Inhibition Zone Diameter Research Articles

Genetic identification of methicillin resistant Staphylococcus aureus (MRSA) isolated from diabetic foot ulcers and evaluating the inhibition activity of reuterin against this bacteria.

To genetically diagnose the isolates of methicillin-resistant staphylococcus aureus taken from patients with severe diabetic foot infections, and to test the inhibitory effect of reuterin on the growth of these bacteria. The experimental study was conducted from June to November 2021 at the Diabetes Unit of Al-Faihaa General Hospital, Basrah, Iraq, and comprised 62 foot ulcer swabs from the necrotic lesions of patients with type 2 diabetes. The swabs were cultivated first in brain heart infusion broth media, and then streaked on Mannitol salt agar and staphylococcus chromogeneic agar media for phenotypic and genetic analysis. The genetic identification of bacteria was confirmed by deoxyribonucleic acid extraction, and methicillin-resistant staphylococcus aureus was confirmed by the presence of plasmid mecA gene. The inhibition activity of reuterin towards methicillin-resistant staphylococcus aureus was determined using the minimum inhibitory concentration test. All data was analyzed with SPSS version 23. A total of 62 swabs were taken from the necrotic lesions of type 2 diabetes mellitus (T2DM) patients with diabetic foot ulcers. Of the total isolates, 9(14.5%) gave mauve to purple colour on staphylococcus chromogeneic agar, which was then genetically confirmed as methicillin-resistant staphylococcus aureus. The minimum inhibitory concentration value of these bacteria was 10μl/ml at 16mm inhibition zone diameter. There was no cytotoxicity of reuterin to human red blood cells. Reuterin was found to be a natural antimicrobial substance suitable for use to disinfect diabetic foot wounds from bacterial contamination and infection, especially those caused by methicillin-resistant staphylococcus aureus.

Facile two step approach of Chitosan/Nickel/ZrO2 bio-nanocomposite and investigation of their antimicrobial activities against Escherichiacoli

Chitosan nanoparticles (CH NPs), ZrO2, Ni/ZrO2. CH/ZrO2 and CH/Ni/ZrO2 complex have been synthesized then its antibacterial mechanisms of nanomaterials against Escherichia coli (E. coli) was evaluated by agar well diffusion and systematically analyzed by measuring the diameter of the inhibition zone. X-ray diffraction (XRD) patterns and Fourier transform infrared (FTIR) spectra and Energy dispersive X-ray (EDX) results demonstrated the formation of CH/Ni/ZrO2 matrix. Also, the crystalline sizes were found to be 15, 13, 10 and 8 nm for ZrO2, Ni/ZrO2, CH/ZrO2 and CH/Ni/ZrO2 respectively. The FTIR spectrum revealed bands ranging from 400 to 800 cm−1, indicating the presence of metal–oxygen bonds. Additionally, bands at 1620, 1523, and 1300 cm−1 suggested the presence of amide groups, confirming the presence of CH in the produced CH/Ni/ZrO2 nanocomposite. In SEM analysis, the irregular spherical nanoparticles are observed in case ZrO2 and CH/ZrO2 samples, while spherical with an oval-shaped structure are observed in case of Ni/ZrO2 and CH/Ni/ZrO2 sample. Mean diameter of inhibition zone were observed to be 13 ± 2.51, 12 ± 2.08, 16 ± 1.3 mm,17 ± 2.3 mm and 18 ± 0.8 nm for CH, ZrO2, Ni/ZrO2, CH/ZrO2 and CH/Ni/ZrO2 respectively. The eco-friendly and cost-effective synthesis of Chitosan assisted Ni/ZrO2 NPs can be utilized as an effective antibacterial agent.

