Ramírez Juan David, Flórez Carolina, Olivera Mario, Bernal María Consuelo, Giraldo Julio Cesar
Grupo de Investigaciones Microbiológicas - UR (GIMUR), Programa de Biología, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá - Colombia.
Grupo de Parasitología, Instituto Nacional de Salud, Bogotá - Colombia.
PLoS One. 2017 Feb 21;12(2):e0172586. doi: 10.1371/journal.pone.0172586. eCollection 2017.
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.
芽囊原虫是一种常见的肠道原生生物，可能定植于超过10亿人以及多种非人类宿主。已观察到其显著的遗传多样性，导致该属被细分为多个亚型（ST），其中一些亚型仅在非人类宿主中发现。本研究的目的是确定哥伦比亚九个地理区域有症状（腹痛、肛门瘙痒、腹泻、头痛、恶心和/或呕吐）和无症状儿童中芽囊原虫STs/18S等位基因的分布。作为一项全国性调查的一部分，共收集了2026份粪便样本，以估计儿童肠道寄生虫的感染率。最终选择了256份芽囊原虫阳性样本。对样本进行DNA提取、实时PCR，并使用针对小亚基rRNA基因的芽囊原虫特异性引物进行测序，以鉴定ST。在芽囊原虫阳性样本中检测到蛔虫（16.4%）、鞭虫（8.2%）、钩虫（美洲板口线虫/十二指肠钩口线虫）（7.3%）、十二指肠贾第虫（23.1%）、内阿米巴复合体（82%）、结肠内阿米巴（55%）、微小膜壳绦虫（0.8%）、纳氏内阿米巴（33.2%）和结肠新膜壳绦虫（2.7%）的DNA。我们检测到ST1（21.4%）、ST2（19.5%）、ST3（55.5%）、ST4（0.8%）、ST6（2%）和ST7（0.8%）；ST1的等位基因1、2、4、81、82和83；ST2的等位基因9、11、12、15、67、71和73；ST3的等位基因34、36、38、45、49、55、134和128；ST4的等位基因42；ST6的等位基因122，以及ST7的等位基因142。有必要开展进一步研究，采用高分辨率分子标记来了解芽囊原虫的传播动态以及这种不等鞭毛类生物在健康和疾病中的作用。
