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First genotyping of Blastocystis in yaks from Qinghai Province, northwestern China



Blastocystis is a common protist that can infect domestic and wild animals worldwide. Yak (Bos grunniens), an ancient species which can survive in alpine regions, has supplied necessities to local residents in plateau areas for generations. However, the infections with Blastocystis in yaks has been ignored for a long time. In the present study, the infections and genotypes of Blastocystis spp. in domestic yaks from Qinghai Province (northwestern China) were explored.


Of 1027 faecal samples collected from yaks in seven regions of Qinghai Province, northwestern China, the total prevalence of Blastocystis was 27.07% (278/1027) targeting the small subunit ribosome rRNA (SSU rRNA) gene. This protist was detected in yaks within each examined age group, geographical origin and season. Significant difference in prevalence was found in yaks from different geographical origins. The highest prevalence (48.94%) was observed in animals from Haixi county. Sequence analysis revealed three animal-specific subtypes (ST10, ST12 and ST14) of Blastocystis spp. in these yaks, with ST10 being the predominant subtype widely distributed in all investigated regions, seasons and age groups. Interestingly, this is the first report about subtype ST12 infecting yaks.


To our knowledge, this is the first systematic report on Blastocystis prevalence in yaks from China, and the findings provide fundamental data for establishing effective control measures for this protist in yaks as well as other animals in China.


Blastocystis is a common anaerobic unicellular protist of animals and humans. Since its first observation in gastrointestinal tracts of humans in 1911 [1], human cases of Blastocystis infections have been reported in Asia, Europe, Africa, America and Oceania [2,3,4,5,6,7,8,9,10,11,12], with prevalences up to 100% in Senegal River Basin [13]. In addition, more than 50 animal species have been reported as reservoirs of Blastocystis, including non-human primates (NHP), birds, reptiles and ruminants, with a prevalence of 0.3–100% [14,15,16,17,18,19,20,21,22,23,24,25,26]. Although controversy on pathogenicity of Blastocystis existed, this parasite has been detected in patients with diarrhea and irritable bowel syndrome (IBS) [13, 27]. Moreover, the presence of Blastocystis has also been recently indicated as a possible indicator of intestinal health [4].

The yak (Bos grunniens), an ancient bovid species from the late Pliocene, is listed as one of the three major cold-resistant species (together with polar bears and Antarctic penguins) of the world, and more than 95% of its population (approximately 16.7 million) are from China [28]. Qinghai (northwestern China) is a Chinese province with the largest stock of yaks (approximately 5.9 million animals are reported), providing meat, dairy, dung, wool and other living necessities, and also serve as means of transportation for local residents [29]. To date, several pathogens (e.g. foot-and-mouth disease virus, bovine viral diarrhea virus, bluetongue virus, Cryptosporidium spp., Enterocytozoon bieneusi and Toxoplasma gondii) have been detected in yaks [30,31,32,33,34,35]. The production performance of yaks is seriously affected by these pathogens, leading to heavy economic losses [30,31,32,33,34,35]. Additionally, significant public health problems caused by zoonotic pathogens (e.g. Cryptosporidium spp., E. bieneusi and T. gondii) due to the close relationship between yaks and local people should not be neglected. In 2017, Blastocystis was found in six wild yaks from Xi’an Qinling Wildlife Park in Shaanxi Province, northwestern China, and two subtypes (ST10 and ST14) were identified [25]. In the present study, the prevalence and subtypes of Blasstocystis in yaks from Qinghai Province were determined on a large-scale by molecular methods based on the small subunit ribosomal RNA (SSU rRNA) gene.



From May 2016 to October 2017, a total of 1027 fresh faecal samples were randomly collected from free-ranged yaks in 7 counties (Xining, Haibei, Golog, Hainan, Huangnan, Yushu and Haixi) of Qinghai Province (Fig. 1). Additionally, the altitude variation among these sites is 1980 m, with the highest spot in Golog (4473 m) and the lowest in Huangnan (2493 m). Each faecal sample was collected immediately after the animal excreted, placed in a plastic bag and marked with age, location and sampling date. Two age groups (> 6 months-old and ≤ 6 months-old) of yaks were determined by their dentition provided by yak owners, and each animal was only sampled once. All faecal samples were immediately transferred on ice to the laboratory, placed into 15 ml centrifuge tubes with 2.5% potassium dichromate, and stored at -20 °C for further study.

