Application of MALDI-TOF MS combined with serum separator tube and turbidimetry for direct identification of pathogens in sterile body fluids
10.16718/j.1009-7708.2025.02.008
- VernacularTitle:基质辅助激光解吸电离飞行时间质谱结合血清分离胶促凝管法及比浊仪直接鉴定无菌体液病原菌的应用
- Author:
Xiao ZHANG
1
;
Hui CAI
Author Information
1. 江苏省苏州市第九人民医院检验科,江苏苏州 215200
- Publication Type:Journal Article
- Keywords:
turbidimetry;
matrix-assisted laser desorption/ionization time-of-flight mass spectrometry;
rapid identification;
sterile body fluid;
pathogen
- From:
Chinese Journal of Infection and Chemotherapy
2025;25(2):168-173
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the application of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF MS)combined with serum separator tube and turbidimetry in the direct identification of pathogens in sterile body fluids.Methods A total of 284 positive sterile body fluid specimens(blood,hydrothorax,ascites,bile,and cerebrospinal fluid)infected by a single pathogen with a blood culture instrument alarm time less than 48 h were collected from January to December 2023 in the Department of Laboratory Medicine at Suzhou Ninth People's Hospital.All the specimens were tested by turbidimeter for pathogen concentration.And the reliability of the identification results was judged by MALDI-TOF MS scores according to different concentrations of the main pathogens.Results The lowest concentration of microorganism for achieving reliable results was 3.0 mcf for Escherichia coli,2.0 mcf for Klebsiella pneumoniae,3.0 mcf for Staphylococcus aureus,3.5 mcf for Enterococcus faecalis and 4.0 mcf for Candida when identified by MALDI-TOF MS.The results were compared between VITEK 2 identification,routine MALDI-TOF MS identification,and direct MALDI-TOF MS identification.The results of routine MALDI-TOF MS identification and VITEK identification were consistent in 282 cases.The concentration greater than 1.7 was found in 272 cases with direct MALDI-TOF MS,and the sensitivity of MALDI-TOF MS was 95.8％(272/284).The results did not show significant difference between the 3 identification methods(x2=2.09,P=0.55).Conclusions MALDI-TOF MS combined with serum separator tube and turbidimetry is a reliable and innovative technique for identifying pathogens in sterile body fluids.It is rapid and accurate,and may be valuable for early etiological diagnosis in clinical practice.
