Antimicrobial Studies Research Articles

Preparation of surfactant‐assisted polycaprolactone/κ‐carrageenan nanofibres

AbstractThe objective of this work was to fabricate nanofibres composed of polycaprolactone (PCL) and κ‐carrageenan (kC) by employing an anionic surfactant, sodium bis(2‐ethylhexyl) sulfosuccinate (AOT). This study examined the role of the surfactant in PCL/kC/AOT (hybrid) nanofibre preparation using SEM, AFM, Fourier transform infrared spectroscopy, XRD and DSC. The wettability and water uptake percentage of the nanofibres were investigated. An antimicrobial study was conducted against bacterial strains using a colony‐counting assay, and changes in bacterial morphology were monitored using TEM. The results demonstrated that the hybrid nanofibres had a uniform and smooth structure, which might be attributed to the improved compatibility between polymers in the presence of the surfactant. The incorporation of AOT in the matrix resulted in a reduction in the mean fibre diameter and surface roughness. The hybrid nanofibres increased water absorbency is evidence of their high hydrophilicity, which can be explained by the simultaneous impact of kC and AOT. The hybrid nanofibres exhibited effective activity against Staphylococcus aureus and Escherichia coli. © 2024 Society of Chemical Industry.

Evaluation of anti-microbial activity of biotite and biotite composite based on crystallographic parameters: Estimation of crystallite size employing X-ray diffraction data

This study dealt with naturally occurring biotite from the river sediment to synthesize biotite based composite to evaluate antimicrobial activities against gram positive bacteria, negative bacteria and fungi. Biotite mineral, and synthesized carbon aerogel –biotite (CBt) composite and carbon aerogel-biotite –ZnO (CBtZ) composites were considered for the antimicrobial study. The samples were characterized by X-ray diffraction technique and different crystallographic parameters were computed applying X-ray diffraction data. Also, FESEM was performed to understand the surface morphology of the samples. Crystal size of the biotite, CBt and CBtZ were computed 103.215, 57.567, and 36.496 nm respectively. Tabulated microstrain are 0.175, 0.499 and 0.935 for the biotite, CBt and CBtZ respectively. Various models and equations were used to justify crystallite size, including the Williamson-Hall plot, linear straight line model, Scherrer equation, Monshi-Scherrer model, Size-strain plot (SSP) model, Halder-Wagner method and Sahadat-Scherrer model. For the both composite samples, following models confirmrd the presence of nanocrystal with a range of 50.789–97.777 nm (CBt) and 36.496–105.843 nm(CBtZ). However, for the biotite, all mentioned models were proved invalid except scherrer equation, SSP model and Monshi-Scherrer model. Linear straight line model was found invalid to calculate crystallite size of the three samples. Moreover, different crystal parameters like dislocation density, volume of the unit cell, lattice parameters were computed. Zone of inhabitation estimation method was employed to estimate antimicrobial activity against Listeria monocytogenes, Staphylococcus aureus, Salmonella abony, Escherichia coli and Candida albicans. Required minimum inhibitory concentration (MIC) together with minimum bactericidal concentration (MBC) also estimated in this study. Crystal size effect on the antimicrobial activities of the samples were evaluated in this study.

Fishwaste Derived Hydroxyapatite Nanostructure Combined with Black Rice Wine for Potential Antioxidant and Antimicrobial Response.

