Beibei Wu

This study aimed to characterize the population structure, predicted antimicrobial resistance gene profiles, and virulence gene repertoire of Group B Streptococcus (GBS) in Zhejiang Province, China, using whole-genome sequencing (WGS). Forty GBS isolates from clinical specimens underwent WGS, multilocus sequence typing (MLST), cgMLST-based phylogenetic analysis, and systematic in silico annotation of predicted antimicrobial resistance and virulence genes. Seven capsular serotypes were identified, with serotype V being predominant. Fifteen sequence types (STs) were detected, including two novel STs (ST2662 and ST2663). Thirteen STs were grouped into eight clonal complexes (CCs), while two STs remained unassigned to any CC. CC19 (11/40, 27.5%) and CC327 (10/40, 25.0%) were the predominant CCs, with CC327 comprising the distinctive ST529-CC327-V clone. Eighteen predicted antimicrobial resistance genes were identified, including genes predicted to confer resistance to macrolide (ermB 60.0%, mefA 37.5%), tetracycline (tetM 47.5%, tetO 42.5%), aminoglycoside (aph(3′)-IIIa 25.0%), and lincosamide (lsaE 30.0%, lnuB 30.0%). All isolates carried multiple predicted virulence genes, with universal carriage of adhesion genes fbsA and fbsB, and the invasion genes cylE, hylB, and cfb. These findings reveal a genetically diverse GBS population with distinctive clonal architecture and high carriage of predicted antimicrobial resistance genes in Zhejiang Province, underscoring the need for continued genomic surveillance to inform region-specific antibiotic stewardship and vaccine development.

Antimicrobial resistance (AMR) is a complex One Health problem involving people, non-human species, and the environment. This review examines the distribution and transmission of multidrug-resistant (MDR) bacteria and antibiotic resistance genes (ARGs) across these domains. One Health has broken the long-standing isolation of MDR research by establishing a unified cross-disciplinary analytical framework, supporting interdisciplinary MDR studies, and systematically mapping the complete transmission chains and pathways of MDR determinants (including drug-resistant pathogens and resistance genes) at the human–animal–environment interface. This holistic perspective has become an indispensable guiding principle for addressing complex global health challenges.

The management of Mycobacterium abscessus infections is critically hindered by its inherent multidrug resistance and the lack of effective therapies, necessitating advanced preclinical models for drug discovery. Here, we developed a sequential screening platform, progressing from conventional assays to a physiologically relevant human tissue model, using azithromycin as a proof-of-concept agent. In vitro, azithromycin exhibited concentration-dependent activity (MIC = 2 µg/mL). This efficacy was corroborated in a THP-1 macrophage infection model. To enhance physiological relevance, we established a robust infection system in standardized, iPSC-derived human alveolar organoids via microinjection. In this complex 3D environment, azithromycin treatment (10× MIC) significantly suppressed intracellular bacterial proliferation over 48 h, as validated by fluorescence microscopy and CFU enumeration, and modulated the host inflammatory response. Our integrated platform successfully demonstrates a tiered strategy for evaluating anti-mycobacterial agents, bridging the gap between simple in vitro assays and human tissue-like contexts. It provides a validated foundation for mechanistic studies and the accelerated identification of novel therapeutics against this formidable pathogen.

Background/Objectives: Tuberculosis, caused by Mycobacterium tuberculosis, remains a major global health challenge requiring novel prevention strategies. This study aims to developed an immunoinformatics-guided framework coupled with experimental screening to prioritize for multi-epitope mRNA vaccine design. Methods: Eight immunologically relevant antigens were computationally analyzed to predict cytotoxic (CTL) epitopes and helper T lymphocyte (HTL) epitopes. Population coverage, immune simulation, molecular docking, and normal mode analysis (NMA) were performed in silico. To evaluate peptide immunoreactivity, human IFN-γELISPOT assays were conducted using the candidate peptides, though HLA restriction was not experimentally validated. Results: The workflow identified 14 candidate CTL and 8 HTL epitopes, yielding an estimated global population coverage of 82.6% (60.7% in China; 51.2% in Indonesia). Immune simulations predicted robust humoral and Th1-associated cellular responses, though sustained CD8⁺ memory responses appeared limited. Docking and NMA suggested favorable structural interactions with TLR3 and TLR4. Crucially, the IFN-γ ELISPOT assay validated eight reactive epitopes that partially coincided with computational predictions within the tested donor group. Conclusions: This study establishes an integrated computational–experimental workflow for T cell epitope prioritization. The identified reactive epitopes provide a preliminary immunological basis and candidate pool for the future design and evaluation of multi-epitope mRNA vaccine strategies against tuberculosis.

