Some Epidemiological Studies on Toxoplasmosis In Khartoum State

Abstract

The present study was carried out to investigate the genetic variation within the intermediate host snails of schistosomiasis in Sudan (Bulinus truncatus and Biomphalaria pfeifferi) utilizing new molecular approaches. Snails were collected from the Gezira-Managil, Seilate, Gamooeya and Faki Hashim agricultural schemes using the scooping method. The snails were identified morphologically using the systematic key of the Danish Bilharziasis Laboratory. The random amplified polymorphic DNA technique (RAPD) was used to determine the intraspecific variation in Bul. truncatus (n=83) and Bio. pfeifferi (n=92) using four random primers; OPA02, OPA10, OPA11 and OPY12. The RAPD analysis showed high similarity coefficients (i.e. low genetic variation) for both Bul. truncatus and Bio. pfeifferi. Intraspecific variation in Bul. truncatus and Bio. pfeifferi was also assayed by polymerase chain reaction (PCR) amplification of the ribosomal internal transcribed spacer (ITS) region followed by restriction fragment length polymorphism (RFLP) analysis of this product with three restriction enzymes (RsaI, AluI and MspI). RFLP analysis of (ITS) with RsaI, AluI and MspI showed intraspecific variation in Bio. pfeifferi. Each restriction enzyme yielded two profiles type in Bio. pfeifferi. No intraspecific variation was detected in Bul. truncatus with the three restriction enzymes. The results of the present study suggest that the RAPD and the RFLP techniques are simple, rapid and easy methods to study intraspecific variation in the intermediate host snails of schistosomiasis