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One aim of the United Nations Children's Fund Sustainable Development Goals is to end preventable deaths among newborns and children In 2015, China had 12.4% (17.8 million) of the 143 [...]

Maternal vaginal/rectal colonization of group B streptococcus (GBS) is a main risk for neonatal invasive infection. Efficient determination of GBS colonization in pregnant women is crucial. This study aimed to investigate the prevalence of GBS carriage and evaluate the diagnostic performance of six methodologies for GBS screening conducted in China, including blood agar plate, liquid chromogenic medium, and loop-mediated isothermal amplification (LAMP) without pre-enrichment, chromogenic agar plate with pre-enrichment, and GBS antigen detection without and with pre-enrichment in comparison with the standard reference method (Lim broth-enriched subculture with plating on 5% sheep blood agar). Vaginal/rectal swabs were collected from 1,281 pregnant women at 35–37 weeks of gestation. Of them, 309 were taken in triplicate, one for Lim broth-enriched subculture, one for blood agar plate, and the third for GBS antigen detection (Reagent W); 177 were acquired in duplicate, one for Lim broth-enriched subculture and the other for GBS antigen detection (Reagent H); 502 were obtained in duplicate, one for Lim broth-enriched subculture and the other for liquid chromogenic medium; 158 were collected in duplicate, one for Lim broth-enriched subculture and the other for LAMP; and 135 were inoculated in Lim broth-enriched for GBS antigen detection (Reagent W) and subculture with chromogenic agar plate and 5% blood agar plate. The overall prevalence of GBS carriage was 10.1% (130/1,281, 95% CI: 8.5–12.1%) according to the standard reference method. Compared with the standard reference method, the LAMP had excellent performance of sensitivity (100%, 95%CI: 83.4–100%), specificity (94%, 95%CI: 88.1–97.1%), and Yoden index (0.940); as well as the blood agar plate with sensitivity (81.5%, 95%CI: 61.3–93.0%), specificity (100%, 95%CI: 98.3–100.0%), and Yoden index (0.815). The other four methods were not sufficient to reach the threshold in terms of sensitivity or specificity compared to the standard reference method. Furthermore, for LAMP, results can be obtained within 0.5–1 h, while for blood agar plate, which needed 24–48 h, and further identification was required. Our data suggested that the performance of LAMP was highly comparable to the standard Lim broth-enriched subculture and LAMP is considered as an alternative for fast and accurate GBS screening. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the performance of Matrix-Assisted Laser Desorption/Ionization Time-of Flight Mass Spectra (MALDI-TOF MS) for automated classification of GBS (Group B Streptococcus ) into five major CCs (clonal complexes) during routine GBS identification., Methods: MALDI-TOF MS of 167 GBS strains belonging to five major CCs (CC10, CC12, CC17, CC19, CC23) were grouped into a reference set ( n = 67) and a validation set ( n = 100) for the creation and evaluation with GBS CCs subtyping main spectrum (MSP) and MSP-M using MALDI BioTyper and ClinProTools. GBS CCs subtyping MSPs-M was generated by resetting the discriminative peaks of GBS CCs subtyping MSP according to the informative peaks from the optimal classification model of five major CCs and the contribution of each peak to the model created by ClinProTools., Results: The PPV for the GBS CCs subtyping MSP-M was greater than the subtyping MSP for CC10 (99.21% vs. 93.65%), but similar for CC12 (79.55% vs. 81.06%), CC17 (93.55% vs. 94.09%), and CC19 (92.59% vs. 95.37%), and lower for CC23 (66.67% vs. 83.33%)., Conclusion: MALDI-TOF MS could be a promising tool for the automated categorization of GBS into 5 CCs by both CCs subtyping MSP and MSP-M, GBS CCs subtyping MSP-M is preferred for the accurate prediction of CCs with highly discriminative peaks., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Huang, Gao, Zhong, Xie, Liang, Ji and Liu.)

Objective: To determine the immune repertoires of peripheral CD4+T cell receptor (TCR) Vb CDR3 in primary biliary cirrhosis (PBC) and analyze TCR diversity and preferred usage at sequence-level resolution., Methods: ARM-PCR and high-throughput sequencing were used to obtain millions of TCR Vb CDR3 sequences from peripheral CD4+T cells isolated from 7 patients with PBC and healthy volunteers. All sequencing data were analyzed, together with corresponding clinical information, by bioinformatic software. The Mann-Whitney U test was used for statistical analysis., Results: The PBC patients showed a lower level of diversity among the peripheral CD4+TCR Vb CDR3 than the healthy volunteers, and patients with higher level progression of the disease showed a greater lack of diversity. In addition, 4 specific preferred-usage amino acid sequences were discovered for the PBC patients: ASSFTGGPVEQY, ASSLISSGNNEQF, ATSRDTLAGGPGDTQY, and SASLEGNTEAF; these sequences were also found in higher frequencies in patients with later stages of PBC., Conclusions: Decreased TCR Vb CDR3 diversities and specific preferred usage of TCR CDR3 sequences in peripheral CD4+T lymphocytes in PBC suggest that clonal expansion of a large number of CD4+T cells may be an important factor for PBC progression. These data provide a better understanding about the general characteristics of CD4+T cells in PBC patients and related to pathogenesis of the disease, and may provide useful insights into potential targets for immunotherapy.