Identification of a proteomic biomarker associated with invasive ST1, serotype VI Group B Streptococcus by MALDI-TOF MS

Abstract Background Group B streptococcus (GBS) is an important pathogen that is responsible for invasive infections, including sepsis and meningitis. GBS serotyping is an essential means for the investigation of possible infection outbreaks and can identify possible sources of infection. Although it is possible to determine GBS serotypes by either immuno-serotyping or geno-serotyping, both traditional methods are time-consuming and labor-intensive. In recent years, the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been reported as an effective tool for the determination of GBS serotypes in a more rapid and accurate manner. Thus, this work aims to investigate GBS serotypes by incorporating machine learning techniques with MALDI-TOF MS to carry out the identification. Results In this study, a total of 787 GBS isolates, obtained from three research and teaching hospitals, were analyzed by MALDI-TOF MS, and the serotype of the GBS was determined by a geno-serotyping experiment. The peaks of mass-to-charge ratios were regarded as the attributes to characterize the various serotypes of GBS. Machine learning algorithms, such as support vector machine (SVM) and random forest (RF), were then used to construct predictive models for the five different serotypes (Types Ia, Ib, III, V, and VI). After optimization of feature selection and model generation based on training datasets, the accuracies of the selected models attained 54.9–87.1% for various serotypes based on independent testing data. Specifically, for the major serotypes, namely type III and type VI, the accuracies were 73.9 and 70.4%, respectively. Conclusion The proposed models have been adopted to implement a web-based tool (GBSTyper), which is now freely accessible at http://csb.cse.yzu.edu.tw/GBSTyper/, for providing efficient and effective detection of GBS serotypes based on a MALDI-TOF MS spectrum. Overall, this work has demonstrated that the combination of MALDI-TOF MS and machine intelligence could provide a practical means of clinical pathogen testing.

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Evaluation of the Results of Group B Streptococcus Screening by MALDI-TOF MS among Pregnant Women in a Hungarian Hospital

Pathogens ◽

10.3390/pathogens9010001 ◽

2019 ◽

Vol 9 (1) ◽

pp. 1 ◽

Cited By ~ 1

Author(s):

Marianna Ábrók ◽

Petra Tigyi ◽

Markus Kostrzewa ◽

Katalin Burián ◽

Judit Deák

Keyword(s):

Pregnant Women ◽

Group B Streptococcus ◽

Premature Delivery ◽

Maldi Tof Ms ◽

Maldi Tof ◽

Increased Risk ◽

High Prevalence ◽

Resistant Strains ◽

Group B ◽

Tof Ms

Pregnant women colonized by Streptococcus agalactiae, or group B streptococcus (GBS), are at an increased risk of premature delivery and stillbirth, and their neonates can be endangered by the development of an invasive GBS disease. In this study, the results of the GBS screening among pregnant women performed between 2012 and 2018 (n = 19267) are presented. For the GBS positive samples, the antibiotic susceptibility of the isolated strains was also tested (n = 3554). During the examined period, the colonization rate varied between 17.4% and 19.8%. The overall rate of erythromycin and clindamycin resistance in the GBS positive samples was 34.9% and 34.6%, respectively. The frequency of the erythromycin and clindamycin resistant strains showed an increasing tendency. An analysis of the MALDI-TOF MS spectra of 260 GBS isolates revealed that 46.5% of them belonged to either the ST-1 or the ST-17 sequence types, indicating a high prevalence of these potentially invasive GBS strains in our region. More than half of the strains identified as ST-1 (52.1%) proved to be resistant to erythromycin and clindamycin.

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Proteomics Analysis of Bone Marrow Cells of Acute Myeloid Leukemia (M2a) and Its Prognosis Significance.

Blood ◽

10.1182/blood.v108.11.4297.4297 ◽

2006 ◽

Vol 108 (11) ◽

pp. 4297-4297

Author(s):

Fan Yi Meng ◽

Shuai Tian ◽

Jia-ming Tang

Keyword(s):