Protein‐Based Polymeric Metal–Nanocomposite Derived From Egg Albumin: A Highly Effective Antimicrobial Agent Against Bacteria

ABSTRACTThe synthesis of four distinct protein‐based metal nanocomposites has been fabricated by employing egg albumin and zinc metal through a simple, straightforward two‐step method. The Fourier transform infrared (FTIR), X‐ray diffraction (XRD), and scanning electron microscopy (SEM) analyses confirmed the successful incorporation of zinc nanoparticles into the protein matrix and revealed an irregular microporous structure with average crystallite sizes of less than 100 nm. Thermal stability was assessed via thermogravimetric (TG) and derivative thermal gravimetry (DTG) analysis, revealing a notable increase in thermal stability in a high‐temperature range (300°C°C–700°C), suggesting remarkable stability at elevated temperatures. Antimicrobial efficacy against both gram‐positive (B. cereus and Lactobacillus spp.) and gram‐negative bacteria (E. coli and K. pneumoniae) was evaluated using paper disk diffusion, pour plate, and minimum inhibitory concentration (MIC) methods. All samples exhibited antibacterial efficacy, with zone of inhibition (ZOI) diameters ranging from 12 to 35 mm, and demonstrated a bactericidal effect by eliminating 93 to 98% of bacteria within 8 to 20 h at their MICs. Notably, protein–ZnO–PANI exhibited potent antimicrobial activity against all four bacterial strains and among all the samples, demonstrated higher antimicrobial activity than the unpolymerized nanocomposites. The disk diffusion study confirmed that a concentration of 25 μg/mL of protein–ZnO–PANI resulted in ZOI measurements of 25 mm and 35 mm, whereas MIC values of 300 μg/mL and 200 μg/mL were observed against Bacillus cereus and E. coli, respectively, and killed 95% of B. cereus and 98% of E. coli within 24 h. Based on the obtained results, a plausible mechanism was also proposed.

Antibacterial Activity of Zinc Oxide Nanoparticles Synthesized by Green Eichhornia Crassipes Extract Method

Purpose: Zinc Oxide Nanoparticle (ZnO NPs) production has become more common because of the benefits of the green strategy, which include its ease of use, environmental friendliness, and cheap operating costs. In order to accomplish the goal of green chemistry, the green synthesis process also uses safe solvents like water and ethanol. ZnO NPs are among the metal oxide-NPs used in antibacterial and bioremediation applications. Materials and Methods: Energy Dispersive X-ray spectroscopy (EDX), Fourier Transform Infrared spectroscopy (FT-IR), X-Ray Diffractometer (XRD), and Field Emission Scanning Electron Microscopy (FESEM) were used to analyze the green-produced ZnO NPs. Results: ZnO nanoparticles have an average size of 22.89 nm, which is corroborated by FESEM pictures, indicating that the particles are tiny. The excellent purity of ZnO NPs has been confirmed by EDX data. The antibacterial activity of ZnO NPs was assessed against a few dangerous pathogens. Zinc oxide nanoparticles were shown to have an interesting antibacterial action against both gram-positive and gram-negative bacteria at micromolar concentrations because they exhibit the maximum diameter of inhibition zone at concentrations 100 mg/ml of S. aureus, E. coli, K. pneumonia, Acintobacret spp, S. fecalis reaching (27,19,18,17, and 14) mm, respectively while S. pneumonia were resistant.The ZnO NPs recorded at a concentration of 12.5 mg/ml lowest areas of the inhibition zone against the same isolates reaching (16, 11, 11, 12, and 10) mm while S. pneumonia were resistant, respectively, as well. Conclusion: ZnO NPs, since they have excellent antibacterial properties, and are biocompatible, they will open up a new line of inquiry for antibacterial agent research because they are stable, nontoxic, and harmless.

Discovery of Active Antibacterial Fractions of Different Plant Part Extracts of clove (Syzigium aromaticum) Against Streptococcus mutans

