Prevalences and characteristics of Trichuris spp. infection in sheep in pastoral areas of the Tianshan, Xinjiang, China

Abstract

Nematodes of the Trichuris genus are commonly reported parasites that can cause trichuriasis in many animals, which leads to inflammation, intestinal bleeding and reductions of productivity in livestock. Knowledge of the prevalence of Trichuris infestation in the Tianshan ovine population and of the nematode species parasitising the population is not exhaustive, and this study aimed to expand the knowledge.

A total of 1,216 sheep slaughtered in five pasture areas in the Tianshan Mountains of Xinjiang were investigated and a phylogenetic analysis based on the mitochondrial cox1 gene was performed to clarify the genetic relationships of the various Trichuris species.

Sheep totalling 1,047 were infected with Trichuris spp. establishing the rate at 86.1%. Using a morphological protocol, six documented and one undefined species were identified, namely T. gazellae, T. lani, T. ovina, T. longispiculus, T. concolor, T. discolor and Trichuris sp. Among them, T. gazellae and T. lani were the dominant species, accounting for 34.5% and 31.0% of Trichuris spp., respectively. Phylogenetic analysis divided the detected species of Trichuris spp. into two genetic clades (clade I and clade II). The six documented species that can infect sheep and the undefined species were clustered into clade I, with inter- and intra-species genetic diversity apparent.

This survey described in detail the morphological characteristics of six known and one undefined species of Trichuris, which not only enriched the taxonomic information on record regarding Trichuris spp., but also provided valuable epidemiological data for the prevention and control of trichuriasis in sheep.