Toxicity assessment of silver nanoparticles synthesized using endophytic fungi against nosacomial infection

Multidrug-resistant Bacillus species isolated from hospital soil environment is controlled by nanobiotics incorporated nanoformulation

Multidrug resistance is a serious hazard to the environment, it claims a large number of lives every year. Lack of drug options and easy transmission of these organisms remain the biggest threat in treating the relative infections whose causative systems have evolved and become stronger in due course of time. Hospitals serve as one of the largest breeding grounds for harbouring these organisms. This study aims to isolate and characterize multidrug-resistant microorganisms from soil samples collected from hospital waste dumping premises. Polyherbal nanoformulation was synthesized from ethno-medicinal source Triphala (three berries) and characterized using various physico-chemical characterization techniques. The antibacterial efficacy of the polyherbal nanoformulation was evaluated by employing various assays to determine MIC, MBC, and biofilm inhibition potential in isolated strains. Bacterial colonies were isolated and the DNA was sequenced. The isolated organisms were identified as Bacillus cereus, Bacillus licheniformis, and Bacillus pumilus and they were subjected to antibiotic susceptibility by using various antibiotics. It was found that all the microorganisms were multidrug-resistant and possessed resistance to various classes of antibiotics. The various antibacterial assays showed that the polyherbal nanoformulation was highly effective in controlling growth and biofilm formation even at lower concentrations when compared with commercial antibiotics. The novelty of this research work lies in combining the beneficial effects of silver and polyherbal drugs into a single Polyherbal nanoformulation. This is the first novel report to utilize polyherbal nanoformulation to control the multidrug-resistant microorganisms thriving in hospital waste dumping sites. Hence, this nanobiotics incorporated polyherbal nanoformulation can be developed into a commercial product to treat the hospital waste material before dumping it into the environment.

Eco-friendly synthesized silver nanoparticles from endophytic fungus Phyllosticta owaniana: KUMBMDBT-32 and evaluation of biomedical properties

The primary objective of the current investigation was the biosynthesis of Phy-AgNPs by the endophytic fungus Phyllosticta owaniana (extracted from Abrus precatorius) and the evaluation of the secondary metabolites from the ethyl acetate extract of P. owaniana cultivated by submerged fermentation. Utilizing bioanalytical strategies, Phy-AgNPs were characterized. The UV-visible spectrophotometer analysis revealed an absorption spectrum with a peak at 420 nm, thus validating the Phy-AgNPs synthesis. The FTIR analysis revealed peaks correlating to various potential functional groups, suggesting that Phy-AgNPs have been reduced and capped. SEM-EDAX and HR-TEM analyses demonstrated the spherical shape of Phy-AgNPs, and the 3 keV EDAX analysis confirmed the existence of silver atoms. XRD analyses showed the Phy-AgNPs crystalline structure. The size and the stability of synthesized Phy-AgNPs (65.81 nm) were measured by DLS and Zeta potential studies. While the ethyl acetate extract was analyzed with GC-MS and FTIR for secondary metabolites. The synthesized Phy-AgNPs showed effective antibacterial activity against Pseudomonas aeruginosa (15.1 ± 0.17 mm, 10 mg/mL), while the antifungal activity of Phy-AgNPs inhibited the growth of Candida albicans extremely efficiently (12.16 ± 0.28 mm, 10 mg/mL). Phy-AgNPs were evaluated for a variety of biomedical properties in which they showed significant activity. In a cell viability assay using the MTT assay, Phy-AgNPs exhibited a cytotoxic impact of up to 30.67% and 34.53% when 200 µg/mL were detected. In both in vitro and in vivo anti-inflammatory examinations, nanoparticles (NPs) exhibited a significant anti-inflammatory effect. These findings support the pharmaceutical and biomedical properties of the synthesized Phy-AgNPs.