Nowadays, dental cavities caused by Streptococcus mutans are a major focus of research in Indonesia. While several antibiotics are available to combat this bacterium, concerns about antibiotic resistance have prompted researchers to explore natural remedies. Clove (Syzigium aromaticum) is a commonly studied natural remedy against dental cavities and S. mutans. Among the different parts of the clove plant, clove bud is the most widely used against dental cavities or S. mutans, and the potential of other clove parts has not been thoroughly explored. Identifying which parts of the clove plant have higher concentrations of active ingredients and exhibit the strongest antibacterial activity is important. Therefore, this study evaluated the antibacterial activity of three different parts, i.e., leaf, stems, and buds of the clove plant ethanolic extracts against S. mutans. The ethanolic extracts of clove leaf, stems, and buds were prepared using the maceration method with 70% ethanol, and their activity against S. mutans was tested using the disc diffusion method at three different concentrations (10%, 5%, 2.5% b/v). Fractionation was carried out using hexane and water to obtain two fractions: hexane and water fraction. These fractions were then subjected to antibacterial assays. The ethanolic leaf, stems, and bud extracts exhibited varying antibacterial activity levels. The best activity was observed with the 10% clove bud ethanolic extract, which produced an inhibition zone of 20.83 ± 0.77 mm. The leaf and stem extracts showed inhibition zones of 16.38 ± 3.84 mm and 17.95 ± 5.15 mm, respectively. Furthermore, the hexane-soluble fraction of the clove bud displayed the highest activity with an inhibition zone diameter of 23.7 ± 3.21 mm at 10%. This activity was twice as high as ampicillin, used as the positive control. In conclusion, clove bud remains the best source of antibacterial compounds against S. mutans. Fractionation of the bud extract using hexane can significantly enhance its activity. Further investigation should be conducted to optimize the effectiveness of this active fraction for use as an anti-dental caries treatment.

Thymus algeriensis essential oil: Phytochemical investigation, bactericidal activity, synergistic effect with colistin, molecular docking, and dynamics analysis against Gram-negative bacteria resistant to colistin

Due to the increasing resistance prevalence to the last line of antibiotics, such as colistin, and the rising threat of multi-drug resistant bacteria, it is crucial to find alternative therapeutic options. The current study focuses on evaluating antibacterial activities alone and in combination with colistin of Thymus algeriensis essential oil (TA-EO) against colistin-resistant Klebsiella pneumoniae, Pseudomonas aeruginosa, and Escherichia coli co-harboring mcr-1 gene. GC/MS was used to determine the chemical composition of TA-EO. Disc diffusion and microdilution techniques were used to evaluate the antimicrobial activities of TA-EO. Synergism between colistin and TA-EO was evaluated by checkerboard assay. The major compounds of TA-EO were docked with known enzymes involved in resistance to colistin, as well as the biosynthesis of peptidoglycan and amino acids. GC/MS revealed that TA-EO was of carvacrol chemotype (67.94 %). The TA-EO showed remarkable antibacterial activities against all Gram-negative bacterial strains, with the diameter of inhibition zones varied between 30 and 50 mm and a ratio MBC/MIC equal to 1 for the vast majority of bacterial isolates. Interestingly, the checkerboard showed synergism between TA-EO and colistin against colistin-resistant Escherichia coli co-harboring mcr-1 gene (FICI˂1) and reduced the MIC of colistin by 16- to 512-fold and those of TA-EO by 4- to 16-fold. The docking study demonstrated that carvacrol had high binding free energies against MCR-1, a phosphoethanolamine transferase extracellular domain, and its catalytic domain implicated in resistance to colistin, and undecaprenyl pyrophosphate synthase in complex with magnesium which is involved in bacterial peptidoglycan biosynthesis. The molecular dynamics study for 100-ns also revealed the stability of the MCR-1/carvacrol complex with a constant surface area over the simulation. These results support using carvacrol or TA-EO as a bactericidal agent, either alone or in combination with colistin, to treat infections caused by colistin-resistant Gram-negative bacteria.

Synthesis and Characterization of a Novel Chitosan-Based Nanoparticle-Hydrogel Composite System Promising for Skin Wound Drug Delivery.

As a natural preservative, nisin is widely used in the food industry, while its application in biomedicine is limited due to its susceptibility to interference from external conditions. In this study, a nanoparticle-hydrogel composite system was designed to encapsulate and release nisin. Nisin nanoparticles were identified with a smooth, spherical visual morphology, particle size of 122.72 ± 4.88 nm, polydispersity coefficient of 0.473 ± 0.063, and zeta potential of 23.89 ± 0.37 mV. Based on the sample state and critical properties, three temperature-sensitive hydrogels based on chitosan were ultimately chosen with a rapid gelation time of 112 s, outstanding reticular structure, and optimal swelling ratio of 239.05 ± 7.15%. The composite system exhibited the same antibacterial properties as nisin, demonstrated by the composite system's inhibition zone diameter of 17.06 ± 0.83 mm, compared to 20.20 ± 0.58 mm for nisin, which was attributed to the prolonged release effect of the hydrogel at the appropriate temperature. The composite system also demonstrated good biocompatibility and safety, making it suitable for application as short-term wound dressings in biomedicine due to its low hemolysis rate of less than 2%. In summary, our nanoparticle-based hydrogel composite system offers a novel application form of nisin while ensuring its stability, thereby deepening and broadening the employment of nisin.

