Genetic Characterization of Hydatid Cysts Isolated from Domestic Animals in Lorestan Province, Western Iran.

Background: Regarding hydatid cyst (cystic echinococcosis, CE) as a human public health problem in the West of Iran, molecular data related to the genotypes of Echinococcus granulosus in cattle and sheep in these regions are still insufficient. Here, we evaluated the genotypes of E. granulosus infecting sheep and cattle in western Iran.

Methods: Totally, 36 hydatid cysts including 18 hydatid cysts of sheep and 18 hydatid cysts of cattle were collected from Khorramabad slaughterhouse (Lorestan Province), Western Iran between May to September 2014. Protoscoleces or germinal layers were collected from individual cysts, DNA was extracted, and genotyping was performed by sequencing and analyzing mitochondrial cytochrome c oxidase subunit 1 ( cox 1) gene.

Results: In sequencing analysis, all of sheep isolates belonged to genotype G1 (sheep strain). Among cattle hydatid cyst isolates, 16/18 (88.9%) were belonged to genotype G1 and 2/18 (11.1%) were belonged to G3 genotype. The phylogenetic analysis showed two clusters; one of the clusters includes cattle G3 genotype and the other cluster represents sheep and cattle G1 genotype that were isolated.

Conclusion: The common sheep strain/G1 is predominant genotype in the western part of Iran, followed by G3 genotype, circulating among the animal hosts in this region. Further studies covering a larger number of isolates might be necessary to see if there are other genotypes in the hydatid cyst population in this region of Iran.