Veterinary World

Fayez A. Bakry ¹, Marwa Th. Atwa ², Marwa M. Attia ³

Affiliations
1 Department of Medical Malacology, Theodor Bilharz Research Institute, Giza, EG
2 Department of Zoology, Fayoum University, Fayoum Governorate, EG
3 Department of Parasitology, Cairo University, Giza, EG

Abstract

Aim: The present study aims to focus on the role of common marine snails (Littorina littorea) as a vector for some trematode parasites.

Materials and Methods: A total of 327 marine water L. littorea snails were collected during the summer of 2016 from a Qarun lake in the EL-Fayoum Governorate, Egypt. The snails were investigated for infection by trematode parthenitae through induction of cercarial shedding by exposure to light and crushing the snails. The species were stored in Search Laboratory of Zoology Department, Faculty of Science, Fayoum University.

Results: Three species of Strigeid littorina cercaria were identified from the infected snails. They are described here and they identified in relation to close-up morphological features and linked to its snail hosts. They give the following names: Cercaria strigeid littorina type 1, C. strigeid littorina type 2, and C. strigeid littorina type 3. The incidence of infection by these cercariae was 33%, 25.7%, and 2.4%, respectively.

Conclusion: This study is clarifying the importance of this marine snail as intermediate hosts for new trematode species.

Keywords

Littorina littorea, Qarun Lake, Strigeid cercaria.

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Marwa M. Attia ¹, Soliman M. Soliman ², Mahmoud A. Khalf ³

Affiliations
1 Department of Parasitology, Cairo University, Giza, P.O. Box 12211, EG
2 Department of Medicine and Infectious Diseases, Cairo University, Giza, P.O. Box 12211, EG
3 Department of Veterinary Hygiene and Management, Cairo University, Giza, P.O. Box 12211, EG

Abstract

Aim: This research was conducted to evaluate the molluscicidal and mosquitocidal efficacy of silica nanoparticles in the eradication of the larvae and pupa of malaria and filariasis vector as well as vectors of rift-valley fever virus (Culex pipiens); Schistosoma mansoni vector (Biomphlaria alexandrina (snail and egg masses)).
Materials and Methods: Hydrophilic nanosilica particles (NSPs) were characterized using transmission electron microscope during the preliminary part of the study; the stages were exposed to upgrade concentrations of NSP from 50 to 1200 ppm each for 24-36 h exposure time. The highly effective concentrations were re-evaluated at lower exposure time as 3, 6, and 12 h.
Results: Lethal concentration (LC₅₀) and LC₉₀ versus mosquito larvae were (350 ppm/24 h and 1400 ppm/24 h, respectively). C. pipiens pupae proved slight high tolerance versus the effect of these nanoparticles as the two previous doses increased to 680 ppm/6 h and 1300 ppm/24 h. The LC₅₀ and LC₉₀ versus B. alexandrina were increased to 590 ppm/6 h and 980 ppm/48 h, respectively. Moreover, the embryonated snail egg masses appear more susceptible to the toxic effect of these nanoparticles than the non-embryonated eggs as the LC₅₀ and LC₉₀ were increased to 1450 ppm/12 h and 1250 ppm/48 h, respectively, for embryonated eggs, and it was 1400 ppm/24 h and 1890 ppm/48 h, respectively, for non-embryonated one.
Conclusion: The results open a new field for controlling the infectious diseases through eradication of their vectors by the way that avoids the resistance recorded from the successive chemical application in this field.

Keywords

Biomphalaria alexandrina, Culex pipiens, Egypt, Nanosilica, Rift Valley Fever, Schistosomiasis.

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