Purpose

This study aimed to determine the molecular characterization and subtype distribution of Blastocystis sp. isolated from cancer children and adolescents in Shiraz, Fars province, southwestern Iran.

Methods

Overall, 200 fecal samples obtained from cancer children and adolescents under 18 years old (107 males and 93 females) and checked by microscopy, culture, and molecular methods (PCR). Possible etiological factors and clinical characteristics of Blastocystis infection were also evaluated and compared between Blastocystis infected and non-infected patients.

Results

Thirteen of 200 (6.5%) stool samples were positive for Blastocystis by microscopy. While 21 of 200 (10.5%) were positive by culture, and 24 of 200 (12%) were positive by PCR. Out of 24 positive samples tested by PCR and sequencing, ST3 was reported as the most common subtype (nine samples, 37.5%), followed by ST2 (eight samples, 33.3%), ST1 (five samples, 20.9%), and ST7 (two samples, 8.3%). The prevalence of Blastocystis infection in males was significantly higher than females (p = 0.024). Also, Blastocystis was more prevalent in patients who had received at least eight chemotherapy cycles than fewer (p = 0.002). However, no associations were found between Blastocystis-positive rate and age, residence, type of cancers, or contact with animals. Also, there was no significant difference between frequency of Blastocystis subtypes in symptomatic and asymptomatic cancer patients.

Conclusions

Various controlled epidemiologic and topographic studies need to confirm or reject these possible associations with Blastocystis infection. The data from this study are an invaluable addition to the growing body of research studies on Blastocystis infection in cancer patients.

中文翻译：

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Blastocystis sp。的分子鉴定和亚型分布。从伊朗儿童和青少年癌症中分离：评估可能的危险因素和临床特征。

目的

本研究旨在确定Blastocystis sp。的分子特征和亚型分布。分离自伊朗西南部Fars省设拉子的癌症儿童和青少年。

方法

总体上，从18岁以下的癌症儿童和青少年（107例男性和93例女性）获得200份粪便样品，并通过显微镜，培养和分子方法（PCR）进行检查。可能的病因和临床特点芽感染也进行评价和比较之间的芽感染和非感染患者。

结果

通过显微镜检查，在200份粪便样本中有13份（6.5％）的囊胚芽孢杆菌呈阳性。200个中的21个（10.5％）通过培养呈阳性，而200个中的24个（12％）通过PCR呈阳性。在通过PCR和测序测试的24个阳性样本中，ST3被报告为最常见的亚型（九个样本，占37.5％），其次是ST2（八个样本，占33.3％），ST1（五个样本，占20.9％）和ST7（两个样本，占8.3％）。男性的囊胚感染的发生率明显高于女性（p  = 0.024）。同样，在接受了至少八个化疗周期的患者中，囊肿的发生率要高于较少的患者（p  = 0.002）。但是，未发现Blastocystis阳性之间的关联。比率和年龄，居住地，癌症类型或与动物的接触。而且，有症状和无症状癌症患者的Blastocystis亚型频率之间也没有显着差异。

结论

各种受控的流行病学和地形学研究都需要确认或拒绝这些与芽孢杆菌感染的可能关联。这项研究的数据为癌症患者的囊胚感染的研究不断发展提供了宝贵的补充。