Department of Internal Medicine, Division of Infectious Diseases, University of Michigan, Ann Arbor, Michigan, USA.
University of Michigan Medical School, Ann Arbor, Michigan, USA.
Clin Infect Dis. 2021 Nov 2;73(9):e2883-e2889. doi: 10.1093/cid/ciaa1395.
In Clostridioides difficile infection (CDI), the relationship between clinical, microbial, and temporal/epidemiological trends, disease severity and adverse outcomes is incompletely understood. In a follow-up to our study from 2010-2013, we evaluate stool toxin levels and C. difficile polymerase chain reaction (PCR) ribotypes. We hypothesized that elevated stool toxins and infection with ribotype 027 associate with adverse outcomes.
In 565 subjects at the University of Michigan with CDI diagnosed by positive testing for toxins A/B by enzyme immunoassay (EIA) or PCR for the tcdB gene, we quantified stool toxin levels via a modified cell cytotoxicity assay (CCA), isolated C. difficile by anaerobic culture, and performed PCR ribotyping. Severe CDI was defined by Infectious Diseases Society of America (IDSA) criteria, and primary outcomes were all-cause 30-day mortality and a composite of colectomy, intensive care unit admission, and/or death attributable to CDI within 30 days. Analyses included bivariable tests and logistic regression.
199 samples were diagnosed by EIA; 447 were diagnosed by PCR. Toxin positivity associated with IDSA severity but not primary outcomes. In 2016, compared with 2010-2013, ribotype 106 newly emerged, accounting for 10.6% of strains, ribotype 027 fell from 16.5% to 9.3%, and ribotype 014-027 remained stable at 18.9%. Ribotype 014-020 associated with IDSA severity and 30-day mortality (P = .001).
Toxin positivity by EIA and CCA associated with IDSA severity but not with subsequent adverse outcomes. The molecular epidemiology of C. difficile has shifted, which may have implications for the optimal diagnostic strategy for and clinical severity of CDI.
在艰难梭菌感染（CDI）中，临床、微生物和时间/流行病学趋势、疾病严重程度和不良结局之间的关系尚未完全阐明。在我们 2010-2013 年的研究的后续研究中，我们评估了粪便毒素水平和艰难梭菌聚合酶链反应（PCR）核糖体分型。我们假设粪便毒素升高和感染 027 型核糖体与不良结局相关。
在密歇根大学的 565 名 CDI 患者中，通过酶联免疫吸附试验（EIA）或 PCR 检测 tcdB 基因阳性检测毒素 A/B 诊断为 CDI，我们通过改良细胞细胞毒性测定法（CCA）定量粪便毒素水平，通过厌氧培养分离艰难梭菌，并进行 PCR 核糖体分型。严重 CDI 由感染病学会（IDSA）标准定义，主要结局是 30 天内全因死亡率和归因于 CDI 的 30 天内结肠切除术、重症监护病房入院和/或死亡的复合指标。分析包括双变量检验和逻辑回归。
199 个样本通过 EIA 诊断；447 个样本通过 PCR 诊断。毒素阳性与 IDSA 严重程度相关，但与主要结局无关。2016 年与 2010-2013 年相比，106 型核糖体新出现，占菌株的 10.6%，027 型核糖体从 16.5%降至 9.3%，014-027 型核糖体保持稳定在 18.9%。014-020 型核糖体与 IDSA 严重程度和 30 天死亡率相关（P=0.001）。
EIA 和 CCA 的毒素阳性与 IDSA 严重程度相关，但与随后的不良结局无关。艰难梭菌的分子流行病学已经发生变化，这可能对 CDI 的最佳诊断策略和临床严重程度产生影响。
