摘要
目的：分析基质辅助激光解吸／电离飞行时间质谱仪（ matrix-assisted laser desorption／ionization time-of-flight mass spectrometry ， MALDI-TOF MS）快速鉴别甲氧西林耐药和甲氧西林敏感金黄色葡萄球菌。方法收集浙江大学医学院附属第二医院已保存的临床分离的耐甲氧西林金黄色葡萄球菌（MRSA）25株和甲氧西林敏感金黄色葡萄球菌（MSSA）30株用于模型的建立。同时选取34株临床分离株（12株MRSA和22株MSSA）用做模型验证菌株。 MALDI-TOF MS对所有菌株进行鉴定，ClinProTools 3．0软件对MALDI-TOF MS鉴定细菌所产生的质谱峰图进行分析。结果 ClinPro-Tools软件的4种算法所得出的结果基本一致，灵敏度均大于95．0％，其中遗传算法（GA）的灵敏度最高（100．0％）；除监督式神经网络算法（ SNN）外，其余3种算法的特异性均大于90．0％。质荷比为3279、6485、6555和3299 m／z的质谱峰是用于区分MRSA和MSSA的最为主要的特征性峰。受试者工作特征曲线（ ROC）显示，这4个特征性峰的曲线下面积（ AUC）均大于0．9；凝胶浏览图显示，MSSA组的3279、6485、6555 m／z峰的蛋白强度高于MRSA组，而3299 m／z峰的蛋白强度低于MRSA组。外部验证显示，GA模型对MRSA组的准确鉴定率为83．3％，对MSSA组的准确鉴定率为90．9％。结论在严格控制实验条件的情况下，MALDI-TOF MS可快速准确地鉴别MRSA和MSSA，具有耗时短，灵敏性高，特异性高的优点。准确鉴定的同时区分MRSA和MSSA，尽早为临床防治MRSA提供参考依据，限制其传播及暴发流行。
Objective To evaluate the capability of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry （ MALDI-TOF MS） for rapid identification of methicillin-resistant Staphylo-coccus aureus （MRSA） and methicillin-sensitive Staphylococcus aureus （MSSA） strains.Methods Twenty-five MRSA and thirty MSSA isolates were collected from the Second Affiliated Hospital of Zhejiang University School of Medicine as the experiment group .Twelve MRSA and twenty-two MSSA clinical strains were isola-ted as the control .All strains were identified by MALDI-TOF MS and the results were further analyzed by ClinProTools 3.0 software.Results Four algorithms including support vector machine （SVM）, genetic al-gorithm （ GA） , supervised neural network （ SNN） and quick classifier （ QC） showed similar results in dis-tinguishing MRSA from MSSA isolates .The sensitivity of GA was 100 .0%and the sensitivities of other algo-rithms were all greater than 95.0%.The specificities of GA, SVM and QC were all greater than 90.0%. The areas under the receiver operating characteristic （ ROC） curves of four characteristic peaks at mass-to-charge ratios （m/z） of 3279, 6485, 6555 and 3299 m/z were all greater than 0.9.The virtual gel view showed that the bands generated by MSSA isolates at 3279 , 6485 and 6555 m/z were obviously deeper in color than those generated by MRSA isolates .However , the bands of MSSA isolates at 3299 m/z were appar-ently lighter in color than those of MRSA isolates .83.3%of MRSA and 90.0%of MSSA isolates from the＆amp;nbsp;control group were correctly identified by the GA model .Conclusion MALDI-TOF MS could rapidly and accurately identify MRSA from MSSA isolates under the strictly controlled experimental conditions with the advantages of less time-consuming, high sensitivity and high specificity .The accurate identification of MRSA from MSSA isolates could be applied for the prevention and treatment of MRSA infection .
出处
《中华微生物学和免疫学杂志》
CAS
CSCD
北大核心
2015年第1期42-45,共4页
Chinese Journal of Microbiology and Immunology
基金
浙江省医药卫生科技计划项目（2012KYA091）
