Jonathan H K Chen1, Kevin K K She1, Oi-Ying Wong1, Jade L L Teng1, Wing-Cheong Yam2, Susanna K P Lau2, Patrick C Y Woo2, Vincent C C Cheng3, Kwok-Yung Yuen2. 1. Department of Microbiology, Queen Mary Hospital, The University of Hong Kong, Hong Kong Special Administrative Region, Hong Kong, China. 2. Department of Microbiology, Queen Mary Hospital, The University of Hong Kong, Hong Kong Special Administrative Region, Hong Kong, China Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong Special Administrative Region, Hong Kong, China. 3. Department of Microbiology, Queen Mary Hospital, The University of Hong Kong, Hong Kong Special Administrative Region, Hong Kong, China Infection Control Team, Queen Mary Hospital, Hong Kong Special Administrative Region, Hong Kong, China.
Abstract
BACKGROUND: Differentiation of Streptococcus pneumoniae from other viridans group streptococci is well known to be challenging in clinical laboratories. Matrix assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF MS) had been reported to be a good alternative for Streptococcus species level identification. However, differentiation of S. pneumoniae from other Streptococcus mitis group organisms was found to be problematic using the Bruker MALDI Biotyper system. METHODS: This study used the Bruker MALDI Biotyper system in addition to a mass spectra model analysis generated by 10 reference strains of S. pneumoniae, 8 strains of S. mitis and 2 strains of S. oralis in the ClinProTools to identify 28 clinical isolates of S. pneumoniae and 47 isolates of S. mitis/oralis. The results were compared with those generated by the MALDI Biotyper system alone. RESULTS: The percentages of correct species level identification using the MALDI Biotyper system alone and the direct transfer and extraction method were 66.7% (50/75) and 70.7% (53/75), respectively. With the additional ClinProTools mass spectra analysis, the percentages of correct identification by the direct transfer and extraction method increased to 85.3% (64/75) and 100% (75/75), respectively. This new workflow significantly improved the accuracy of S. pneumoniae and S. mitis/oralis identification. CONCLUSIONS: The additional ClinProTools mass spectra analysis with extraction method after MALDI Biotyper identification significantly improved the accuracy of identification among S. pneumoniae, S. oralis and S. mitis. The extra 15 min processing time of spectra analysis should be affordable in most clinical laboratories. We suggest that the same approach could be further explored in handling other bacterial species with high similarities. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
BACKGROUND: Differentiation of Streptococcus pneumoniae from other viridans group streptococci is well known to be challenging in clinical laboratories. Matrix assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF MS) had been reported to be a good alternative for Streptococcus species level identification. However, differentiation of S. pneumoniae from other Streptococcus mitis group organisms was found to be problematic using the Bruker MALDI Biotyper system. METHODS: This study used the Bruker MALDI Biotyper system in addition to a mass spectra model analysis generated by 10 reference strains of S. pneumoniae, 8 strains of S. mitis and 2 strains of S. oralis in the ClinProTools to identify 28 clinical isolates of S. pneumoniae and 47 isolates of S. mitis/oralis. The results were compared with those generated by the MALDI Biotyper system alone. RESULTS: The percentages of correct species level identification using the MALDI Biotyper system alone and the direct transfer and extraction method were 66.7% (50/75) and 70.7% (53/75), respectively. With the additional ClinProTools mass spectra analysis, the percentages of correct identification by the direct transfer and extraction method increased to 85.3% (64/75) and 100% (75/75), respectively. This new workflow significantly improved the accuracy of S. pneumoniae and S. mitis/oralis identification. CONCLUSIONS: The additional ClinProTools mass spectra analysis with extraction method after MALDI Biotyper identification significantly improved the accuracy of identification among S. pneumoniae, S. oralis and S. mitis. The extra 15 min processing time of spectra analysis should be affordable in most clinical laboratories. We suggest that the same approach could be further explored in handling other bacterial species with high similarities. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
Authors: Jonathan H K Chen; Vincent C C Cheng; Chun-Pong Wong; Sally C Y Wong; Wing-Cheong Yam; Kwok-Yung Yuen Journal: J Clin Microbiol Date: 2017-06-21 Impact factor: 5.948
Authors: Jade L L Teng; Yuanchao Ma; Jonathan H K Chen; Ruibang Luo; Chuen-Hing Foo; Tsz Tuen Li; Jordan Y H Fong; Weiming Yao; Samson S Y Wong; Kitty S C Fung; Susanna K P Lau; Patrick C Y Woo Journal: Microbiol Spectr Date: 2022-05-05
Authors: Yeow-Kuan Chong; Chi-Chun Ho; Shui-Yee Leung; Susanna K P Lau; Patrick C Y Woo Journal: Comput Struct Biotechnol J Date: 2018-08-28 Impact factor: 7.271