Fig. 1
figure 1

Geographical distribution of faecal samples from yaks in Qinghai Province, northwestern China. The proportion represents the frequency of each ST in the overall positive samples in certain location (ST10/ST12/ST14)

Extraction of genomic DNA, nested PCR amplification and sequencing

Approximately 0.3 g of each faecal sample was washed with distilled water at 13,000× g for 1 min to remove potassium dichromate, and genomic DNA was extracted by commercial E.Z.N.A.TM. Stool DNA Kit (D4015-02) (Omega Bio-Tek Inc., Norcross, GA, USA) under the manufacturer’s instructions and then stored at -20 °C for further analysis.

Nested PCR was used to determine the presence of Blastocystis in faecal samples of yaks targeting the SSU rRNA gene with primers synthesized by ABI PRISM 3730 XL DNA Analyzer (Applied Biosystems, Carlsbad, USA), which were described previously [36, 37]. The reaction was performed in a 25 μl mixture containing 1 μl of genomic DNA, 2.5 μl 10 × Ex Taq Buffer (Mg2+ free), 2 μl dNTP Mixture, 1.5 μl MgCl2, 1 μl of each primer and 0.125 μl of TaKaRa Ex Taq (TaKaRa Bio Inc., Tokyo, Japan). The first amplification was implemented under the cycling condition previously described by Clark [36], while that of the secondary amplification was the same as the first one except that the first amplicon was used as template and the annealing temperature was 49 °C. All amplicons of the secondary amplification were examined by electrophoresis in 1% agarose gel with ethidium bromide.

All positive amplicons of the secondary amplification were sent to Sangon Biotech Co., Ltd., Shanghai (China) for sequencing.

Sequence and phylogenetic analysis

The obtained sequence of each sample was assembled with the software DNAStar 5.0 [38], subsequently submitted to Basic Local Alignment Search Tool (BLAST) ( for alignment with Clustul X 1.83 [39] and amended by the eye. To determine Blastocystis subtype, each of the corrected sequence was compared with the sequences from GenBank by BLAST analysis. The proofread sequences were then used to construct a phylogenetic analysis by the Neighbor-Joining (NJ) method within the software MEGA 7.0.26 [40]. Kimura 2-parameter model and bootstrap analysis (1000 replicates) were used [41], and Blastocystis lapemi (AY590115) was selected as the outgroup. In addition, Bayesian analysis (MrBayes 3.1.1) [42] was conducted with Hasegawa-Kishino-Yano 1985 (HKY) model of nucleotide substitution with four categories of among-site variation and the proportion of invariant sites, the best-fit model selected by jModelTest [43] using the Akaike information criterion (AIC) [44]. Bayesian analysis adopted four Markov chain Monte Carlo (MCMC) strands, 1,000,000 generations, with trees sampled every 100 generations. The tree was implemented in MEGA 7.0.26 after excluding an initial ‘burn-inʼ of 25% of the samples, as recommended.

Statistical analysis

The differences in prevalence among different age groups, geographical origins and seasons were analyzed by Chi-square test/Chi-square goodness-of-fit test with the software SPSS 21.0 for Windows (SPSS Inc., Chicago, USA). The difference was considered statistically significant when P< 0.05.


Prevalence of Blastocystis in yaks

In the present study, sequencing revealed that 278 faecal samples were positive for Blastocystis infection, with an overall prevalence of 27.07% in yaks from Qinghai Province (Table 1). Blastocystis was detected in the seven counties studied, and significant differences (χ2 = 35.652, df = 6, P = 0.002) in prevalence were found among these areas, with the highest prevalence in yaks from Haixi (48.94%) and the lowest in Hainan (19.75%) (Table 1). However, no significant differences of Blastocystis infection rates between seasons were detected (χ2 = 9.231, df = 3, P = 0.447) (Table 1). Furthermore, no significant differences between age groups were found (χ2 = 0.000005, df = 1, P = 0.556) (Table 1).

