title: Application of matrix-assisted laser desorption ionization time-of-flight mass spectrometry in the screening of vanA-positive Enterococcus faecium.
abstract: In order to evaluate a rapid matrix-assisted laser desorption ionization-time of flight mass spectrometry (MAIDI-TOF MS) assay in screening vancomycin-resistant Enterococcus faecium, a total of 150 E. faecium clinical strains were studied, including 60 vancomycin-resistant E. faecium (VREF) isolates and 90 vancomycin-susceptible (VSEF) strains. Vancomycin resistance genes were detected by sequencing. E. faecium were identified by MALDI-TOF MS. A genetic algorithm model with ClinProTools software was generated using spectra of 30 VREF isolates and 30 VSEF isolates. Using this model, 90 test isolates were discriminated between VREF and VSEF. The results showed that all sixty VREF isolates carried the vanA gene. The performance of VREF detection by the genetic algorithm model of MALDI-TOF MS compared to the sequencing method was sensitivity = 80%, specificity = 90%, false positive rate =10%, false negative rate =10%, positive predictive value = 80%, negative predictive value= 90%. MALDI-TOF MS can be used as a screening test for discrimination between vanA-positive E. faecium and vanA-negative E. faecium.
authors.affiliation: Department of Laboratory Medicine, Beijing Tsinghua ChangGung Hospital, Medical Centre, Tsinghua University, Beijing 102218, China.. 120265085@qq.com.
authors.forename: Li-jun
authors.initials: LJ
authors.lastname: Wang
authors.affiliation: Department of Laboratory Medicine, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China. luxinxin66@sohu.com.
authors.forename: Xin-xin
authors.initials: XX
authors.lastname: Lu
authors.affiliation: Department of Laboratory Medicine, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China. 1187160706@qq.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Wu
authors.affiliation: Department of Laboratory Medicine, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China. suiwenjun2008@126.com.
authors.forename: Wen-jun
authors.initials: WJ
authors.lastname: Sui
authors.affiliation: Department of Laboratory Medicine, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China. chinazhanggui@sina.com.
authors.forename: Gui
authors.initials: G
authors.lastname: Zhang