<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Rapid identification of microorganisms in urine is essential for patients with urinary tract infections (UTIs). Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been proposed as a method for the direct identification of urinary pathogens. Our purpose was to compare centrifugation-based MALDI-TOF MS and short-term culture combined with MALDI-TOF MS for the direct identification of pathogens in urine specimens. We collected 965 urine specimens from patients with suspected UTIs, 211/965 isolates were identified as positive by conventional urine culture. Compared with the conventional method, the results of centrifugation-based MALDI-TOF MS were consistent in 159/211 cases (75.4%), of which 135/159 (84.9%) had scores ≥ 2.00; 182/211 cases (86.3%) were detected using short-term culture combined with MALDI-TOF MS, of which 153/182 (84.1%) had scores ≥ 2.00. There were no apparent differences among the three methods (<italic>p</italic> = 0.135). MALDI-TOF MS appears to accelerate the microbial identification speed in urine and saves at least 24 to 48 hours compared with the routine urine culture. Centrifugation-based MALDI-TOF MS is characterized by faster identification speed; however, it is substantially affected by the number of bacterial colonies. In contrast, short-term culture combined with MALDI-TOF MS has a higher detection rate but a relatively slow identification speed. Combining these characteristics, the two methods may be effective and reliable alternatives to traditional urine culture.</p></abstract>

Rapid identification of microorganisms in urine is essential for patients with urinary tract infections (UTIs). Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been proposed as a method for the direct identification of urinary pathogens. Our purpose was to compare centrifugation-based MALDI-TOF MS and short-term culture combined with MALDI-TOF MS for the direct identification of pathogens in urine specimens. We collected 965 urine specimens from patients with suspected UTIs, 211/965 isolates were identified as positive by conventional urine culture. Compared with the conventional method, the results of centrifugation-based MALDI-TOF MS were consistent in 159/211 cases (75.4%), of which 135/159 (84.9%) had scores ≥ 2.00; 182/211 cases (86.3%) were detected using short-term culture combined with MALDI-TOF MS, of which 153/182 (84.1%) had scores ≥ 2.00. There were no apparent differences among the three methods (p = 0.135). MALDI-TOF MS appears to accelerate the microbial identification speed in urine and saves at least 24 to 48 hours compared with the routine urine culture. Centrifugation-based MALDI-TOF MS is characterized by faster identification speed; however, it is substantially affected by the number of bacterial colonies. In contrast, short-term culture combined with MALDI-TOF MS has a higher detection rate but a relatively slow identification speed. Combining these characteristics, the two methods may be effective and reliable alternatives to traditional urine culture.

Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry for Identification of Microorganisms in Clinical Urine Specimens after Two Pretreatments

Polish Journal of Microbiology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Rapid identification of microorganisms in urine is essential for patients with urinary tract infections (UTIs). Matrix-assisted laser desorption ionization...

Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry for Identification of Microorganisms in Clinical Urine Specimens after Two Pretreatments

Article Category: original-paper

Published Online: Dec 06, 2021

Page range: 207 - 213

Received: Jan 26, 2021

Accepted: Apr 06, 2021

DOI: https://doi.org/10.33073/pjm-2021-018

Keywords
Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), rapid identification, urinary tract infection

© 2021 Deru Lei et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry for Identification of Microorganisms in Clinical Urine Specimens after Two Pretreatments

Article Category: original-paper

Published Online: Dec 06, 2021

Page range: 207 - 213

Received: Jan 26, 2021

Accepted: Apr 06, 2021

DOI: https://doi.org/10.33073/pjm-2021-018

KeywordsMatrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), rapid identification, urinary tract infection

© 2021 Deru Lei et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Keywords
Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), rapid identification, urinary tract infection