Several methods of Deoxyribonucleic acid (DNA) extraction have been applied to extract bacterial DNA. The amount and the quality of the DNA obtained for each one of those methods are variable. The study aimed to evaluate bacterial DNA extraction using conventional boiling method followed by alcohol precipitation. DNA extraction from Gram negative bacilli was extracted and precipitated using boiling method with further precipitation by ethanol. The extraction procedure performed using the boiling method resulted in high DNA yields for both E. coli and K. pneumoniae bacteria in (199.7 and 285.7μg/ml, respectively) which was close to control method (229.3 and 440.3μg/ml). It was concluded that after alcohol precipitation boiling procedure was easy, cost-effective, and applicable for high-yield quality of DNA in Gram-negative bacteria.

Acinetobacter baumannii is a Gram-negative coccobacillus responsible for severe hospital-acquired infections, particularly in intensive care units (ICUs). The current study was designed to characterize the virulence traits of biofilm-forming carbapenem-resistant A. baumannii causing pneumonia in ICU patients using a Galleria mellonella model. Two hundred and thirty patients with hospital-acquired or ventilator-associated pneumonia were included in our study. Among the total isolates, A. baumannii was the most frequently isolated etiological agent in ICU patients with pneumonia (54/165, 32.7%). All A. baumannii isolates were subjected to antimicrobial susceptibility testing by the Kirby–Bauer disk diffusion method, while the minimum inhibitory concentrations of imipenem and colistin were estimated using the broth microdilution technique. The biofilm formation activity of the isolates was tested using the microtiter plate technique. Biofilm quantification showed that 61.1% (33/54) of the isolates were strong biofilm producers, while 27.7% (15/54) and 11.1% (6/54) showed moderate or weak biofilm production. By studying the prevalence of carbapenemases-encoding genes among isolates, blaOXA-23-like was positive in 88.9% of the isolates (48/54). The BlaNDM gene was found in 27.7% of the isolates (15/54 isolates). BlaOXA-23-like and blaNDM genes coexisted in 25.9% (14/54 isolates). Bap and blaPER-1 genes, the biofilm-associated genes, coexisted in 5.6% (3/54) of the isolates. For in vivo assessment of A. baumannii pathogenicity, a Galleria mellonella survival assay was used. G. mellonella survival was statistically different between moderate and poor biofilm producers (p < 0.0001). The killing effect of the strong biofilm-producing group was significantly higher than that of the moderate and poor biofilm producers (p < 0.0001 for each comparison). These findings highlight the role of biofilm formation as a powerful virulence factor for carbapenem-resistant A. baumannii that causes pneumonia in the ICU.

Bionanotechnology is the combination of biotechnology and nanotechnology for the development of biosynthetic and environmentally friendly nanomaterial synthesis technology. The presented research work adopted a reliable and environmentally sustainable approach to manufacturing silver nanoparticles from Brachychiton populneus (BP-AgNPs) leaf extract in aqueous medium. The Brachychiton populneus-derived silver nanoparticles were characterized by UV–Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy dispersive X-ray analysis (EDX). In addition, the antioxidant, anti-inflammatory, antidiabetic, and cytotoxic activities of AgNPs were brought to light. The synthesis of BP-AgNPs was verified at 453 nm wavelength by UV–Vis spectrum. FTIR analysis revealed that synthesis, stability, and capping of AgNPs depend on functional groups such as alkane, alkene, nitro, flouro, phenol, alcoholic, and flavones, present in plant extract. The SEM analysis revealed evenly distributed cubical-shaped nanoparticles. The average diameter of AgNPs was 12 nm calculated from SEM image through ImageJ software. EDX spectrum confirmed the presence of Ag at 3 keV and other trace elements such as oxygen and chlorine. The biosynthesized silver nanoparticles exhibited proven antioxidant (DPPH assay), antidiabetic (alpha amylase assay), anti-inflammatory (albumin denaturation assay), and cytotoxic (MTT assay) potential against U87 and HEK293 cell lines in comparison to standard drugs. In these assays, BP-AgNPs exhibited inhibition in a concentration-dependent manner and had lower IC50 values compared to standards. All these outcomes suggest that silver nanoparticles work as a beneficial biological agent. The salient features of biosynthesized silver nanoparticles propose their effective applications in the biomedical domain in the future.

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In this study, the antibacterial and antifungal properties of silver nanoparticles synthesized with the aqueous plant extract of Acer oblongifolium leaves were defined using a simplistic, environmentally friendly, reliable, and cost-effective method. The aqueous plant extract of Acer oblongifolium, which served as a capping and reducing agent, was used to biosynthesize silver nanoparticles. UV visible spectroscopy, X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and scanning electron microscopy were used to analyze the biosynthesized Acer oblongifolium silver nanoparticles (AgNPs). Gram-positive bacteria (Bacillus paramycoides and Bacillus cereus) and Gram-negative bacteria (E. coli) were used to test the AgNPs’ antibacterial activity. The presence of different functional groups was determined by FTIR. The AgNPs were rod-like in shape. The nanoparticles were more toxic against Escherichiacoli than both Bacillus cereus and Bacillus paramycoides. The AgNPs had IC50 values of 6.22 and 9.43 and mg/mL on HeLa and MCF-7, respectively, proving their comparatively strong potency against MCF-7. This confirmed that silver nanoparticles had strong antibacterial activity and antiproliferative ability against MCF-7 and HeLa cell lines. The mathematical modeling revealed that the pure nanoparticle had a high heat-absorbing capacity compared to the mixed nanoparticle. This research demonstrated that the biosynthesized Acer oblongifolium AgNPs could be used as an antioxidant, antibacterial, and anticancer agent in the future.