Genotyping Echinococcus granulosus from dogs from Western Iran

Area of Science:

• Veterinary Parasitology
• Molecular Epidemiology
• Zoonotic Diseases

Background:

• Cystic echinococcosis, caused by Echinococcus granulosus, is a significant zoonotic disease.
• Understanding the genetic diversity of E. granulosus is crucial for disease control and epidemiology.
• Previous studies have identified various genotypes of E. granulosus, but data from Western Iran is limited.

Purpose of the Study:

• To genetically characterize Echinococcus granulosus isolates from dogs in Western Iran.
• To determine the prevalence of different genotypes in the study population.
• To report novel genotype findings in the region.

Main Methods:

• Adult E. granulosus worms were collected from 71 dogs in Western Iran.
• DNA sequencing of mitochondrial genes cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase 1 (nad1) was performed.
• Phylogenetic analysis using the Bayesian Inference approach was conducted on concatenated nucleotide sequences.

Main Results:

• Twenty adult E. granulosus specimens yielded consensus sequences for cox1 (366 bp) and nad1 (471 bp).
• Nine distinct cox1 and seven distinct nad1 sequences were observed among the isolates.
• Three genotypes were identified: G1 (75%), G2 (10%), and G3 (15%). G2 sequences showed 100% homology with reference sequences, while G3 sequences exhibited two cox1 profiles with 99% homology to the reference.

Conclusions:

• The G1 genotype (sheep strain) of E. granulosus sensu stricto is the dominant genotype circulating in dogs in Western Iran.
• This study reports the first detection of the E. granulosus sensu stricto G2 genotype in Iran.
• Genetic characterization provides valuable insights into the population structure and transmission dynamics of E. granulosus in the region.