Table 1 Occurrence of Blastocystis from yaks in Qinghai Province

Subtype analysis

After amendment, sequences c.1000 bp long were used to reconstruct phylogenetic trees for subtyping. Of 278 Blastocystis-positive samples, three known Blastocystis subtypes were identified, including ST10, ST12 and ST14 (Figs. 2, 3). Among them, the subtype ST10 (61.15%, n = 170) was the predominant subtype, which was detected in all positive geographical regions, seasons and age groups, as well as the subtype ST14 (25.18%, n = 70). However, ST12 (13.67%, n = 38) was not found in yaks younger than six months (Table 1). No new subtype was found in this study as all sequences had homologies over 96% with published sequences on GenBank. In this sense, a previously proposed standard was used for naming a new subtype, as the nucleotide sequence divergences must be up to 5% [45].

Fig. 2
figure 2

Phylogenic tree based on SSU rRNA gene sequences of Blastocystis using the Neighbor-Joining (NJ) method. New sequences are indicated in bold text. Only bootstrap values > 70% are shown (1000 pseudoreplicates). A sequence of Blastocystis lapemi (AY590115) was used as the outgroup. The scale-bar represents 0.02 substitutions per nucleotide site

Fig. 3
figure 3

Bayesian analysis phylogenic tree based on SSU rRNA gene sequences of Blastocystis using Markov chain Monte Carlo (MCMC) method. Only posterior probabilities > 0.95 are shown. New sequences are indicated in bold text. The scale-bar represents 0.1 substitutions per nucleotide site


Blastocystis spp. has been found worldwide in humans and several animal species [46]. In the present study, this enteric parasite was detected in domestic yaks from Qinghai Province. Previous studies have shown a prevalence of Blastocystis with a wide range of 0.3–100% in domestic and wild ruminants from several regions of Brazil, China, Colombia, Iran, Japan, Spain, Thailand and many other countries [17, 25, 47,48,49,50,51]. The overall prevalence (27.07%) in domestic yaks from Qinghai Province was within the range mentioned above; however, it was lower than that in captive yaks from Qinling Wildlife Park in Shaanxi Province [25]. The number of samples examined might result in these differences since in the study of Zhao et al. [25] only six captive yaks were examined, whereas in the present study 1027 faecal samples were examined.

Although in the present study no significant differences of Blastocystis prevalence were found between age groups, nor between sampling seasons, the infection status in the domestic yaks examined was significantly different depending on the geographical area of origin in Qinghai Province, with the highest prevalence (48.94%) in Haixi and the lowest (19.75%) in Hainan. Similar differences in the prevalence of this protist between regions have been observed previously in cattle from China [26]. Several reasons may lead to the prevalence differences, such as animal age, the different amounts of samples in different seasons, ecological environments, and one obvious difference among these seven sites which is the altitude variation mentioned above, caused a very different living conditions for both yaks and parasites [52].

Genetic variation has been reported in Blastocystis isolated from animals and humans worldwide [27, 46, 53, 54], and at least 17 known subtypes have been identified based on the sequence heterogeneity in the SSU rRNA gene [45, 54, 55]. Among these subtypes, ST10 was reported as predominant in species of the Artiodactyla [25]. Previously, in a study of wild animals in Qinling Mountains, two subtypes (ST10 and ST14) were found in captive yaks [25]. In the present study, these two subtypes were also detected in domestic yaks in Qinghai Province, suggesting a wide distribution of these subtypes. Additionally, subtype ST12 which was first detected in giraffes and kangaroos from Western Australia zoos in 2010 [56], was found in domestic yaks in Qinghai Province. As this subtype was mainly found in animals, like giraffes from Sydney Zoo (Australia. 2013) [57] and Qinling Wildlife Park (China, 2017) [25], waterbuck from Qinling Wildlife Park (China, 2017) [25], and cattle and goats from Thailand (2018) [50], it was not believed to be a zoonotic agent. However, subtype ST12 was identified in three stool samples in humans from Bolivia in 2016 [58]. The present study revealed for the first time the presence of subtype ST12 in the yak, indicating a possible transmission from yaks to humans which should be considered of great importance in the future as most herdsmen spend all the time with their yaks. Therefore, future study should be conducted to evaluate the zoonotic potential of this subtype.