Bone Marrow ◽

Zinc Finger Protein ◽

Differentially Expressed ◽

Leukemic Cells ◽

Differentially Expressed Proteins ◽

Maldi Tof Ms ◽

Maldi Tof ◽

Group A ◽

Group B ◽

Tof Ms

Abstract Objective:The distinct proteins of leukemic cells were investigated by proteomics technology between AML-M2a patients before inductive treatments with evidently different duration of first continuous complete remission(CCR1) and AML-M2a patients at replase in order to find their relations with prognosis of AML-M2a. Methods:The bone marrow mononuclear cells(BMMNCs) from 17 cases of AML-M2a patients before inductive treatment were grouped with different duration of CCR1: group A with CCR1 duration exceeded 12 months(11 cases), group B within 6 months(6 cases), and group C was composed of 3 patients at replase among group B. The proteins of BMMNCs from all the patients were separated by two-dimensional electrophoresis, and the part of differentially-expressed proteins were identified by matrix assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF-MS). Results: 6 differentially-expressed proteins were identified between group A and B by MALDI-TOF-MS: tubulin-specific chaperone B, myeloperoxidase, <TT>Solution Structure Of The Ch Domain Of Human Transgelin-2,</TT> glutathione S-transferase, RING zinc finger protein, glyceraldehyde-3-phosphate dehydrogenase.3 differentially-expressed proteins were identified in group C: NAD(P)H dehydrogenase, hypothetical protein, HES1. Conclusion: The distinct proteins of leukemic cells of AML-M2a patients before inductive treatments were involved in prognosis, and the proteins of BMMNCs from patients at replase have changed.

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Evaluation of matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS) for the Identification of Group B Streptococcus

BMC Research Notes ◽

10.1186/s13104-019-4119-1 ◽

2019 ◽

Vol 12 (1) ◽

Cited By ~ 4

Author(s):

Ka-Ning To ◽

Emma Cornwell ◽

Roger Daniel ◽

Sweenie Goonesekera ◽

Elita Jauneikaite ◽

...

Keyword(s):

Mass Spectrometry ◽

Group B Streptococcus ◽

Time Of Flight ◽

Laser Desorption ◽

Maldi Tof Ms ◽

Flight Mass Spectrometry ◽

Group B ◽

Tof Ms ◽

Matrix Assisted Laser ◽

Matrix Assisted Laser Desorption

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Rapid Classification of Multilocus Sequence Subtype for Group B Streptococcus Based on MALDI-TOF Mass Spectrometry and Statistical Models

Frontiers in Cellular and Infection Microbiology ◽

10.3389/fcimb.2020.577031 ◽

2021 ◽

Vol 10 ◽

Author(s):

Lianfen Huang ◽

Kankan Gao ◽

Guanglian Chen ◽

Huamin Zhong ◽

Zixian Li ◽

...

Keyword(s):

Mass Spectrometry ◽

Statistical Models ◽

Cross Validation ◽

Diagnostic Efficiency ◽

K Nearest Neighbor ◽

Molecular Monitoring ◽

Maldi Tof Ms ◽

Maldi Tof ◽

Group B ◽

Tof Ms

Group B Streptococcus (GBS) is an important etiological agent of maternal and neonatal infections as well as postpartum women and individuals with impaired immunity. We developed and evaluated a rapid classification method for sequence types (STs) of GBS based on statistic models with Matrix-Assisted Laser Desorption/Ionization Time-of Flight Mass Spectrometry (MALDI-TOF/MS). Whole-cell lysates MALDI-TOF/MS analysis was performed on 235 well-characterized GBS isolates from neonatal invasive infections in a multi-center study in China between 2015 and 2017. Mass spectra belonging to major STs (ST10, ST12, ST17, ST19, ST23) were selected for model generation and validation. Recognition and cross validation values were calculated by Genetic Algorithm-K Nearest Neighbor (GA-KNN), Supervised Neural Network (SNN), QuickClassifier (QC) to select models with the best performance for validation of diagnostic efficiency. Informative peaks were further screened through peak statistical analysis, ST subtyping MSP peak data and mass spectrum visualization. For major STs, the ML models generated by GA-KNN algorithms attained highest cross validation values in comparison to SNN and QC algorithms. GA-KNN models of ST10, ST17, and ST12/ST19 had good diagnostic efficiency, with high sensitivity (95–100%), specificity (91.46%–99.23%), accuracy (92.79–99.29%), positive prediction value (PPV, 80%–92.68%), negative prediction value (NPV, 94.32%–99.23%). Peak markers were firstly identified for ST10 (m/z 6250, 3125, 6891) and ST17 strains (m/z 2956, 5912, 7735, 5218). Statistical models for rapid GBS ST subtyping using MALDI-TOF/MS spectrometry contributes to easier epidemical molecular monitoring of GBS infection diseases.

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