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Updated: Apr 23, 2026

Rapid Identification of Gram Negative Bacteria from Blood Culture Broth Using MALDI-TOF Mass Spectrometry
Published on: May 28, 2014
Use of MALDI-TOF mass spectrometry for rapid identification of group B Streptococcus on chromID Strepto B agar
Lu Binghuai1, Shi Yanli1, Zhang Shuchen1
1Department of Laboratory Medicine, Civil Aviation General Hospital, No. 1, Gaojing Street, Chaoyang District, Beijing 100123, PR China.
Background:
Group B Streptococcus (GBS) is a known leading causative pathogen of neonatal infection. Efficient screening and identification of women colonized with GBS is important for the prevention of invasive neonatal infections.
Methods:
A total of 628 vaginal/rectal specimens were collected from pregnant women in Beijing, China. The chromogenic medium chromID Strepto B agar (STRB) was evaluated for its reliability in screening GBS from the vaginal/rectal swabs; results were compared to those of blood agar plates (BAP). Furthermore, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) was used to confirm the colonies suspected of being GBS on STRB.
Results:
STRB showed excellent performance for GBS detection and outperformed BAP due to its higher sensitivity. Furthermore, MALDI-TOF MS could reliably differentiate the putative GBS isolates on STRB.
Conclusions:
This study demonstrated that STRB combined with MALDI-TOF MS is a fast, sensitive, and accurate method for the identification of GBS-colonized pregnant women.
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