formation of inhibition zones, with PES-0.07 membranes (21.00 mm) showing more pronounced zones. The incorporation of GOQDs proved to be a promising and sustainable approach for modifying PES membranes, enhancing their flux, rejection performance, and antibacterial properties, which could be beneficial in removing pharmaceutical compounds from aqueous solution.

Mechanical activation and silver supplementation as determinants of the antibacterial activity of titanium dioxide nanoparticles

Metals and metal oxides have subpar antibacterial activities compared to those of small-molecule antibiotics, yet there are hopes that with proper compositional and structural adjustments this gap might be bridged. In this study, titanium dioxide (TiO2) nanoparticles were mechanically activated and combined with particulate silver through simple reduction process elicited by UV irradiation and assisted with the ultrasound. The resulting powders in various combinations (Ag vs. no Ag, activated vs. non-activated) were characterized using a range of experimental techniques and assessed for their antibacterial activities. The preparation procedure presented in this work prevails over the disadvantages of many chemical routes, most critically by avoiding the use of toxic substances. The mechanical activation did not reduce the particle size or crystallinity of TiO2 nor did it consistently alter the bandgap, yet it enabled the doubling of the amount of silver incorporable into the material. Further, while both mechanical activation and the addition of silver in the amount not exceeding 0.5 wt% produced barely detectable structural changes in the material, they both augmented its antibacterial activity. The precursor TiO2 powder produced no inhibition zone against any of the four bacterial species tested, while the mechanical activation of TiO2 led to the formation of distinct inhibition zones against each of the four bacterial species tested. The addition of silver to activated TiO2 further widened the inhibition zones and it also imparted the antibacterial activity to non-activated TiO2. The boost in the antibacterial activity achieved by the short mechanical activation was of a similar magnitude as the boost obtained after the addition of silver. The antibacterial activity was not different for different species when no silver was added to the system. However, with the addition of silver, species selectivity was obtained, as the composites were more effective against the two Gram-negative species (Escherichia coli and Klebsiella pneumoniae) than against the two Gram-positive ones (Staphylococcus aureus and Bacillus subtilis). The antibacterial activity increased with the addition of silver in the broth assay, but it was mediocre compared to that detected in the agar assay, attesting to the poor dispersability of the powders and their best performance when the bacterial cells migrate to the composite surface than vice versa. The findings of this study give hope that with appropriate microstructural or compositional alterations, the antibacterial activity of metal oxide powders and inorganic materials in general can be made comparable to that of small-molecule antibiotics.

Phytosynthesis of zinc oxide nanoparticles for enhanced antioxidant, antibacterial, and photocatalytic properties: A greener approach to environmental sustainability

Multifunctional nanoparticles (NPs) production from phytochemicals is a sustainable process and an eco-friendly method, and this technique has a variety of uses. To accomplish this, we developed zinc oxide nanoparticles (ZnONPs) using the medicinal plant Tinospora cordifolia (TC). Instruments such as UV–Vis, XRD, FTIR, FE-SEM with EDX, and high-resolution TEM were applied to characterize the biosynthesized TC-ZnONPs. According to the UV–vis spectra, the synthesized TC-ZnONPs absorb at a wavelength centered at 374 nm, which corresponds to a 3.2 eV band gap. HRTEM was used to observe the morphology of the particle surface and the actual size of the nanostructures. TC-ZnONPs mostly exhibit the shapes of rectangles and triangles with a median size of 21 nm. The XRD data of the synthesized ZnONPs exhibited a number of peaks in the 2θ range, implying their crystalline nature. TC-ZnONPs proved remarkable free radical scavenging capacity on DPPH (2,2-Diphenyl-1-picrylhydrazyl), ABTS (2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid), and NO (Nitric Oxide). TC-ZnONPs exhibited dynamic anti-bacterial activity through the formation of inhibition zones against Pseudomonas aeruginosa (18 ± 1.5 mm), Escherichia coli (18 ± 1.0 mm), Bacillus cereus (19 ± 0.5 mm), and Staphylococcus aureus (13 ± 1.1 mm). Additionally, when exposed to sunlight, TC-ZnONPs show excellent photocatalytic ability towards the degradation of methylene blue (MB) dye. These findings suggest that TC-ZnONPs are potential antioxidant, antibacterial, and photocatalytic agents.

