Echinococcus granulosus genotypes in livestock of Iran indicating high frequency of G1 genotype in camels.

In this study, 112 Echinococcus granulosus isolates from different livestock of Iran were genotyped by PCR amplification of ribosomal DNA-internal transcribed spacer 1 (rDNA-ITS1) region followed by restriction fragment length polymorphism (RFLP) with the enzyme RsaI. The possibility of intra-genotype variation was also investigated using randomly amplified polymorphic DNA (RAPD) analysis. Isolates from sheep, goats, cattle and the majority of camels (12 of 18; 66.7%) were identified as the G1 genotype and a few camel isolates (6 of 18; 33.3%) belonged to the G6 genotype. Overall G1 and G6 genotypes were identified in 94.6% (106 of 112) and 5.3% (6 of 112) of all isolates, respectively. RAPD analysis based on 15 separate primers showed 7-14 bands of 200-3000bp for strain G1. Considering each individual primer, no differences observed among isolates from different hosts and between livers and lungs. This study confirmed the existence of G1 and G6 genotypes in Iran. Moreover, G1 is much more prevalent even in camels, indicating the importance of sheep-dog cycle in public health. Studying intra-genotypic variation of E. granulosus warrants more research using other primers and methods.