Collectively, the presence of Blastocystis was found in domestic yaks from Qinghai Province (northwestern China) with statistically significant variation of infection rates in relation to geographical origin. Moreover, susceptible populations should be alert because among the three subtypes found in this study, ST12 has been reported having a zoonotic potential in humans before, while ST10 and ST14 are considered infectious to animals only. To our knowledge, this is the first time ST12 infections are discovered in yaks.



small subunit ribosomal RNA


non-human primates


irritable bowel syndrome


Basic Local Alignment Search Tool




Hasegawa-Kishino-Yano 1985


Akaike Information Criterion


Markov chain Monte Carlo


  1. Alexeieff A. Sur la nature des formations dites “kystes de Trichomonas intestinalis”. CR Soc Biol. 1911;71:296–8.

    Google Scholar 

  2. Abu-Madi MA, Behnke JM, Ismail A, Boughattas S. Assessing the burden of intestinal parasites affecting newly arrived immigrants in Qatar. Parasit Vectors. 2016;9:619.

    Article  Google Scholar 

  3. Adao DE, Dela Serna AO, Belleza ML, Bolo NR, Rivera WL. Subtype analysis of Blastocystis sp. isolates from asymptomatic individuals in an urban community in the Philippines. Ann Parasitol. 2016;62:193–200.

    PubMed  Google Scholar 

  4. Alinaghizade A, Mirjalali H, Mohebali M, Stensvold CR, Rezaeian M. Inter- and intra-subtype variation of Blastocystis subtypes isolated from diarrheic and non-diarrheic patients in Iran. Infect Genet Evol. 2017;50:77–82.

    Article  CAS  Google Scholar 

  5. Dogan N, Aydin M, Tuzemen NU, Dinleyici EC, Oguz I, Dogruman-Al F. Subtype distribution of Blastocystis spp. isolated from children in Eskisehir, Turkey. Parasitol Int. 2017;66:948–51.

    Article  CAS  Google Scholar 

  6. Koltas IS, Eroglu F. Subtype analysis of Blastocystis isolates using SSU rRNA-DNA sequencing in rural and urban population in southern Turkey. Exp Parasitol. 2016;170:247–51.

    Article  CAS  Google Scholar 

  7. Mohamed RT, Elbali MA, Mohamed AA, Abdelfatah MA, Elmalky MA, Mowafy NM, et al. Subtyping of Blastocystis sp. isolated from symptomatic and asymptomatic individuals in Makkah, Saudi Arabia. Parasit Vectors. 2017;10:174.

    Article  Google Scholar 

  8. Noradilah SA, Moktar N, Anuar TS, Lee IL, Salleh FM, Snaa M, et al. Molecular epidemiology of blastocystosis in Malaysia: does seasonal variation play an important role in determining the distribution and risk factors of Blastocystis subtype infections in the Aboriginal community? Parasit Vectors. 2017;10:360.

    Article  Google Scholar 

  9. Osman M, El SD, Cian A, Benamrouz S, Nourrisson C, Poirier P, et al. Prevalence and risk factors for intestinal protozoan infections with Cryptosporidium, Giardia, Blastocystis and Dientamoeba among schoolchildren in Tripoli, Lebanon. PLoS Negl Trop Dis. 2016;10:e0004496.

    Article  Google Scholar 

  10. Sanpool O, Laymanivong S, Thanchomnang T, Rodpai R, Sadaow L, Phosuk I, et al. Subtype identification of human Blastocystis spp. isolated from Lao Peopleʼs Democratic Republic. Acta Trop. 2017;168:37–40.

    Article  CAS  Google Scholar 

  11. Tan KSW. New insights on classification, identification, and clinical relevance of Blastocystis spp. Clin Microbiol Rev. 2008;21:639–65.

    Article  CAS  Google Scholar 

  12. Zhang SX, Zhou YM, Xu W, Tian LG, Chen JX, Chen SH, et al. Impact of co-infections with enteric pathogens on children suffering from acute diarrhea in southwest China. Infect Dis Poverty. 2016;5:1–13.

    Article  Google Scholar 

  13. El Safadi D, Gaayeb L, Meloni D, Cian A, Poirier P, Wawrzyniak I, et al. Children of Senegal River Basin show the highest prevalence of Blastocystis sp. ever observed worldwide. BMC Infect Dis. 2014;14:164.

    Article  Google Scholar 

  14. Abe N. Molecular and phylogenetic analysis of Blastocystis isolates from various hosts. Vet Parasitol. 2004;120:235–42.

