Blastocystis is a protozoan that parasitizes the intestines (Jiménez et al., 2019; Paik et al., 2019). It can infect a variety of hosts, such as mammals, amphibians, birds, and insects (Zhu et al., 2020). Blastocystis is transmitted through the fecal–oral route or water and food between susceptible hosts (Asghari et al., 2019; Deng et al., 2019). Hosts infected with Blastocystis could develop clinical signs, e.g., diarrhea, abdominal pain, and vomiting. Immunocompromised individuals are more susceptible to Blastocystis (Wang et al., 2018a; Paik et al., 2019).

Blastocystis was first isolated from animal feces in 1911 (Alexeieff, 1911). Since then, more and more animals and humans, such as cattle, deer, sheep, and goats, were identified to be the hosts of Blastocystis ( Table 1 ). In China, Blastocystis was first reported in children in 1990 (Li et al., 1990). A large number of investigations regarding Blastocystis prevalence in different hosts were performed previously (Song et al., 2017; Zhao et al., 2017; Wang et al., 2018a; Wang et al., 2018b). So far, the infection of Blastocystis has been reported in many animals, including domestic and wild animals (Zhao et al., 2017; Wang et al., 2018a).

To date, approximately 29 proposed Blastocystis subtypes have been identified in a large number of literatures (Ma et al., 2020). ST1-9 and ST12 subtypes were identified in humans, while ST10-17 and ST21-28 subtypes were detected in animals (Stensvold and Clark, 2016; Ning et al., 2020; Hublin et al., 2021). Of note, some subtypes were identified in both humans and animals, such as ST1, ST3, and ST5 subtypes (Song et al., 2017; Wang et al., 2018a). ST4 was found in deer (Wang et al., 2018b; Kim et al., 2020; Shirozu et al., 2021), and ST12 was found in yaks in the plateau area (Ren et al., 2019).

Tibetan antelope (Pantholops hodgsonii) belongs to genus Pantholops, family Bovidae, order Cetartiodactyla according to the IUCN Red List in 2016 (IUCN SSC Antelope Specialist Group, 2016). Tibetan antelope is one of the most rare and endangered wild animals. There are approximately 100,000 to 150,000 Tibetan antelope in India and China (IUCN SSC Antelope Specialist Group 2016). Tibetan antelope can carry various pathogens, such as Mycoplasma capricolum subspecies, capripneumoniae (Mccp) (Yu et al., 2012), and Escherichia coli (Bai et al., 2016).

However, the existing data indicate that sheep may carry several potential Blastocystis subtypes, including ST1, ST3, ST4, ST5, ST6, and ST7 (Tan et al., 2013; Song et al., 2017; Wang et al., 2018a; Salehi et al., 2021). So far, studies on the prevalence and subtype diversity of Blastocystis in Tibetan antelope are unknown and the relevant public health impact is still unclear. This study provides important information on the diversity of Blastocystis subtypes in Tibetan antelope, and would help determine the role of Tibetan antelope in the transmission of Blastocystis to humans and other animals.

The overall infection rate of Blastocystis in Tibetan antelope was 4.8% (30/627) in Tibet, which was lower than the prevalence of 5.5% (6/109) and 6.0% (50/832) identified in sheep (Wang et al., 2018a; Li et al., 2018) in China and 19.3% (9/150) and 32.0% (32/100) in sheep in Iran (Rostami et al., 2020; Salehi et al., 2021). The difference in the prevalence of Blastocystis may be related to the living environment and geographical factors of different countries (Tan, 2008). The infection rate of Blastocystis in different species is different. For example, the prevalence of Tibetan antelope in this study and sheep, goats, and cattle in other studies were 4.8% (30/627), 0.75% (3/400) (Ghimire and Bhattarai, 2019), and 14.43% (72/500) (Hastutiek et al., 2019), respectively. The results showed that the prevalence of Blastocystis might be related to the sensitivity of animals to Blastocystis. Therefore, future research should collect more samples to better understand the population characteristics of Blastocystis in Tibetan antelope.

The average temperature in Baingoin County is −17.1°C annually, which is much lower than that of other counties. The survival of Blastocystis may be affected by the low-temperature environment in Baingoin County. Blastocystis might survive in warm and humid environment (Sari et al., 2021). This is probably the reason why the infection rate of Blastocystis in Baingoin County (0.0%, 0/133) was significantly lower than that of the other three counties.

Previous studies have shown that the infection rate of Blastocystis in males (4.8%, 25/517) was higher than that in females (3.1%, 9/291) in cattle (Lee et al., 2018) and in sambar (males: 38.2%, 21/55 vs. females: 23.3%, 7/30) (Kim et al., 2020). This study also found that the infection rate of Blastocystis (6.7%, 22/327) was higher in males than in females (2.7%, 8/300) of Tibetan antelope. This may be due to the fact that males have a wider range of activities than females, and have a relatively higher chance for contacting with cysts.

At present, 29 proposed Blastocystis subtypes have been identified (Maloney and Santin, 2021). Among them, ST1, ST3, ST5, ST10, and ST14 subtypes were detected in sheep and goats (Song et al., 2017; Li et al., 2018; Wang et al., 2018a), among which ST10 and ST14 were the most common subtypes (Fayer et al., 2012; Zhao et al., 2017; Hublin et al., 2021). ST10 and ST14 were also detected in Tibetan antelope. However, it is worth noting that ST10 (n = 4) and ST14 (n = 2) were not common in the samples of Tibetan antelope in this study. On the contrary, ST13 (n = 24) represented the infection trend of Blastocystis in Tibetan antelope. ST13 subtype is a relatively rare subtype. ST13 has been detected in deer, flying squirrels, kangaroo, monkeys, and other animals (Parkar et al., 2010; Alfellani et al., 2013; Wang et al., 2018b; Li et al., 2019; Xiao et al., 2019). Compared with domestic animals, ST13 may be more common in wild animals. Therefore, the follow-up research should focus on the distribution of Blastocystis genotypes in wild animals.

In summary, this is the first report of Blastocystis infection in Tibetan antelope in Tibet, China. The total prevalence of Blastocystis was 4.11% (30/627). Moreover, ST10, ST13, and ST14 subtypes were found in Tibetan antelope, among which ST13 was the dominant subtype. These results not only expanded the knowledge of hosts of Blastocystis, but also provided data for further studies on the distribution of Blastocystis subtypes in Tibetan antelope, and also provided data supporting for the prevention of Blastocystis infection in wild animals.

The datasets presented in this study can be found in online repositories. The names of the repository/repositories and accession number(s) can be found in the article/supplementary material.

The animal study was reviewed and approved by the Ethics Committee of Jilin University.

H-BN and JJ conceived and designed the study and critically revised the manuscript. S-YQ, H-TS, J-HZ, Z-JW, and TM collected the samples. H-LG, Y-ZS, Y-GL, and N-YX performed the experiments. H-LG and Y-ZS analyzed the data and drafted the manuscript. All authors contributed to the article and approved the submitted version.

This work was supported by the Research Foundation for Distinguished Scholars of Qingdao Agricultural University (665-1120046).

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.