Matrix-assisted laser desorption ionization-time of flight mass spectrometry for identification of nonfermenting gram-negative bacilli isolated from cystic fibrosis patients
Matrix-assisted laser desorption ionization-time of flight mass spectrometry for identification of nonfermenting gram-negative bacilli isolated from cystic fibrosis patients
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DOI：
10.1128/jcm.00569-08
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发表时间：
2008-10-01
影响因子：
9.4
通讯作者：
Ferroni, Agnes
中科院分区：
文献类型：
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作者：
Degand, Nicolas;Carbonnelle, Etienne;Ferroni, Agnes
从囊性纤维化 (CF) 患者中分离出的非发酵革兰氏阴性杆菌的鉴定通常是通过使用基于表型的技术和最终的分子工具来实现的。这些技术仍然耗时、昂贵且技术要求高。我们使用基于基质辅助激光解吸电离飞行时间质谱 (MALDI-TOF-MS) 的方法来鉴定这些细菌。使用属于 58 种临床相关非发酵革兰氏阴性杆菌的一组参考菌株。为了识别区分这些不同物种的峰，对每个参考菌株从 10 个不同传代获得的 10 个分离菌落进行了分析。保留相对强度大于 0.1 的保守峰。然后将 559 个临床分离株的光谱与 58 个参考菌株的光谱进行比较，如下：400 株铜绿假单胞菌、54 株木糖氧化无色杆菌、32 株嗜麦芽寡养单胞菌、52 株洋葱伯克霍尔德菌复合体 (BCC)、1 剑兰伯克霍尔德菌、14 解甘露醇拉尔斯顿菌、2 Ralstonia pickettii、1 个 Bordetella hinzii、1 个 Inquilinus limosus、1 个 Cupriavidus respiraculi 和 1 个 Burkholderia thailandensis。使用该数据库，正确鉴定了 549 株菌株。九个 BCC 菌株和一个 R.mannitolilytica 菌株被鉴定为属于适当的属，但不是正确的种。随后，我们使用其他参考菌株设计了 BCC 和 Ralstonia 特异性数据库。使用这些数据库，这些物种的正确识别率分别从 83% 增加到 98%，从 94% 增加到 100%。总之，这些数据表明，在 CF 患者中，MALDI-TOF-MS 是快速鉴定非发酵革兰氏阴性杆菌的强大工具。
The identification of nonfermenting gram-negative bacilli isolated from cystic fibrosis (CF) patients is usually achieved by using phenotype-based techniques and eventually molecular tools. These techniques remain time-consuming, expensive, and technically demanding. We used a method based on matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) for the identification of these bacteria. A set of reference strains belonging to 58 species of clinically relevant nonfermenting gram-negative bacilli was used. To identify peaks discriminating between these various species, the profile of 10 isolated colonies obtained from 10 different passages was analyzed for each referenced strain. Conserved peaks with a relative intensity greater than 0.1 were retained. The spectra of 559 clinical isolates were then compared to that of each of the 58 reference strains as follows: 400 Pseudomonas aeruginosa, 54 Achromobacter xylosoxidans, 32 Stenotrophomonas maltophilia, 52 Burkholderia cepacia complex ( BCC), 1 Burkholderia gladioli, 14 Ralstonia mannitolilytica, 2 Ralstonia pickettii, 1 Bordetella hinzii, 1 Inquilinus limosus, 1 Cupriavidus respiraculi, and 1 Burkholderia thailandensis. Using this database, 549 strains were correctly identified. Nine BCC strains and one R. mannnitolilytica strain were identified as belonging to the appropriate genus but not the correct species. We subsequently engineered BCC- and Ralstonia-specific databases using additional reference strains. Using these databases, correct identification for these species increased from 83 to 98% and from 94 to 100% of cases, respectively. Altogether, these data demonstrate that, in CF patients, MALDI-TOF-MS is a powerful tool for rapid identification of nonfermenting gram-negative bacilli.