Distribution and phylogenetic analysis of Blastocystis sp. subtypes isolated from IBD patients and healthy individuals in Iran

• Published in: European journal of clinical microbiology & infectious diseases Vol. 36; no. 12; pp. 2335 - 2342
• Main Authors: Mirjalali, H., Abbasi, M. R., Naderi, N., Hasani, Z., Mirsamadi, E. S., Stensvold, C. R., Balaii, H., Asadzadeh Aghdaei, H., Zali, M. R.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-12-2017; Springer Nature B.V
• Subjects: Adult; Biomedical and Life Sciences; Biomedicine; Blastocystis - classification; Blastocystis - genetics; Blastocystis - isolation & purification; Colonization; Correlation; Disease control; Genetic diversity; Genetic Variation; Healthy Volunteers; Humans; Inflammatory bowel disease; Inflammatory bowel diseases; Inflammatory Bowel Diseases - diagnosis; Inflammatory Bowel Diseases - microbiology; Internal Medicine; Intestine; Iran; Medical Microbiology; Middle Aged; Original Article; Parasites; Patients; Phylogenetics; Phylogeny; Ribonucleic acid; RNA; RNA, Ribosomal, 18S - genetics; rRNA; Samples; Statistical analysis; Statistical methods; Statistical significance; Ulcerative colitis; Young Adult; Subtypes (ST); Stool Samples; Intra-subtype Variation; Healthy Control Group; Blastocystis Carriage
• ISSN: 0934-9723; 1435-4373
• DOI: 10.1007/s10096-017-3065-x

Blastocystis
is a single-celled intestinal parasite commonly found in humans and a broad range of animals all over the world. In humans, its role in health and disease remains unsettled. The aim of our study was to investigate the distribution of
Blastocystis
and
Blastocystis
subtypes (ST) in patients with inflammatory bowel disease (IBD) and control subjects. A total of 71 stool samples were collected from IBD patients, 69 and 2 of whom had ulcerative colitis (UC) and Crohn’s Disease (CD), respectively. Moreover, 166 stool samples from healthy subjects were included as control samples. All stool samples were cultivated, and 550-bp fragments of the small subunit ribosomal RNA gene was amplified from
Blastocystis
-positive cultures. All PCR-positive samples were sequenced.
Blastocystis
was observed in 9 (12.67%) and 35 (21.1%) IBD patients and healthy controls, respectively. 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. No significant correlation between gender and colonization was observed. ST1 and ST3 were obtained from 1 (12.5%) and 7 (87.5%) IBD patients, respectively, while in the healthy control group, subtypes 1, 2, and 3 were found in 14 (40%), 12 (34.28%), and 9 (25.72%), respectively. Phylogenetic analysis showed no variation in the distribution of subtypes nor intra-subtype genetic diversity between samples acquired from IBD patients and healthy controls. This study showed a trend towards a lower prevalence of
Blastocystis
in IBD patients than in control subjects. ST3 sequences isolated from IBD patients and control individuals did not appear to differ genetically.