Potential of Silver Nanoparticles in Overcoming the Intrinsic Resistance of Pseudomonas aeruginosa to Secondary Metabolites from Carnivorous Plants

Diversity of biofilm-specific antimicrobial resistance genes in Pseudomonas aeruginosa recovered from various clinical isolates

Background and Objectives

The resistance of Pseudomonas aeruginosa to antibiotics offers a significant challenge in the treatment of patients. This study aimed to investigate the antimicrobial resistance profile, biofilm-specific antimicrobial resistance genes, and genetic diversity of P. aeruginosa recovered from clinical samples.

Materials and Methods

Totally 47 non-duplicate isolates of P. aeruginosa were recovered from various clinical samples. toxA, algD, ndvB, and tssC1 genes were detected in biofilm-producing isolates. The DNA sequences of the toxA and tssC1 genes were analyzed, by creating phylogenetic trees.

Results

The findings revealed that 30 (63.8%) of the isolates tested positive for Extended spectrum β-lactamase (ESBL), whereas 31 (65.9%) tested positive for Metallo-β-lactamase (MBL) and all of the isolates presented the toxA genes, and 19.1%,17%, 6.3% presented by algD, ndvB and tssC1 genes. Besides, the phylogenetic trees of the toxA and tssC1 gene isolates suggested a genotype that was closely aligned with others. Gene sequencing similarity revealed 99% identity with other isolates deposited in GenBank.

Conclusion

The occurrence of toxA was most prevalent. One isolate was recorded as a novel isolate in the global gene bank as a locally isolated strain from the city of Erbil that has never been identified in global isolates due to genetic variation.

Biological Potential of Carnivorous Plants from Nepenthales

Since Charles Darwin and his book carnivorous plants have aroused interest and heated debate. In addition, there is growing interest in this group of plants as a source of secondary metabolites and in the application of their biological activity. The aim of this study was to trace the recent literature in search of the application of extracts obtained from families Droseraceae, Nepenthaceae, and Drosophyllaceae to show their biological potential. The data collected in the review clearly indicate that the studied Nepenthales species have great biological potential in terms of antibacterial, antifungal, antioxidant, anti-inflammatory, and anticancer use. We proposed that further investigations should include: (i) bioactivity-guided investigations of crude plant extract to connect a particular type of action with a specific compound or a group of metabolites; (ii) a search for new bioactive properties of carnivorous plants; (iii) establishment of molecular mechanisms associated with specific activity. Furthermore, further research should be extended to include less explored species, i.e., Drosophyllum lusitanicum and especially Aldrovanda vesiculosa.

Carnivorous Plants from Nepenthaceae and Droseraceae as a Source of Secondary Metabolites

Carnivorous plants are able to attract small animals or protozoa and retain them in their specialized traps. Later, the captured organisms are killed and digested. The nutrients contained in the prey bodies are absorbed by the plants to use for growth and reproduction. These plants produce many secondary metabolites involved in the carnivorous syndrome. The main purpose of this review was to provide an overview of the secondary metabolites in the family Nepenthaceae and Droseraceae, which were studied using modern identification techniques, i.e., high-performance liquid chromatography or ultra-high-performance liquid chromatography with mass spectrometry and nuclear magnetic resonance spectroscopy. After literature screening, there is no doubt that tissues of species from the genera Nepenthes, Drosera, and Dionaea are rich sources of secondary metabolites that can be used in pharmacy and for medical purposes. The main types of the identified compounds include phenolic acids and their derivatives (gallic, protocatechuic, chlorogenic, ferulic, p-coumaric acids, gallic, hydroxybenzoic, vanillic, syringic caffeic acids, and vanillin), flavonoids (myricetin, quercetin, and kaempferol derivatives), including anthocyanins (delphinidin-3-O-glucoside, cyanidin-3-O-glucoside, and cyanidin), naphthoquinones (e.g., plumbagin, droserone, and 5-O-methyl droserone), and volatile organic compounds. Due to the biological activity of most of these substances, the importance of the carnivorous plant as a pharmaceutical crop will increase.

Green Synthesis and Characterisation of Silver Nanoparticles Using Cassia tora Seed Extract and Investigation of Antibacterial Potential

Nanoparticle research is fascinating and getting hold of consequences due to the wide variety of applications in the biomedical field. Green synthesis of nanoparticles is a cost-effective and eco-friendly approach. It can be synthesised using fungi, algae, plant, yeast, bacteria, microbial enzymes etc. Our current research study focuses on the green synthesis of silver nanoparticles using seed extract of Cassia tora. The colour change from yellow to red colour confirms the formation of silver nanoparticles. The synthesised silver nanoparticles were characterised by Ultraviolet-Visible spectroscopy, Fourier-transform infrared (FTIR), X-ray diffraction analysis (XRD), Scanning Electron Microscopy (SEM) and antibacterial efficacy against three different strains were analysed. The surface plasmon resonance of synthesised AgNPs using Cassia tora seed extract shows maximum absorption peak at 423 nm in UV-visible spectroscopy. X-ray diffraction displays the crystalline nature of synthesised AgNPs and they exhibited four distinct peaks at 36.69°, 42.92°, 63.27° and 76.46°. The particle size of synthesised AgNPs observed through SEM was found to be 55.80 nm, 58.97 nm, 61.06 nm, 63.26 nm and 64.80 nm. S.aureus exhibited maximum zone of inhibition of 12 mm and 13 mm when treated with 25 and 50 μl of the synthesised nanoparticles. Thus, the green synthesised silver nanoparticle using Cassia tora seed extract proved to possess strong anti-bacterial activity.