血培养中不同菌属细菌阳性报警时间在鉴别血流感染和采血污染中的意义

Significance of different bacteria time to positivity of blood culture in differentiating bloodstream infection and contamination during blood withdrawal

目的研究血培养中不同菌属细菌阳性报警时间在鉴别血流感染(bloodstream infection,BSI)和采血污染中的效果及临床意义。方法回顾性分析我院自2017年5月~2020年5月收集的血培养阳性样本1237份,分析血培养阳性样本的病原菌分布及阳性菌株的报警时间。结果阳性预警共109份,假阳性6份,获得103株病原菌,阳性率为8.33%(103/1237);其中病原菌组(血流感染)61株(59.22%);污染菌组(采血污染)42株(40.78%)。病原菌组与污染菌组比较,大肠埃希菌、肺炎克雷伯菌菌株报阳时间较短,差异具有统计学意义(P<0.05)。病原菌组与污染菌组比较,金黄色葡萄球菌、凝固酶阴性葡萄球菌菌株报阳时间较短,差异具有统计学意义(P<0.05)。病原菌组与污染菌组真菌报阳时间比较,差异无统计学意义(P>0.05)。结论血培养报警时间在早期判断不同病原菌污染或者采血污染方面具有较高的应用价值,能够为临床医生准确选择抗菌药物提供合理的依据。

Objective To explore the effect of different bacteria time to positivity(TTP)of blood culture in differentiating bloodstream infection(BSI)and contamination druing blood withdrawal.Methods Data of 1237 positive blood culture samples received in our hospital from May 2017 to May 2020 were retrospectively analyzed,the distribution of pathogenic bacteria in positive blood culture samples and TTP of blood culture positive strains were analyzed.Results During the identification of 1237 samples,there were 109 positive warnings and 6 false positives,and 103 pathogenic bacteria were obtained,with a positive rate of 8.33%(103/1237).Among them,there were 61 pathogens(59.22%)in the pathogenic bacteria group(bloodstream infection);42 strains(40.78%)in the contaminated bacteria group(blood collection contamination).Compared with the contaminated bacteria group,the pathogenic bacteria group had shorter TTP of Escherichia coli and Klebsiella pneumoniae strains,and the difference between the groups was statistically significant(P<0.05).Compared with the contaminated bacteria group,TTP of Staphylococcus aureus and coagulase-negative Staphylococcus strains was shorter in the pathogenic bacteria group,and the difference between the groups was statistically significant(P<0.05).There was no significant difference in TTP of fungi between the pathogenic bacteria group and the contaminated bacteria group(P>0.05).Conclusion TTP of blood culture has high application value in the early judgment of different pathogenic bacteria contamination or contamination during blood withdrawal,which can provide an accurate and reasonable way for clinicians to choose antibiotics.