Genetic variability of antigen B among Echinococcus granulosus Egyptian isolates.

Genetic polymorphisms of encoding antigen B2 gene (AgB2) in Echinococcus granulosus were studied using PCR-RFLP and DNA sequencing among 20 Egyptian isolates. Five isolates from different host origins (humans, camels, pigs, and sheep) were collected and used. All examined isolates of each host group gave very similar patterns of PCR-RFLP after restriction enzyme digestion with AluI, with the gene size of approximately 140 bp and 240 bp for sheep and human isolates, and approximately 150 bp and 250 bp for pig and camel isolates. No digestion pattern was obtained after incubation of all studied isolates with EcoRI. These results reveal high intra-group homogeneity. DNA sequence analysis highlighted that human infecting strain showed 100% identity with respect to sheep infecting isolate, 96% and 99% with pig and camel infecting isolates, respectively.