Nanotechnology is an integrative approach in the branches of science, engineering and technology which has numerous numbers of utilization in all the fields. It entails manipulating matter on a nano scale to conceive a new and modified product that can be used in various ways. To stress on one important property of the nanoparticles is that they have high surface to volume ratio which could help in bring about the change and thus making it use for many antimicrobial applications . Biotechnology is a field of science which is the utilizes the biological processes for the benefit of mankind in industrial and other purposes, it encompasses especially the use of genetic manipulation of microorganisms for the production of antibiotics, hormones and many other useful products . Nano biotechnology is another logical field that is arising at the convergence of materials research, nano sciences, and molecular biotechnology. This exceptionally interdisciplinary field is connected to the physical and synthetic properties of natural and inorganic nanoparticles, alongside different aspects of sub-atomic science, Genetic Engineering and protein engineering, and immunology .
Nanoparticles are primarily synthesized using two approaches: physical (top down) and chemical (bottom up). The top down or physical method entails converting bulk material into nano-scale fragments. It encompasses techniques such as laser ablation, chemical vapour deposition, and electro deposition. The disadvantage of these methods is that they do not allow for the creation of nanoparticles of a specific size or structure. Bottom-up approach, on the other hand, entails creating nanoparticles from a small structure, such as atoms, to a larger structure, i.e. from the bottom. This method is typically preferred because it provides greater precision in synthesizing these particles. Hydrothermal synthesis, sonochemical methods, and radiolytic methods are examples of this approach.
Technological advancement has resulted in the discovery of alternative methods for synthesizing nanoparticles, one of which is the biological method of synthesis. Bacteria, fungi, and plants are some of the biological sources of nanoparticle production. Green nanotechnology is the utilization of like plants, plant-based materials, microbes, organisms, and secondary metabolites as a reducing material during the synthesis of nanoparticles . Nanoparticles can be engineered to perform multiple functions, such as antibacterial, antifungal, and anticancer drugs. Silver Nanoparticles have been shown to be effective against fungal species and other prokaryotes even at very low concentrations. In the development of safer, less expensive, and more environmentally friendly technologies, nanomaterial synthesis is in high demand. Thus, biogenic synthesis of silver nanoparticles has picked the interest of research groups due to their unique properties such as size and shape, ease of production, easily scaled up for large scale, environmentally friendly, and strong physico-chemical properties and optical properties [5, 6]. Silver nanoparticles are used to replace antibacterial agents in wastewater treatment, the textiles, medical and food packaging, and other applications. Silver nanoparticles are also involved in counteracting adhesive substances, inhibiting the formation of biofilms .
Endophytes are endosymbionts that live within plants for at least part of their lives without causing deadly disease. Endophytes are mandated for plant growth and development because they obtain chemical energy from the atmosphere, soil, water, and organic matter. Endophytic fungi are essential for nutrient uptake. Thus, plants and endophytes have a symbiotic relationship in which both the plant and the endophytes benefited through their symbiotic relationship through protective mechanisms and plant growth . Endophyte-mediated nanoparticle synthesis is a novel research area that combines biology and nanotechnology. On the planet, there are approximately 300,000 plant species, each with its own set of endophytic organisms. The unique properties of endophytes can be harnessed to produce AgNPs, which can be used in a variety of applications. Many studies can be carried out to examine the world of endophytes and see how the synthesis methods and applications differs . Colletotrichum gloeosporioides is a plant pathogen that is found all over the world. For optimal development, it requires a temperature of 25–28°C and a pH of 5.8–6.5. This organism is dormant during the dry season and transforms into dynamic stages when exposed to favourable natural conditions and when it changes it will act as pathogen . Secondary metabolites which are obtained from endophytic fungi are consistently considered as rich sources and have normally active molecules and these molecules have good antimicrobials, drugs and herbicidal properties. Therefore, the portrayal of secondary metabolites found in different Colletotrichum species could assist with revealing insight into the identification of this family of endophytes and to additionally it clarifies the role of the metabolites in the pathogenicity of these organisms .
The aim of the study is to accomplish and synergise the antimicrobial application of CgAgNPs. Plasmid-encoded CTX-M sort extended range Beta- lactamases (ESBLs), which have been broadly revealed all through the most recent years, are generally found and connected with Escherichia coli [11, 12]. CTX-M-15, found in India since 2001 and is currently perceived as the most appropriated CTX-M compound . It differs from CTX-M-3 by one amino corrosive substitution at position 240 (Asp-240 Gly), which appears to present increased ceftazidime reactant movement. . Since the last part of the 1970s, amp C beta-lactamases have been perceived as one of the goes between of antimicrobial opposition in Gram negative microscopic organisms. These enzymes are cephalosporinases, which can hydrolyze all beta-lactams to some degree. There are two types of amp C beta- lactamases: plasmid-mediated ampC and chromosomal or inducible ampC . The CTX-M pandemic is caused by E. coli delivering CTXM catalyst, which spread throughout the world as a result of the onset of UTIs. CTXM-15, which was discovered in 2001, is the most commonly used catalyst. CTXM is in charge of diseases picked up at emergency rooms. CTX-M beta-lactamases hydrolyze ceftriaxone, cefotaxime, and, most notably, ceftazidime. CTXM-15 ESBLs were discovered in India and Japan in K. pneumoniae, E. coli, and Enterobacter aerogenes. Southern India has a higher prevalence of CTXM-15 type ESBLs. In the current study, CTXM-15 encoding clinical E. coli strains were used to reduce the antibacterial impact of endophytic fungal compound-based silver nanoparticles. .
This research work focuses on the green synthesis of endophytic fungal extract mediated silver nanoparticles CgAgNPs from the aqueous extract of the endophyte Colletotrichum gloeosporioides and evaluated for its antibacterial efficacy in Escherichia coli ATCC 25922 and its pathogenic strains. In silico analysis was done to check the efficiency of secondary metabolites of endophyte against the gene of interest which are CTX-M-15 and AmpC of Escherichia coli using Molecular docking and fungal lead compounds were screened using Lipinski Rule of five and pharmacokinetic properties was checked using Swiss ADME.