Blastocystis subtyping and its association with intestinal parasites in children from different geographical regions of Colombia

• Published in: PloS one Vol. 12; no. 2; p. e0172586
• Main Authors: Ramírez, Juan David, Flórez, Carolina, Olivera, Mario, Bernal, María Consuelo, Giraldo, Julio Cesar
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 21.02.2017; Public Library of Science (PLoS)
• Subjects: Adolescent; Alleles; Ancylostoma duodenale; Ascaris; Ascaris lumbricoides; Asymptomatic Diseases; Biology and Life Sciences; Blastocystis; Blastocystis - classification; Blastocystis - genetics; Blastocystis hominis; Blastocystis Infections - epidemiology; Blastocystis Infections - parasitology; Child; Child, Preschool; Children; Coinfection; Colombia - epidemiology; Control; Deoxyribonucleic acid; Diarrhea; Disease transmission; DNA; DNA Barcoding, Taxonomic; DNA sequencing; DNA, Protozoan - analysis; DNA, Protozoan - isolation & purification; DNA, Ribosomal - analysis; DNA, Ribosomal - isolation & purification; Endolimax nana; Entamoeba; Entamoeba coli; Ethics; Feces; Feces - parasitology; Female; Gene sequencing; Genetic diversity; Genetic Variation; Geography, Medical; Giardia; Giardia duodenalis; Giardia intestinalis; Headache; Health Surveys; Heterokonts; Humans; Hymenolepis nana; Infections; Intestinal Diseases, Parasitic - parasitology; Intestinal parasites; Intestine; Irritable bowel syndrome; Male; Medicine and Health Sciences; Microscopy; Necator americanus; Neobalantidium coli; Pain; Parasites; People and places; Primers; Pruritus; Real-Time Polymerase Chain Reaction; Research and Analysis Methods; Ribotyping; Risk factors; RNA; RNA, Protozoan - genetics; RNA, Ribosomal, 18S - genetics; rRNA; Species Specificity; Studies; Trichuris trichiura; Zoonoses; Colombia; Armenia; Brazil; Argentina; Latin America
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0172586

Blastocystis is a common enteric protist colonizing probably more than 1 billion people with a large variety of non-human hosts. Remarkable genetic diversity has been observed, leading to the subdivision of the genus into multiple subtypes (ST), some of which are exclusively found in non-human hosts. The aim of this study was to determine the distribution of Blastocystis STs/18S alleles in symptomatic (abdominal pain, anal pruritus, diarrhea, headache, nauseas and/or vomit) and asymptomatic children from nine geographical regions of Colombia. A total of 2026 fecal samples were collected as part of a national survey to estimate the frequency of intestinal parasites in children. A set of 256 samples that were Blastocystis positive was finally selected. The samples were submitted to DNA extraction, Real Time PCR and sequencing using Blastocystis-specific primers targeting the small subunit rRNA gene for ST identification. DNA of Ascaris lumbricoides (16.4%), Trichuris trichiura (8.2%), hookworms (Necator americanus/Ancylostoma duodenale) (7.3%), Giardia duodenalis (23.1%), Entamoeba complex (82%), Entamoeba coli (55%), Hymenolepis nana (0.8%), Endolimax nana (33.2%) and Neobalantidium coli (2.7%) was detected in the Blastocystis-positive samples. We detected ST1 (21.4%), ST2 (19.5%), ST3 (55.5%), ST4 (0.8%), ST6 (2%) and ST7 (0.8%); alleles 1, 2, 4, 81, 82 and 83 for ST1; alleles 9, 11, 12, 15, 67, 71 and 73 for ST2; alleles 34, 36, 38, 45, 49, 55, 134 and 128 for ST3; allele 42 for ST4; allele 122 for ST6, and allele 142 for ST7. Further studies implementing high-resolution molecular markers are necessary to understand the dynamics of Blastocystis transmission and the role of this Stramenopila in health and disease.