Comparison of Direct Colony Method versus Extraction Method for Identification of Gram-Positive Cocci by Use of Bruker Biotyper Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry
Comparison of Direct Colony Method versus Extraction Method for Identification of Gram-Positive Cocci by Use of Bruker Biotyper Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry
复制标题
DOI：
10.1128/jcm.00506-11
复制
发表时间：
2011-08-01
影响因子：
9.4
通讯作者：
Patel, Robin
中科院分区：
文献类型：
--
作者：
Alatoom, Adnan A.;Cunningham, Scott A.;Patel, Robin
通过比较直接集落法和预提取法，对Bruker Biotyper（2.0版）基质辅助激光解吸电离飞行时间（MALDI-TOF）质谱法（MS）鉴定305株葡萄球菌、链球菌及相关属的临床分离株进行了评价。分离株先前通过表型检测和/或16S rRNA基因测序进行鉴定。使用制造商指定的属和种水平鉴定的评分截止值。在排除了7株未出现在Biotyper文库中的分离株后，Biotyper通过提取将284株（95%）和207株（69%）分离株分别正确识别到属和种水平。通过直接菌落测试，bityper在属和种水平分别鉴定出168株（56%）和60株（20%）分离物。总体而言，预备提取比直接菌落检测鉴定出更多的属和种水平的分离物（P < 0.0001）。将分离株分为葡萄球菌、链球菌和肠球菌两个亚群（n = 217）和“相关属”（n = 81），重复分析。对于前一个亚群，提取法分别鉴定出属和种水平的菌株213株（98%）和171株（79%），而直接菌落法分别鉴定出属和种水平的菌株136株（63%）和56株（26%）。在相关属亚群中，提取法分别鉴定出属级和种级菌株71株（88%）和36株（44%），而直接集落法分别鉴定出属级和种级菌株32株（40%）和4株（5%）。在属和种水平上，预备提取的分离菌株鉴定效果优于直接菌落检测（P < 0.0001）。根据生产商指定的分界点，使用Biotyper方法对相当大比例的革兰氏阳性球菌进行鉴定，需要进行预备提取。
We evaluated Bruker Biotyper (version 2.0) matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS) for the identification of 305 clinical isolates of staphylococci, streptococci, and related genera by comparing direct colony testing with preparatory extraction. Isolates were previously identified by use of phenotypic testing and/or 16S rRNA gene sequencing. Manufacturer-specified score cutoffs for genus-and species-level identification were used. After excluding 7 isolates not present in the Biotyper library, the Biotyper correctly identified 284 (95%) and 207 (69%) isolates to the genus and species levels, respectively, using extraction. By using direct colony testing, the Biotyper identified 168 (56%) and 60 (20%) isolates to the genus and species levels, respectively. Overall, more isolates were identified to the genus and species levels with preparatory extraction than with direct colony testing (P < 0.0001). The analysis was repeated after dividing the isolates into two subgroups, staphylococci, streptococci, and enterococci (n = 217) and "related genera" (n = 81). For the former subgroup, the extraction method resulted in the identification of 213 (98%) and 171 (79%) isolates to the genus and species levels, respectively, whereas the direct colony method identified 136 (63%) and 56 (26%) isolates to the genus and species levels, respectively. In contrast, for the subgroup of related genera, the extraction method identified 71 (88%) and 36 (44%) isolates to the genus and species levels, respectively, while the direct colony method identified 32 (40%) and 4 (5%) isolates to the genus and species levels, respectively. For both subgroups, preparatory extraction was superior to direct colony testing for the identification of isolates to the genus and species levels (P < 0.0001). Preparatory extraction is needed for the identification of a substantial proportion of Gram-positive cocci using the Biotyper method according to manufacturer-specified score cutoffs.