Graduate School, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, 40002, Thailand.
Parasitol Res. 2013 Apr;112(4):1781-6. doi: 10.1007/s00436-012-3218-x. Epub 2012 Dec 9.
The present study is aimed to identify the prevalence of Blastocystis subtypes isolated from patients in a major hospital in northeastern Thailand. A total of 562 stool samples were examined by culture technique, and 56 Blastocystis-positive samples were analyzed further by the combination of restriction fragment length polymorphism (RFLP) followed by polymerase chain reaction with sequence-tagged site primers (PCR-STS). By RFLP profiles, Blastocystis genotypes were categorized into four groups: group A (12, 21.4%), group B (32, 57.1%), group C (10, 17.9%), and group D (2, 3.6%). By PCR-STS, only four subtypes were identified. All 12 (21.4%) isolates in group A were identified as subtype 1. Similarly, all 32 (57.1%) isolates in group B were subtype 3. In group C, 10 (17.9%) samples were all subtype 7, and two samples (3.6%) in group D were both subtype 6. Of 56 Blastocystis-positive patients, 31 (55.4%) were asymptomatic and 22 (39.4%) have gastrointestinal symptoms. No significant association was observed between the Blastocystis subtypes and the clinical features. Among the Blastocystis-positive patients, the most characteristic stool samples were loose (78.6%) and soft (17.9%). In conclusion, the most common Blastocystis spp. in northeastern Thailand was subtype 3 followed by subtype 1. Relatively minor subtypes, subtype 6 and subtype 7 which are considered as avian subtypes, were found for the first time in humans in Thailand.
本研究旨在鉴定从泰国东北部一家大医院的患者中分离出的 Blastocystis 亚型的流行率。通过培养技术检查了 562 份粪便样本，并用限制性片段长度多态性（RFLP）结合聚合酶链反应与序列标记位点引物（PCR-STS）进一步分析了 56 个 Blastocystis 阳性样本。通过 RFLP 图谱，Blastocystis 基因型分为 4 组：A 组（12 个，21.4%）、B 组（32 个，57.1%）、C 组（10 个，17.9%）和 D 组（2 个，3.6%）。通过 PCR-STS，仅鉴定出 4 种亚型。A 组的 12 个（21.4%）分离株均鉴定为 1 型。同样，B 组的 32 个（57.1%）分离株均为 3 型。在 C 组中，10 个（17.9%）样本均为 7 型，D 组的 2 个样本（3.6%）均为 6 型。在 56 例 Blastocystis 阳性患者中，31 例（55.4%）无症状，22 例（39.4%）有胃肠道症状。Blastocystis 亚型与临床特征之间无显著相关性。在 Blastocystis 阳性患者中，最典型的粪便样本为松散（78.6%）和软（17.9%）。综上所述，泰国东北部最常见的 Blastocystis spp.为 3 型，其次为 1 型。相对较少的亚型 6 和亚型 7 被认为是禽类亚型，这是它们在泰国首次在人类中发现。
