DataSheet_1_Identification and Characterization of Three Spore Wall Proteins of Enterocytozoon Bieneusi.docx

Enterocytozoon bieneusi is the most common microsporidian pathogen in farm animals and humans. Although several spore wall proteins (SWPs) of other human-pathogenic microsporidia have been identified, SWPs of E. bieneusi remain poorly characterized. In the present study, we identified the sequences of three E. bieneusi SWPs from whole genome sequence data, expressed them in Escherichia coli, generated a monoclonal antibody (mAb) against one of them (EbSWP1), and used the mAb in direct immunofluorescence detection of E. bieneusi spores in fecal samples. The amino acid sequence of EbSWP1 shares some identity to EbSWP2 with a BAR2 domain, while the sequence of EbSWP3 contains a MICSWaP domain. No cross-reactivity among the EbSWPs was demonstrated using the polyclonal antibodies generated against them. The mAb against EbSWP1 was shown to react with E. bieneusi spores in fecal samples. Using chromotrope 2R staining-based microscopy as the gold standard, the sensitivity and specificity of the direct immunofluorescence for the detection of E. bieneusi were 91.4 and 73.7%. Data generated from the study could be useful in the characterization of E. bieneusi and immunological detection of the pathogen.

比氏肠胞虫（Enterocytozoon bieneusi）是感染畜禽与人类的最常见微孢子虫病原。尽管已从其他致病人源微孢子虫中鉴定出多种孢子壁蛋白（SWPs），但比氏肠胞虫的孢子壁蛋白仍未得到充分表征。本研究从全基因组测序数据中鉴定出3种比氏肠胞虫孢子壁蛋白的编码序列，在大肠杆菌（Escherichia coli）中完成了重组表达，针对其中一种靶标蛋白（EbSWP1）制备了单克隆抗体（mAb），并利用该单克隆抗体对粪便样本中的比氏肠胞虫孢子开展直接免疫荧光检测。EbSWP1的氨基酸序列与携带BAR2结构域的EbSWP2存在一定序列同源性，而EbSWP3的氨基酸序列则包含MICSWaP结构域。针对各比氏肠胞虫孢子壁蛋白制备的多克隆抗体均未表现出交叉反应性。实验证实，针对EbSWP1的单克隆抗体可与粪便样本中的比氏肠胞虫孢子发生特异性结合。以铬变素2R染色镜检法作为金标准，该直接免疫荧光检测方法检测比氏肠胞虫的灵敏度为91.4%，特异性为73.7%。本研究所得数据可为比氏肠胞虫的特征鉴定及该病原的免疫学检测提供参考依据。