PCR-RFLP Fails to Reveal Variability Within Schistosoma haematobium Detected in Loum (Cameroon) by Isoelectrofocusing Technique

Schistosoma haematobium, which causes urinary schistosomiasis in humans is responsible for the largest number of infections in the word. Genetic variability among parasite populations is an important factor in their potential for producing harmful effects on the human populations they infect. In many areas, S. haematobium is sympatric with related schistosome parasites (most of other mammals) (i.e., S. bovis, S. mattheei, S. curassoni, S. intercalatum, S. guineensis and S. margrebowiei). PCR-RFLP analysis of ITS-2 rDNA loci is an usefull tools to detect hybrids amongs Schistosoma haematobium group. Many studies have been carry out in the town of Loum (Cameroon) in order to characterize Schistosoma haematobium species from this locality. However, no study based on PCR-RFLP analysis succeeds to detect any genetic variability as reported before using electrofocusing (IEF) technique. PCR-RFLP analysis realised on 10 isolates of Schistosoma haematobium from Loum reveals a DNA fragment of 501 bp after amplification of ITS2 ribosomal gene. For all the samples, the enzymatic digestion of the mentioned DNA fragment gene with Taq I reveals two DNA bands of 158 bp and 199 bp which is characteristic of Schistosoma haematobium. In summary, molecular characterization of S. haematobium in Loum using PCR-RFLP approach reveals once more the absence of hybrids and no genetic variability. Further studies on a larger geographic scale involving many schools in Loum should be encouraged to screen more parasite isolates with different primers and molecular toolS. Information from such studies would provide better insight into the local lineages of S. haematobium. This knowledge might play a major role in establishing control strategies for urogenital schistosomiasis in Loum.