Friday, December 30, 2016

This Month in Blastocystis Research (DEC 2016)

I would like to end the year by briefly highlight three of the most important/interesting papers in Blastocystis research published in 2016 (and not co-authored by me).

The first article that comes to my mind is one by Pauline Scanlan and colleagues, who took to investigating the prevalence of Blastocystis in US households (family units). The reason why I'm mentioning this article is not so much due to its approach; it's much more related to the fact that even when molecular methods are used (i.e., highly sensitive methods), the prevalence in this population was only 7%, and the vast majority of Blastocystis carriers were adults. The prevalence is much lower in this population (Colorado) than in a country such as Denmark. I'm interested in knowing the reason for this difference. Are people in Colorado less exposed or are they less susceptible than people in Denmark? I'm also interested in knowing why there was only one child among the carriers... we see similar trends elsewhere: Blastocystis is a parasite that emerges only in adolescence and adulthood. Meanwhile, we see a lot of Dientamoeba in toddlers and smaller children, with more or less all children being infected at some point - at least in Denmark; here, geographical differences may exist as well. Mixed infection with Blastocystis and Dientamoeba in adults is not uncommon, so it's not that they outcompete each other.

Next up, is the article by Audebert and colleagues who published in the Nature-affiliated Scientific Reports on gut microbiota profiling of Blastocystis-positive and -negative individuals. I already made a small summary of the article in this post.

While we gain valuable insight into gut microbiota structure, we also need to know what these microbes are able to do. We need to know about the interaction with the host and how they influence our metabolism. I hope to see more studies emerging on the metabolic repertoire of Blastocystis and how the parasite may be capable of influencing the diversity and abundance of bacterial, fungal and protist species in the gut. What would also be useful is a drug that selectively targets Blastocystis so that we can be able to selectively eradicate the parasite from its niche in order to see what happens to the surrounding microbiota and - if in vivo - to the host.

The last article is authored by my Turkish colleagues Özgür Kurt, Funda Dogruman-Al, and Mehmet Tanyüksel, who pose the rhetorical question: "Blastocystis eradication - really necessary for all?" in the special issue on Blastocystis in Parasitology International. For some time I have been thinking of developing a reply to the authors as a Letter to the Editor with the title "Blastocystis eradication - really necessary at all?" Nevermind, quite similar to what we did back in 2010, the authors review the effect of various drugs that have been used to try eradicate Blastocystis. Moreover, they acknowledge the fact that Blastocystis is often seen in healthy individuals, and that its role in the development of gut microbiota and host immune responses should be subject to further scrutiny. They even suggest that the role of Blastocystis as a probiotic should be investigated. It's great to see clinicians think along these lines, since this is an important step towards expanding the revolution lately seen in Blastocystis research, exemplified by studies such as that by Audebert et al. mentioned above.

So, wishing you all a Happy New Year and a great 2017, I'd like to finish by encouraging you to stay tuned; soon, I will be posting some very... interesting... neeeeeeewwwws...


Audebert C, Even G, Cian A, Blastocystis Investigation Group., Loywick A, Merlin S, Viscogliosi E, & Chabé M (2016). Colonization with the enteric protozoa Blastocystis is associated with increased diversity of human gut bacterial microbiota. Scientific Reports, 6 PMID: 27147260 

Kurt Ö, Doğruman Al F, & Tanyüksel M (2016). Eradication of Blastocystis in humans: Really necessary for all? Parasitology International, 65 (6 Pt B), 797-801 PMID: 26780545

Scanlan PD, Knight R, Song SJ, Ackermann G, & Cotter PD (2016). Prevalence and genetic diversity of Blastocystis in family units living in the United States. Infection, Genetics and Evolution, 45, 95-97 PMID: 27545648

Friday, December 2, 2016

This Month in Blastocystis Research (NOV 2016)

Oftentimes, I receive emails from colleagues wanting to know how you subtype Blastocystis, how to grow them in culture, and how to freeze down cultures.

I'm very pleased to announce that Dr Graham Clark and I have developed protocols for exactly these activities and published them in Wiley's 'Current Protocols in Microbiology'; please go here for the subtyping protocol and here for the culture and cryopreservation protocols.
These should not only be seen as SOPs but also as a resource that enables standardization within the field.

Unfortunately, we have not yet come up with a protocol on how to axenise Blastocystis cultures, i.e., get rid of metabolically active organisms other than Blastocystis in cultures while keeping Blastocystis alive and multiplying.

We are well aware that many might not have access to these protocols because they haven't subscribed to Wiley Online Library; good news is that reprints will be available on request!


Stensvold CR, & Clark CG (2016). Molecular Identification and Subtype Analysis of Blastocystis. Current Protocols in Microbiology, 43 PMID: 27858971  

Clark CG, & Stensvold CR (2016). Blastocystis: Isolation, Xenic Cultivation, and Cryopreservation. Current Protocols in Microbiology, 43 PMID: 27858970