Department of Veterinary Medicine, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan.
Parasitol Int. 2022 Apr;87:102490. doi: 10.1016/j.parint.2021.102490. Epub 2021 Nov 1.
Blastocystis is an intestinal eukaryote found globally in humans and a wide range of animals. Blastocystis has been reported in domestic pigs, with subtype (ST) 5 being the most dominant, followed by ST1 and ST3. PCR-sequencing is commonly used for ST identification in pigs, but it often results in an underestimation of the prevalence of mixed infections. Here, we aimed to investigate the ST distribution and prevalence of mixed ST infections of Blastocystis in pigs from Chiba Prefecture in eastern Japan. A total of 82 fecal samples positive for Blastocystis were collected from two different farms, A and B. PCR was performed using ST-specific primers for ST1, ST2, ST3, and ST5. The prevalence of single ST5 infections was 37.8% (31/82), whereas that of mixed infections with ST5 and other STs was 57.3% (47/82) . A high percentage of single ST5 infections was observed in sows, piglets, and weaners from farm A (13/15, 86.7%), whereas mixed infections of ST5 and other STs (ST1 and ST3) were observed in 3- to 5-month-old grower pigs (15/18, 83.3%). Similarly, in farm B, most sows and piglets under 1 month of age showed a single ST5 infections (12/17, 70.6%), whereas weaner, grower, and finisher pigs showed mixed infections with ST5 and other STs, including ST1, ST2, and ST3 (27/28, 96.4%). In domestic pigs, diet and rearing environments change dramatically over the course of the animal's lifetime, which may have caused this difference in the prevalence of mixed ST infections among different age groups.
肠道真核生物 Blastocystis 广泛存在于全球人类和各种动物中。在猪中已报道有 Blastocystis，其中亚型（ST）5 最为常见，其次是 ST1 和 ST3。PCR 测序常用于猪中 ST 的鉴定，但常导致混合感染的流行率被低估。本研究旨在调查日本东部千叶县猪中 Blastocystis 的 ST 分布和混合 ST 感染的流行率。从两个不同的农场 A 和 B 共采集了 82 份 Blastocystis 阳性粪便样本。使用针对 ST1、ST2、ST3 和 ST5 的 ST 特异性引物进行 PCR。单一 ST5 感染的流行率为 37.8%（31/82），而 ST5 与其他 ST 的混合感染流行率为 57.3%（47/82）。A 场的母猪、仔猪和断奶猪中观察到高比例的单一 ST5 感染（13/15，86.7%），而 3 至 5 月龄生长猪中观察到 ST5 与其他 ST（ST1 和 ST3）的混合感染（15/18，83.3%）。类似地，B 场的大多数 1 个月以下的母猪和仔猪表现为单一 ST5 感染（12/17，70.6%），而断奶猪、生长猪和育肥猪表现为 ST5 与其他 ST（包括 ST1、ST2 和 ST3）的混合感染（27/28，96.4%）。在猪中，动物一生的饮食和饲养环境会发生巨大变化，这可能导致不同年龄组混合 ST 感染的流行率存在差异。