Hospital-acquired infection remains a serious threat globally, due to development of resistance to conventional antibiotics, which necessitates the urge for alternative therapy. Green nanotechnology has emerged as a holistic approach to address antibiotic resistance by combining environmental sustainability with improved therapeutic outcome. Nanostructure hydroxyapatite (HAP) has received significant attention in therapeutic and regenerative purposes due to its porous scaffold structure and biocompatible nature. In the present study, hydroxyapatite (HAP) nanoparticle was fabricated from the fish scale waste of red snapper fish. Black rice wine (BRW) was extracted from black rice commonly termed as Karupu kavuni/forbidden rice known for its nutritious effects. The present study focused on encapsulation of BRW within HAP nanoparticles (HAP@BRW) and evaluated its potential against nosocomial infections. Spectral and microscopic characterization of HAP@BRW revealed uniform encapsulation of BRW in HAP nanoparticles, aggregated irregular-shaped morphology of size 117.6nm. Maximum release of BRW (72%) within 24h indicates HAP as suitable drug delivery system suitable for biomedical applications. Antimicrobial studies revealed that HAP@BRW exhibited potent bactericidal effect against MRSA, MSSA, and Pseudomonas aeruginosa. Furthermore, HAP@BRW significantly inhibited the biofilm forming ability of MSSA and P. aeruginosa. Rich antioxidant property of HAP@BRW might be due to the presence of rich source of total polyphenolic, flavonoid, and anthocyanin content in BRW. In vitro and in vivo toxicity studies revealed biocompatible nature of HAP@BRW. Antibiofilm, antimicrobial, antioxidant, and biocompatible nature of HAP@BRW makes it a promising candidate for coating medical implants to avoid implant-associated infections and nosocomial infections.

A new bio‐active Schiff base ligand and its Ni(II), Cu(II), Ag(I), Zn(II), Cd(II), and La(III) binuclear complexes: synthesis, DFT analysis, antimicrobial, DNA interaction, COXII inhibition, and molecular docking studies

A new bio‐active Schiff base ligand and its Ni(II), Cu(II), Ag(I), Zn(II), Cd(II), and La(III) binuclear complexes: synthesis, DFT analysis, antimicrobial, DNA interaction, COXII inhibition, and molecular docking studies

Growing Mycobacterial Biofilm as a Model to Study Antimicrobial Resistance.

Many bacteria thrive in intricate natural communities, exhibiting key attributes of multicellularity such as communication, cooperation, and competition. The most prevalent manifestation of bacterial multicellular behavior is the formation of biofilms, often linked to pathogenicity. Biofilms offer a haven against antimicrobial agents, fostering the emergence of antimicrobial resistance. The conventional practice of cultivating bacteria in shake flask liquid cultures fails to represent their proper physiological growth in nature, consequently limiting our comprehension of their intricate dynamics. Notably, the metabolic and transcriptional profiles of bacteria residing in biofilms closely resemble those of naturally growing cells. This parallelism underscores the significance of biofilms as an ideal model for foundational and translational research. This article focuses on utilizing Mycobacterium smegmatis as a model organism to illustrate a technique for cultivating pellicle biofilms. The approach is adaptable to various culture volumes, facilitating its implementation for diverse experimental objectives such as antimicrobial studies. Moreover, the method's design enables the qualitative or quantitative evaluation of the biofilm-forming capabilities of different mycobacterial species with minor adjustments.

Biotite and ZnO embedded carbon aerogel composite for enhanced photocatalytic activity to degrade ciprofloxacin under sunlight stimulation

This study was explored the photocatalytic efficiency of biotite and ZnO embedded carbon aerogel (CA) photocatalyst to degrade ciprofloxacin (CIP) antibiotic from an aqueous medium by sunlight harvesting. CA came from waste newspaper through pyrolysis technique. Biotite was extracted from Bramapurta River's sand through high-tension magnetic separation techniques. The developed catalyst was characterized by applying FESEM, EDS, XRD, and XPS. The bandgap (1.69 eV) of the catalyst was determined from Tauc's plot. The photocatalytic study showed that, optimum degradation was achieved at 98.471 %, 84.576 %, 77.997 % and 59.607 % for 2, 5, 10 and 20 mg/L CIP containing solution respectively in 180 min at its natural pH applying only employing 0.25 g/L dosage. Moreover, in the pH study, catalyst showed maximum degradation 88.773 % for 5 mg/L CIP containing solution at pH 7 exposing the same irradiation time and dosage. The degradation followed pseudo-first-order kinetics with a maximum rate constant of 0.01831 min−1 which attributes to the first degradation of CIP through ROS. The scavenger test suggested that •OH− and e− played a vital role in the photodegradation process. Regeneration studies confirmed that photocatalysts showed better degradation efficiency until five cycles. Fusion of metal oxides in the catalyst might play a vital role in the multiple photodegradation cycles without losing stability of the composite. FESEM, EDS, and XPS characterization of the spent catalyst was performed for understanding its morphological and chemical change. An antimicrobial study was performed to confirm its efficiency against of gram-negative bacteria (E. coli) and gram-positive bacteria (S. aureus), which suggested that the catalyst is very effective in destroying gram-negative bacteria compared to gram-positive bacteria.