    Article  CAS  Google Scholar 

  15. Alfellani MA, Tanermulla D, Jacob AS, Imeede CA, Yoshikawa H, Stensvold CR, et al. Genetic diversity of Blastocystis in livestock and zoo animals. Protist. 2013;164:497–509.

    Article  CAS  Google Scholar 

  16. Fayer R, Santin M, Macarisin D. Detection of concurrent infection of dairy cattle with Blastocystis, Cryptosporidium, Giardia, and Enterocytozoon by molecular and microscopic methods. Parasitol Res. 2012;111:1349–55.

    Article  Google Scholar 

  17. Li WC, Wang K, Gu Y. Occurrence of Blastocystis sp. and Pentatrichomonas hominis in sheep and goats in China. Parasit Vectors. 2018;11:93.

    Article  Google Scholar 

  18. Parkar U, Traub RJ, Kumar S, Mungthin M, Vitali S, Leelayoova S, et al. Direct characterization of Blastocystis from faeces by PCR and evidence of zoonotic potential. Parasitology. 2007;134:359–67.

    Article  CAS  Google Scholar 

  19. Ramírez JD, Sánchez LV, Bautista DC, Corredor AF, Flórez AC, Stensvold CR. Blastocystis subtypes detected in humans and animals from Colombia. Infect Genet Evol. 2014;22:223–8.

    Article  Google Scholar 

  20. Santín M, Gómezmuñoz MT, Solanoaguilar G, Fayer R. Development of a new PCR protocol to detect and subtype Blastocystis spp. from humans and animals. Parasitol Res. 2011;109:205–12.

    Article  Google Scholar 

  21. Song JK, Hu RS, Fan XC, Wang SS, Zhang HJ, Zhao GH. Molecular characterization of Blastocystis from pigs in Shaanxi Province of China. Acta Trop. 2017;173:130–5.

    Article  CAS  Google Scholar 

  22. Song JK, Yin YL, Yuan YJ, Tang H, Ren GJ, Zhang HJ, et al. First genotyping of Blastocystis sp. in dairy, meat, and cashmere goats in northwestern China. Acta Trop. 2017;176:277–82.

    Article  Google Scholar 

  23. Stensvold CR, Alfellani MA, Nørskov-Lauritsen S, Prip K, Victory EL, Maddox C, et al. Subtype distribution of Blastocystis isolates from synanthropic and zoo animals and identification of a new subtype. Int J Parasitol. 2009;39:473–9.

    Article  CAS  Google Scholar 

  24. Yamada M, Yoshikawa H, Tegoshi T, Matsumoto Y, Yoshikawa T, Shiota T, et al. Light microscopical study of Blastocystis spp. in monkeys and fowls. Parasitol Res. 1987;73:527–31.

    Article  CAS  Google Scholar 

  25. Zhao GH, Hu XF, Liu TL, Hu RS, Yu ZQ, Yang WB, et al. Molecular characterization of Blastocystis sp. in captive wild animals in Qinling Mountains. Parasitol Res. 2017;116:2327–33.

    Article  CAS  Google Scholar 

  26. Zhu W, Tao W, Gong B, Yang H, Li Y, Song M, et al. First report of Blastocystis infections in cattle in China. Vet Parasitol. 2017;246:38–42.

    Article  Google Scholar 

  27. Stensvold CR, Clark CG. Current status of Blastocystis: a personal view. Parasitol Int. 2016;65:763–71.

    Article  Google Scholar 

  28. Lan D, Xiong X, Mipam TD, Fu C, Li Q, Ai Y, et al. Genetic diversity, molecular phylogeny and selection evidence of Jinchuan yak revealed by whole-genome resequencing. G3 (Bethesda). 2018;8:945–52.

    Article  Google Scholar 

  29. Wang G, Wang G, Li X, Zhang X, Karanis G, Jian Y, et al. Prevalence and molecular characterization of Cryptosporidium spp. and Giardia duodenalis in 1–2-month-old highland yaks in Qinghai Province, China. Parasitol Res. 2018;117:1–8.

    Article  CAS  Google Scholar 

  30. Chang H, Ma Y, Tong L, Cong G, Du J, Ma J. Foot-and-mouth disease virus carrier status in Bos grunniens yaks. Virol J. 2013;10:1–5.

