Blastocystis is a single-celled intestinal monoxenus parasite with fecal-oral transmission. To date, based on the SSU rDNA and MLST loci analysis, it was discovered to comprise 17 subtypes (STs), likely representing distinct species. They colonize humans, other mammals, birds, reptiles and amphibians. Some STs from animals are zoonotic to humans. Despite being among the most common intestinal parasites infecting humans, the pathogenicity of STs still remains uncertain. Recent findings indicate that some STs can be considered as "markers" of gastrointestinal health rather than of disease; so far, little is known about whether and how STs alter the faecal bacterial microbiota.
The Project aims to: 1) carry out a molecular epidemiological analysis of Blastocystis STs on: a) human groups from developing countries, HIV-positive and immunocompetent patients; b) domestic and sylvatic animals; 2) compare the faecal microbiota in human groups infected with STs; 3) detect protease in distinct STs and their gene expression level which could be implicated in the pathogenicity; 4) improve the rapid and specific molecular detection of STs in humans by RT-PCR DNA primers/probes systems; 5) evaluate the human immune response (IgA and IgE) to STs' antigens.
Results that will be obtained will add knowledge on the association between STs, faecal microbiota and intestinal disorders in different patients groups. Studying the genetic variation of STs, as well as gene expression analysis of molecules/proteins of STs having a pathogenic role, could further clarify the pathological aspects, which they could cause to humans. The improvement of qRT-PCR-DNA assay will represent a rapid, sensitive and specific tool in the diagnosis of STs in humans. The RT-RNA analysis of target proteins could be also used as "marker" of pathogeny of STs in humans. Finally, exploring the occurrence of STs in animals could add knowledge about possible sources of blastocystosis to humans, in Italy.
