Background

Microsporidia infection was originally described as an immunocompromised associated pathogen. Limitations to correct microscopic diagnosis of microsporidia include size of the organism presenting a challenge even to a highly competent laboratory expert.

Objective

The present study aimed to detect microsporidia infection among leukemic children. The performance of modified trichrome stain and PCR in the diagnosis of microsporidia was evaluated with further speciation.

Methods

Stool samples of 100 leukemic children on chemotherapy were examined microscopically for microsporidia. DNA was extracted from all samples. Amplification was performed by conventional and nested PCR. Sequencing of amplified products was performed on unspeciated samples.

Results

Microsporidia were detected in 23% of the children by MTS and 29% by PCR. The 29 positive samples were subjected to PCR for speciation. Enterocytozoon bieneusi was found to predominate in 20 cases, Encephalitozoon intestinalis in three cases, two cases had co-infection, and the remaining four samples were not amplified with either E. bieneusi or E. intestinalis specific primers. By DNA sequencing of the unspeciated samples, three samples shared high homology with Encephalitozoon hellem and one sample with Encephalitozoon cuniculi. Referring to PCR as a gold standard, MTS exhibited 72.4% sensitivity and 97.2% specificity with 90% accuracy. Among a number of studied variables, diarrhea and colic were significantly associated with microsporidia infection when diagnosed by either technique.

Conclusion

The use of sensitive and discriminative molecular tools will contribute to determining the true prevalence of microsporidiosis and possibly their potential transmission source depending on species identification.

中文翻译：

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白血病儿童肠道微孢子虫感染：显微镜和分子检测

背景

微孢子虫感染最初被描述为一种免疫功能低下的相关病原体。对微孢子虫进行正确显微镜诊断的限制包括有机体的大小，即使对非常称职的实验室专家来说也是一个挑战。

客观的

本研究旨在检测白血病儿童中的微孢子虫感染。改良的三色染色和 PCR 在诊断微孢子虫中的性能通过进一步的物种形成进行了评估。

方法

用显微镜检查了 100 名接受化疗的白血病儿童的粪便样本中的微孢子虫。从所有样品中提取 DNA。通过常规和巢式 PCR 进行扩增。扩增产物的测序是在未指定的样品上进行的。

结果

通过 MTS 检测到 23% 的儿童和通过 PCR 检测到 29% 的微孢子虫。对 29 个阳性样品进行 PCR 以进行物种形成。在 20 例中发现肠细胞虫占主导地位，在 3 例中发现肠道脑炎，2 例合并感染，其余 4 个样本均未用E. bieneusi或E.肠道特异性引物扩增。通过对非物种样本进行DNA测序，3个样本与Hencephalitozoon hellem具有高度同源性，1个样本与Encephalitozoon cuniculi. 将 PCR 作为金标准，MTS 表现出 72.4% 的灵敏度和 97.2% 的特异性，以及 90% 的准确度。在许多研究变量中，腹泻和绞痛与通过任一技术诊断的微孢子虫感染显着相关。

结论

使用敏感和有区别的分子工具将有助于确定微孢子虫病的真实流行率，并根据物种鉴定可能确定其潜在的传播源。