    Article  CAS  Google Scholar 

  31. Gao J, Liu M, Meng X, Han Z, Zhang D, Hou B, et al. Seroprevalence of bovine viral diarrhea infection in Yaks (Bos grunniens) on the Qinghai-Tibetan Plateau of China. Trop Anim Health Prod. 2013;45:791–3.

    Article  Google Scholar 

  32. Li J, Li K, Shahzad M, Han Z, Nabi F, Gao J, et al. Seroprevalence of bluetongue virus in domestic yaks (Bos grunniens) in Tibetan regions of China based on circulating antibodies. Trop Anim Health Prod. 2015;47:1221–3.

    Article  Google Scholar 

  33. Li K, Gao J, Shahzad M, Han Z, Nabi F, Liu M, et al. Seroprevalence of Toxoplasma gondii infection in yaks (Bos grunniens) on the Qinghai-Tibetan Plateau of China. Vet Parasitol. 2014;205:354–6.

    Article  Google Scholar 

  34. Ma J, Cai J, Ma J, Feng Y, Xiao L. Occurrence and molecular characterization of Cryptosporidium spp. in yaks (Bos grunniens) in China. Vet Parasitol. 2014;202:113–8.

    Article  CAS  Google Scholar 

  35. Ma J, Cai J, Ma J, Feng Y, Xiao L. Enterocytozoon bieneusi genotypes in yaks (Bos grunniens) and their public health potential. J Eukaryot Microbiol. 2015;62:21–5.

    Article  CAS  Google Scholar 

  36. Clark CG. Extensive genetic diversity in Blastocystis hominis. Mol Biochem Parasitol. 1997;87:79–83.

    Article  CAS  Google Scholar 

  37. Wong KH, Ng GC, Lin RT, Yoshikawa H, Taylor MB, Tan KS. Predominance of subtype 3 among Blastocystis isolates from a major hospital in Singapore. Parasitol Res. 2008;102:663–70.

    Article  Google Scholar 

  38. Burland TG. DNASTAR’s Lasergene sequence analysis software. Methods Mol Biol. 2000;132:71–91.

    CAS  PubMed  Google Scholar 

  39. Thompson JD, Gibson TJ, Plewniak F, Jeanmougin F, Higgins DG. The CLUSTAL_X Windows interface: flexible strategies for multiple sequence alignment aided by quality analysis tools. Nucleic Acids Res. 1997;25:4876–82.

    Article  CAS  Google Scholar 

  40. Kumar S, Stecher G, Tamura K. MEGA7: Molecular Evolutionary Genetics Analysis version 7.0 for bigger datasets. Mol Biol Evol. 2016;33:1870–4.

    Article  CAS  Google Scholar 

  41. Navarro C, Domínguezmárquez MV, Garijotoledo MM, Vegagarcía S, Fernándezbarredo S, Pérezgracia MT, et al. High prevalence of Blastocystis sp. in pigs reared under intensive growing systems: frequency of ribotypes and associated risk factors. Vet Parasitol. 2008;153:347–58.

    Article  CAS  Google Scholar 

  42. Huelsenbeck JP, Ronquist F. MRBAYES: Bayesian inference of phylogenetic trees. Bioinformatics. 2001;17:754–5.

    Article  CAS  Google Scholar 

  43. Posada D. jModelTest: phylogenetic model averaging. Mol Biol Evol. 2008;25:1253–6.

    Article  CAS  Google Scholar 

  44. Posada D, Buckley TR. Model selection and model averaging in phylogenetics: advantages of Akaike information criterion and Bayesian approaches over likelihood ratio tests. Syst Biol. 2004;53:793–808.

    Article  Google Scholar 

  45. Alfellani MA, Stensvold CR, Vidal-Lapiedra A, Onuoha ESU, Fagbenro-Beyioku AF, Clark CG. Variable geographic distribution of Blastocystis subtypes and its potential implications. Acta Trop. 2013;126:11–8.

    Article  Google Scholar 

  46. Wang J, Gong B, Liu X, Zhao W, Bu T, Zhang W, et al. Distribution and genetic diversity of Blastocystis subtypes in various mammal and bird species in northeastern China. Parasit Vectors. 2018;11:522.

    Article  Google Scholar 

  47. Badparva E, Sadraee J, Kheirandish F. Genetic diversity of Blastocystis isolated from cattle in Khorramabad, Iran. Jundishapur J Microbiol. 2015;8:e14810.

