Phylogenetic Study of cox1 Gene in Echinococcus granulosus Sensu Lato Genotypes in Southwestern Iran.

INTRODUCTION

Cystic echinococcosis (CE) is a serious global health concern. CE is an endemic zoonotic disease in Iran. The substantial genetic diversity of Echinococcus granulosus is closely linked to its life cycle, transmission mechanisms and pathogenesis. This study aimed to explore the phylogenetic structure of the genotypes of E. granulosus sensu lato (s.l.) in southwestern Iran (SWI).

METHODS

Seventy-two hydatid cyst samples were collected from various intermediate hosts, including goats, cattle, sheep, camels, buffalo and humans, primarily from the lungs, liver, spleen and heart of livestock slaughtered in local and industrial abattoirs, as well as from patients in several hospitals (Namazi, Golestan, Arvand and Shahid Beheshti) in southwestern Iran (Bushehr, Fars, Kohgiluyeh and Boyerahmad and Khuzestan provinces).

RESULTS

Sequence analysis revealed three genotypes of E. granulosus s.l. in the SWI: G1 (n = 69, 95.8%), G3(n = 1, 1.4%) and genotype like G6/G7 (n = 2, 2.8%). Twenty-one different haplotypes were identified in this study. According to the phylogenetic tree topology, the cox1 gene sequence similarities can be shown for some G1 and G6/G7 isolates in some vast areas, but these genotypes generally show a heterogeneous population worldwide. High similarity was shown between G3 isolates from some countries (Spain, Turkey, India and Iran) and different hosts (sheep, human and buffalo).

CONCLUSIONS

The presence of the G6/G7 genotype in the SWI may be due to the transmission of this genotype from other regions or the role of camel/wild boar and other possible intermediate hosts in the expansion of this genotype in the SWI. The results of the present study can be used in CE control programs, molecular epidemiology and phylogenetic studies in Iran and other countries for future goals.