Ultraviolet Protection and Antibacterial Properties of Polylactic Acid Nonwoven Fabrics Coated with Water-Borne Polyurethane/Zinc Oxide Composite Coatings

This study aimed to create thermally curable, water-borne polyurethane/zinc oxide (WPU/ZnO) composite coating pastes with varying ZnO concentrations. ZnO nanoparticles were synthesized using a wet chemical process, and the resulting WPU/ZnO coating pastes were applied to PLA nonwoven fabrics (NWFs). In characterization studies, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), Fourier transform-infrared (FTIR) spectroscopy, and X-ray diffraction (XRD) analyses were conducted. Ultraviolet (UV) protection and antibacterial activity of fabrics were investigated. With WPU/ZnO composite coatings, the UV protection properties of the coated fabrics were enhanced compared to the uncoated fabric. The highest UPF value of 53.57 was obtained with the fabric coated with the formulation containing a ZnO concentration of 10%. This fabric also demonstrated more effective antibacterial activity against both S. aureus and E. coli bacteria. Inhibition zone diameters against E. coli and S. aureus bacteria were measured as 15.5 ± 0.70 mm and 18.25 ± 0.35 mm, respectively. The results of this study illustrate that functional composite coatings for bio-based NWF structures hold great promise for producing effective UV protective and antibacterial materials, potentially setting the stage for future applications.

Probiotic Properties of Lactobacilluscasei and L. plantarum Isolated From Overripe Avocado Pear

Probiotics have been researched for their benefit to gut health. Research for sources of probiotic bacteria has moved from milk to plants, as they have been found to be an inexhaustible source of lactic acid bacteria (LAB). The probiotic properties of lactic acid bacteria isolated from Over ripe Avocado pear on selected bacterial species were assessed. Fifty Unripe Avocado pears were purchased from different markets and allowed to ferment. Enumeration of the microorganisms and pure culture isolation were done on MRS agar supplemented with1.0% CaCO3 at 37 oC for 48 hours; using the pour plate and streak plate methods respectively. The isolates were identified based on their microscopic, macroscopic, biochemical and molecular characteristics. They include Lactobacillus casei and L. plantarum. LAB isolates were tested for their phenol tolerance, bile salt tolerance, acid tolerance and antimicrobial activity. All the isolates were tolerant to simulated gastrointestinal conditions. Growth of the isolates was observed at different temperature between 15 oC to 60 oC. They exhibited tolerance to phenol ranging from 0.085±0.01% to 2.40±0.02%. Tolerance to bile salt ranged from 1.06x101± 0.96x101 to 3.04x103±1.15x102. The acid tolerance level of the LAB obtained ranged from 2.98x102±1.30x102 to 8.78x102±2.22x102. Agar-well diffusion method was used to determine the antimicrobial susceptibility of the bacterial species. The test showed that the isolates were susceptible to the LAB isolates as zones of inhibition were observed. The inhibition zones diameter obtained ranged from 8.35±1.34mm to 13.77±2.21mm. Avocado pear, asides from their high nutritional content, also have the potential to serve as source of probiotic bacteria.

The impact of agar depth on antimicrobial susceptibility testing by disc diffusion.

Introduction. The European Committee on Antimicrobial Susceptibility Testing (EUCAST) specifies the agar depth (4±0.5 mm) when performing antimicrobial susceptibility testing (AST). Since the infrastructure to produce standardized agar may be lacking in settings with limited resources, we wanted to examine to what extent variation in agar depth affects the inhibition zone diameters of quality control (QC) strains and AST of clinical isolates.Methods. The inhibition zone diameters on Mueller-Hinton II agar with different depths (2-6 mm) were tested for various QC strain-antimicrobial agent combinations using Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 29213. The relationship between zone diameters at different agar depths and MICs was investigated for 35 clinical isolates (E. coli, Klebsiella pneumoniae, S. aureus and P. aeruginosa) from Sierra Leone using MICs as the reference.Results. The inhibition zone diameters were within the acceptance ranges as defined by the EUCAST for the majority of QC strains and antimicrobials, independent of the agar depth. At extreme agar depths, inhibition zones were more frequently out of range. The accuracy of AST varied for clinical isolates at different agar depths for categorical agreement (85.8-94.6%), major error rate (0.4-2.1%) and very major error rate (VME: 3.3-12.5%).Conclusions. Even if the QC strains were in the acceptance range at different agar depths, this does not rule out unacceptably high VME rates (>3%) in clinical isolates.