    Article  Google Scholar 

  48. Moura RGF, de Oliveira-Silva MB, Pedrosa AL, Nascentes GAN, Cabrine-Santos M. Occurrence of Blastocystis spp. in domestic animals in Triangulo Mineiro area of Brazil. Rev Soc Bras Med Trop. 2018;51:240–3.

    Article  Google Scholar 

  49. Quilez J, Clavel A, Sanchez-Acedo C, Causape AC. Detection of Blastocystis sp. in pigs in Aragon (Spain). Vet Parasitol. 1995;56:345–8.

    Article  CAS  Google Scholar 

  50. Udonsom R, Prasertbun R, Mahittikorn A, Mori H, Changbunjong T, Komalamisra C, et al. Blastocystis infection and subtype distribution in humans, cattle, goats, and pigs in central and western Thailand. Infect Genet Evol. 2018;65:107–11.

    Article  Google Scholar 

  51. Wang J, Gong B, Yang F, Zhang W, Zheng Y, Liu A. Subtype distribution and genetic characterizations of Blastocystis in pigs, cattle, sheep and goats in northeastern Chinaʼs Heilongjiang Province. Infect Genet Evol. 2018;57:171–6.

    Article  Google Scholar 

  52. Feng XW, Xu GS, Zhang L. Seasonal variation of nutritive value of pasture in Haixi Prefecture and Hainan Prefecture of Qinghai Province. Heilongjiang Anim Sci Vet Med. 2011;3:87–8 (In Chinese).

    Google Scholar 

  53. Arisue N, Hashimoto TH. Sequence heterogeneity of the small subunit ribosomal RNA genes among Blastocystis isolates. Parasitology. 2003;126:1–9.

    Article  CAS  Google Scholar 

  54. Stensvold CR, Suresh GK, Tan KS, Thompson RC, Traub RJ, Viscogliosi E, et al. Terminology for Blastocystis subtypes - a consensus. Trends Parasitol. 2007;23:93–6.

    Article  Google Scholar 

  55. Andersen LO, Stensvold CR. Blastocystis in health and disease: are we moving from a clinical to a public health perspective? J Clin Microbiol. 2016;54:524.

    Article  CAS  Google Scholar 

  56. Parkar U, Traub RJ, Vitali S, Elliot A, Levecke B, Robertson I, et al. Molecular characterization of Blastocystis isolates from zoo animals and their animal-keepers. Vet Parasitol. 2010;169:8–17.

    Article  CAS  Google Scholar 

  57. Roberts T, Stark D, Harkness J, Ellis J. Subtype distribution of Blastocystis isolates from a variety of animals from New South Wales, Australia. Vet Parasitol. 2013;196:85–9.

    Article  CAS  Google Scholar 

  58. Ramírez JD, Sánchez A, Hernández C, Flórez C, Bernal MC, Giraldo JC, et al. Geographic distribution of human Blastocystis subtypes in South America. Infect Genet Evol. 2016;41:32–5.

    Article  Google Scholar 

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Authors’ contributions

QL and JKS conceived and designed the experiments. MR, FY and DW collected the samples. MR, MZ and PXW performed the experiments. MR and HJZ performed the sequence analyses. MR, JKS and GHZ wrote this paper. All authors read and approved the final manuscript.


We are grateful to the yak owners for cooperation during the process of sampling.

Competing interests

The authors declare that they have no competing interests.

Availability of data and materials

Datasets supporting the conclusions of this article are included within the article. The nucleotide sequences generated in this study were submitted to the GenBank database under the accession numbers MH358361-MH358376, MH507324-MH507327.

Ethics approval and consent to participate

This study was conducted strictly according to the legal requirements of guide for the Care and Use of Laboratory Animals of the Ministry of Health, China and approved by the Research Ethics Committee of Northwest A&F University. Sampling was permitted by yak owners and no specific authority was needed for sample collection.

Consent for publication

Not applicable.


The present study was partly supported by the Project of Qinghai Science & Technology Department (2016-ZJ-754 and 2016-ZJ-Y01) and the Open Project of State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University (2017-ZZ-08).

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Ren, M., Song, Jk., Yang, F. et al. First genotyping of Blastocystis in yaks from Qinghai Province, northwestern China. Parasites Vectors 12, 171 (2019).

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