title: Molecular epidemiology and genetic diversity of Blastocystis infection in humans in Italy.
abstract: In order to describe the molecular epidemiology of Blastocystis infection in Italy, 189 isolates, which had been collected during the years 2012-2014 from mildly symptomatic patients, or those affected by inflammatory bowel disease (IBD), irritable bowel syndrome (IBS) or chronic diarrhoea, or otherwise immunosuppressed, were subtyped by sequence analysis of the SSU rRNA gene (536 bp). Six subtypes (STs) were detected: ST1 (15·3%), ST2 (13·8%), ST3 (46·0%), ST4 (21·7%), ST6 (3·2%) and ST8 (0·5%). They clustered in distinct clades, as inferred from Bayesian inference phylogenetic and median joining network analyses. A high genetic differentiation was found at the inter-subtype level; it ranged from Jukes-Cantor (JC) distance = 0·02 (between ST1 and ST4) to JC = 0·11 (between ST6 and ST2). At the intra-ST level, a high genetic homogeneity was registered in ST4, whereas higher genetic variation was found in isolates corresponding to ST1 and ST2. Accordingly, high values of haplotype and nucleotide diversity were observed in ST1, ST2 and ST3. No association was found between patient gender and ST, whereas ST3 and ST1 were significantly more prevalent in patients aged 15-50 years. A significant occurrence of Blastocystis ST4 in patients suffering from IBS, IBD or chronic diarrhoea was observed; in addition, a slight significant association between ST1 and ST3 and IBS patients was found. Multiple correspondence analysis showed some significant contribution of different variables (subtypes, haplotypes, age) in the observed pattern of ordination of the 189 patients in the symptom categories.
authors.affiliation: Department of Public Health and Infectious Diseases,Section of Parasitology,'Sapienza' University and 'Umberto I' Teaching Hospital,Rome,Italy.
authors.forename: S
authors.initials: S
authors.lastname: Mattiucci
authors.affiliation: Department of Public Health and Infectious Diseases,Section of Parasitology,'Sapienza' University and 'Umberto I' Teaching Hospital,Rome,Italy.
authors.forename: B
authors.initials: B
authors.lastname: Crisafi
authors.affiliation: Department of Public Health and Infectious Diseases,Section of Parasitology,'Sapienza' University and 'Umberto I' Teaching Hospital,Rome,Italy.
authors.forename: S
authors.identifier: http://orcid.org/0000-0002-1596-8036
authors.initials: S
authors.lastname: Gabrielli
authors.affiliation: Department of Biological and Ecological Sciences,Tuscia University,Viterbo,Italy.
authors.forename: M
authors.initials: M
authors.lastname: Paoletti
authors.affiliation: Department of Public Health and Infectious Diseases,Section of Parasitology,'Sapienza' University and 'Umberto I' Teaching Hospital,Rome,Italy.
authors.forename: G
authors.initials: G
authors.lastname: Cancrini
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D016844:Blastocystis / Q000235:genetics*; D016776:Blastocystis Infections / Q000453:epidemiology*; D002648:Child; D002908:Chronic Disease; D004275:DNA, Ribosomal / Q000235:genetics; D003967:Diarrhea / Q000453:epidemiology / Q000469:parasitology; D005260:Female; D014644:Genetic Variation; D006239:Haplotypes; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000453:epidemiology / Q000469:parasitology; D043183:Irritable Bowel Syndrome / Q000453:epidemiology / Q000469:parasitology; D007558:Italy; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D010802:Phylogeny; D055815:Young Adult
chemical_list: D004275:DNA, Ribosomal
keywords: Blastocystis subtypes; IBD; IBS; Italy; genetic diversity; molecular epidemiology