Table_6_Untargeted serum metabolomic profiling for early detection of Schistosoma mekongi infection in mouse model.xlsx

Mekong schistosomiasis is a parasitic disease caused by blood flukes in the Lao People’s Democratic Republic and in Cambodia. The standard method for diagnosis of schistosomiasis is detection of parasite eggs from patient samples. However, this method is not sufficient to detect asymptomatic patients, low egg numbers, or early infection. Therefore, diagnostic methods with higher sensitivity at the early stage of the disease are needed to fill this gap. The aim of this study was to identify potential biomarkers of early schistosomiasis using an untargeted metabolomics approach. Serum of uninfected and S. mekongi-infected mice was collected at 2, 4, and 8 weeks post-infection. Samples were extracted for metabolites and analyzed with a liquid chromatography-tandem mass spectrometer. Metabolites were annotated with the MS-DIAL platform and analyzed with Metaboanalyst bioinformatic tools. Multivariate analysis distinguished between metabolites from the different experimental conditions. Biomarker screening was performed using three methods: correlation coefficient analysis; feature important detection with a random forest algorithm; and receiver operating characteristic (ROC) curve analysis. Three compounds were identified as potential biomarkers at the early stage of the disease: heptadecanoyl ethanolamide; picrotin; and theophylline. The levels of these three compounds changed significantly during early-stage infection, and therefore these molecules may be promising schistosomiasis markers. These findings may help to improve early diagnosis of schistosomiasis, thus reducing the burden on patients and limiting spread of the disease in endemic areas.

湄公河血吸虫病（Mekong schistosomiasis）是由血吸虫引发的寄生虫病，流行于老挝人民民主共和国及柬埔寨境内。当前血吸虫病的标准诊断方法为从患者样本中检出寄生虫虫卵，但该方法无法有效检测无症状感染者、低虫卵载量感染者或早期感染病例，因此亟需灵敏度更高的早期疾病诊断方法以填补这一空白。本研究旨在通过非靶向代谢组学（untargeted metabolomics）方法筛选早期湄公河血吸虫病的潜在生物标志物。研究采集了感染湄公血吸虫（S. mekongi）与未感染小鼠在感染后2、4、8周的血清样本。对样本进行代谢物提取后，采用液相色谱-串联质谱（liquid chromatography-tandem mass spectrometer）开展分析。使用MS-DIAL平台对代谢物进行注释，并通过Metaboanalyst生物信息学工具进行数据分析。多变量分析可区分不同实验条件下的代谢物特征。生物标志物筛选采用三种方法：相关系数分析、基于随机森林（random forest）算法的特征重要性检测，以及受试者工作特征（receiver operating characteristic, ROC）曲线分析。最终鉴定出三种疾病早期阶段的潜在生物标志物：十七烷酰乙醇酰胺（heptadecanoyl ethanolamide）、苦木素（picrotin）与茶碱（theophylline）。这三种化合物在早期感染过程中水平发生显著变化，因此有望成为血吸虫病的诊断标志物。本研究结果有助于改善血吸虫病的早期诊断，从而减轻患者负担并限制疾病在流行地区的传播。