Cure, Mechanical, Swelling, Antimicrobial and Biodegradability Studies of Biocomposites of Acrylonitrile Butadiene Rubber and Chitosan

Cure, Mechanical, Swelling, Antimicrobial and Biodegradability Studies of Biocomposites of Acrylonitrile Butadiene Rubber and Chitosan

Pharmacognostic, Phytochemical and Antimicrobial Study of Vidangadi Churna - An Experimental Study

Herbal medicines are gaining more and more attention all over the world as they have been in use since ancient times and have no side effects if taken under proper supervision. But they have their own limitations as data about standardization and quality control are not widely available. Therefore, it is the need of the hour to revalidate this herbal compound under the lens of advance tools or procedures. Method: Vidangadi Churna was prepared according to the classical reference. Physiochemical and Phytochemical study was performed by proper WHO guidelines and Antimicrobial activity of Vidangadi Churna was tested by Agar well diffusion method. Result and Discussion: In this study Vidangadi Churna showed the presence of phytochemical constituents having antimicrobial properties. This preparation was treated with different reagents and examined under UV light. Different reagents showed different colours of the preparation at different wavelengths. Various physiological active compounds like phenolic compounds, Tannins, Amino acids, alkaloids etc. were found in Vidangadi Churna. Antimicrobial study revealed the activity of this drug on different micro-organisms. Conclusion: Vidangadi Churna is poly-herbal Ayurveda formulation described in Yogratnakar in Kustha Roga Chikitsa Adhyay. By this study it is concluded that Vidangadi churna fulfilled all the standard criteria with effective parameters and it could be used as anti-microbial agent against infections caused by Klebsiella aerogenes, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus.

Synthesis and Superficial Modification "In Situ" of Copper Selenide (Cu2-x Se) Nanoparticles and Their Antibacterial Activity.

Copper selenide nanoparticles (Cu2-x Se NPs) have received a lot of attention in recent decades due to their interesting properties and potential applications in various areas such as electronics, health, solar cells, etc. In this study, details of the synthesis and characterization of copper selenide nanoparticles modified with gum arabic (GA) are reported. Also, through transmission electronic microscopy (TEM) analysis, the transformation of the morphology and particle size of copper selenide nanoparticles in aqueous solution was studied. In addition, we present an antimicrobial study with different microorganisms such as Staphylococcus aureus (S. aureus), Escherichia coli (E. coli) and Candida albiacans (C. albicans). Copper selenide nanoparticles were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry analysis (DSC) and TEM. XRD confirmed the crystal-line structure of the nanoparticles such as cubic berzelanite with a particle size of 6 nm ± 0.5. FTIR and TGA corroborated the surface modification of copper selenide nanoparticles with gum arabic, and DSC suggested a change in the structural phase from cubic to hexagonal. TEM analysis demonstrated that the surface modification of the Cu2-x Se NPs stabilized the nanostructure of the particles, preventing changes in the morphology and particle size. The antimicrobial susceptibility analysis of copper selenide nanoparticles indicated that they have the ability to inhibit the microbial growth of Staphylococcus aureus, Escherichia coli and Candida albicans.

Synthesis, antimicrobial, antioxidant and molecular docking studies of novel multifunctional chloroacetamide derivatives

