Biological and biochemical studies in Bullinus truncatus snails collected from Saudi Arabia

In Saudi Arabia three species of snails namely, Bulinus truncatus, B. beccarii and B. wrighti, have been incriminated as intermediate hosts for Schistosoma haematobium. The present work was conducted on Saudi Arabian B. truncatus snails, [growth, survival rate and fecundity] in addition to comparison of some enzymatic activities between B. trunctus [control and infected with S. heamatobium] snails from Egypt and Saudi Arabia. Under laboratory constant temperature 24 +/- 1°C and after 20 weeks, the results show that the growth of Saudi Arabian Bulinus snails can be differentiated into two groups: the 1[st] one [70%] of the tested snails showed a total growth of 600% and 2[nd] one [30%] with a growth rate of 327.8%. The snails egg laying started at the 10[th] and 20[th] weeks without differences in their sizes [3.6 +/- 0.86 and 3.85 +/- 0.82] for these two groups respectively. A considerable survival rate was recorded for the 1[st] group after 20 weeks [68%] with mean life span 10.8 +/- 6.7 weeks. A convenient number of eggs were laid by survived snails with a net reproductive rate [Ro] of 129.12. In Egyptian and Saudi Arabian B. truncatus snails, the activities of enzymes, aspartate aminotransferase [AST], alanine aminotransferase [ALT] and alkaline phosphatase [AlkP] were significantly [P<0.0001] altered in the tissue homogenate of infected snails compared to control ones, in contrast acid phosphatase [AcP] was increased in infected snails than control ones, Both snail strains were classified as oxyphilic, poorly adapted to anaerobic conditions with the AST/ALT ratio higher than 2 in both control and infected ones

trial to assess the susceptibility of Biomphalaria Alexandrina to Schistosoma mansoni by protein electrophoresis, hepatic enzymes activities and random amplification polymorphic DNA [RAPD]

The identification of susceptible from refractory Biomphalaria alexandrina snails to Schistosoma mansoni is important in transmission studies and control programs. In this study, a trial was made in this respect utilizing three techniques, namely protein electrophoresis, assay for hepatic enzymes activities and Random Amplification Polymorphic DNA [RAPD]. The results show that, in protein electrophoresis there is one shard band only between susceptible and refractory snails [68.41KD]. The activities of hepatic enzymes, aspartate aminotransferase [AST] and alanine aminotransferase [ALT], alkaline [ALKP] and acid phosphatase [AcP], were higher in the tissue homogenate and hemolymph of susceptible snails than refractory ones. In RAPD, utilizing OPA-9 primer, approximately 1,900 bp band was characteristic for susceptible snails but did not appear in refractory ones