Effectiveness of Cellulose Acetate Nanofiber from Banana Leaf Waste (Musa paradisiaca L.) as an Antibacterial Filter in Masks

The COVID-19 pandemic requires all people in Indonesia to comply with health protocols, from washing hands to wearing masks. Cloth masks are one of the masks that are widely used by the community. However, the public needs to pay attention to the rules of the cloth masks used. The purposes of this study were to produce an antibacterial filter on masks and to find out the effective and efficient processing of banana stems as an antibacterial filter on masks. Banana stems were chosen as the raw material because it is easy to obtain, has a cellulose content of ± 63%, and has antibacterial compounds in it. The stages of this research were sample preparation, phytochemical screening of banana stems, isolation of α-cellulose and synthesis of cellulose acetate from α-cellulose which were further characterized by using FTIR, manufacture of dop solution, manufacture of nanofiber membranes by electrospinning, and product application. The resulting product was then tested by pressure drop test, contact angle test, antibacterial activity test, SEM test, and porosity test. The test results showed that the resulting product was a nanofiber with a fiber diameter of ± 220.74075 nm, had antibacterial activity which was indicated by the formation of inhibition zone with a diameter of ± 14.8 mm in Escherichia coli and ± 9.8 mm in Staphylococcus. aureus, the filter is hydrophilic with an average contact angle of 60°. From the observations, it can be concluded that banana stems have the potential as an antibacterial filter on masks.

Antibacterial Activity Edible Coating of Jackfruit Seed Starch and Alginate Incorporated with ZnO Nanoparticles Applied to Cherry Tomatoes

Cherry tomatoes have many health benefits and have high economic value. However, cherry tomatoes are perishable and short lived. To protect and maintain the quality of cherry tomatoes, you can apply an edible coating. The materials used in this study were jackfruit seed starch, alginate, and ZnO nanoparticles. This study aims to determine the effect of edible coating on jackfruit seed starch and alginate incorporating ZnO nanoparticles applied to cherry tomatoes in terms of antibacterial activity and shelf life. Variations in the treatment in this study were edible coating materials for jackfruit seed starch and alginate, and the concentration of ZnO nanoparticles (0%; 5%; 10%; 15%). Antibacterial activity was analyzed against E. coli and S. aureus bacteria. The results showed that the edible coating of jackfruit seed starch with 10% and 15% ZnO nanoparticles incorporation was able to form an inhibition zone against E. coli bacteria, while the 5%, 10%, and 15% ZnO nanoparticle variations were able to form an inhibition zone against S bacteria. aureus. In edible coating alginate with 15% ZnO nanoparticles incorporation was able to form an inhibition zone against E. coli bacteria, whereas in all variations of ZnO nanoparticles it was able to form an inhibition zone against S. aureus bacteria. The addition of ZnO nanoparticles proved the formation of a larger bacterial inhibition zone compared to edible coatings without ZnO nanoparticles. The results also showed that cherry tomatoes coated with an edible coating of jackfruit seed starch and alginate with a variation of ZnO nanoparticles had a longer shelf life compared to cherry tomatoes that were not coated with an edible coating.

Antibacterial Activity Test of Secang Wood (Caesalpinia sappan L.) Ethanol Extract Against Streptococcus mutans

Dental caries is caused by the Streptococcus mutans bacteria, which causes a food deposit to harden and adhere to the tooth surface. Cavities will develop if food residue is not removed. Herbal plants, specifically sappan wood, can be used as an antibiotic. The purpose of this study was to look at the secondary metabolite content of sappan wood extract, antibacterial activity, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of sappan wood extract against Streptococcus mutans bacteria. This research method includes the maceration of sappan wood extract with 96% ethanol solvent, phytochemical screening of sappan wood extract, inhibition zone test with paper disc method, and MIC and MBC tests. Qualitative testing revealed that the sappan wood extract contained alkaloids, flavonoids, tannins, and saponins. Flavonoids, tannins, and saponins are all constituents of plants. Secang wood extract has antibacterial activity against Streptococcus mutans, as evidenced by the formation of inhibition zones at concentrations of 20%, 40%, 60%, 80%, and 100%, namely 8.75±0.354; 11±1.41;, 12.75±0.354; 16.25±0.354; and 17.5±0.000 mm. Sappan wood ethanol extract had a MIC of 12.5% against Streptococcus mutans and an MBC of 25%.

