Background We used an ultrasensitive, quantitative single molecule array (Simoa) immunoassay to test whether concentrations of Clostridioides (formerly Clostridium) difficile toxins A and/or B in the stool of adult inpatients with C. difficile infection (CDI) were higher than in asymptomatic carriers of toxinogenic C. difficile. Methods Patients enrolled as CDI-NAAT had clinically significant diarrhea and a positive nucleic acid amplification test (NAAT), per US guidelines, and received CDI treatment. Potential carriers had recently received antibiotics and did not have diarrhea; positive NAAT confirmed carriage. Baseline stool samples were tested by Simoa for toxin A and B. Results Stool toxin concentrations in both CDI-NAAT (n = 122) and carrier-NAAT (n = 44) cohorts spanned 5 logs (0 pg/mL to >100000 pg/mL). Seventy-nine of 122 (65%) CDI-NAAT and 34 of 44 (77%) carrier-NAAT had toxin A + B concentration ≥20 pg/mL (clinical cutoff). Median toxin A, toxin B, toxin A + B, and NAAT cycle threshold (Ct) values in CDI-NAAT and carrier-NAAT cohorts were similar (toxin A, 50.6 vs 60.0 pg/mL, P = .958; toxin B, 89.5 vs 42.3 pg/mL, P = .788; toxin A + B, 197.2 vs 137.3 pg/mL, P = .766; Ct, 28.1 vs 28.6, P = .354). However, when CDI/carrier cohorts were limited to those with detectable toxin, respective medians were significantly different (A: 874.0 vs 129.7, P = .021; B: 1317.0 vs 81.7, P = .003, A + B, 4180.7 vs 349.6, P = .004; Ct, 25.8 vs 27.7, P = .015). Conclusions Toxin concentration did not differentiate an individual with CDI from one with asymptomatic carriage. Median stool toxin concentrations in groups with CDI vs carriage differed, but only when groups were defined by detectable stool toxin (vs positive NAAT).

中文翻译：

---

使用超灵敏定量免疫测定法比较成人有症状感染和无症状支架的难辨梭状芽胞杆菌毒素浓度。

背景我们使用超灵敏的定量单分子阵列（Simoa）免疫测定法来测试成年梭状芽胞杆菌感染（CDI）病人粪便中梭状芽胞杆菌艰难梭菌毒素A和/或B的浓度是否高于无症状的梭状芽胞杆菌。毒素艰难梭菌的携带者。方法按照美国指南，加入CDI-NAAT的患者有临床上明显的腹泻和核酸扩增试验（NAAT）阳性，并接受了CDI治疗。潜在的携带者最近接受了抗生素治疗，没有腹泻。积极的NAAT确认运输。Simoa测试了基准粪便样本中毒素A和B的含量。结果CDI-NAAT（n = 122）和携带者NAAT（n = 44）队列中的粪便毒素浓度跨越5个对数（0 pg / mL至> 100000 pg /毫升）。122个（65％）CDI-NAAT中的七十九个和44个（77％）载体NAAT中的34个具有≥20 pg / mL的毒素A + B浓度（临床临界值）。CDI-NAAT和载体-NAAT队列中的毒素A，毒素B，毒素A + B和NAAT循环阈值（Ct）的中位数相似（毒素A，50.6 vs 60.0 pg / mL，P = .958；毒素B， 89.5 vs 42.3 pg / mL，P = .788;毒素A + B，197.2 vs 137.3 pg / mL，P = .766; Ct，28.1 vs 28.6，P = .354）。但是，当CDI /携带者队列仅限于可检测到毒素的人群时，各自的中位数存在显着差异（A：874.0 vs 129.7，P = .021; B：1317.0 vs 81.7，P = .003，A + B，4180.7 vs 349.6 ，P = .004； Ct，25.8和27.7，P = .015）。结论毒素浓度不能将CDI患者与无症状携带者区分开。CDI组与粪便组的粪便中毒浓度中位数有所不同，