Hsiao-Chuan Lin1, Jang-Jih Lu2, Lee-Chung Lin3, Cheng-Mao Ho4, Kao-Pin Hwang1, Yu-Ching Liu5, Chao-Jung Chen6. 1. School of Medicine, China Medical University, Taichung, Taiwan; Department of Pediatric Infectious Diseases, China Medical University Children's Hospital, Taichung, Taiwan. 2. Department of Laboratory Medicine, Linkou Chang-Gung Memorial Hospital, Taoyuan, Taiwan; Department of Medical Research, China Medical University Hospital, Taichung, Taiwan; Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Kwei-Shan, Taoyuan, Taiwan. 3. Department of Laboratory Medicine, Linkou Chang-Gung Memorial Hospital, Taoyuan, Taiwan. 4. Division of Infectious Diseases, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan. 5. Proteomics Core Laboratory, Department of Medical Research, China Medical University Hospital, Taichung, Taiwan. 6. Proteomics Core Laboratory, Department of Medical Research, China Medical University Hospital, Taichung, Taiwan; Graduate Institute of Integrated Medicine, China Medical University, Taichung, Taiwan. Electronic address: cjchen@mail.cmu.edu.tw.
Abstract
BACKGROUND: Group B Streptococcus (GBS) is an important invasive pathogen in neonates, pregnant women and the elderly. Serotype VI GBS, which has been rarely reported globally, has emerged as a significant pathogen in Asia. However, traditional serologic latex agglutination (LA) methods may fail to type isolates that lack of or low expression of CPS. METHODS: A total of 104 GBS strains were analyzed by MALDI-TOF MS. Multiplex PCR and multilocus sequence typing (MLST) were also performed to confirm their strains. The protein markers were purified with gel electrophoresis and LC-column, followed by identification with nanoLC-MS/MS analysis. RESULTS: Protein peak of 6251-Da was appeared in most (20/24, 92%) serotypes VI (94% ST-1 or single locus variant of ST-1), and protein peak of 6891-Da was appeared in most serotypes III (15/18, 83%) and Ib (19/23, 83%) strains. The protein peak of 6251-Da and 6891-Da were identified as CsbD family protein and UPF0337 protein gbs0600, respectively. CONCLUSIONS: The protein peak of 6251 Da may play a role of emergence of ST-1 clone, serotype VI GBS in central Taiwan and could be useful in rapid identifying invasive serotype VI from III isolates, which is hardly achieved by LA.
BACKGROUND:Group B Streptococcus (GBS) is an important invasive pathogen in neonates, pregnant women and the elderly. Serotype VI GBS, which has been rarely reported globally, has emerged as a significant pathogen in Asia. However, traditional serologic latex agglutination (LA) methods may fail to type isolates that lack of or low expression of CPS. METHODS: A total of 104 GBS strains were analyzed by MALDI-TOF MS. Multiplex PCR and multilocus sequence typing (MLST) were also performed to confirm their strains. The protein markers were purified with gel electrophoresis and LC-column, followed by identification with nanoLC-MS/MS analysis. RESULTS: Protein peak of 6251-Da was appeared in most (20/24, 92%) serotypes VI (94% ST-1 or single locus variant of ST-1), and protein peak of 6891-Da was appeared in most serotypes III (15/18, 83%) and Ib (19/23, 83%) strains. The protein peak of 6251-Da and 6891-Da were identified as CsbD family protein and UPF0337 protein gbs0600, respectively. CONCLUSIONS: The protein peak of 6251 Da may play a role of emergence of ST-1 clone, serotype VI GBS in central Taiwan and could be useful in rapid identifying invasive serotype VI from III isolates, which is hardly achieved by LA.
Keywords:
Group B Streptococcus; Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry; Multilocus sequence typing; Sequence type