引起血流感染常见的革兰氏阴性杆菌蛋白指纹图谱的建立

Establishment of protein fingerpritings of common gram negative bacteria causing bloodstream infection

目的建立引起血流感染的临床常见革兰氏阴性杆菌的蛋白指纹图谱,为血流感染快速诊断奠定基础。方法在血培养分析仪报阳后8小时内抽取报阳血培养基3 ml,经离心、红细胞裂解液溶解红细胞及无菌去离水洗涤后,留取细菌悬液,应用表面增强激光解吸电离飞行时间质谱技术(surface-enhanced laser desorption/ionization time-of-flight mass spectrome-try,SELDI-TOF-MS)和Au蛋白芯片检测细菌蛋白,采用Ciphergen Proteinchip软件自动采集数据。每个标本重复测定4次评价SELDI-TOF-MS检测细菌蛋白的重复性。结果在分子量5～20 kD范围内不同种细菌具有不同的蛋白指纹图谱;同种细菌具有相似的蛋白指纹图谱,主要蛋白峰分子量的变异系数<0.1%;同一株细菌蛋白指纹图谱具有很好的重复性,主要蛋白峰分子量的变异系数<0.05%。结论在分子量5～20 kD范围内不同种细菌具有特征性蛋白指纹图谱,为血流感染病原菌的快速鉴定提供了新思路。

Objective To establish protein fingerpritings of common gram negative bacteria causing bloodstream infection and lay a foundation for rapid diagnosis of bloodstream infection. Methods Three milliliter positive blood culture broth was collected within 8 hours after the blood culture bottle was detected as positive by Bact/Alert 3D 120.After the broth was centrifugated and washed,the precipitation of the bacteria was analyzed by surface enhanced laser desorption/ionization time-of-flight mass spectra and proteinchip golden array.The data were collected by Ciphergen Proteinchip software.Each specimen was measured four times to evaluate the reproducibility. Results Bacteria of different species had various protein fingerpritings ranging from 5 KD to 20 KD.The same species had similar protein fingerpritings,and the variation coefficient（CV）of molecular weight of the main protein biomarkers was less than 0.1%.The protein profiling of the same bacterium had good reproducibility,and CV of main protein biomarkers was less than 0.05%. Conclusions There are various characteristic protein fingerpritings in bacteria of different species,which provides a new approach for rapid diagnosis of bloodstream infection.