Myconanoparticles Break Antibiotic Resistance in Staphylococcus aureus and Acinetobacter baumannii

In this current study, the extracts of endophytic fungi (Aspergillus niger) were utilized to synthesize the silver nanoparticles (AnNps). In silico screening was carried out by docking secondary metabolites of Aspergillus niger with drug-resistant proteins such as penicillin-binding protein (pbp2a) and clumping factor A of Staphylococcus aureus, penicillin-binding protein (PBP3), and outer membrane protein of Acinetobacter baumannii. The molecular docking analysis revealed the interaction between secondary metabolites of Aspergillus niger with virulence factors of the pathogenic bacteria. AnNps are characterized by various physicochemical methods to determine the size, shape, and stability. Antibacterial efficacy of synthesized nanoparticles (AnNps) was screened in clinical pathogens. AnNp treatment significantly reduced the growth of MDR pathogens. The results suggested that AnNps can be incorporated to produce antimicrobial agents to control drug resistant pathogenic bacteria.

Moringa oleifera Nanoparticles Demonstrate Antifungal Activity Against Plant Pathogenic Fungi

Fungal diseases in plants are creating numerous problems in the developed and developing nations. Silver, a notable metal because of its inertness and its role in nanoscience, has received a considerable amount of focus in the development of an ecofriendly green solution to control many microbial infections. The herbal product from various plant sources with the combination of silver was used to develop nanoparticles, against the pathogens. In this study, we developed Moringa oleifera leaf- and flower-mediated silver nanoparticles with the particle size of 77.45 nm and 63.20 nm respectively. Fungicidal activity of both Moringa oleifera leaf (MLNp) and flower (MFNp) nanoparticles was studied in vitro against plant pathogenic fungi Pestalotiopsis mangiferae isolated from infected coconut palm. Nanoparticles from Moringa oleifera leaves and flowers reduced the radial growth of fungi significantly even at lower concentrations and acted as a potent fungistatic agent.

Protein corona on biogenic silver nanoparticles provides higher stability and protects cells from toxicity in comparison to chemical nanoparticles

The development of environmentally friendly new procedures for the synthesis of metallic nanoparticles is one of the main goals of nanotechnology. Proteins and enzymes from plants, filamentous fungi, yeast, and bacteria to produce nanoparticles are both valuable and viable alternatives to conventional synthesis of nanomaterials due to their high efficiency and the low cost to scale up and generate large quantities. The aim of this work is to compare biogenic silver nanoparticles (AgNPs) obtained from cell-free filtrates from the fungus Macrophomina phaseolina to conventional chemical AgNPs, in biocidal activity and toxicity. Our results show that bio-AgNPs displayed similar bactericidal activity than chemical AgNPs, but less toxicity in the model organism Caenorhabditis elegans. We employed biochemical and proteomic techniques to profile the unique surface chemistry of the capping in the bio-AgNPs and therefore to identify the proteins involved in their synthesis and stability. These results not only suggest that the proteins involved in the synthesis of the nanoparticles and corona formation in the bio-AgNPs are responsible for keeping the silver core preserved making them more stable in time, but also masking and protecting eukaryotic cells from metal toxicity.

Silver Decorated Myconanoparticles Control Growth and Biofilm Formation in Uropathogenic E. coli

Nanotechnology involves the synthesis of nanoparticles that have been used in the therapeutic application for treating diseases. In this present study, we have adopted the synthesis of myconanoparticles from the extracellular extract of endophytic fungi Penicillium sclerotiorum (PsNps) and validated its antibacterial potential against antibiotic-resistant uropathogenic E. coli and ATCC (25,922) strain of Escherichia coli. Endophytic fungi were isolated from the healthy leaves of Tamarindus indica. The genomic DNA from endophytic fungi was isolated and the ITS region was amplified by polymerase chain reaction (PCR) using universal fungal primers ITS1 and ITS4 and sequenced for the identification of endophytic fungal isolates. Penicillium sclerotiorum extract was used for the synthesis of silver nanoparticles (PsNps) and was characterized by UV-vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), zeta potential, FE-SEM, and Energy dispersive X-ray analysis (EDAX). Antibacterial activity of PsNps was tested against the antibiotic-resistant uropathogenic E. coli and ATCC (25,922) strain of E. coli. Further experiments were carried out to explore the potential of PsNps in regulating the CTX-M-15 gene. The antimicrobial activity showed that the PsNps inhibited growth, biofilm formation in both the strains of E. coli. The expression of the gene encoding CTX-M-15 was downregulated in a resistant strain of uropathogenic E. coli. Our results suggest that the PsNps could be used as an alternative source for antibiotics. Thus, further studies can be conducted to prove the in vivo potential of PsNps and can be formulated for commercialization.