Cell-free supernatant of probiotic bacteria exerted antibiofilm and antibacterial activities against Pseudomonas aeruginosa: A novel biotic therapy.

Aim: This study aims to verify the antibacterial and antibiofilm action of cell-free spent medium (CFSM) from four lactic acid bacteria with potential probiotic characteristics (Lactiplantibacillus plantarum, Lactobacillus acidophilus, Lactobacillus johnsonii, and Lactobacillus delbrueckii) against two Pseudomonas aeruginosa strains. Main methods: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the CFSM, antibacterial activity by analysing the formation of inhibition zones, and inhibition of planktonic cultures were determined. Whether an increase in the concentration of CFSM influenced the growth of pathogenic strains and the anti-adhesive activity of the CFSM in biofilm formation (crystal violet and MTT assays) were determined, which were all corroborated by using scanning electron microscopy. Key findings: The relationship between the MIC and MBC values showed a bactericidal or bacteriostatic effect for all the cell-free spent media (CFSMs) tested for P. aeruginosa 9027™ and 27853™ strains. The CFSM supplemental doses of 18 or 22%, 20 or 22%, 46 or 48%, and 50 or 54% of L. acidophilus, L. delbrueckii, L. plantarum, and L. johnsonii, respectively, could completely inhibit the growth of both pathogen strains. The antibiofilm activity of the CFSM in three biofilm conditions (pre-coated, co-incubated, and preformed) demonstrated values ranging between 40% and 80% for biofilm inhibition, and similar results were observed for cell viability. Significance: This work provides strong evidence that the postbiotic derived from different Lactobacilli could be practical as an adjuvant therapy for reducing the use of antibiotics, being a good candidate to overcome the growing challenge of hospital infections due to this pathogen.

Identifikasi Senyawa Aktif Antibakteri dari Ekstrak Bajakah (Spatholobus Littoralisk Hask) dengan GCMS (Gass Chromatography Mass Spectroscopy)

Bajakah wood (Spatholobus Littoralisk Hask) is empirically used by the community to treat stomach pain, diarrhea and is even believed to be able to treat cancer. Several studies have shown its activity as an antibacterial. The purpose of this study was to identify compounds with antibacterial properties using Gas Chromatography Mass Spectroscopy (GCMS). The method used in this research is the experimental method. Bajakah plants were obtained from seven different areas, then extracted and fractionated. The fraction identified in this study was the n-hexan fraction. Preliminary tests were carried out using thin layer chromatography (TLC) bioautography for compounds that have the potential as antibacterial. Compounds in the n-Hexan fraction were further identified using Gass Chromatography Mass Spectroscopy (GCMS). The results showed Bajakah wood from seven regions had antibacterial activity seen from the formation of inhibition zones on compound spots on TLC that had been planted in agar media. There are 23 types of compounds identified by GCMS in this n-hexan fraction. In this study, the dominant compound seen from the largest area was Stigmast-5-en-3-ol, (3.beta.,24S)- (CAS) Clionaster (26.74%). The results of TLC bioautography of the n-Hexan fraction showed antibacterial activity and the dominant compound was Stigmast-5-en-3-ol, (3.beta.,24S)- (CAS) Clionaster.

Effectiveness Test of Okra Fruit (Abelmoschus esculentus) Extract on The Growth of Trichophyton rubrum

Dermatophytosis is an infectious disease of the skin caused by one of the pathogenic agents of the fungus Trichophyton. Trichophyton rubrum is a dermatophyte fungus that is included in the anthropophilic classification, where transmission occurs through direct human-to-human contact. This experiment was conducted to determine the effectiveness of giving okra fruit extract (Abelmoschus esculentus) to the growth of Trichophyton rubrum using well method, media that is used to do that is SDA (Sabouraud Dextrose Agar) with various concentrations of 25 %, 50%, 75%, 100%. Based on the results of phytochemical tests, the active compounds contained in okra fruits extract are alkaloids, flavonoids, saponins, steroid, triterpenoids, phenolics and tannins. Variations in concentration of okra fruit extract and negative control tested against Trichophyton rubrum did not show the formation of inhibition zones in the media. Meanwhile for positive control using 2% ketoconazole, an inhibition zone 35 mm was formed. This research showed that Trichophyton rubrum was resistant to okra fruit extract.

