Friday, March 29, 2013

Happy Birthday!

In these very hours, my daughter is turning two years old! This blog was put up one year ago as she was celebrating the conclusion of her first year on this planet, and given all the fun I've had along the way putting up posts on this and that, I'd like to dedicate the blog to her. In return(!), I take the liberty of using some of her artwork for this post which marks the birthday of the Blastocystis Parasite Blog.

Artwork by Raiya Rochelle Traub

It's surprising to me that this blog has had more than 50,000 views in only one year. Due to all the feedback I get, I'm prone to believe that most of the page views reflect factual "blog consumption" (rather than referral spam and bots). Anyway, even if there were only a few people out there who'd stop by every now and then, my efforts would certainly be worthwhile. 
Blastocystis has been known for more than 100 years. But it is only recently that we have found tools to enable accurate distinction of Blastocystis carriers from non-carriers, thanks to DNA-based diagnostic methods. Last year, we published a paper on our new real-time PCR in Journal of Clinical Microbiology, and it seems as if we now finally have the chance to try and use it for screening a larger panel of faecal DNAs from patients with and without intestinal symptoms to get an idea about the factual prevalence of Blastocystis in this type of samples with the added benefit of analysis of colonisation intensity. It's very exciting...

And to those who are involved in Blastocystis subtyping, -  in case you didn't see it, there is a paper out on the comparison of the two principal methods used for subtyping which you might find useful.
I've also added a few lines on barcoding in "Lab Stuff" for those who are new to subtyping and want to practice a bit - please go here.

We are currently trying to strengthen collaborative efforts of different labs across the world and we are facing some very exciting challenges, involving the generation and analysis of data output related to genomics, transcriptomics, metagenomics and possibly proteomics; more about that in "Season II" of the Blastocystis Parasite Blog!

But for now: Happy birthday, Raiya! And Happy Easter everyone!

Suggested reading:

Stensvold CR (2013). Comparison of sequencing (barcode region) and sequence-tagged-site PCR for Blastocystis subtyping. Journal of Clinical Microbiology, 51 (1), 190-4. PMID: 23115257 

Stensvold, C., Ahmed, U., Andersen, L., & Nielsen, H. (2012). Development and Evaluation of a Genus-Specific, Probe-Based, Internal-Process-Controlled Real-Time PCR Assay for Sensitive and Specific Detection of Blastocystis spp. Journal of Clinical Microbiology, 50 (6), 1847-51. DOI: 10.1128/JCM.00007-12

Thursday, March 21, 2013

LUMINEX xMAP Technology in Parasite Diagnostics

Over the past few years nucleic acid based methods have revolutionised parasite diagnostics in modern clinical microbiology (CM) labs. Real-time PCR is really gaining a foothold in CM labs, but despite the opportunity for plexing, mostly only up to 6 DNA targets can be included in each assay (due to the number of available channels).

LUMINEX xMAP technology used for detection of specific nucleic acids (Dunbar, 2006) bypasses this limit, and up to 100 DNA targets can be included in one single assay in a 96-well plate format. You can read about the technology here.

Thursday, March 14, 2013

Extremophilic Eukaryotes

My recent post Blastocystis aux Enfers was my "literary take" on biological adaptation of intestinal parasitic protists, using Blastocystis as an example. As a parasitologist you'd come across many peculiar and shrewd biological adaptations and life cycles, and I hope to be able to give some examples in a future post. Actually, there is a parasite which is quite common in humans, maybe even just as common as Blastocystis, which is also single-celled, but which may have a much more complicated life cycle than Blastocystis, namely Dientamoeba fragilis; a colleague of mine is currently doing his PhD on Dientamoeba and he has collected multiple sources of evidence to confirm the hypothesis that this parasite is transmitted by a vector, namely pinworm, probably along the same way that Histomonas meleagridis – the cause of blackhead disease in especially turkeys – is transmitted by heterakids (which again are transmitted by parathenic hosts such as earthworms, which get eaten by turkeys, chickens, etc.). Anyway, I’ll probably get back to Dientamoeba, once his data are out.

Meanwhile, Blastocystis comes out of a very heterogeneous group of organisms called Stramenopiles, many of which are algae. Algae are photosynthetic organisms found in habitats as diverse as glacial ice and hot springs.One of these algae is named Galdieria sulphuraria, which is a remarkable unicellular eukaryote inhabiting hostile environments such as volcanic hot sulfur springs where it is responsible for about 90% of the biomass; indeed this certainly qualifies as "Galdieria aux enfers"!

Tuesday, March 12, 2013

Blastocystis video

Just saw this on YouTube and had to share it. This is Blastocystis (and other microorganisms) viewed through a microscopy (light microscopy). Note that this is Blastocystis from a chicken, but Blastocystis from humans looks the same; at least I don't know how to tell the difference. I wonder whether this is from a culture or a completely fresh egestion... looks more like a culture to me. Note how the Blastocystis looks almost like fat cells...

The video comes with some nice music as well!

Wednesday, March 6, 2013

Open Access papers in Nature Reviews on functional dyspepsia

"Functional dyspepsia is one of the most common functional gastrointestinal disorders worldwide. Although the condition does not affect life expectancy, it can have a marked influence on quality of life, and is associated with a high economic burden; an estimated US$1 billion per year is spent on the management of functional dyspepsia in the USA alone. This comprehensive Focus issue from Nature Reviews Gastroenterology & Hepatology contains seven Reviews that have been specially commissioned to cover key themes in functional dyspepsia. Experts from around the world provide up-to-date overviews of the most important topics in the field, including the influence of dietary, lifestyle and psychosocial factors, relevance of Helicobacter pylori infection, overlap with GERD, changes in gastrointestinal tract structure and function, symptom pattern and validity of the Rome III criteria, as well as current and emerging treatment options."

For the bunch of papers, please go here.