Epidemiology and Genetic Variants within Echinococcus granulosus Identified based on ITS-1 Ribosomal DNA in North-West Egypt

Abstract

Echinococcus granulosus, the etiologic agent of Cystic Echinococcosis (CE) is one of the most important zoonotic helminths with worldwide distribution in humans and animals. The current study aimed to survey the population genetic pattern of CE isolated from humans and slaughtered animals in NorthWest Egypt by sequencing of ITS-1 ribosomal DNA. A total of 4047 animals (1512 camels, 1575 cattle, 192 donkeys, 867 sheep, 703 goats, 98 buffaloes) and 100 suspected cases in humans were surveyed, for their fertility and viability. It was collected from different abattoirs and hospitals in NorthWest Egypt and identified by using nested-PCR-ITS1 of rDNA. The isolates amplify 800 bp were sequenced and BLASTn. Nucleic acid sequence maximum likelihood method was used to create the consequence tree and subsequent phylogeny to compare these sequences with globally and retrieved reference strains of Echinococcus granulosus from GenBank. Results revealed that 155 hydatid cysts were found fertile and viable and consequently subjected to nPCR-ITS1 of rDNA. Molecularly, they identified as 99 (63.9%) were G6 strain whereas 56 (36.1%) were as G1 strain. The similarity between submitted isolates and preserved from the same species deposited in GenBank ranged from 98.3-96.9%. It was more similar to Australian and Indian sheep than Iranian isolates. We concluded that the sheep G1 and camel G6 genotypes of Echinococcus granulosus are prevalent with the possibility of transmission between livestock animals and humans are likely to be exposed to G1 strain in NorthWest Egypt.