Polysaccharides as Green Fuels for the Synthesis of MgO: Characterization and Evaluation of Antimicrobial Activities.

The synthesis of structured MgO is reported using feedstock starch (route I), citrus pectin (route II), and Aloe vera (route III) leaf, which are suitable for use as green fuels due to their abundance, low cost, and non-toxicity. The oxides formed showed high porosity and were evaluated as antimicrobial agents. The samples were characterized by energy-dispersive X-ray fluorescence (EDXRF), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The crystalline periclase monophase of the MgO was identified for all samples. The SEM analyses show that the sample morphology depends on the organic fuel used during the synthesis. The antibacterial activity of the MgO-St (starch), MgO-CP (citrus pectin), and MgO-Av (Aloe vera) oxides was evaluated against pathogens Staphylococcus aureus (ATCC 6538P) and Escherichia coli (ATCC 8739). Antifungal activity was also studied against Candida albicans (ATCC 64548). The studies were carried out using the qualitative agar disk diffusion method and quantitative minimum inhibitory concentration (MIC) tests. The MIC of each sample showed the same inhibitory concentration of 400 µg. mL-1 for the studied microorganisms. The formation of inhibition zones and the MIC values in the antimicrobial analysis indicate the effective antimicrobial activity of the samples against the test microorganisms.

Amoxicillin doped hyaluronic acid/fucoidan multifunctional coatings for medical grade stainless steel orthopedic implants

This work investigated the potential of amoxicillin-doped hyaluronic acid/fucoidan multifunctional coatings on medical grade stainless steel as biocompatible, osteointegration enhancing, antimicrobial, and bacterial biofilm inhibiting coatings for orthopedic implants. The coatings were prepared by layer-by-layer spin coating and confirmed by optical contact angle goniometry and infrared spectroscopy. Time-of-flight secondary ion mass spectrometry showed a homogeneous distribution of the individual layers. In contrast, thermal diffusivity, and thermal conductivity measurements by photothermal beam deflection spectrometry showed diffusion of the amoxicillin into the hyaluronic acid and fucoidan layers. In vitro release of amoxicillin showed complete release within one hour, as reflected by the formation of inhibition zones against Staphylococcus aureus and Escherichia coli. Synergistic effects were observed between the hyaluronic acid and amoxicillin in inhibiting S.Aureus biofilm, and between the fucoidan and amoxicillin in improving the antioxidant properties by an ABTS radical scavenging assay. Biocompatibility was determined with human osteoblasts, confirming the potential of such multifunctional coatings to enhance the bioactivity of steel-based orthop edic implants.

Antibacterial Activities of Ni Substituted Ferrite Particles for Biological Applications

In this research work Mg0.45Mn0.55-xNixFe2O4 ferrite particles of varying compositions (x=0.05, x=0.15, x=0.25, x=0.45 and x=0.55) were synthesized using cost effectual co-precipitation route. The synthesized ferrite particles were characterized by collection of techniques. XRD analysis confirmed the formation of cubic spinel structure of the ferrite particles. SEM and AFM analyses illustrated the morphology and size distribution of obtained ferrite particles. FT-IR study exposed that the absence of any additional peak related to second phase. VSM results indicated magnetic analyses such as saturation magnetization (MS), Coercivity (HC) and Remanence (Mr) of ferrite particles. The major objective of the present investigation is to synthesize MgMnNiFe2O4 ferrite particles on cotton fabrics in order to obtain finished fabrics; it is very significant in biological applications. The antibacterial activities of the ferrite particles coated cotton fabrics were tested against selected Gram positive and Gram negative bacteria which showed tremendous results via formation of inhibition zones. The fabricated ferrite particles on cotton fabrics showed great durability evidenced by their antibacterial activities even after 20 washing cycles. Hence, the functionalized cotton fabrics could be used as potential antibacterial agent.