A series of chloroacetamide derivatives (1-22) was synthesized to address the urgent need for new antimicrobial and antioxidant agents. The chemical structures were confirmed by 1H-NMR, 13C-NMR and MS spectroscopic analyses. Most compounds inhibited in vitro Gram-positive bacteria S. aureus and B. cereus as well as Gram-negative bacteria (E. coli and P. aeruginosa) and yeast (C. albicans). Interestingly, compound 13 showed the broadest spectrum, especially against B. cereus (MIC = 10 mg/L). Compounds 6 and 20 displayed potent activity against C. albicans (EC50 = 197.02 and 189.13 mg/L, respectively). All compounds exhibited antioxidant activity, with 14 compounds surpassing α-tocopherol (standard) in DPPH radical scavenging. In silico analyses were conducted using molecular docking, drug-likeness data, physicochemical properties, and ADMET parameters to evaluate the potential of the compounds. Molecular docking simulations against the active sites of NADPH oxidase, penicillin-binding protein (bacterial target), and lanosterol 14-alpha demethylase (fungal target) revealed favorable binding energies for the majority of the compounds, indicating good affinity towards the targeted proteins. Overall, the research on novel multifunctional chloroacetamide derivatives is a valuable contribution to the field of biological chemistry and has the potential to lead to the development of new and improved products for a variety of microbes.

Synthesis of Piperazine-containing Derivatives and their Antimicrobial, Antimycobacterial, Antimalarial and Antioxidant Activities

Background: One of the most crucial heterocycles is piperazine for the creation of novel medication candidates with a variety of medicinal applications. The piperazine moiety is a cyclic compound with four carbon atoms and two nitrogen atoms in positions 1 and 4. Objective: The objective of this studty is the development of 1-((3,4-dimethoxyphenyl) (substitutedphenyl) substituted -piperazine (A1-A10) analogs via the one-pot synthesis method and evaluation for their preliminary antibacterial, antifungal, antimycobacterial, antioxidant, and antimalarial activity. Methods: Desired piperazine derivatives were obtained in a single step reaction using piperazine, aldehydes, and boronic acid derivatives. The structures of all newly synthesized compounds have been established based on analytical and spectral data. An in silico molecular docking study was carried out for the series. Results: The spectral data using IR, 1 H NMR, and 13C NMR and mass spectra confirmed the structure of the synthesized compounds. Compounds A6 and A10 were found to be the most promising agents for antimalarial activity. A1-A10 showed a higher IC50 value and found less antioxidant activity. Some of the compounds showed higher potency when compared to the standard drugs in this antimicrobial study. Conclusion: The structure-activity study showed that changes in substituents either on aldehyde, piperazine, or boronic acid derivatives can lead to potential active compounds. These facts make the compounds interesting candidates for further evaluation of their efficacy in the treatment of microbial, tubercular and malarial diseases.

L-Phenylalanine-tethered Peptide Hydrazones of Chloro-based Thiophene-2-carboxamides: Design, Synthesis, and Anti-Microbial Studies

L-Phenylalanine-tethered Peptide Hydrazones of Chloro-based Thiophene-2-carboxamides: Design, Synthesis, and Anti-Microbial Studies

Antimicrobial and antioxidant studies of the leaf extracts of Lophira lanceolata (Male Shaere)

Antimicrobial and antioxidant studies of the leaf extracts of Lophira lanceolata (Male Shaere)

Antioxidant and Antimicrobial Study Effects of (Agaricus bisporus) Extracts Which was Cultured in Our Mushroom’s Farm

Antioxidant and Antimicrobial Study Effects of (Agaricus bisporus) Extracts Which was Cultured in Our Mushroom’s Farm

Novel multi-purpose herbal topical formulation

The commercial need for herbal formulations is increasing now a days as natural remedies are more favored in the belief that they are safer with fewer side effects than synthetic ones. Therefore, it is rational to develop a multipurpose herbal cream that is free from toxic side effects, safe and effective with better patient compliance as compare to allopathic preparations. The present research work related to a multipurpose herbal cream was formulated and subjected to various evaluation parameters, and the findings obtained were evaluated for the limits. The herbal ingredients used to develop the herbal cream comprises aloe vera, Neem oil, turmeric, and rose water. The novel formulations were evaluated for various physicochemical parameters, including appearance, emulsion, pH, texture, homogeneity, irritancy, SPF, antimicrobial studies and identification of constituents. Among all the prepared creams both F1 & F2 were observed as the best formulations. The present research work comprises assessing the moisturizing ability and skin protective ability of the formulated multipurpose herbal topical cream.

