Zoonotic transmission of Teladorsagia circumcincta and Trichostrongylus species in Guilan province, northern Iran: molecular and morphological characterizations

摘要

Background: Parasitic trichostrongyloid nematodes have a worldwide distribution in ruminants and frequentlyhave been reported from humans in Middle and Far East, particularly in rural communities with poor personalhygiene and close cohabitation with herbivorous animals. Different species of the genus Trichostrongylus are themost common trichostrongyloids in humans in endemic areas. Also, Ostertagia species are gastrointestinalnematodes that mainly infect cattle, sheep and goats and in rare occasion humans. The aim of the present studywas to identify the trichostrongyloid nematodes obtained from a familial infection in Guilan province, northern Iran,using morphological and molecular criteria.Methods: After anthelmintic treatment, all fecal materials of the patients were collected up to 48 h and male adultworms were isolated. Morphological identification of the adult worms was performed using valid nematode keys.Genomic DNA was extracted from one male worm of each species. PCR amplification of ITS2-rDNA region wascarried out, and products were sequenced. Phylogenetic analysis of the nucleotide sequence data was performedusing MEGA 6.0 software.Results: Adult worms expelled from the patients were identified as T. colubriformis, T. vitrinus and Teladorsagiacircumcincta based on morphological characteristics of the males. Phylogenetic analysis illustrated that each speciesobtained in current study was placed together with reference sequences submitted to GenBank database.Conclusions: The finding of current study confirms the zoonotic aspect of Trichostrongylus species and T.circumcincta in inhabitants of Guilan province. The occurrence of natural human infection by T. circumcincta isreported for the first time in Iran and the second time in the world.