Antibacterial actifity of kecombrang (Etlingera elatior) leaf ethanol extract to against Klebsiella pneumoniae

Infectious diseases caused by bacteria in generals can be cured using antibacterial. The use of antibacterials tends to cause local hypersensitivity either on the skin or mucous membranes so that their use is starting to be reduced. Therefore, the development of natural antibacterials made from plants to reduce resistance is very necessary. kecombrang (Etlingera elatior) is one of the plants that has been shown to have activity in inhibiting bacterial growth. This research is an experimental study that aims to determine the effectiveness of the ethanol extract of the leaves of kecombrang in inhibiting the growth of Klebsiella pneumoniae bacteria in vitro. The method used is the well method with a completely randomized design. The sample came from the Klebsiella pneumoniae bacteria culture. Kecombrang leaf ethanol extract was made in concentrations of 20%, 40%, 60%, 80% and 100%. The extract was tested on Klebsiella pneumoniae bacteria and observed for the formation of inhibition zones. Inhibition the results of the zone measuremens were then analyzed descriptively. The results showed kecombrang leaf ethanol extract 20%, 40%, 60%, 80%, and 100% produce inhibition zone diameter 1.9 mm; 2.6 mm; 7.7 mm; 12.1 mm; and 14.7 mm, 0.4 mm for the negative control and positive control 22.0 mm. Concentration 100% has better antibacterial ability due to higher compound content. The test results show the class of secondary metabolites kecombrang leaf ethanol extract contains flavonoids, tannin, and saponin. The conclusion of this study that the ethanol extract of kecombrang leaves has potential to inhibit the growth of Klebsiella pneumoniae bacteria.

Multi-physics simulation and experimental study of the reaction kinetics process of oxygen inhibition zone formation in constrained-surface stereolithography process

In this paper, based on the mechanism of oxygen inhibiting the curing of acrylate-based monomers, the reaction kinetics model for the formation of the oxygen inhibition zone is established. This model is applied to study the variation of the thickness of the oxygen inhibition zone with the process parameters and the microscopic characteristics of the constrained substrate with the PDMS film as the oxygen permeation window. Experiments are performed on substrates with different micropore area ratios, and the experimental results are in good agreement with the simulation. The research results show that the thickness of the oxygen inhibition zone can be up to 28 µm while the thickness of cured layer can be over 140 µm. The thickness of the oxygen inhibition zone increases with the increasing PDMS film diffusion coefficient, oxygen concentration, constrained substrate area ratio, and micropore size, but decreases with the increasing light intensity, photoinitiator concentration, and PDMS film thickness. When the micropore area ratio are too small, or the micropore diameter is too large under the same area ratio, an obvious periodic microstructure will appear on the surface of the cured layer, affecting the quality of the cured layer surface. The reaction kinetics multi-physics model for the formation of inhibition zone in constrained-surface stereolithography process has been established, considering the photopolymerization reaction kinetics and the effect of oxygen polymerization inhibition, as well as the influence of the substrate’s micropore array and PDMS film’s characteristics on oxygen mass transfer during polymerization. The effects of factors such as the microscopic characteristics of the substrate and the oxygen diffusion coefficient of the PDMS film on the inhibition zone have been investigated. Photopolymerization experiments are performed on substrates with different micropore area ratios, and the experimental results are in good agreement with the simulation. The research results show that the thickness of the oxygen inhibition zone can be maintained at 28 µm under reasonable control parameters, while the thickness of cured layer can be over 140 µm, meeting the requirement of achieving the minimum oxygen inhibition zone for continuous printing. • The reaction kinetics multi-physics model for the formation of inhibition zone has been established. • The effects of factors on the inhibition zone have been investigated. • Photopolymerization experiments are performed and the experimental results are in agreement with the simulation. • The optimized parameters meet the requirement of achieving the minimum oxygen inhibition zone for continuous printing.

Incorporation of 45S5 bioglass via sol-gel in β-TCP scaffolds: Bioactivity and antimicrobial activity evaluation

