Molecular Characterization and Analysis of Human Trichostrongylus Species in an Endemic Region of Iran Based on COX 1 Gene; A Cross-Sectional Study

Background and Aims

Trichostrongylus species are the causative agents of zoonotic disease, which has been frequently reported from animals in Iran. The aim of this study was to identify, molecular characterization and analysis of Trichostrongylus species isolated from humans, in an endemic region, based on cytochrome c oxidase (COX) 1.

Methods

A total of 206 fresh stool samples were collected from residents of endemic villages of sampling area. All samples had been examined using conventional parasitological methods, along with the PCR technique. After amplification and sequencing of a discriminative region of COX1 gene, the phylogeny relationship, haplotype network, and molecular diversity between Trichostrongylus spp., were scrutinized using PopART networking, DnaSP v.6, and MEGA10 software.

Results

In total, from 206 fecal samples, 71 people (34.4%) were infected with Trichostrongylus spp. The ~700-bp fragment of the COX1 was amplified in all 71 morphological positive samples, however, 33 samples were successfully sequenced, belonging to Trichostrongylus spp. In this study, T. colubriformis was the predominant species and one sequence was characterized as T. vitrinus. Our sequences were grouped together with sequences, which were obtained from animals in the same region (97.17% similarity). In total, 26 haplotypes were identified and haplotype diversity ranged from 0.988 ± 0.012.

Conclusions

In view of the importance of Trichostrongylosis to public health as zoonotic infection, information about its prevalence in animal and human populations can provide valuable information on how different types of this parasite are transmitted between people and animal's host.