The latest Paper of the Month from Parasitology is ‘Genetic diversity of Blastocystis in non-primate animals’ by Emma L. Betts, Eleni Gentekaki, Adele Thomasz, et al.

The gastrointestinal (GI) tract harbors a vast amount of microbes collectively called the microbiome. These microbes include both prokaryotes and eukaryotes. Most microbiome-related studies have focused on humans with only a few exploring the microbiome of other animals, mostly primates. Even so, only a handful of research investigations examine the eukaryotic residents of the gut. The eukaryome of non-primate animals remains largely uncharted and holds great research interest for investigators. This is because of the potential of such work to uncover novel and currently unculturable microbial eukaryotes. For example, the first organism with atypical mitochondria was previously collected from a fecal sample of a chinchilla. Gut eukaryotic microbes affect the quality of life of their hosts, but unlike the bacterial residents, their abundance, diversity and distribution is unexplored. For instance, currently, animal conservation and rehabilitation studies, strategies and policies do not take into account the microbial eukaryotes present in the gut of the animals involved.

Therefore, in this study we began examining the eukaryome of non-primate animals kept in captivity. During Dr. Eleni Gentekaki’s visit in Kent in the summer of 2016 (from Mae Fah Luang University in Thailand sponsored by the University of Kent’s Internalization Funds) we met with the education and conservation staff at Wildwood Trust in Herne Bay and collectively designed our sampling strategy. Wildwood Trust is a wildlife park not far from the University of Kent in Canterbury (UK). The park is involved in captive breeding and reintroduction schemes of a number of endangered species, such as hazel dormice, pine martens, red squirrels, water voles and Scottish wildcat. It was, therefore, the ideal place to start the journey of exploring the gut eukaryome. During our visit, we brought all the equipment necessary for sampling (tubes, media, slides), placed in a wheel barrow, and off we went around the park (Picture 1). Faecal collection is a non-invasive process, but for the purpose of our study, the faeces had to be as fresh as possible. You might be thinking, “how exactly do you get a fresh faecal sample? Do you have to wait around for the animal to do its business?” Indeed, that is exactly what we did. We would “glue” our eyes on the animal of interest, eagerly waiting for it to expel the “treasure”. Most of the time this strategy worked and we were able to trace individual faecal samples to specific individuals. Other times, we just had to rely on whether the “treasure” was warm enough indicating recent defecation. This involved “feeling” the temperature of the sample by placing our (gloved) hands in what many would describe as uncomfortable proximity. We were very enthusiastic, when we found fresh faeces, and dipped our hands in the “poop” with gusto (Picture 2). It was literally a “sh***” job.

Bringing the samples back to the lab, we looked at them under the microscope and noticed that Blastocystis was present in many samples. Thus we firstly focused on this abundant eukaryote, but several other eukaryotes are currently being explored. Molecular work and phylogenetic analyses revealed that Blastocystis was present in 41% of animal species. The presence of Blastocystis in elk, pine marten and water vole hosts has not been previously reported. One Blastocystis sequence is genetically different to all the other sequences of Blastocystis previously reported.

Hence, this work sets the foundation for future discoveries. We are currently monitoring and comparing microbial eukaryotes of animals living in their natural environment, captive animals and animals that have been recently reintroduced. We envision that this collaborative study between University of Kent and Wildwood Trust will pave the way for interventions and successful reintroduction strategies for some of these endangered species. It has led to the establishment of new biosecurity protocols at the Trust, following these findings, and thus providing a mutually beneficial partnership.

1. Emma Betts and Eleni Gentekaki marking the tubes containing freshly collected faecal samples 
2. Anastasios Tsaousis displaying palpable enthusiasm, while collecting bison’s faeces (picture kindly provided by Nicola Baker).












Read the full article ‘Genetic diversity of Blastocystis in non-primate animals’ in full for free until 3rd April 2018.


  1. Dear colleagues,
    First of all, congratulations for your nice study reinforcing our understanding of the epidemiology and circulation of Blastocystis in various animal groups.

    You mention several times in your article that prevalence data and molecular characterization of Blastocystis sp. in animals in captivity remain sparse. Thus we were very surprised not to see mentioned and discussed the study by Cian et al. published in Plos One in January 2017 and available on-line.

    In this study were screened by real-time PCR 307 stool samples from 161 mammalian including numerous non-primate and non-mammalian species in two French zoos. Interestingly 32.2% of the animal samples and 37.9% of the species tested were shown to be infected with Blastocystis sp. This last value is very similar to that observed in your study. In addition, 11 of the 17 mammalian and avian STs were identified in the French study as well as potential additional STs.

    Therefore it is a pity that these molecular data obtained in France were not taken into account and compared with those of your study concerning in particular Carnivora, Artiodactyla, birds, rodents and reptiles. This type of comparison was made in the French study by conducting a synthesis of all previously published studies and provides a global view of the circulation of Blastocystis sp. STs in the animal population.

    With our best regards

    1. Cambridge University Press on behalf of Eleni Gentekaki and Anastasios Tsaousis:
      Dear colleagues,

      We would like to thank you for bringing this up. We recognise the importance and magnitude of the Cian et al. 2017 paper. Our study was focused exclusively on non-primates whereas, the aforementioned paper included both primates and non-primates (including invertebrates). Thus the prevalence rates referred to only non-primates, whereas in your paper estimation of these rates referred to both. Having said that, we are now in the process of preparing a second manuscript in which we do examine primates along with other animals and will definitely cite your paper as it is particularly relevant.

      We would like to thank you for your comment and we are looking forward for our teams to collaborate in the near future.

      Kind regards,

      Eleni Gentekaki and Anastasios Tsaousis

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