title: Biosynthesis, mosquitocidal and antibacterial properties of Toddalia asiatica-synthesized silver nanoparticles: do they impact predation of guppy Poecilia reticulata against the filariasis mosquito Culex quinquefasciatus?
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 study, silver nanoparticles (AgN) were biosynthesized a cheap aqueous extract of T. asiatica leaves as reducing and stabilizing agent. The formation of nanoparticle was confirmed by surface Plasmon resonance band illustrated in UV-vis spectrophotometer. AgN were characterized by FTIR, SEM, EDX, and XRD analyses. AgN were mostly spherical in shape, crystalline in nature, with face-centered cubic geometry, and their mean size was 25-30 nm. T. asiatica aqueous extract and green-synthesized AgN showed excellent larvicidal and pupicidal toxicity against the filariasis vector Culex quinqufasciatus, both in laboratory and field experiments. AgN LC50 ranged from 16.48 (I instar larvae) to 31.83 ppm (pupae). T. asiatica-synthesized were also highly effective in inhibiting growth of Bacillus subtilis, Klebsiella pneumoniae, and Salmonella typhi using the agar disk diffusion and minimum inhibitory concentration protocol. Lastly, we evaluated if sublethal doses of nanoparticles affect predation rates of fishes, Poecilia reticulata, against C. quinquefasciatus. In AgN-contaminated environment, predation of guppies against mosquito larvae was slightly higher over normal laboratory conditions. Overall, this study highlighted that T. asiatica-synthesized AgN are easy to produce, stable over time, and may be employed at low dosages to reduce populations of filariasis vectors, without detrimental effects on predation rates of mosquito natural enemies.
authors.affiliation: Division of Entomology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, 641046, Tamil Nadu, India.
authors.forename: Kadarkarai
authors.initials: K
authors.lastname: Murugan
authors.affiliation: Division of Entomology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, 641046, Tamil Nadu, India.
authors.forename: Joseph Selvaraj Eugine
authors.initials: JS
authors.lastname: Venus
authors.affiliation: Division of Entomology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, 641046, Tamil Nadu, India.
authors.forename: Chellasamy
authors.initials: C
authors.lastname: Panneerselvam
authors.affiliation: Department of Agriculture, Food and Environment, University of Pisa, via del Borghetto 80, 56124, Pisa, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Bedini
authors.affiliation: Department of Agriculture, Food and Environment, University of Pisa, via del Borghetto 80, 56124, Pisa, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Conti
authors.affiliation: Department of Environmental Biology, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185, Rome, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Nicoletti
authors.affiliation: Department of Marine Science, University of Calcutta, West Bengal, 700019, India.
authors.forename: Santosh Kumar
authors.initials: SK
authors.lastname: Sarkar
authors.affiliation: Institute of Marine Biology, National Taiwan Ocean University, Keelung, 202-24, Taiwan.
authors.forename: Jiang-Shiou
authors.initials: JS
authors.lastname: Hwang
authors.affiliation: Division of Entomology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, 641046, Tamil Nadu, India.
authors.forename: Jayapal
authors.initials: J
authors.lastname: Subramaniam
authors.affiliation: Division of Entomology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, 641046, Tamil Nadu, India.
authors.forename: Pari
authors.initials: P
authors.lastname: Madhiyazhagan
authors.affiliation: Division of Entomology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, 641046, Tamil Nadu, India.
authors.forename: Palanisamy Mahesh
authors.initials: PM
authors.lastname: Kumar
authors.affiliation: Division of Entomology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, 641046, Tamil Nadu, India.
authors.forename: Devakumar
authors.initials: D
authors.lastname: Dinesh
authors.affiliation: Division of Entomology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, 641046, Tamil Nadu, India.
authors.forename: Udaiyan
authors.initials: U
authors.lastname: Suresh
authors.affiliation: Department of Agriculture, Food and Environment, University of Pisa, via del Borghetto 80, 56124, Pisa, Italy. g.benelli@sssup.it.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Benelli
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D003465:Culex / Q000187:drug effects*; D007306:Insecticides / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D007814:Larva / Q000187:drug effects; D053758:Nanoparticles / Q000737:chemistry / Q000378:metabolism; D010936:Plant Extracts / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D011036:Poecilia; D011235:Predatory Behavior / Q000187:drug effects*; D027821:Rutaceae / Q000737:chemistry*; D012834:Silver / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D007306:Insecticides; D010936:Plant Extracts; D012834:Silver
keywords: Antibacterial activity; Aquatic predators; Culicidae; Green-synthesis; Mosquitocidal nanoparticles; Nanobiotechnologies; Poecilidae; Water purification