目的 基于DynNom动态评分构建碳青霉烯类耐药肠杆菌（CRE）血流感染预测模型，并对模型的预测效能进行验证。 方法 选取2021年1月至2024年1月苏州大学附属第一医院和附属第四医院收治的肠杆菌科细菌血流感染患者作为研究对象，根据病原菌情况将患者分为CRE组（n = 173）和碳青霉烯类敏感肠杆菌（CSE）组（n = 102），使用单因素和多因素logistic回归分析在肠杆菌科血流感染患者中，病原体为CRE（对比CSE）的独立危险因素，并据此建立相关DynNom动态评分预测模型。 结果 恶性肿瘤、留置中心静脉导管、使用碳青霉烯类抗菌药物、Pitt菌血症评分较高和外周血中性粒细胞绝对值（ANC）< 0.5 × 10⁹·L ^-1是发生CRE血流感染的独立危险因素（P < 0.05）。模型验证结果：C-index为0.812（95%CI：0.787 ~ 0.837），校准曲线均趋近于理想曲线，ROC曲线的AUC为0.817（95%CI：0.788 ~ 0.846），在23% ~ 100%预测范围内，模型的净获益值≥ 0。 结论 恶性肿瘤、留置中心静脉导管、使用碳青霉烯类抗菌药物、Pitt菌血症评分较高和ANC < 0.5 × 10⁹·L ^-1是肠杆菌科血流感染患者病原体为CRE的独立危险因素。基于危险因素构建的DynNom动态评分预测模型，对于在肠杆菌科血流感染患者中鉴别病原体是否为CRE具有良好的预测价值。

Objective To develop a prediction model for identifying carbapenem-resistant Enterobacteriaceae （CRE） as the causative pathogen in bloodstream infections （BSI） using a DynNom dynamic nomogram， and to validate its predictive performance. Methods Patients with Enterobacteriaceae BSI admitted to the First Affiliated Hospital and the Fourth Affiliated Hospital of Soochow University between January 2021 and January 2024 were enrolled. Based on antimicrobial susceptibility， patients were classified into a CRE group （n = 173） and a carbapenem-susceptible Enterobacteriaceae （CSE） group （n = 102）. Univariate and multivariate logistic regression analyses were employed to identify independent risk factors for a CRE （vs. CSE） etiology among these patients. A DynNom dynamic nomogram prediction model was subsequently constructed based on these factors. Results Malignancy， indwelling central venous catheter， prior use of carbapenem antibiotics， higher Pitt bacteremia score， and an absolute neutrophil count （ANC） < 0.5 × 10?/L were identified as independent risk factors for CRE BSI （P < 0.05）. Internal validation of the model yielded a C-index of 0.812 （95% CI： 0.787 - 0.837）. The calibration curve closely approximated the ideal line. The area under the receiver operating characteristic （ROC） curve was 0.817 （95% CI： 0.788 - 0.846）. Decision curve analysis indicated a positive net benefit of the model across a threshold probability range of 23% to 100%. Conclusions Malignancy， indwelling central venous catheter， prior carbapenem use， higher Pitt bacteremia score， and ANC < 0.5 × 10?/L are independent risk factors for a CRE etiology in patients with Enterobacteriaceae BSI. The DynNom dynamic nomogram developed based on these factors demonstrates good predictive value for discriminating between CRE and non-CRE pathogens in this patient population.