| Autor: |
Abou-El-Naga IF; Medical Parasitology Department, Faculty of Medicine, Alexandria University, Alexandria, EG., Sadaka HA; Medical Parasitology Department, Faculty of Medicine, Alexandria University, Alexandria, EG., Amer EI; Medical Parasitology Department, Faculty of Medicine, Alexandria University, Alexandria, EG., Diab IH; Medical Biochemistry and Molecular Biology Department, Faculty of Medicine, Alexandria University, Alexandria, EG., Khedr SI; Medical Parasitology Department, Faculty of Medicine, Alexandria University, Alexandria, EG. |
| Abstrakt: |
Of the approximately 34 identified Biomphalariaspecies,Biomphalaria alexandrinarepresents the intermediate host of Schistosoma mansoniin Egypt. Using parasitological and SOD1 enzyme assay, this study aimed to elucidate the impact of the age of B. alexandrinasnails on their genetic variability and internal defence against S. mansoniinfection. Susceptible and resistant snails were reared individually for self-reproduction; four subgroups of their progeny were used in experiment. The young susceptible subgroup showed the highest infection rate, the shortest pre-patent period, the highest total cercarial production, the highest mortality rate and the lowest SOD1 activity. Among the young and adult susceptible subgroups, 8% and 26% were found to be resistant, indicating the inheritance of resistance alleles from parents. The adult resistant subgroup, however, contained only resistant snails and showed the highest enzyme activity. The complex interaction between snail age, genetic background and internal defence resulted in great variability in compatibility patterns, with the highest significant difference between young susceptible and adult resistant snails. The results demonstrate that resistance alleles function to a greater degree in adults, with higher SOD1 activity and provide potential implications for Biomphalariacontrol. The identification of the most susceptible snail age enables determination of the best timing for applying molluscicides. Moreover, adult resistant snails could be beneficial in biological snail control. |
