血流感染患者血清降钙素原水平与病原菌的相关性分析

目的 探讨已使用抗菌药物的血流感染患者血清降钙素原（procalcitonin，PCT）水平与病原菌的相关性。方法 回顾性收集苏州大学附属第一医院2011年9月至2016年12月住院患者使用抗菌药物过程中同一时刻行PCT检测和血培养，且培养结果为单一病原菌的血流感染患者，对其血培养结果与PCT水平进行相关性分析。结果 共有119例患者符合入组标准，其中G⁺菌37例（31.1%），PCT浓度为0.49（0.16~1.59）ng/ml，G^-菌82例（68.9%），PCT浓度为0.71（0.27~2.74）ng/ml，G⁺菌和G^-菌PCT水平无显著性差异（P=0.109）。G⁺菌中以肠球菌属的PCT浓度最高，为3.35（0.95~28.79）ng/ml，G^-菌中以肠杆菌属的PCT浓度最高，为5.25（0.22~35.89）ng/ml，不同菌属感染的PCT水平存在显著性差异（P=0.001）。结论 对于已使用抗菌药物的血流感染患者，血清PCT水平无法判断是G⁺菌还是G^-菌感染。

Correlational analysis of procalcitonin levels between gram-positive and gram-negative bloodstream infection

Objective To investigate the relationship between procalcitonin (PCT) levels and bacteria in patients with bloodstream infection who were already administered antimicrobial therapy. Methods Retrospective collected the patients with monomicrobial bloodstream infection who were already administered antimicrobial therapy in First Hospital Affiliated to Soochow University from Sept. 2011 to Dec. 2016. Blood samples for PCT testing and culture were collected at the same time. Correlational analysis of PCT levels and bacteria was performed. Results 119 patients were in accordance with the inclusive criteria. 37 patients(31.1%)were infected with gram-positive(G⁺) bacteria and 82 patients(68.9%)were infected with gram-negative(G^-) bacteria.The median (interquartile range, IQR) of PCT were 0.49 (0.16-1.59) ng/ml and 0.71 (0.27-2.74) ng/ml for G⁺ and G^- infection, respectively (P=0.109). Enterococcus and enterobacter had the highest PCT levels among G⁺ and G^- bacteria, the median (IQR) of PCT were 3.35(0.95-28.79) ng/ml and 5.25 (0.22-35.89) ng/ml, respectively. PCT levels in different cohorts existed significant differences (P=0.001). Conclusion For patients with bloodstream infection who were already administered antimicrobial therapy, PCT levels were unable to distinguish G^- from G⁺ bacteria.