Background and Aims The goal was to identify microbial drivers of IBD, by investigating mucosal-associated bacteria and their detrimental products in IBD patients. Methods We directly cultured bacterial communities from mucosal biopsies from pediatric gastrointestinal patients and examined for pathogenicity-associated traits. Upon identifying C. perfringens as toxigenic bacteria present in mucosal biopsies, we isolated strains and further characterized toxicity and prevalence. Results Mucosal biopsy microbial composition differed from corresponding stool samples. C. perfringens was present in 8 of 9 patients’ mucosal biopsies, correlating with hemolytic activity, while not in all corresponding stool samples. Large IBD datasets showed higher C. perfringens prevalence in stool samples of IBD adults (18.7-27.1%) versus healthy (5.1%). In vitro, C. perfringens supernatants were toxic to cell types beneath the intestinal epithelial barrier, including endothelial, neuroblasts, and neutrophils, while impact on epithelial cells was less pronounced, suggesting C. perfringens may be damaging particularly when barrier integrity is compromised. Further characterization using purified toxins and genetic insertion mutants confirmed PFO toxin was sufficient for toxicity. Toxin RNA signatures were found in the original patient biopsies by PCR, suggesting intestinal production. C. perfringens supernatants also induced activation of neuroblast and dorsal root ganglion neurons in vitro, suggesting C. perfringens in inflamed mucosal tissue may directly contribute to abdominal pain, a frequent IBD symptom. Conclusions Gastrointestinal carriage of certain toxigenic C. perfringens may have an important pathogenic impact on IBD patients. These findings support routine monitoring of C. perfringens and PFO toxins and potential treatment in patients.

中文翻译：

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从高危儿科炎症性肠病患者体内分离出产毒梭状芽胞杆菌

背景和目的 目标是通过研究 IBD 患者的粘膜相关细菌及其有害产物来确定 IBD 的微生物驱动因素。方法 我们直接从儿科胃肠道患者的粘膜活检中培养细菌群落，并检查致病性相关特征。在将产气荚膜梭菌鉴定为粘膜活检中存在的产毒细菌后，我们分离了菌株并进一步表征了毒性和患病率。结果粘膜活检微生物组成与相应的粪便样本不同。9 名患者的粘膜活检中有 8 名产气荚膜梭菌存在，与溶血活性相关，但并非所有相应的粪便样本中都存在产气荚膜梭菌。大型 IBD 数据集显示，IBD 成人粪便样本中产气荚膜梭菌的患病率 (18.7-27.1%) 高于健康人 (5.1%)。在体外，产气荚膜梭菌上清液对肠上皮屏障下方的细胞类型具有毒性，包括内皮细胞、神经母细胞和中性粒细胞，而对上皮细胞的影响不太明显，这表明产气荚膜梭菌可能具有破坏性，特别是当屏障完整性受损时。使用纯化毒素和基因插入突变体的进一步表征证实 PFO 毒素足以产生毒性。通过 PCR 在最初的患者活检中发现了毒素 RNA 特征，表明肠道产生了毒素。产气荚膜梭菌上清液还在体外诱导神经母细胞和背根神经节神经元的激活，这表明发炎的粘膜组织中的产气荚膜梭菌可能直接导致腹痛，这是一种常见的IBD症状。结论 胃肠道携带某些产毒产气荚膜梭菌可能对 IBD 患者产生重要的致病影响。这些发现支持产气荚膜梭菌和 PFO 毒素的常规监测以及患者的潜在治疗。