Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for the identification of beta-hemolytic streptococci

Chunmei Zhou; Lili Tao; Bijie Hu; Jian Ma; Xiangru Ye; Shenglei Huang; Yan Ma; Yuzhang Shan

doi:10.3978/j.issn.2072-1439.2015.03.02

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for the identification of beta-hemolytic streptococci

J Thorac Dis. 2015 Apr;7(4):591-5. doi: 10.3978/j.issn.2072-1439.2015.03.02.

Authors

Chunmei Zhou¹, Lili Tao¹, Bijie Hu¹, Jian Ma¹, Xiangru Ye¹, Shenglei Huang¹, Yan Ma¹, Yuzhang Shan¹

Affiliation

¹ 1 Department of Clinical microbiology laboratory, Zhongshan Hospital, Fudan University, Shanghai 200032, China ; 2 Department of Respiratory Medicine, Huangdong Hospital, Fudan University, Shanghai 200040, China ; 3 Department of Respiratory Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China ; 4 Department of Respiratory Medicine, Yingzhou Hospital, Ningbo University, Ningbo 315040, China.

PMID: 25973224
PMCID: PMC4419311
DOI: 10.3978/j.issn.2072-1439.2015.03.02

Abstract

Objective: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has emerged as promising technology for species identification. The purpose of this investigation was to compare the performance of MS and the traditional method for identification of beta-hemolytic streptococci (BHS).

Methods: Clinical BHS isolates were identified by the BD Phoenix SMIC/ID Streptococcal panels, and two MALDI-TOF MS platforms: the VITEK MS and the Bruker MALDI Biotyper systems respectively. In case of discordant results, 16sRNA sequencing was performed to provide the reference ID.

Results: A total of 96 isolates of BHS were analyzed. Thirty-six isolates (20.8%) were re-tested by BD Phoenix for identification failure; and four isolates (4.2%) were rerun on the Bruker system for low identification score. No isolate need a second run for identification by Vitek MS system. Overall, BD Phoenix, BioTyper and Vitek MS automated system accurately identified 76 strains (79.2%), 91 (94.7%) strains and 92 (95.8%) strains, respectively.

Conclusions: Our study suggests that MALDI-TOF MS is a superior method to conventional phenotypic methods for BHS identification.

Keywords: MS; Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS); beta-hemolytic streptococci (BHS); identification.