Euphorbia rothiana-Fabricated Ag Nanoparticles Showed High Toxicity on Aedes aegypti Larvae and Growth Inhibition on Microbial Pathogens: A Focus on Morphological Changes in Mosquitoes and Antibiofilm Potential Against Bacteria

Abstract

The green synthesis of pesticides and antibiotics is gaining increasing importance nowadays. We fabricated Euphorbia rothiana-capped Ag nanoparticles (Er-AgNPs), testing their antibiofilm and growth inhibition potential on various microbial pathogens. We evaluated the toxicity of E. rothiana-capped Ag nanoparticles on larvae of the Zika virus vector Aedes aegypti, shedding light on histological changes post-exposure to the plant leaf extract and Er-AgNPs. Nanoparticles were characterized by UV–Vis, and FTIR spectroscopy, XRD and TEM. Light microscopy showed the greatest inhibition of biofilm formation in Gram positive and Gram-negative bacteria post-treatment with E. rothiana-capped Ag nanoparticles at 75 μg/ml. Confocal microscopy confirmed the biofilm interruption and disintegration post-treatment with nanoparticles at 75 μg/ml. E. rothiana extract and Er-AgNPs showed 100% larvicidal activity on A.aegypti at 50 and 8 mg/L, respectively. AgNO3 led to 100% mortality of A. aegypti larvae at 40 mg/L after 48 h. Stereomicroscopic and histopathological analysis reported tissue damages and loss of cuticular parts in mosquito larvae.