血培养仪阳性报警时间在血培养检出菌性质鉴别中的应用

目的 探讨血培养仪阳性报警时间(TP)对所检出的凝固酶阴性葡萄球菌(CoNS)性质鉴别中的应用价值.方法 对236例血培养检出CoNS的新生儿血培养标本TP和定量血培养(QBCs)检测结果 进行比较分析,根据QBCs、TP,并结合临床资料,判断CoNS是感染菌或污染菌.结果 TP和QBCs呈显著负相关:TP≤16 h时,QBCs＞100 CFU/mL;TP>20 h时,QBCs＜10 CFU/mL.QBCs检测结果 与患儿临床症状严重程度和抗菌药物治疗的必要性呈明显正相关:QBCs＜10 CFU/mL,即TP≥20 h,预示细菌污染;QBCs＞100 CFU/mL,即TP≤16 h,预示血液中细菌浓度较高,存在血流感染,需积极采取抗菌药物治疗.结论 TP作为判断细菌浓度的指标,也可用于鉴别血培养检出CoNS是否提示血流感染.

Application of time-to-positivity in blood culture instrument for the identification of bacteria detected by blood culture

Objective To explore the application value of time-to-positivity(TP) in blood culture instrument for the characteristic identification of detected coagulase negative staphylococcus(CoNS).Methods TP and quantitative blood cultures(QBCs) were analyzed for 236 cases of neonatal blood samples,in which CoNS could be detected,and the nature of CoNS was analyzed by combined analysis of QBCs,TP and clinical data.Results There was negative correlation between TP and QBCs.When TP was less or equal with 16 h,QBCs was more than 100 CFU/mL,and when TP was more than 20 h,QBCs was less than 10 CFU/mL.QBCs was positively correlated with clinical syndromes and the necessity of antibacterial drug therapy.QBCs,less than 10 CFU/mL,indicated the detected bacteria might be contamination,and QBCs,more than 100 CFU/mL,indicated that there might be high content of bacteria in blood and antibacterial drug therapy should be performed as soon as possible.Conclusion TP,an indicator for the judgment of the concentration of bacteria,could also be used for the identification of blood stream infection of CoNS.