New polymeric molluscicide-attractant (niclosamide-l-glutamate) for control of Biomphalaria alexandrina

• Published in: Egyptian journal of aquatic research 2020-03, Vol.46 (1), p.13-18
• Main Authors: Kenawy, El-Refaie, Harras, Samar F., Rizk, El-Sayed T., Mona, Mohamed H., ElMehlawy, Mostafa H.
• Format: Article
• Language: English
• Subjects: Biomphalaria alexandrina; Control of schistosomiasis; Controlled release molluscicides; l-glutamate attractant; Niclosamide
• ISSN: 1687-4285; 2090-3278
• DOI: 10.1016/j.ejar.2019.09.002

Controlled-release technology was introduced to offer an incredible guarantee for improving the adequacy of the existing active molecules and solving the related environmental troubles. Our study attempts to utilize the controlled release of alginate niclosamide-l-glutamate formulation to control Schistosoma mansoni intermediate host (Biomphalaria alexandrina snail) and to evaluate the amount of niclosamide released in relation to its attraction and mortality rate. Results: polymeric formulations B3-4b at a concentration of 0.3 ppm niclosamide in combination with 75% l-glutamate caused 100% mortality of B. alexandrina snails 5-day post-exposure. Stable snails mortality rates were obtained post-exposure to polymer B3-4a (R2 = 0.9823). The high potential of the polymeric formulations B3-4a (0.2 ppm niclosamide and 75% l-glutamate) to attract snail toward polymer direction was manifested by 80%, 14%, 6% and 0% snail in areas (I), (II), (III) and (IV), respectively 24-hr post-exposure. While, B3-4a showed a high mortality rate of attracted snails resembled by 40% and 100% on the 2nd and 7th days, respectively. The modified structure of polymer-niclosamide-l-glutamate prolonged the validity and efficiency of the niclosamide. Slowly released molluscicide was effective at lower concentrations with increasing concentrations of the applied attractant that could reduce its toxicity to the water ecosystem.