The Effects of Blue Vitriol and Brimstone on Etiological Agents of Bacterial Vulvovaginitis

Vulvovaginitis is an inflammation of the vulva and/or the vagina which may be symptomatic or asymptomatic. It is a common public health problem that can affect women and girls of all ages. The study aimed at evaluating the effects of blue vitriol and brimstone on etiological agents of bacterial vulvovaginitis. One hundred high vaginal swab specimens were aseptically and properly collected from suspected cases of vulvovaginitis. Plates of nutrient agar and blood agar were inoculated and incubated aerobically at 25 oC for 24 hours. The isolates were identified based on their morphological, physiological, biochemical and molecular characteristics. The antimicrobial activity of blue vitriol and brimstone was determined using the agar-well diffusion method. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of the test samples were determined using the broth dilution method. The isolates include Staphylococcus epidermidis, Eschericha coli, Lactobacillus spp. and Staphylococcus aureus. The inhibition zone diameter (IZD) of blue vitriol against the isolates ranges from 30.00±0.00mm to 31.50±2.12mm at concentrations of 50mg/ml to 200mg/ml. The IZD of brimstone against the isolates ranges from 29.00±1.41mm to 11.00±0.00mm at concentrations of 50mg to 200mg/ml. The positive control, ciprofloxacin gave IZD of 17.50±2.12mm to 21.50±2.12mm. The MIC of blue vitriol against all the isolates was 12.50mg/ml; while the MBC ranges between 25mg/ml to 50mg/ml. The MIC of brimstone was 25mg/ml to 200mg/ml; while the MBC was 50mg/ml to 200mg/ml. Ciprofloxacin gave MIC and MBC ranging from 25mg/ml to 100mg/ml against all the isolates. The study has shown that natural compounds such as blue vitriol and brimstone are good antimicrobials; and could serve as substitutes to conventional antimicrobial agents in the treatment of bacterial vulvovaginitis. Keywords: Vagina, Vulva, Vulvovaginitis, Blue vitriol, Brimstone, Antimicrobials.

Preparation of antibacterial composite film based on arginine-modified chitosan and its application in the preservation of ready-to-eat sea cucumber

An edible composite film was developed and applied for ready-to-eat sea cucumber storage to improve the product quality. The PAC film base is first prepared by mixing 0.5 % glycerin (GL) with 4 % polyvinyl alcohol (PVA) and 1 % arginine-modified chitosan (Arg-CTS) in the same volume. After the addition of nano-ZnO (ZnO) and thymol (Thy) to the PAC film base, the mechanical properties and functions were tested. Compared to the PAC film, the PAC-ZnO-ThyH composite film showed a 1.34-fold increase in the DPPH scavenging rate and a 2.19-fold increase in the ABTS scavenging rate. Contrary to the PAC film, the inhibition zone diameter of Escherichia coli and Staphylococcus aureus significantly increased by 2.35 and 4.08 folds in the PAC-Zno-ThyH film, respectively. After applying the PAC-ZnO-ThyH film to store ready-to-eat sea cucumber for 10 days, there was a significant reduction in weight loss, total volatile basic nitrogen (TVB-N), and lipid oxidation levels to 1.47 and 1.26 folds to the Ctrl group. After preservation, the hardness and chewiness of ready-to-eat sea cucumber were maintained at 1079.62 ± 138.86 N and 913.73 ± 175.79 N, respectively. The novel PAC-ZnO-ThyH composite film can be used as an active food packaging for promising seafood applications.

A Novel Bioprotective Strain of Lactiplantibacillus plantarumF2-Physiological, Genetical, and Antimicrobial Characterization.

