Blastocystis is a highly prevalent single-celled parasite that infects the gastrointestinal tract of humans and animals. It has become the most prevalent gastrointestinal parasitic infection in developed and many developing countries, and it will produce long-term diarrhea, abdominal pain, and other symptoms in healthy individuals.
BRF’s web site has written and audio descriptions from patients, information on the newest research in diagnosis and treatment of Blastocystis ’hominis’ infection, and information on BRF”s advocacy program.
Researching Blastocystis infection requires many things – skilled and motivated researchers, access to Blastocystis patients or cultures, specialized equipment and supplies. In many cases, laboratories have all of the required items, but purchasing disposable supplies can be an obstacle.
Because of this, BRF’s board has voted to begin a Blastocystis Supplies Grant Program. Researchers interested in pursuing Blastocystis studies can apply to BRF to have part or all of the cost of their supplies covered by BRF. BRF, at its option, may either reimburse researchers for supplies, or pay suppliers directly to ship supplies to their lab. Researchers interested in pursuing grant opportunities should be associated with a University or research institution in their country, or should have prior peer reviewed publications in the area of Blastocystis or similar microbial research.
For details on the supplies grant program, and an application form, please contact BRF at firstname.lastname@example.org.
The Internal Transcribed Spacer, a region situated between structural ribosomes, has been useful in tracking genetic differentiation and variation in fungal organisms and yeasts for some time, and now researchers at the University of Mexico (Mexico City) have reported that it can be used for this purpose in Blastocystis as well. Using Blastocystis samples from 47 children who were symptomatic with diarrhea, the researchers analyzed stool samples for other parasites, and also extracted DNA from fecal samples, and then amplified and analyzed Blastocystis sequences. None of the children selected were found to have bacterial pathogens, and none were identified as carrying any pathogenic parasitic infection other than Blastocystis. DNA extracted from fecal samples, subtyped Blastocystis isolates using the standard methodology, and almost all infections were found to be of type ST1, ST2, or ST3, with a roughly even distribution between the three subtypes. Examining existing sequences in Genbank, the researchers found that a high gene flow exists between European and American isolates for ST1 and ST2. ST3 showed extremely high gene flow between Asia and Africa. Also, there was a high gene flow for ST3 between Asia and the Americas, and between Asia and Europe. The full text of the article is available for free at BMC Parasites and Vectors site.
Russian physicians have reported on extra-intestinal Blastocystis infection in a 65-year old female patient suffering from a liver abscess, following surgery for removal of colonic polyps. Pathologists identified Blastocystis cells, along with liver cells and inflammatory cells in aspirates from the patient’s liver. The patient made a full recovery following treatment with broad spectrum antibiotics and an imidazole antiparasitic drug (imidazole drugs are of the miconazole, fluconazole, clotrimazole family) The study authors suggested this case illustrated the importance of investigating Blastocystis infection in immunocompromised patients. Link to NIH Pubmed entry.
A study of 674 Moroccan children from rural and urban areas found that overall, 20% were infected with Giardia intestinalis and 64% with Blastocystis. Blastocystis was found at the same prevalence in children from urban and rural schools. Despite the high rate of parasitism, only 8% of rural children and 7% of urban children had diarrhea, and diarrhea in Blastocystis patients occurred in those co-infected with another parasite. Researchers genotyped Giardia isolates from the children, and found that both Assemblage A (AII) and Assemblage B (BIII, BIV) were present, with the majority of isolates belonging to Assemblage BIV (73%). The full free text of the study is available at the web site of the Parasite Journal.
Researchers from Oregon State University (USA) studying over 300 animal shelter and family pets report that Blastocystis was not found in any family pets, although it was present in about 10% of pets from animal shelters. Researches studied about 103 shelter-resident dogs, 105 shelter-resident cats, 51 client owned dogs, and 52 client owned cats. Blastocystis presence was determined by direct DNA extraction of fecal samples, PCR amplification, followed by sequencing to determine subtype. Blastocystis sequences were further phylogenetically analyzed and compared to existing sequences in Genbank. Researchers found that shelter pets hosted a variety of Blastocystis sequences, with a wide genetic diversity. One shelter pet hosted a Blastocystis strain reported in a previous study from the area, isolated from a symptomatic patient in the same community. Overall, shelter-resident pets carrying Blastocystis were not symptomatic.
Researchers from Oregon State University, publishing in the journal PLOS-One, report that Blastocystis infection is highly prevalent in animals studied at a local animal shelter.
The researchers report that Blastocystis was found in 10/103 (9.7%) shelter-resident canines, and 12/103 (11.65%) shelter-resident felines. In contrast, Blastocystis was not detected in any of the pets owned by families in the study.
For details, or to view the study, follow this link to PLOS-One.
In 2014, ICOPA hosted the world’s first Blastocystis research forum in Mexico City.
Work on the following topics was presented by:
Pauline Scanlan – Blastocystis Surveillance in UK population
Rune Stensvold – Blastocystis in IBS patients
Pablo Maravilla – Host Genetics + Blastocystis
Ken Boorom (BRF) – Confounding factors in Blastocystis Population Studies
Slides are available for Pablo Maravilla’s presentation, as well as Ken Boorom’s presentation.
BRF’s contribution focused on why data from population studies sometimes shows a pathogen to be uncorrelated with symptoms, conflicting with data from animal studies and human treatment studies that show it causes illness. Briefly, when the prevalence of an pathogen becomes very high in a population where acquired or innate immunity also exists, the presence of an organism can become uncorrelated or even inversely correlated with symptoms. A similar paradoxical inverse correlation can occur if all etiological causes are not detected and analyzed as a group. The presentation provided a quantitative analysis to prior work contributed by BRF to Springer’s Text, Blastocystis: Pathogen or Passenger
Attendees at the Blastocystis Forum, ICOPA 2014
Springer-Verlag has published the world’s first major textbook on Blastocystis. The text, assembled by Parasitology Research editor Heinz Mehlhorn and long-time Blastocystis researchers Kevin Tan and Hisao Yoshikawa.
BRF co-founder Ken Boorom contributed two chapters that investigate the analytical process behind using research studies to make a decision about pathogenicity, and suggest that the difficulties associated with Blastocystis recur frequently in the medical community.
The text is sure to become a classic work in this field, and has both scientific and historical significance. It would be a valuable addition to any collection or library.
Read excerpts on Springer-Verlag’s Site, purchase there
Read excerpts on Amazon.com, purchase the text there