COMPARATIVE STUDY OF THE MOTHER SPOROCYST OF SCHISTOSOMA MANSONI IN THE SUSCEPTIBLE AND RESISTANT SNAILS OF BIOMPHALARIA GLABRATA

Department of Anatomy and Histology, Sindh Agriculture University, Tando Jam; ¹Department of Biological Sciences, Quaid-I-Azam University, Islamabad, Pakistan 

Abstract 

    The comparative studies of the susceptible and resistant snails of Biomphalaria glabrata mass exposed to miracidia of Schistosoma mansoni were conducted from 1 to10 days post-exposure (DPE). Histological sections of 50 susceptible and 50 resistant snails revealed that many single, multiple, mature and migratory mother sporocysts were observed in the foot, head, lip, tentacle, mantle, anus, buccal mass, neck, kidney, oesophagus, respiratory epithelium of the lung and pericardial cavity of the heart of susceptible snails. Whereas, few single and multiple mother sporocysts were visible in the earlier mentioned first eight organs of the resistant snails throughout infection period. Single mother sporocyst was located in the foot, head, lip and tentacles of susceptible snails at 1-2 DPE. At 3 DPE, multiple mother sporocysts were found in the above organs, and very few of them were observed in the mantle and muscles of the anus of these snails. In the resistant snails, such mother sporocysts were only found in the tentacle and columellar muscles at 9 DPE. At few mother sporocysts reached the buccal mass of the susceptible snails at 4 DPE. Increasing in the number of the single and multiple mother sporocysts were observed in the foot, head and tentacles, whereas a few of them were also visible in the neck and kidney of these snails at 5 DPE. Most of the mother sporocysts grew further in the foot, head, tentacles, mantle and kidney and developed into the mature form at 6 DPE onwards. At 8 DPE, some mature mother sporocysts were observed in the above mentioned organs and oesophagus of these snails. In the foot, head, lip and tentacle at 8 DPE, tegument of mature mother sporocyst was ruptured due to the increase number, and size of the embryos, and a few of them migrated towards the deeper tissues of the organs of the body of the snails. At 9 and 10 DPE, most of the above types of mother sporocyst remained in the earlier mentioned organs, very few were also found in the pericardial cavity of the heart and respiratory epithelium of the lung of the susceptible snails. Chi-square test results showed highly significant differences in the total infected snails with mother sporocyst in the various organs of the susceptible and resistant snails.