Lactiplantibacillus plantarum is a member of lactic acid bacteria that improves the quality of fermented foods while also having a positive impact on human health. In this study, L. plantarum F2 was studied for characteristics such as biochemical and genetic identification, metabolite production, antimicrobial activity, and plasmid content. This strain exerts antimicrobial activity against some Gram-positive and Gram-negative pathogens (Listeria monocytogenes, Staphylococcus aureus, Salmonella, and Escherichia coli) with inhibition zone diameters ranging between 17.0 and 29.0 mm; it can ferment glucose, arabinose, galactose, lactose, and demonstrated the ability to grow at high temperature (50°C). Another physiological specification of the strain was the morphology of the isolate in selective medium, the de Man, Rogosa, Sharpe medium (MRS medium containing triphenyl tetrazolium chloride), which exhibits a chromogenic colony (characterized as purple colonies) on the modified-MRS (mMRS) medium. Metabolites such as lactic acid and diacetyl production of the strain F2 were also investigated using chromatography and found to be 10.07 and 0.05 µg/mL, respectively. The peptides of the isolate's cell-free supernatant were determined to be ∼80 kDa, and finally, the plasmid isolated from the strain F2 was identified as L. plantarum strain KLDS1.0386 plasmid p4, which may be responsible for some characteristic properties, such as antimicrobial peptide production of the strain.

The Study of Calcium Chloride Effect on Silver Nanoparticles Capping with Roselle Extract Granule against Aggregatibacter actinomycetemcomitans

Abstract Objectives The primary aim of this research is to investigate the influence of calcium chloride on the synthesis of silver nanoparticles coated with roselle extract and enclosed within alginate and calcium chloride (SNP-Ro-CaCl2) beads, designated as SNP-Ro-CaCl2 beads. Additionally, the study aims to assess their antimicrobial activity. Materials and Methods For the preparation of SNP-Ro-CaCl2 beads, SNPs and alginate gel were mixed, followed by dropping in three different concentrations of CaCl2 solution (1%, 3%, and 5% w/v). The morphological structure of the SNP-Ro-CaCl2 beads was analyzed using a stereoscope and scanning electron microscope (SEM). Over a period of 14 days, the release of SNPs was monitored using ultraviolet-visible (UV-Vis) spectroscopy. Additionally, the activity against Aggregatibacter actinomycetemcomitans was evaluated using the disk diffusion technique. Statistical Analysis The data for this experiment were analyzed using one-way analysis of variance (ANOVA) and Scheffe's method. Results The results revealed that varying concentrations of calcium chloride had distinct crosslinking effects on alginate, resulting in different voids and porosity within the SNP-Ro-CaCl2 beads. In the SNP-Ro-1% CaCl2 beads, the inner element exhibited higher porosity, facilitating faster activation and greater efficiency in releasing SNPs. Regarding activity against A. actinomycetemcomitans after 14 days, SNP-Ro-1% CaCl2 beads showed a larger inhibition zone diameter compared to other concentrations, while no statistically significant difference in the inhibition zone diameter was observed between SNP-Ro-3% CaCl2 and SNP-Ro-5% CaCl2 beads. Additionally, it was observed that the antimicrobial effectiveness diminished after 17 days through testing of the lifetimes of the three concentrations. Conclusions This study developed a method for depositing SNP-Ro into alginate gel and crosslinking it with CaCl2 to produce small beads for the sustained release of SNP-Ro in periodontal lesions. Consequently, the SNP-Ro-CaCl2 beads have the potential to be developed as adjunctive locally delivered antimicrobial agents in periodontal therapy.

Synthesis and characterization of a zinc-triazole coordination complex with potent antimicrobial and anticancer properties

