title: Prevalence and subtype analysis of Blastocystis in healthy Indian individuals.
abstract: There is a growing interest in subtype (ST) analysis of the intestinal parasite Blastocystis due to its extensive genetic diversity that might reflect differences in pathogenicity. Although essential for reference, few studies are available on Blastocystis in healthy individuals. Moreover, molecular epidemiology data on Blastocystis in India still remain to emerge. In the present study we identified the prevalence and ST distribution of Blastocystis in healthy Indian individuals. A total of 220 stool samples were obtained; four of 100 samples from 100 adults were chosen randomly for construction of small subunit (SSU) rRNA gene clone libraries in order to elucidate micro-eukaryotic diversity in the human gut. From the SSU rDNA library, 64 sequences annotated to Blastocystis were used for ST analysis along with sequences obtained by direct sequencing of SSU rDNA PCR products amplified from the remaining samples and generated using primers targeting Blastocystis. Of 220 stool samples collected, 120 samples from 30 infants (aged 1week to 1year) were PCR-negative. Of the remaining 100 samples from 100 adults, 27 resulted in specific amplification. Out of these 27, four samples were suspected of mixed ST infection and so these samples were further analyzed by construction of clone libraries. Analysis of cloned sequences revealed that indeed 2 samples had mixed ST infection (ST1 and ST3) while the remaining two showed infection with two separate ST3 strains. ST3 was the most common ST present in our study group (100%) followed by ST1 (7.4%); ST1 was seen only in mixed infections. SSU rDNA clone library sequences generated by processing of pooled samples were identified as ST3. The majority of ST3 sequences exhibited allele 34 commonly found in the European population.
authors.affiliation: Molecular Biology Unit, National Centre for Cell Science, Pune 411007, Maharashtra, India.
authors.forename: Prashant Kumar
authors.initials: PK
authors.lastname: Pandey
authors.affiliation: Marine Biotechnology Lab, National Institute of Ocean Technology, Chennai, India.
authors.forename: Pankaj
authors.initials: P
authors.lastname: Verma
authors.affiliation: Molecular Biology Unit, National Centre for Cell Science, Pune 411007, Maharashtra, India.
authors.forename: Nachiket
authors.initials: N
authors.lastname: Marathe
authors.affiliation: Molecular Biology Unit, National Centre for Cell Science, Pune 411007, Maharashtra, India.
authors.forename: Sudarshan
authors.initials: S
authors.lastname: Shetty
authors.affiliation: Department of Paediatrics [A.V], KEM Hospital, Pune 411011, Maharashtra, India.
authors.forename: Ashish
authors.initials: A
authors.lastname: Bavdekar
authors.affiliation: Molecular Biology Unit, National Centre for Cell Science, Pune 411007, Maharashtra, India.
authors.forename: Milind Shivaji
authors.initials: MS
authors.lastname: Patole
authors.affiliation: Department of Microbiology and Infection Control, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen S, Denmark.
authors.forename: Christen Rune
authors.initials: CR
authors.lastname: Stensvold
authors.affiliation: Molecular Biology Unit, National Centre for Cell Science, Pune 411007, Maharashtra, India. Electronic address: yogesh@nccs.res.in.
authors.forename: Yogesh Shreepad
authors.initials: YS
authors.lastname: Shouche
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016844:Blastocystis / Q000145:classification* / Q000235:genetics; D016776:Blastocystis Infections / Q000453:epidemiology* / Q000469:parasitology*; D058893:DNA Barcoding, Taxonomic; D016054:DNA, Protozoan; D004275:DNA, Ribosomal; D019143:Evolution, Molecular; D005260:Female; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010802:Phylogeny; D015995:Prevalence; D055815:Young Adult
chemical_list: D016054:DNA, Protozoan; D004275:DNA, Ribosomal
keywords: DNA; Epidemiology; Genetic diversity; Microbiology; Parasite; Public Health