S argassum muticum-synthesized silver nanoparticles: an effective control tool against mosquito vectors and bacterial pathogens

Abstract

Mosquito-borne diseases represent a deadly threat for millions of people worldwide. Furthermore, pathogens and parasites polluting water also constitute a severe plague for populations of developing countries. In this research, silver nanoparticles (AgNP) were synthesized using the aqueous extract of the seaweed Sargassum muticum. The production of AgNP was confirmed by surface plasmon resonance band illustrated in UV-vis spectrophotometry. AgNP were characterized by FTIR, SEM, EDX, and XRD analyses. AgNP were mostly spherical in shape, crystalline in nature, with face-centered cubic geometry, and mean size was 43-79 nm. Toxicity of AgNP was assessed against Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus. In laboratory, AgNP were highly toxic against larvae and pupae of the three mosquito species. Maximum efficacy was observed against A. stephensi larvae, with LC50 ranging from 16.156 ppm (larva I) to 28.881 ppm (pupa). In the field, a single treatment with AgNP (10 × LC50) in water storage reservoirs was effective against the three mosquito vectors, allowing complete elimination of larval populations after 72 h. In ovicidal experiments, egg hatchability was reduced by 100% after treatment with 30 ppm of AgNP. Ovideterrence assays highlighted that 10 ppm of AgNP reduced oviposition rates of more than 70% in A. aegypti, A. stephensi, and C. quinquefasciatus (OAI = -0.61, -0.63, and -0.58, respectively). Antibacterial properties of AgNP were evaluated against Bacillus subtilis, Klebsiella pneumoniae, and Salmonella typhi using the agar disk diffusion and minimum inhibitory concentration protocol. AgNP tested at 50 ppm evoked growth inhibition zones larger than 5 mm in all tested bacteria. Overall, the chance to use S. muticum-synthesized AgNP for control of mosquito vectors seems promising since they are effective at low doses and may constitute an advantageous alternative to build newer and safer mosquito control tools. This is the first report about ovicidal activity of metal nanoparticles against mosquito vectors.

A Facile One-Pot Synthesis of Eco-Friendly Nanoparticles Using Carissa carandas: Ovicidal and Larvicidal Potential on Malaria, Dengue and Filariasis Mosquito Vectors

“…LC 50 and LC 90 were calculated using the method by Finney [35]. Data from ovicidal experiments were analyzed using ANOVA followed by Tukey's HSD test (p B 0.05).…”

Acute toxicity and repellent activity of the Origanum scabrum Boiss. & Heldr. (Lamiaceae) essential oil against four mosquito vectors of public health importance and its biosafety on non-target aquatic organisms

“…Plant-borne insecticides, as well as essential oils (EOs), are encouraging since they are effective at reduced doses, environmental-friendly, biodegradable, and often economical (Benelli 2015b;Pavela 2015a;Govindarajan and Benelli 2016a, b, c;Govindarajan et al 2011Govindarajan et al , 2013a. Thus, recent research focused on plant EOs and extracts as possible sources of arthropod ovicidal, larvicidal, adulticidal, and repellent compounds (e.g., Cheng et al 2003Cheng et al , 2004Govindarajan 2010a;Govindarajan et al 2011;Dinesh et al 2015;Madhiyazhagan et al 2015;Murugan et al 2015a, b, c;Pavela 2015b;Suresh et al 2015;Benelli et al 2016b;Jaganathan et al 2016;Panneerselvam et al 2016).…”

Eco-friendly drugs from the marine environment: spongeweed-synthesized silver nanoparticles are highly effective on Plasmodium falciparum and its vector Anopheles stephensi, with little non-target effects on predatory copepods

“…As regards to seaweeds, our results are comparable with the toxicity of Caulerpa scalpelliformissynthesized AgNP against Culex quinquefasciatus, with LC 50 values of 3.08 ppm (I), 3.49 (II), 4.64 (III), 5.86 ppm (IV), and 7.33 (pupa) (Murugan et al 2015a). Furthermore, Madhiyazhagan et al (2015) reported that the S. muticum-synthesized AgNP were highly toxic against larvae and pupae of Aedes aegypti, A. stephensi, and C. quinquefasciatus. Recently, Murugan et al (2016) showed that AgNP synthesized using an aqueous extract of C. clavulatum were highly effective against larvae and pupae of A. aegypti, with LC 50 ranging from 21.460 ppm (I) to 33.877 ppm (pupa).…”

“…A. vera-fabricated AgNP led to zones of inhibition higher than 19 mm in all targeted bacteria. Recently, Madhiyazhagan et al (2015) reported that the S. muticum-synthesized AgNPs showed good anti-bacterial properties against B: subtilis, K. pneumoniae, and S. typhi. AgNP tested at 50 ppm evoked growth inhibition zones larger than 5 mm in all tested bacteria, while inhibition zones were larger than 10 mm when nanoparticles were tested at 150 ppm.…”