呼吸机相关肺炎患者病原菌分布及血清miR-146a、miR-155的检测分析

Distribution of pathogenic bacteria and detection and analysis of serum miR-146a and miR-155 in patients with ventilator-associated pneumonia

目的探讨呼吸机相关肺炎(VAP)患者病原菌分布及血清微小RNA-146a(miR-146a)、miR-155表达水平及临床意义。方法选择2018年12月-2021年4月在大连大学附属中山医院进行机械通气治疗的患者197例作为观察对象,其中符合VAP诊断标准的107例患者作为VAP组,未感染患者90例作为非VAP组,另选择同期健康体检人员100人作为对照组。采用实时荧光定量PCR法(RT-qPCR)检测血清miR-146a、miR-155表达,采用ELISA方法检测血清C-反应蛋白(CRP)、肿瘤坏死因子-α(TNF-α)水平,Pearson法分析miR-146a、miR-155与CRP、TNF-α相关性,ROC曲线分析miR-146a、miR-155对VAP的诊断价值。结果107例VAP患者共分离出170株致病菌,以革兰阴性菌为主共91株占53.53%,其次是革兰阳性菌73株占42.94%,真菌6株(3.53%)。革兰阴性菌以铜绿假单胞菌为主,革兰阳性菌以金黄色葡萄球菌为主。与对照组比较,非VAP组、VAP组患者血清miR-146a、miR-155及CRP、TNF-α表达水平显著升高,差异有统计学意义(P<0.05);与非VAP组比较,VAP组患者血清miR-146a、miR-155及CRP、TNF-α表达水平显著升高,差异有统计学意义(P<0.05)。相关性分析显示,VAP患者血清miR-146a、miR-155表达水平均与CRP、TNF-α水平呈正相关(P<0.05)。miR-146a、miR-155联合诊断VAP的灵敏度为87.57%,特异度为92.44%,曲线下面积为0.920。结论VAP患者以革兰阴性菌为主要致病菌,血清miR-146a、miR-155表达水平升高,二者联合检测对VAP有一定诊断价值。

Objective To investigate the distribution of pathogenic bacteria and serum miR-146 a and miR-155 expression levels and clinical significance in patients with ventilator-associated pneumonia(VAP).Methods A total of 197 patients who were treated in Zhongshan Hospital Affiliated to Dalian University from December 2018 to April 2021 were selected as observation objects.Among them,107 patients meeting the diagnostic criteria of VAP were regarded as the VAP group,and90 patients without infection were regarded as the non-VAP group.In addition,100 health examiners during the same period were selected as the control group.Real-time fluorescent quantitative PCR(RT-qPCR)was used to detect the expression of serum miR-146 a and miR-155;ELISA method was used to detect the levels of serum C-reaction protein(CRP)and tumor necrosis factor-α(TNF-α).Pearson method was used to analyze the correlation between miR-146 a,miR-155 and CRP,TNF-α,and ROC curve was used to analyze the diagnostic value of miR-146 a and miR-155 for VAP.Results A total of 170 pathogenic bacteria were isolated from 107 patients.Among them,91 were Gram-negative bacteria,accounting for 53.53%,mainly Pseudomonas aeruginosa;73 were Gram-positive bacteria,accounting for 42.94%,mainly Staphylococcus aureus;6 were fungi,accounting for 3.53%.Compared with the control group,the levels of serum miR-146 a,miR-155,CRP and TNF-αin the non-VAP group and VAP group were significantly increased,and the difference was statistically significant(P<0.05);compared with the non-VAP group,the levels of serum miR-146 a,miR-155,CRP and TNF-αin the VAP group were significantly increased,and the difference was statistically significant(P<0.05);correlation analysis showed that the expression levels of serum miR-146 a and miR-155 in VAP patients were positively correlated with CRP and TNF-αlevels(P<0.05);the sensitivity of miR-146 a combined with miR-155 in the diagnosis of VAP was 87.57%,the specificity was92.44%,and the area under the curve was 0.920.Conclusions Gram-negative bacteria were the main pathogens in VAP patients,and serum miR-146 a and miR-155 expression levels were elevated.The combined detection of the two had a certain diagnostic value for VAP.