Related Experiment Video
Updated: Nov 14, 2025
Evaluation of Antimicrobial Activities of Nanoparticles and Nanostructured Surfaces In Vitro
Published on: April 21, 2023
Isolation, biosynthesis and antimicrobial activity of gold nanoparticles produced with extracts of Anabaena spiroides
Chinmayee Priyadarshini Mandhata1, Chita Ranjan Sahoo1, Chandrika Saloni Mahanta1
1Central Research Laboratory, Institute of Medical Sciences and SUM Hospital, Siksha O Anusandhan Deemed To Be University), Kalinga Nagar, Bhubaneswar, Odisha, 751003, India.
Abstract:
Multidrug-resistant (MDR) pathogenic bacteria have become dangerous in bringing sporadic outbreaks in public health and nosocomial spreads from the addition of antibacterials/antibiotics continually. Obviously, the pharmacy world is in search of antibacterials that would be invincible by the evolved bacteria. Green synthesis of gold-nanoparticles (AuNps) was focused on the use of aqueous chloroauric acid (HAuCl4) and cell-free aqueous extract of the N2-fixing cyanobacterium (blue-green alga) Anabaena spiroides collected from a brackish-water, Bay of Bengal at Puri, Odisha; green-synthesized AuNps could be used as antibacterials against MDR bacteria. The synthesized AuNps were subjected to the following characterizations, UV-Vis spectrophotometry, SEM-EDX, XRD and ART-FTIR analysis. An absorption peak at 538 nm by UV-Vis spectrophotometry and the FTIR analysis confirmed the presence of AuNps. A. spiroides-AuNps were monitored for antibacterial activities against MDR pathogenic bacterial strains isolated from clinical samples, namely, Klebsiella oxytoca, MRSA and Streptococcus pyogenes, in vitro; the individual antibiograms of those bacteria were known. The recorded MIC dose values were 25, 20 and 30 mg A. spiroides-AuNps (As-AuNps) against K. oxytoca, MRSA and S. pyogenes, in vitro, respectively. Thus, As-AuNps bear promises as possible antibacterials, in future.
Insights
Green synthesis of gold nanoparticles using Anabaena spiroides shows promise as a novel antibacterial agent against multidrug-resistant bacteria. These synthesized nanoparticles demonstrate effective antimicrobial activity, offering a potential new strategy in combating resistant infections.
Area of Science:
- * Nanotechnology and Materials Science
- * Microbiology and Infectious Diseases
- * Environmental Science and Biotechnology
Background:
- * Rising prevalence of multidrug-resistant (MDR) pathogenic bacteria poses a significant threat to public health, causing outbreaks and hospital-acquired infections.
- * Continuous use of antibiotics has led to bacterial evolution, necessitating the development of novel, invincible antibacterial agents.
- * The search for alternative antimicrobial strategies is critical in modern medicine and pharmacy.
Purpose of the Study:
- * To green synthesize gold nanoparticles (AuNps) using the cyanobacterium Anabaena spiroides.
- * To characterize the synthesized Anabaena spiroides-gold nanoparticles (As-AuNps).
- * To evaluate the in vitro antibacterial efficacy of As-AuNps against clinically relevant MDR bacterial strains.
Main Methods:
- * Green synthesis of AuNps using chloroauric acid and cell-free extract of Anabaena spiroides.
- * Characterization of As-AuNps using UV-Vis spectrophotometry, SEM-EDX, XRD, and ART-FTIR analysis.
- * In vitro antibacterial activity assessment against Klebsiella oxytoca, MRSA, and Streptococcus pyogenes, determining Minimum Inhibitory Concentration (MIC) values.
Main Results:
- * UV-Vis spectrophotometry confirmed AuNps synthesis with an absorption peak at 538 nm.
- * FTIR analysis verified the presence and stabilization of AuNps by Anabaena spiroides extract.
- * As-AuNps exhibited significant in vitro antibacterial activity with MIC values of 25 mg/mL for K. oxytoca, 20 mg/mL for MRSA, and 30 mg/mL for S. pyogenes.
Conclusions:
- * Anabaena spiroides can be effectively utilized for the green synthesis of gold nanoparticles.
- * Synthesized As-AuNps demonstrate potent antibacterial properties against key MDR pathogens.
- * As-AuNps represent a promising future therapeutic candidate for combating multidrug-resistant bacterial infections.