The synthesis, characterization, and biological appraisement of a novel coordination compound [Zn(C4N4H5O)2(H2O)2]Cl have been comprehensively studied. The compound was synthesized using N-(1H-1,2,4-triazol-3-yl) acetamide and ZnCl2·6H2O, yielding a product characterized by FT-IR, elemental analysis, thermogravimetric analysis (TGA), and single crystal X-ray diffraction. FT-IR spectra confirmed the successful coordination of the ligand to the zinc ion, with significant shifts in characteristic absorption bands such as CO (1685 cm⁻¹), CN (1624 cm⁻¹), and NH (3394 cm⁻¹). Single crystal X-ray diffraction analyses revealed that the complex crystallized in the monoclinic system with space group P21/c and forms six-membered chelate rings. The unit cell parameters were a = 6.0595(3) Å, b = 14.2956(7) Å, c = 9.4762(4) Å, and β = 93.275(4)°. Thermal analysis showed that the complex undergoes stepwise decomposition with significant mass losses at various temperature intervals, including an overall mass loss of 71.09 % between 200 °C and 885 °C. Molecular docking studies indicated strong interactions between the [Zn(C4N4H5O)2(H2O)2]Cl complex and the 6QF6 cancer-related protein antigen A4, with low binding energy values (-9.32 to -8.44 kcal/mol) suggesting high binding affinity and potential biological activity. In vitro antimicrobial screening against several pathogenic microorganisms, viz. both gram-positive and gram-negative bacteria, demonstrated that the [Zn(C4N4H5O)2(H2O)2]Cl complex exhibited superior antibacterial activity, with inhibition zone diameters of 15.3 ± 0.47 mm for Bacillus subtilis and 24.17±0.56 mm for Agrobacterium tumefaciens, compared to N-(1H-1,2,4-triazol-3-yl) acetamide alone and some standard antibiotics. These findings highlight the [Zn(C4N4H5O)2(H2O)2]Cl complex as a promising candidate for developing new antimicrobial and anticancer agents, providing a foundation for further research and potential therapeutic applications.

Antibacterial Activity Test of Sumbawa White Honey against Escherichia coli ATCC 25922

Due to their high mortality and morbidity rates, E. coli infections are a serious issue. Antimicrobial Resistance (AMR) is a result of this indiscriminate antibiotic use. One approach to address this issue is to utilize natural antimicrobials such as Sumbawa white honey. Sumbawa white honey contains antibacterial components like glucose and fructose (80%), water (17%), polyphenols, and hydrogen peroxide. This study aimed to analyze the antibacterial activity of white honey from Sumbawa against E. coli ATCC 25922. The research method employed was a laboratory experiment using a post test only control group design. Antibacterial testing was conducted using disc diffusion at concentrations of 25%, 75%, and 100%, with chloramphenicol as positive control and DMSO as negative control, and honey processing involved dilution. Antibacterial tests were repeated five times and antibacterial activity was observed based on the diameter of inhibition zones around the disc. The outcomes showed that there was a restraint zone at 100 percent grouping of honey, to be specific 0.90 mm, while at 25% and 75% fixations there were no hindrance zones. According to the findings of this study, white honey from Sumbawa has a low antibacterial activity (0.90 mm), but this activity is ineffective against E. coli ATCC 25922. Further identification of the chemical components in Sumbawa white honey that are primarily responsible its antibacterial effect.

Antibacterial and Antibiofilm Activity Related to the Mechanism of Work of the Active Fraction of Moringa Leaves (Guilandina Moringa L.) to Staphylococcus Aureus

Biofilm-associated S. aureus bacterial infections are difficult to treat because bacterial cells encased in biofilms can be highly resistant to antibiotics and the immune response of the host. Moringa leaf extract contains active compounds of tannins, saponins, alkaloids, and phenols that have activity as antibacterial and antibiofilm. This study aims to determine the antibacterial activity and of extracts, mechanism of action of the most active fraction of moringa leaf ethanol extract against S. aureus.Extraction of Moringa leaves using maceration method with 96% ethanol solvent, fractionated using n-hexane, ethyl acetate, and water solvents. Antibacterial test using disc diffusion method, followed by dilution test. Observations were made using SEM and AAS. Data from the diffusion test, inhibition of biofilm formation, and biofilm degradation were analyzed using One Way ANOVA. Based on the results of the study, the ethyl acetate fraction is the most active fraction in inhibiting the growth of S. aureus in the diffusion test with an inhibition zone diameter of 15,7 mm at a concentration of 100 mg/mL and a minimum kill concentration value of 25 mg/mL. The water fraction was the most active fraction in inhibiting the formation and degradation of biofilm against S. aureus with an IC50 value of 4,049 ± 0,063 mg/mL and an EC50 value of 4,246 ± 0,050 mg/mL

Antibacterial, antifungal, and phytochemical properties of Salsola kali ethanolic extract.

