الفهرس 
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Abstract
Among the species of schistosomes infecting humans, Schistosoma haematobium is responsible for the largest number of infections in Africa and subsequently Egypt. It is considered one of the major human health problems across Africa.
The resultant pathology of S. haematobium infection is linked to the virulence of different strains and the study of genetic differences might explain disease variation. This study was designed to investigate the genetic diversity of S. haematobium disease in Sohag Governorate, Upper Egypt.
DNA extraction
DNA extraction was performed from the preserved positive urine samples after defreezing by Thermo Scientific GeneJET Whole Blood Genomic DNA Purification Mini Kit #K0781, #K0782. Out of the 50 positive specimens, 27 samples showed good purified genomic DNA which were selected to be amplified by RAPD-PCR.
RAPD-PCR amplification protocol:
RAPD-PCR technique was performed and the genotyping of S. haematobium was assessed using Taq PCR master Mix Kit, Qiagen.
5 oligo primers were selected, and the sequences were as following: (A01/ CAGGCCCTTC, A02/ TGCCGAGCTG, A12/ TCGGCGATAG, A13/ CAGCACCCAC and Y20/ AGCCGTGGAA). The similarity between isolates and positive control was estimated by calculating the Similarity index as described Nei and Li 1979.
PCR was performed in Thermo Cycler using the following protocol : an initial denaturation at 95°C for 5 minutes followed by 40 cycles each consisting of denaturation at 95°C for 1 minute then annealing at 35 for 2 minutes then extension at 72°C for 2 minutes. Lastly final extension was at 72°C.
Agarose gel electrophoresis for PCR products
DNA electrophoresis was done on a 1.2% agarose gel in TE buffer stained with ethidium bromide. Samples were run with two molecular weight standards.
The study results were as follow:
positive bands (54%). The similarity index was in average 69.3% with primer A01, 47.9% with primer A02, no shared bands (0% similarity index) with primer A12, 62% with primer A13 and 60.8% with primer Y20. This means that there is obvious genetic variability with primers/ loci A12 followed by A02 while the similarity is higher with primers A01, A13 and Y20 with similarity indices ≥ 60%.
The highest similarity and hence the lowest genetic variability were with primer/ locus A01 where the similarity index with 69.3% (range 44 to 100%). The plotted bands and their corresponding molecular weights were very similar (Figure 11). The similarity was less with primers A13, 62.5% (range 40 to 80%) and with Primer Y30, 60.8% (range 0 to 80%).
No significant correlation could be found between detected bands or similarity indices and patients’ gender and symptomatology.
Conclusion
The present work revealed that amplification patterns of the extracted S. haematobium isolates showed distinct variation in the size and number of amplified fragments, indicating that there is high genetic polymorphism among these isolates in our governorate.
As far as we know, this study is one of the few studies in Upper Egypt to characterize the genetic diversity of S. haematobium in human populations.
Further studies are recommended on a larger scale in wide districts in Upper Egypt in this field to try to find out significant correlation between genetic variations in S. haematobium and the resultant pathology or drug resistance. Such studies may have a major role in establishing control strategies for urogenital schistosomiasis in Upper Egypt.