Italian researchers report on a case of Blastocystis infection, mis-diagnosed as gluten intolerance, which subsequently resolved, possibly due to treatment with Saccharomyces. The researchers report that, ” 41-year-old Italian man came to the clinician’s observation reporting cramps, bloating and watery diarrhoea a few days after drinking water indicated as unpotable from a fountain in a farm area. The medical suspicion was directed at both gluten intolerance and enteric infection, eventually of waterborne origin. Gluten intolerance was investigated by intestinal biopsy and excluded, while stool analyses ruled out infective bacteriological or viral agents and parasites. Subsequently, a persistent eosinophilia was revealed and a parasitological analysis was again suggested, planning for a more sensitive molecular method.” The study was published in New Microbiologica.
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Using a murine model of Blastocystis infection, an Egyptian research team has reported that the anti-cholesterol statin drug Atorvastatin increases the efficacy of metronidazole in treatment of Blastocystis infection in a murine model. The researchers report that, “Anti-Blastocystis efficacy of AVA was evaluated parasitologically, histopathologically and by transmission electron microscopy using MTZ (10 mg/kg) as a control. Therapeutic efficacy of AVA was apparently dose-dependent. Regimens of AVA (20 and 40 mg/kg) proved effective against Blastocystis infections with high reduction in Blastocystis shedding (93.4-97.9%) compared to MTZ (79.3%). The highest reductions (98.1% and 99.4%) were recorded in groups of combination treatments AVA 20-40 mg/kg and MTZ 10 mg/kg. Blastocystis was nearly eradicated by the 20th day post infection. Genotype analysis revealed that genotype I was most susceptible, genotype III was less. ” The study was published in the Korean Journal of Parasitology.
Although Blastocystis prevalence is frequently reported in adults, there are few studies of Blastocystis infection in infants. In a study published from Ireland, researchers “surveyed the prevalence and diversity of Blastocystis in an infant population (n = 59) from an industrialized country (Ireland) using Blastocystis-specific primers at three or more time-points up to 24 months old. Only three infants were positive for Blastocystis (prevalence = 5%) and this was only noted for samples collected at month 24. This rate is comparatively low relative to previously reported prevalence rates in the contemporaneous adult population.” The work was reported in the journal Parasitology.
A research team from Turkey has reported on an improved method of DNA extraction for Blastocystis detection in human stool samples, known as the “sand method”, comparing results to the QIAamp DNA Stool Mini Kit (Qiagen) . The study notes that, “results indicated that, the mean DNA concentrations obtained by the sand method and the commercial kit were 48 and 55 ng/μl, respectively. Also, no DNA inhibitors were detected in two methods. The sand method was capable of detecting 16 parasites per 50 mg feces. DNA samples extracted by both methods were subjected to PCR. Blastocystis spp. were detected in 11 (31.4%) of 35 samples, and perfect agreement (κ: 1.000) was found between the PCR-sand method and PCR-commercial kit method. The samples that were detected positive by PCR-sand method were successfully sequenced, and Blastocystis subtypes (STs) were identified as ST3, ST2 and ST1.
The study was published in Experimental Parasitology.
Researchers reporting in the Turkish Digest of Parasitology have noted a positive correlation between Blastocystis infection and both gastrointestinal symptoms and urticaria. The study reports, “Of the evaluated 37108 stool samples, 2573 (6.93 %) were identified to be positive for Blastocystis spp. The patients with gastrointestinal complaints comprised 68.4% of Blastocystis spp. positive samples (1.761 samples) while 30.1% of patients had dermatologic symptoms (urticaria) (776 samples). Blastocystis spp. density in the non-amplified (without using any stool concentration technique) stool samples of the patients with GIS and dermatological symptoms was as follows: 2.47%, 1.35% rare, 21.73%, 22.17% few, 49.65%, 54.29% medium, 26.27%, and 22.17% dense, respectively.” The study was published in the December 2018 of the Turkish Digest of Parasitology.
Researchers evaluating the Roche LightMix Gastro assay report that it shows promise for the detection of Blastocystis. The comparison study reports that, “EZ1® (Qiagen) and QIAamp® DNA Stool Mini Kit (Qiagen) yielded similar performances for the detection of Cryptosporidium spp. and D. fragilis, significant lower Ct values (p < 0.002) pointed out a better performance of EZ1® on the five remaining pathogens. DNA extraction using the semi-automated EZ1® procedure was faster and as efficient as the manual procedure in the seven eukaryotic enteric pathogens tested. This procedure is suitable for DNA extraction from stools in both clinical laboratory diagnosis and epidemiological study settings.” The study was published in BMC Research Notes.
A genetic study of Blastocystis obtained from a rural population in Central Mexico shows that the local population carries Blastocystis with much less genetic diversity than isolates found world-wide. The researchers report that, “we collected and targeted the SSU-rDNA region in fecal samples from this population and further compared its genetic diversity and structure with that previously observed in populations of Blastocystis ST3 from other regions of the planet. Our analyses reveled that diversity of Blastocystis ST3 showed a high haplotype diversity and genetic structure to the world level; however, they were low in the Morelos population. The haplotype network revealed a common widespread haplotype from which the others were generated recently. Finally, our results suggested a recent expansion of the diversity of Blastocystis ST3 worldwide.” The study was published in Biomed Research International.
A research team from Iran has published a study of Blastocystis in patients with Inflammatory Bowel Disease. The study reports that although infection with Blastocystis was similar in controls and IBD patients, IBD patients showed a statistically significant correlation between age and infection that was not seen in healthy controls. The study noted that, “. There was no statistically significant correlation between IBD and presence of Blastocystis (P = 0.147). There was a statistically significant correlation between age and Blastocystis colonization in the IBD group (P < 0.05), but not among healthy controls.” The paper was published in The European Journal of Clinical Microbiology and Infectious Disease.
A study of 251 stool samples collected from patients in Angola has noted a high prevalence of multiple parasites. In this study, researchers used genetic tools to genotype each of the parasites detected, creating one of the few studies to provide genotyping of multiple parasitic infections in a single paper. The researchers report that, “Prevalences of S. stercoralis, G. duodenalis, Cryptosporidium spp., and Blastocystis spp. were estimated at 21.4% (95% CI: 17.1-25.7%), 37.9% (95% CI: 32.8-43.0%), 2.9% (95% CI: 1.1-4.5%) and 25.6% (95% CI: 21.18-30.2%), respectively.” The study was published in BMC Parasites and Vectors.
Researchers from Mexico and Canada have collaborated on a review describing the relationship of intestinal microbiota and the immune system. The reviewers note that, “This review focuses on intestinal protozoa, especially those still representing a public health problem in Mexico, and their interactions with the microbiome and the host. The decrease in prevalence of intestinal helminthes in humans left a vacant ecological niche that was quickly occupied by protozoa. ….. Insights into such protection may facilitate the manipulation of microbiota components to prevent and treat intestinal protozoan infections. Here we discuss recent findings about the immunoregulatory effect of intestinal microbiota with regards to intestinal colonization by protozoa, focusing on infections by Entamoeba histolytica, Blastocystis spp, Giardia duodenalis, Toxoplasma gondii and Cryptosporidium parvum. The possible consequences of the microbiota on parasitic, allergic and autoimmune disorders are also considered.”
The review was published in the Archives of Medical Research.