The research into the use of plants as plentiful reservoirs of bioactive chemicals shows significant potential for agricultural uses. This study focused on analyzing the chemical composition and potency of an ethanolic extract obtained from the aerial parts (leaves and stems) of Salsola kali against potato pathogenic fungal and bacterial pathogens. The isolated fungal isolates were unequivocally identified as Fusarium oxysporum and Rhizoctonia solani based on morphological characteristics and internal transcribed spacer genetic sequencing data. The antifungal activity of the extract revealed good inhibition efficacy against R. solani (60.4%) and weak activity against F. oxysporum (11.1%) at a concentration of 5,000 µg/mL. The S. kali extract exhibited strong antibacterial activity, as evidenced by the significant inhibition zone diameter (mm) observed in all three strains of bacteria that were tested: Pectobacterium carotovorum (13.33), Pectobacterium atrosepticum (9.00), and Ralstonia solanacearum (9.33), at a concentration of 10,000 µg/mL. High-performance liquid chromatography analysis revealed the presence of several polyphenolic compounds (μg/g), with gallic acid (2942.8), caffeic acid (2110.2), cinnamic acid (1943.1), and chlorogenic acid (858.4) being the predominant ones. Quercetin and hesperetin were the predominant flavonoid components, with concentrations of 1110.3 and 1059.3 μg/g, respectively. Gas chromatography-mass spectrometry analysis revealed the presence of many bioactive compounds, such as saturated and unsaturated fatty acids, diterpenes, and phytosterols. The most abundant compound detected was n-hexadecanoic acid, which accounted for 28.1%. The results emphasize the potential of S. kali extract as a valuable source of bioactive substances that possess good antifungal and antibacterial effects, which highlights its potential for many agricultural uses.

In vitro antibacterial effect of a nano-zinc oxide eugenol sealer alone and in combination with chitosan, propolis, and nanosilver on Enterococcus faecalis

ABSTRACT Background: This study aimed to assess the antibacterial effect of a nano-zinc oxide eugenol (nZOE) sealer alone and in combination with chitosan, propolis, and nanosilver on Enterococcus faecalis. Materials and Methods: In this in vitro, experimental study, nanosilver, chitosan, and propolis with 10wt%, 20wt%, and 60wt% concentrations, respectively, were added to nZOE sealer, and their antibacterial activity against E. faecalis was evaluated by agar diffusion and broth microdilution tests. The diameter of the growth inhibition zones was measured, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were calculated for all materials. Data were analyzed by t-test (alpha = 0.05). Results: The addition of nanosilver, chitosan, and propolis to nZOE did not change the diameter of growth inhibition zone in agar diffusion test. Propolis and eugenol alone showed the lowest MIC and MBC. Chitosan alone showed the highest MIC and MBC. Furthermore, nZOE showed lower MBC than micro-ZOE (P = 0.000). All groups containing nZOE showed the lowest MIC and MBC values. Conclusion: The addition of propolis to nZOE can enhance its antibacterial activity against E. faecalis in vitro.

Comparison of Dracocephalum Moldavica Essential Oil with Chlorhexidine on Cariogenic Bacteria.

Dental caries and periodontal disease are the most common oral problems. Chemical antibacterial agents often have side effects; thus, researchers have long been in search for organic and herbal products to prevent dental caries and periodontal disease. The present study has aimed to assess the effects of Dracocephalum moldavica essential oil on Streptococcus mutans, Streptococcus salivarius, Streptococcus sobrinus, and Lactobacillus acidophilus compared to Chlorhexidine (CHX). In this in vitro study, the plants were collected from Zanjan Province, Iran. Analysis of the essential oil was carried out by gas chromatography/mass chromatography. Micro-broth dilution and disc diffusion methods were used for assessment of the antimicrobial activity, and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were evaluated. The mean diameter of the growth inhibition zones in the well plate method for Dracocephalum moldavica showed that it had greater antimicrobial activity against Lactobacillus acidophilusthan others (p Value= 0.01). Furthermore, Dracocephalum moldavica had higher antimicrobial activity than CHX. The results of MIC and MBC showed that Dracocephalum moldavica had lower antibacterial activity than CHX. Dracocephalum moldavica essential oil demonstrated antibacterial properties against cariogenic bacteria. Given that other favorable properties of these essential oils are confirmed, they may be suitable for use as antibacterial agents in the formulation of oral healthcare products.