Green Synthesis of ZnO Nanoparticles Using Delonix elata & Gynura cusimbua Leaf Extracts and Evaluating Their In-vitro Antibacterial Properties

Hiranmayi Devadula Sai Rama, Anzila Yumlembam, Suba Gnana Abraham Manuel — Tue, 31 Dec 2024 00:00:00 +0000

With an increasing focus on the application of nanoparticles in the field of research, this study aims to evaluate the in-vitro antibacterial properties of chemically and green synthesized zinc oxide nanoparticles (ZnO NPs) from two plant sources Delonix elata and Gynura cusimbua. The bioactive compounds present in the leaf extracts were utilized to stabilize the nanoparticles. UV-Visible spectrophotometry (UV-Vis), X-ray diffraction (XRD), and Scanning electron microscopy (SEM) were used to elucidate the optical and structural properties of the synthesized ZnO NPs. The in-vitro antibacterial potential of ZnO NPs were evaluated by Agar Disc Diffusion Assay against two pathogenic bacterial strains: Bacillus cereus, a gram-positive animal pathogen and Pseudomonas syringae, a gram-negative plant pathogen, making it a well-rounded approach. The UV–visible spectrum was measured in 250 – 400 nm range and the crystallite structure was analyzed via XRD. SEM-EDS (Energy-Dispersive X-ray Spectroscopy) analysis confirmed the nanostructures with partial nanoflakes and aggregates for all three samples of the synthesized ZnO NPs. The D. elata ZnO NPs showed relatively greater antimicrobial activity against both the bacterial strains than that of G. cusimbua ZnO NPs. Consequently, plant-based NPs may be an excellent strategy for developing versatile and environmentally friendly biomedical products. They have an added advantage due to their pre-existing medicinal properties, which make them a more suitable alternative to the broadly used chemically synthesized nanoparticles.

KEY WORDS: Delonix elata, Gynura cusimbua, Zinc oxide Nanoparticle, antimicrobial activity, Bacillus cereus, Pseudomonas syringae.

Study of Antibiotic Resistance in the Fish Gut and Antibacterial Potential of Lactic acid bacteria against the isolated Multiple Drug-resistant bacteria.

Yadav Ansuya, Shweta Ashish Patil, Jategaonkar Vinaya M — Tue, 31 Dec 2024 00:00:00 +0000

The One Health approach integrates human, animal, and environmental health to address emerging diseases. Antibiotic resistance spread among microorganisms has been a concern in all ecosystems including aquatic environments. This resistance is spreading horizontally in ways that are both hidden and unfathomable. The search for alternatives is the most important need for combating the spread of antibiotic resistance. This work aims to study the spread of antibiotic resistance through horizontal transmission via plasmids and the ability of bacteria to form biofilms. In this study, a total of 31 isolates were obtained from different fishes. Cultural, microscopic, and biochemical tests were performed to identify them. The antibiotic sensitivity was performed using the disc diffusion method with Oxytetracycline, Linezolid, Vancomycin, Imipenem, Cefoxitin, Ampicillin, and Amoxicillin. Plasmid extraction and biofilm-producing capacity of the resistant isolates were studied. 67 % of isolates were found to be gram-negative and 23 % gram-positive. Antibiotic resistance profiling showed a higher percentage of resistance in gram-negative organisms with maximum resistance to Oxytetracycline. Plasmids were found in 43% of the gram-negative isolates and out of these 83% were able to form biofilms. To screen for alternatives to antibiotics, cell-free extracts of Lactic acid bacteria were tested by the agar diffusion method, and a zone of inhibition was noted. This study highlights the challenging trend of antibiotic resistance spread in aquatic ecosystems and the need for antibiotic substitutes.

Journal of Advanced Scientific Research

Green Synthesis of ZnO Nanoparticles Using Delonix elata & Gynura cusimbua Leaf Extracts and Evaluating Their In-vitro Antibacterial Properties

Study of Antibiotic Resistance in the Fish Gut and Antibacterial Potential of Lactic acid bacteria against the isolated Multiple Drug-resistant bacteria.