In vitro activity of the novel antimicrobial peptide WR-286 in combination with vancomycin against methicillin-resistant Staphylococcus aureus

Background: Multidrug resistance bacteria are a serious problem for health specialists and all the people in the world. The main reasons for this problem are the misuse of antibiotics and the limited number of antibiotics as compared to different human diseases. The important antibiotic-resistant bacteria include Methicillin-resistant Staphylococcus aureus (MRSA). Antimicrobial peptides (AMPs) are regarded as promising antimicrobial agents because they satisfy the requirements for the creation of innovative antimicrobial drugs. The aim of the study: To design a novel antimicrobial peptide and study its effect against MRSA when we combined it with vancomycin. Materials and methods: To produce the hexapeptide WR-286, 1-(2, 6-difluorobenzyl)-1H-1, 2, 3-triazole-4-carboxylic acid, tryptophan (W), and arginine (R) were rationally combined. Different bacterial strains were used to test WR-286's antibacterial properties. Investigations of WR-286's hemolytic activity toward human erythrocytes were also conducted. Finally, utilizing the checkerboard approach and the fractional inhibitory index, synergistic tests with vancomycin were carried out. Results: With MIC values as low as 35 μM, WR-286 demonstrated strong antibacterial activity against MRSA. The toxicity of WR-286 to human red blood cells was very low. Additionally, the peptide and vancomycin's activity were improved by the synergistic experiments. Conclusion: According to the current investigation, WR-286 has little hemolytic activity and displays promising antibacterial activity against MRSA. Additionally, when coupled with vancomycin, the peptide has synergistic effect. The novel AMPs described in this work are promising potential candidates for antimicrobial drug development.

Synthesis of graphene-based nanocomposites with superior doxycycline removal efficiency and antimicrobial studies

Herein, we report the successful preparation of high-quality graphene (G) nanosheets up to the kg scale using an electrochemical technique using graphite rods from scrap dry cell batteries. The as-prepared graphene was then decorated in-stiu with niobium oxide (Nb2O5) and silver (Ag) nanoparticles to prepare Nb2O5@G and Ag@G nanocomposites. Powdered X-ray diffraction (p-XRD), Fourier-transform (FT-IR) infrared spectroscopy, UV–visible (UV–vis) spectroscopy, Raman spectroscopy, and scanning electron microscopy (SEM) were used to characterize the as-prepared nanocomposite material. This binary Nb2O5@G nanocomposite was subsequently used to degrade doxycycline antibiotic with an efficiency of 98.5 % in 120 min under visible light conditions. To determine the optimal scope of the as-prepared composite catalyst, degradation studies were performed at different pH values, photocatalyst doses and temperatures. Kinetics studies revealed that the processes followed pseudo-first-order kinetics. In addition, the as-synthesized graphene, Nb2O5@G and Ag@G nanocomposites were used for selective application against E. coli bacterial strains. Overall, Ag@G has shown good potential application prospects in the development of antibacterial materials in comparison with Nb2O5@G and pristine graphene. This study highlights the potential of as-prepared graphene-based nanocomposites for use in waste treatment and environmental bioremediation.

Synthesis, Physicochemical and Antimicrobial Studies of Schiffbase Ligand derived from Benzaldehyde and Urea and its Ni(II) and Cu(II) Metal Complexes

Synthesis, Physicochemical and Antimicrobial Studies of Schiffbase Ligand derived from Benzaldehyde and Urea and its Ni(II) and Cu(II) Metal Complexes

Antimicrobial potential and protein binding affinity of a hybrid ternary nanocomposite matrix: Zinc oxide functionalization with poly(vinyl alcohol)-sulphonated graphene oxide-poly pyrrole

