Center for Inflammatory Bowel Diseases, Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, California; Department of Gastroenterology, First Affiliated Hospital, China Medical University, Shenyang City, Liaoning Province, China.
Center for Inflammatory Bowel Diseases, Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, California.
Gastroenterology. 2018 May;154(6):1737-1750. doi: 10.1053/j.gastro.2018.01.026. Epub 2018 Jan 31.
BACKGROUND & AIMS: Clostridium difficile induces intestinal inflammation by releasing toxins A and B. The antimicrobial compound cationic steroid antimicrobial 13 (CSA13) has been developed for treating gastrointestinal infections. The CSA13-Eudragit formulation can be given orally and releases CSA13 in the terminal ileum and colon. We investigated whether this form of CSA13 reduces C difficile infection (CDI) in mice.
C57BL/6J mice were infected with C difficile on day 0, followed by subcutaneous administration of pure CSA13 or oral administration of CSA13-Eudragit (10 mg/kg/d for 10 days). Some mice were given intraperitoneal vancomycin (50 mg/kg daily) on days 0-4 and relapse was measured after antibiotic withdrawal. The mice were monitored until day 20; colon and fecal samples were collected on day 3 for analysis. Blood samples were collected for flow cytometry analyses. Fecal pellets were collected each day from mice injected with CSA13 and analyzed by high-performance liquid chromatography or 16S sequencing; feces were also homogenized in phosphate-buffered saline and fed to mice with CDI via gavage.
CDI of mice caused 60% mortality, significant bodyweight loss, and colonic damage 3 days after infection; these events were prevented by subcutaneous injection of CSA13 or oral administration CSA13-Eudragit. There was reduced relapse of CDI after administration of CSA13 was stopped. Levels of CSA13 in feces from mice given CSA13-Eudragit were significantly higher than those of mice given subcutaneous CSA13. Subcutaneous and oral CSA13 each significantly increased the abundance of Peptostreptococcaceae bacteria and reduced the abundance of C difficile in fecal samples of mice. When feces from mice with CDI and given CSA13 were fed to mice with CDI that had not received CSA13, the recipient mice had significantly increased rates of survival. CSA13 reduced fecal levels of inflammatory metabolites (endocannabinoids) and increased fecal levels of 4 protective metabolites (ie, citrulline, 3-aminoisobutyric acid, retinol, and ursodeoxycholic acid) in mice with CDI. Oral administration of these CSA13-dependent protective metabolites reduced the severity of CDI.
In studies of mice, we found the CSA13-Eudragit formulation to be effective in eradicating CDI by modulating the intestinal microbiota and metabolites.
艰难梭菌通过释放毒素 A 和 B 引发肠道炎症。阳离子类固醇抗菌 13（CSA13）这种抗菌化合物已被开发用于治疗胃肠道感染。CSA13-尤特奇制剂可口服给予，并在回肠末端和结肠中释放 CSA13。我们研究了这种形式的 CSA13 是否能减少小鼠的艰难梭菌感染（CDI）。
C57BL/6J 小鼠在第 0 天感染艰难梭菌，随后给予 CSA13 皮下注射或 CSA13-尤特奇口服（10 mg/kg/d，连续 10 天）。一些小鼠在第 0-4 天给予腹腔万古霉素（50 mg/kg/天），在停药后测量复发情况。监测小鼠直至第 20 天；在第 3 天收集结肠和粪便样本进行分析。采集血液样本进行流式细胞术分析。每天收集接受 CSA13 注射的小鼠的粪便颗粒，并通过高效液相色谱或 16S 测序进行分析；还将粪便在磷酸盐缓冲液中匀浆，通过灌胃给予 CDI 小鼠。
CDI 导致小鼠 60%死亡，感染后第 3 天体重显著减轻，结肠损伤；CSA13 皮下注射或 CSA13-尤特奇口服可预防这些事件。停止 CSA13 给药后，CDI 复发减少。给予 CSA13-尤特奇的小鼠粪便中的 CSA13 水平明显高于给予 CSA13 皮下注射的小鼠。CSA13 皮下注射和口服均显著增加了粪样中消化链球菌科细菌的丰度，降低了艰难梭菌的丰度。当给予 CSA13 的 CDI 小鼠的粪便给予未接受 CSA13 的 CDI 小鼠时，接受者小鼠的存活率显著提高。CSA13 降低了 CDI 小鼠粪便中炎症代谢物（内源性大麻素）的水平，并增加了粪便中 4 种保护代谢物（即瓜氨酸、3-氨基异丁酸、视黄醇和熊去氧胆酸）的水平。口服这些依赖 CSA13 的保护代谢物可降低 CDI 的严重程度。
在对小鼠的研究中，我们发现 CSA13-尤特奇制剂通过调节肠道微生物群和代谢物，有效地根除 CDI。
