Environmental Microbial and Food Safety Laboratory, Agricultural Research Service, United States Department of Agriculture, Beltsville, MD, USA.
Laboratório de Parasitologia, Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Av. Pará, 1720, Campus Umuarama, Uberlândia, Minas Gerais, 38400-902, Brazil.
Parasitol Res. 2021 Jun;120(6):2219-2231. doi: 10.1007/s00436-021-07170-3. Epub 2021 Apr 27.
Blastocystis sp. is an intestinal protist parasite commonly found in the feces of humans and animals worldwide. Blastocystis exhibits extensive genetic diversity and has been identified in humans and a variety of animals including other mammals and birds. Blastocystis subtypes do not exhibit strict host specificity which raises the possibility of zoonotic transmission through either direct contact or fecal contamination of food or water. However, reports detailing the subtypes and prevalence of Blastocystis in avian species are limited. Therefore, this study investigated the presence of Blastocystis in chickens by molecular characterization of the small subunit rRNA (SSU rRNA) gene. Fecal samples from 130 chickens were collected from local markets in Uberlândia and Belo Horizonte in the state of Minas Gerais, Brazil. To detect and identify subtypes of Blastocystis, a next-generation amplicon sequencing protocol was used. Forty-four of the 130 (33.8%) chickens examined were positive for Blastocystis. Blastocystis subtypes ST6 (23/130; 17.7%), ST7 (43/130; 33.1%), ST10 (1/130; 0.8%), ST14 (5/130; 3.8%), ST25 (1/130; 0.8%), and a novel subtype (ST29) (2/130; 1.5%) were observed. A nanopore sequencing strategy was used to obtain the near full-length SSU rRNA gene nucleotide sequence and validate novel subtype ST29. Mixed infections containing multiple subtypes were common and identified in 63.6% of Blastocystis-positive chickens. All positive samples contained one or both potentially zoonotic subtypes ST6 and ST7. The prevalence of Blastocystis in chickens was high, and molecular characterization mostly identified subtypes previously found in humans. Thus, chickens may be a source of human infection and environmental contamination.
肠内原生动物寄生虫 Blastocystis sp. 常见于全球人类和动物的粪便中。Blastocystis 表现出广泛的遗传多样性，已在人类和多种动物中发现，包括其他哺乳动物和鸟类。Blastocystis 亚型没有严格的宿主特异性，这增加了通过直接接触或食物和水的粪便污染发生人畜共患传播的可能性。然而，详细描述鸟类中 Blastocystis 亚型和流行情况的报告有限。因此，本研究通过小亚基 rRNA (SSU rRNA) 基因的分子特征，调查了巴西米纳斯吉拉斯州 Uberlândia 和 Belo Horizonte 当地市场采集的 130 只鸡中 Blastocystis 的存在情况。为了检测和鉴定 Blastocystis 的亚型，使用了下一代扩增子测序方案。在检查的 130 只鸡中，有 44 只（33.8%）检测出 Blastocystis 阳性。Blastocystis 亚型 ST6（23/130；17.7%）、ST7（43/130；33.1%）、ST10（1/130；0.8%）、ST14（5/130；3.8%）、ST25（1/130；0.8%）和一种新的亚型（ST29）（2/130；1.5%）被观察到。使用纳米孔测序策略获得了近全长 SSU rRNA 基因核苷酸序列，并验证了新型亚型 ST29。混合感染含有多种亚型，在 63.6%的 Blastocystis 阳性鸡中发现。所有阳性样本均含有一种或两种潜在的人畜共患病亚型 ST6 和 ST7。鸡中 Blastocystis 的流行率很高，分子特征主要鉴定出以前在人类中发现的亚型。因此，鸡可能是人类感染和环境污染的来源。