The present study focuses on the application of a ternary PVA/sGO/ZnO-NP/PP nanocomposite as an antibacterial and antifungal agent. The process involved utilizing a solution casting technique to fabricate the inorganic–organic blend material, where 4-sulfophthalic acid (SPTA) was used in the sulfonation of graphitic oxide (GO) sheets. The amalgamation of polyvinyl alcohol polymer (PVA) and sulphonated GO (sGO) was achieved through a chemical oxidation polymerization process carried out in a water-based environment. This process developed a PVA/sGO film, in which zinc oxide nanoparticles (ZnO-NP) and pyrrole monomers were introduced. The PVA/sGO film served as the initial stage for the in-situ deposition and formation of polypyrrole (PP), leading to the fabrication of PVA/sGO/ZnO-NP/PP membrane. The structure was stabilized by hydrogen bonding and electrostatic interactions between the components, while SPTA acted as a cross-linker and a sulphonating agent. The Fourier transform infrared (FTIR) spectra of the quad-component composite unraveled the presence of distinctive functional groups, including PVA, sGO, PP, and Zn-O bands. The UV–visible spectra of PVA/sGO/ZnO-NP/PP nanocomposite membrane revealed a peak in the UV-B region, while in-depth X-ray diffraction (XRD) analyses provided strong evidence of its amorphous nature. The scanning electron microscopy (SEM) image showed that the top surface of the organic film was adorned with PP polymeric chains. The membrane exhibited great water retention capabilities due to its high ion exchange capacity (IEC) value.Additionally, the minimal water loss observed underscores its extended shelf life. Due to their inherent hydrophilic properties, the ternary nanocomposite membranes exhibited enhanced hydrophilicity, porosity, zeta potential, and water uptake. The BET and BJH analyses revealed that PVA/sGO/ZnO-NP/PP nanocomposites had a substantial surface area. Remarkably, the nanocomposite membrane exhibited significantly improved antimicrobial efficacy against bacteria and fungi. The type of interactions between Human serum lysozyme (HSL) and nanocomposite at the molecular level was studied through fluorescence spectroscopy. Stern-Volmer plot revealed the occurrence of both static and dynamic quenching. However, the precise mechanisms underlying the antimicrobial and protein binding (HSL) studies of PVA/sGO/ZnO-NP/PP-based nanocomposites require further investigation.

Green Synthesis of Chitosan-Coated Silver Nanoparticles (Ch-AgNPs): Harnessing Nature for Sustainable and Safe Nanomaterial Production

The production of silver nanoparticles (AgNPs) using green synthesis methods promotes the use of environmentally friendly materials and facilitates a more sustainable production process by reducing environmental impact. In addition, combining the metal nanoparticles with biopolymers are getting important to enhance the safety profiles of formulations to determine the biological activities. With this concept, AgNPs were synthesized by green synthesis method from Betula spp. tree branches as reported previously by us and in current study, synthesized AgNPs were coated by one of biopolymer. Herein, Chitosan was used as capping and stabilizing agent. Characterization of the biosynthesized silver nanoparticles (AgNPs) and Chitosan coated silver nanoparticles (Ch-AgNPs) were evaluated with various techniques. Through this analysis, it was elucidated that the phenolic compounds present in Betula extract and Chitosan played dual roles as both reducing and capping agents, facilitating the formation of Ch-AgNPs. Particular size analysis by dynamic light scattering (DLS) and scanning electron microscopy (SEM) indicated that the Ch-AgNPs ranged from 49 to 118 nm in size, with a narrow size distribution. X-Ray Differentiation (XRD) patterns confirmed the high crystallinity of the resulting particles. Fourier transform infrared (FTIR) analysis further supported these findings, revealing the involvement of phenolic compound extracts in both the formation and stabilization of AgNPs. Additionally, FTIR confirmed the surface modification of AgNPs by chitosan. The efficiency of surface modified Ch-AgNPs was compared with uncoated AgNPs for their antimicrobial activity, antiproliferative efficiency and biocompatibility. Cell culture studies demonstrated that AgNPs were less toxic to L929 cells while maintaining effective cytotoxicity against HT-29 cells. Moreover, surface modification with chitosan enhanced the toxicity of AgNPs against HT-29 cells Furthermore, the first synthesized and evaluated Ch-AgNPs with this study from Betula extract, exhibited potent antimicrobial activity against both Gram-positive and Gram-negative bacteria. Our findings indicate that novel synthesized Ch-AgNPs formula may present a biocompatible and safety approach for further anticancer and antimicrobial studies.