In this work, β-TCP (β-tricalcium phosphate) bioresorbable scaffolds were prepared by the gel casting method. Then, they were impregnated with a 45S5 bioglass sol gel solution to improve biocompatibility and promote bioactivity and antimicrobial activity. The β-TCP scaffolds had an apparent porosity of 72%, and after the incorporation of the bioglass, this porosity was maintained. The elements of the bioglass were incorporated into β-TCP matrix and there was a partial transformation from the β-TCP phase to the α-TCP (α-tricalcium phosphate) phase, besides the formation of bioactive calcium and sodium‑calcium silicates. The scaffolds β-TCP with 45S5 bioglass incorporated (β-TCP/45S5) did not show a reduction in their values of mechanical strength and Weibull modulus, despite the partial transformation to the α-TCP phase. Bioactivity, cell viability, and antimicrobial activity improved significantly for the β-TCP/45S5 scaffold comparing to the scaffold without the bioglass. The mineralization of carbonated hydroxyapatite was verified in Simulated Body Fluid (SBF). The cell viability, evaluated by the reduction of 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide – MTT in MG63 cells, increased by 178%, and β-TCP/45S5 scaffold also enhanced cell activity and osteoblast differentiation observed by means of total protein contend and alkaline phosphatase activity, respectively. The formation of growth inhibition zones was also observed in the disk diffusion assay for three tested microorganisms: Staphylococcus aureus, Escherichia coli and Candida albicans. To conclude, the vacuum impregnation method in 45S5 bioglass sol gel solution was effective in penetrating all the interconnected macroporosity of the scaffolds and covering the surface of the struts, which improved their biological properties in vitro, bioactivity and antibacterial activity, without reducing mechanical strength and porosity values. Thus, the β-TCP/45S5 scaffolds are shown as potential candidates for use in tissue engineering, mainly in bone tissue regeneration and recovery.

Antibacterial activity test on ethanol extract fraction of Kirinyuh (Chromolaena odorata L.) leaves for multi-drug resistant organisms bacteria

The resistance of pathogenic bacteria to antibiotics is increasing due to antibiotics with incorrect doses, wrong diagnostics, and the wrong target. Bacteria that have been resistant to several antibiotics are called multi-drug resistant organisms (MDRO) bacteria. Bacterial resistance to some antibiotics requires alternative herbal treatments, one of which is the Chromolaena odorata L. Research must therefore be conducted on the antibacterial activity of the ethanol extract fraction of C. odorata L. leaves for MDRO bacteria, such as Staphylococcus lugdunensis methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa extended-spectrum beta-lactamase (ESBL), and Klebsiella pneumoniae ESBL. This study aims to determine the antibacterial activity of the ethanol extract of Kirinyuh leaves (C. odorata L.) and the antibacterial activity of the fractionation against MDRO bacteria. Test results of kirinyuh leaf ethanol extract for S. lugdunensis MRSA, P. aeruginosa ESBL, and K. pneumoniae ESBL bacteria each resulted in an inhibition zone with an average diameter of 11.6 mm (strong), 11.5 mm (strong), and 11.13 mm (strong), respectively. Testing the antibacterial activity of the ethanol fraction against MDRO bacteria can show antibacterial activity against all tested bacteria, namely Fraction 5. The results of the antibacterial activity of fraction 5 against K. pneumoniae ESBL, P. aeruginosa ESBL, and S. lugdunensis MRSA bacteria with the formation of inhibition zones formed of 10.2 mm (strong), 8.8 mm (moderate), and 7.9 mm (moderate), respectively. The results of thin-layer chromatography showed that the secondary metabolites contained in the fifth fraction were terpenoids, steroids, and flavonoids.

Microalgae produced during phycoremediation of swine wastewater contains effective bacteriostatic compounds against antibiotic-resistant bacteria

Studies on the antimicrobial effects of microalgae extracts are commonly reported using algae biomass grown in sterile synthetic mineral medium and controlled laboratory conditions. However, variations in environmental conditions and culture medium composition are known to alter microalgae biochemical structure possibly affecting the type and concentrations of bioactive compounds with antimicrobial properties. In this work, solvent extracts of the microalgae Chlorella spp. were tested for antimicrobial effects against gram-positive and multidrug resistant pathogenic bacteria Staphylococcus hyicus, Enterococcus faecalis and Streptococcus suis. Microalgae was cultivated at field scale open pond reactor using raw swine wastewater as growth substrate. Dichloromethane or methanol were used to obtain the microalgae extracts. Characterization of the extracts by ultra-high performance liquid chromatography-quadrupole mass spectrometry revealed the presence of 23 phytochemicals with recognized antimicrobial properties. Bacteriostatic activity was observed in plating assays by formation of inhibition zones ranging from 7 to 18 mm in diameter. Only dichloromethane extracts were inhibitory to all three model bacteria. The minimum inhibitory concentration assessed for dichloromethane extracts were 0.5 mg mL−1 for Staphylococcus hyicus and Enterococcus faecalis and 0.2 mg mL−1 for Streptococcus suis. Bactericidal effects were not observed using solvent-extracts at 2 or 5 mg L−1. To the best of authors knowledge, this is the first report on the antimicrobial effects of Chlorella spp. extracts against Staphylococcus hyicus and Streptococcus suis. Overall, Chlorella spp. grown on swine wastewater contains several phytochemicals that could be further explored for the treatment of infections caused by antibiotic-resistant bacteria pathogens.

