早期血清降钙素原对成人细菌性血流感染病原菌种属的鉴别价值

Identification Value of Early Procalcitonin Levels in Pathogenic Bacteria Species of Bacterial Bloodstream Infection in Adults

目的探讨早期降钙素原(procalcitonin,PCT)水平对成人革兰氏阳性菌和革兰氏阴性菌的诊断意义以及对病原菌种属的鉴别价值。方法抽取河南科技大学附属许昌市中心医院2014年5月-2019年4月血培养结果阳性病例,筛选出符合要求病历460份(革兰氏阴性菌360例,革兰氏阳性菌100例);分组记录患者抽取血培养前后<12 h血清PCT。采用受试者工作曲线(ROC曲线)分析早期PCT水平对革兰氏阴性菌和革兰氏阳性菌的诊断意义;并针对早期PCT水平对血流感染临床常见的革兰氏阴性菌4个种属病原菌和革兰氏阳性菌4个种属病原菌的鉴别价值进行比较。结果革兰氏阴性菌组PCT水平[7.42(1.51~33.04)]显著高于革兰氏阳性菌组PCT水平[0.70(0.24~3.66)]。ROC曲线下面积0.749,P<0.01;当以1.88 ng·mL^-1为界点时,对革兰氏阴性菌诊断的灵敏度为73.3%,特异性为75.0%。在鉴别菌属价值方面:革兰氏阴性菌中,铜绿假单胞菌组PCT浓度水平显著高于大肠埃希菌组(P<0.01)、肺炎克雷伯菌组(P<0.01)和鲍曼不动杆菌组(P<0.01);革兰氏阳性菌中,链球菌属组PCT浓度水平显著高于凝固酶阴性葡萄球菌组(P<0.05),其他各组之间无统计学差异。结论血流感染患者早期PCT水平对革兰氏阳性菌和革兰氏阴性菌的诊断效果显著,对病原菌种属的鉴别具有辅助作用。

OBJECTIVE To explore diagnostic significance of early procalcitonin(PCT) levels between gram-positive and gram-negative bacteria, as well as its identification value in pathogenic bacteria species. METHODS The positive cases of blood culture in the Xuchang Central Hospital Affiliated to Henan University of Science and Technology between May 2014 and April 2019 were selected and 460 copies of the medical records were obtained after screening. Among them, 360 copies were gram-negative and 100 copies were gram-positive bacteria. Serum PCT levels(<12 h) before or after haemospasia for blood culture was recorded. A receiver operating characteristic(ROC) curve analysis was used to discriminate gram-negative from gram-positive bloodstream infections. The diagnostic value of early PCT levels at clinical common gram-negative bacteria species and gram-positive bacteria species(n=4 each) were compared. RESULTS PCT levels of gram-negative bacteria group[7.42(1.51?33.04)]was significantly higher than gram positive group[0.70(0.24?3.66)]. The area under the ROC curve was 0.749, P<0.01. When the cut-off for PCT was 1.88 ng·mL^-1, the sensitivity and specificity of gram-negative bacteria infection was 73.3% and 75.0%, respectively. Among gram-negative bacteria, early PCT level of Pseudomonas aeruginosa group was significantly higher than Escherichia coli group(P<0.01), Klebsiella pneumoniae(P<0.01) and Acinetobacter baumannii group(P<0.01). Among gram-positive bacteria, early PCT level of Streptococcus group was significantly higher than coagulase negative Staphylococcus group(P<0.05). There was no statistical difference among other groups. CONCLUSION PCT level in early stage of bloodstream infection has significant effect on the diagnosis of gram-positive bacteria and gram-negative bacteria and plays a supporting role in identification for pathogenic bacteria species.