Introduction: Brucella abortus poses a serious zoonotic threat in China, however its genomic epidemiology in Zhejiang Province remains largely uncharacterized. This study addresses this knowledge gap by conducting the first integrated genomic analysis of seven B. abortus isolates obtained from patients and cows in the region. Methods: The phenotypic, genotypic, and phylogenomic characters of the isolates were illustrated by BCSP-31 and AMOS-PCR, MLST, ANI, cgSNP, and Pan-Genome analysis. Results: All seven isolates were identified as B. abortus via AMOS-PCR and belonged to a single sequence type (ST2) based on MLST, a classification further corroborated by an average nucleotide identity (ANI) of 99.99% to the reference strain B. abortus 544. Pan-genome analysis disclosed a highly conserved genome comprising 3,084 core genes and a minimal accessory genome of only 10 shell genes, alongside the prediction of 68 virulence-associated factors and one AMR gene, mprF . Core genome SNP phylogeny indicated that the Zhejiang strains form a monophyletic cluster with Russian references and trifurcate into three distinct subclades. Each subclade demonstrates specific phylogenetic connections to strains from separate northern Chinese provinces. Discussion: As the first study to integrate phenotypic, genotypic, and phylogenomic data for B. abortus in this region, our work substantially expands the understanding of its local population structure and provides a critical evidence base for proactive genomic surveillance, thereby informing targeted public health interventions against brucellosis.

Introduction: The direct zoonotic risks associated with the growing online trade of live pets remain in adequately understood. Methods: We investigate a human case of severe psittacotic pneumonia in Zhejiang Province, China, in which the patient’s only avian exposure was through parrots recently purchased online. Using targeted probe-capture sequencing—a method designed for uncultivable, low-biomass pathogens—we recovered 13 high-quality Chlamydia psittaci genomes directly from the patient, the asymptomatic parrots, and their shared home environment. Results: Comparative genomic analysis revealed >99.99% average nucleotide identity across all samples, providing definitive evidence of parrot-to-human transmission. The causative strain was identified as a novel sequence type (ST388) within the known virulent genotype A. Conclusion: This investigation provides the first whole-genome confirmation of psittacosis transmission via online pet commerce. It establishes a practical genomic framework for investigating similar sporadic zoonoses and underscores the urgent need for targeted surveillance of this emerging and risk communication in this growing digital marketplace.

The continuous evolution of SARS-CoV-2 and its variants poses persistent challenges to global public health. As a sublineage of the XDV.1 variant, NB.1.8.1 has rapidly emerged as a dominant strain worldwide, triggering a new wave of infections. Representing a product of viral adaptation, this variant has acquired several critical amino acid mutations—including A435S and T478I—which enhance its transmissibility and immune evasion capabilities compared to the ancestral XDV.1 lineage. This review systematically summarizes the genomic characteristics, epidemiological features, and immune escape potential of NB.1.8.1. It emphasizes that sustained genomic surveillance and serological assessments are crucial for informing public health response strategies, guiding vaccine development, and optimizing containment measures.

The continuous evolution of SARS-CoV-2 and its variants poses persistent challenges to global public health. As a sublineage of the XDV.1 variant, NB.1.8.1 has rapidly emerged as a dominant strain worldwide, triggering a new wave of infections. Representing a product of viral adaptation, this variant has acquired several critical amino acid mutations—including A435S and T478I—which enhance its transmissibility and immune evasion capabilities compared to the ancestral XDV.1 lineage. This review systematically summarizes the genomic characteristics, epidemiological features, and immune escape potential of NB.1.8.1. It emphasizes that sustained genomic surveillance and serological assessments are crucial for informing public health response strategies, guiding vaccine development, and optimizing containment measures.

A Streptococcus suis strain isolated from the blood of a patient in Zhejiang Province, China, was analysed using whole-genome sequencing and tested for antimicrobial resistance. The isolated strain was identified as S. suis serotype 2, and classified to ST25 on multilocus sequence typing (MLST). The minimum core genome group of the strain was identified as Group 4, and multilocus variable-number tandem-repeat analysis (MLVA) assigned it as type 2, 4.4, 0, 9, 3, 2, 0, 0. An antimicrobial resistance analysis showed that the strain was resistant to clindamycin, tetracycline, azithromycin, and erythromycin but sensitive to 11 other antibiotics. In a genomic evolution analysis, this isolate clustered on the same branch as North American pig isolate, Chinese pig isolates from Tianjin, and Hubei pig isolates.