Punica granatum L. extract contributes to phytopathogens control and enhances Eruca vesicaria (L.) Cav. germination in vitro and in vivo

The study aimed to investigate antimicrobial activity of the hydroalcoholic crude extract from the fruit peel of Punica granatum (Pp) and punicalagin compound (Pg) on phytopathogenic bacterial isolates and its potential use as a sustainable alternative in treatment of vegetable seeds. The antimicrobial activity in vitro was tested by agar well diffusion assay and through viability tests in liquid medium. In vivo treatment with Pp was tested on Eruca vesicaria seeds infected with Xanthomonas campestris pv. campestris. Pp induced the formation of large inhibition zones to the growth of the tested pathogens (35.33 mm – 6.66 mm), with dose-dependent effect. Viability tests confirmed the antimicrobial activity of the Pp on X. campestris pv. campestris and P. carotovorum subsp. carotovorum with minimum inhibitory concentration (MIC) of 125 μg/mL. Punicalagin compound presented MIC of the 31.25 μg/mL. The seed treatment with Pp indicated control of pathogen-induced symptoms in seedlings of the E. vesicaria and positive effect in seed germination, emergence and in stomatal functionality. The results indicate strong potential of the extract from the fruit peel of P. granatum and Punicalagin for formulating botanical pesticides for plant disease control.

The Antifungal Effect of WHO Hand Sanitizer to Candida Albicans in Improving Personal Hygiene

Hand hygiene is one of the important factors that determine a person's health status. Hands are easily contaminated by microbes from the environment such as bacteria, viruses, and fungi through direct contact. Hand sanitizer is a type of media that can be used to clean hands from disease-causing microbes other than soap. Hand sanitizers are widely used by the community because they are considered more practical to use. This study aims to determine the anti-fungal activity of the hand sanitizer recommended by the World Health Organization (WHO) against Candida albicans. Anti-fungal activity was tested using the well diffusion method. The results showed that the higher the concentration of the hand sanitizer, the bigger the inhibition zone formed. The statistical test results obtained a significance value of p <0.05 at the variation of the concentration of hand sanitizer 50%, 75%, 100%, and treatment control. These results indicate that there is a significant difference between the hand sanitizer treatment and control of the inhibition zone formation in C. albicans. The WHO recommended hand sanitizer has medium inhibitory power against C. albicans bacteria.

Antimicrobial Activity of Non-bond Colicin on Candida albicans Biofilm

Two hundred fifty mid-stream urine specimens were collected from Baqubah Teaching Hospital and Al-Batool Teaching Hospital from patients with urinary tract infections (UTI). Of these investigated urine specimens, 66 (26.4%) specimens showed positive growth culture of Gram-negative bacteria. From these, Escherichia coli was the most prevalent bacteria of the examined culture (41, 62.12%). Additionally, the cup assay was used to determine colicin producers while the most efficient colicin producers were estimated by the formation of larger inhibition zone. Approximately half of the investigated E. coli isolates (20, 49 %) was colicin producers. Colicins was extracted after induction by mitomycin-C showed a concentration of 3020 μg/ml, as estimated utilizing the Lowry method, while its activity was 80 U/ml. Our study results showed that colicin had significant antibiofilm activity (P≤ 0.05) against Candida albicans and the effect seemed to be concentration dependent. . However, the values of biofilm inhibition varied depending on the different tested isolates. The biofilm of isolate 5 showed the most significant inhibition (P≤ 0.05) by colicin with a value of 46%, while isolate 3 was less affected with an inhibition rate of 19% at the concentration of 2500 μl/ml.