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Biomedical subjects

Sheng Chen

Publications and source records attributed to Sheng Chen.

6 recordsLinked to original sources

"One Health"-based epidemiological investigation reveals the emergence of carbapenem-resistant Morganella spp. across diverse ecological niches.

OBJECTIVES: To investigate the prevalence, genomic relatedness, and resistance characteristics of carbapenemase-gene-positive Morganella spp. (CRM) across human, animal, fly, and aquatic sources. METHODS: A total of 163 Morganella isolates were collected from humans (n=124), animals (n=5), flies (n=21), aquatic environment (n=13) across 13 provinces or municipalities during 2018-2024. A subset of 71 representative isolates was subjected to antimicrobial susceptibility testing (AST), whole-genome sequencing and conjugation experiments. RESULTS: Among 163 isolates, 18 were carbapenemase-gene-positive: 15 carried blaNDM-1 alone, two carried blaKPC-2 alone, and one carried both genes. They were recovered from humans, flies, and hospital sewage. Five isolates carried blaPER-4; four carbapenemase-negative carriers were resistant to both ceftazidime/avibactam and aztreonam/avibactam. The aac(3)-IV gene was associated with high apramycin MICs and was most frequent in animal- and fly-derived isolates. Phylogenetic analysis showed diverse lineages, with limited low-SNP links between human and urban-river isolates. blaNDM-1 was transferred successfully from 11 of 16 donor isolates. CONCLUSION: CRM occur across multiple One Health niches. The findings highlight environmental and non-human reservoirs as potential contributors to their dissemination and identify blaPER-4 and aac(3)-IV as resistance-associated genes requiring further study.

Animal

Desmodium styracifolium Total Flavone Capsules for Urolithiasis: A Phase 3 Randomized Clinical Trial.

IMPORTANCE: No oral medication is currently approved for the management of urolithiasis. Guang Jing Qian Cao (Desmodium styracifolium total flavone capsules; hereinafter, Guang Jing), a traditional Chinese herbal extract, has shown clinical benefits for urolithiasis, but randomized clinical trials are needed to assess its effectiveness. OBJECTIVE: To evaluate whether Guang Jing improves stone passage rates (SPRs) compared with placebo in adults with urolithiasis. DESIGN, SETTING, AND PARTICIPANTS: This double-blind, placebo-controlled, phase 3 randomized clinical trial was conducted at 34 sites in China from December 2017 to April 2020. Participants included adults (aged 18-70 years) with diagnosed ureteral stones. Data analysis was conducted on November 4, 2020. INTERVENTION: Participants were randomized 3:1 to receive oral Guang Jing (0.6 g) or matching placebo 3 times daily for 28 days, in addition to investigator-prescribed background medication. MAIN OUTCOMES AND MEASURES: The primary outcome was SPR by day 28, confirmed by computed tomography. Secondary outcomes included SPR by day 14, stone migration rate, and stone migration distance. Between-group comparisons were performed using the Cochran-Mantel-Haenszel test for categorical outcomes and t tests for continuous outcomes. RESULTS: A total of 606 participants were randomly assigned to receive Guang Jing (n = 458) or placebo (n = 148). Their mean (SD) age was 43.0 (12.0) years, 474 (78.2%) were male, and the mean (SD) stone size was 0.6 (0.1) cm. The SPR by day 28 was significantly higher for the Guang Jing group compared with the placebo group (204 of 457 [44.6%] vs 50 of 148 [33.8%]; relative risk, 1.32 [95% CI, 1.03-1.69]; P = .03), with an absolute risk difference of 10.9 (95% CI, 2.0-19.7) percentage points. No significant between-group differences in SPR by day 14 (Guang Jing vs placebo: 133 [29.1%] vs 33 [22.3%]; P = .14) or stone migration distance (mean [SD], 29.5 [51.8] mm vs 29.7 [43.8] mm; P = .11) were observed. Adverse event rates were similar for the Guang Jing and placebo groups (88 [19.3%] vs 27 [18.2%]). CONCLUSIONS AND RELEVANCE: In this randomized clinical trial, treatment with Guang Jing significantly increased the expulsion of 5- to 10-mm ureteral stones by day 28, with a favorable safety profile. These findings suggest that Guang Jing may be an additional medical expulsive therapy option for appropriately selected patients. TRIAL REGISTRATION: Chinese Clinical Trial Registry Identifier: ChiCTR-IIR-17013275.

Humans

Genome-wide cyclin gene evolution in Arabidopsis and Brassica reveals polyploidization-driven duplication and flowering-time associations.

Cyclin genes are plant cell cycle regulators that play essential roles in growth, development, and reproduction. However, the evolutionary dynamics and genomic organization of cyclin genes across the Brassicaceae family remain poorly understood, particularly in the context of allotetraploid genome evolution. Here, we investigated the diversity, expansion mechanisms, and potential functional diversification of cyclin genes across ten Brassicaceae genomes, including four Arabidopsis and six Brassica species. A total of 1087 cyclin genes representing 23 cyclin types were identified. Comparative genomic analyses revealed that cyclin gene expansion was strongly influenced by polyploidization in Brassica species, with 1845 duplication events involving 1063 genes. Whole-genome duplication was the predominant mechanism driving expansion, while both inter- and intra-genomic duplications contributed to gene retention in tetraploid Brassica species, with the highest duplication frequency observed in Brassica juncea. Across genomes, 120 physical gene clusters were identified, including homogeneous and heterogeneous types. Ortholog analysis between progenitor and allotetraploid species identified 852 orthologous pairs involving 366 genes, indicating extensive conservation following allotetraploid formation. Phylogenetic analysis resolved cyclins into three major clades, while expression-based clustering in Brassica napus grouped genes into four major clusters, suggesting functional diversification. Integration of pan-genomic and flowering-time QTL analyses further identified two cyclin genes, Bna21cycA2 and Bna113cycD4, which contain amino acid polymorphisms and represent putative candidate variations potentially associated with flowering-time variation across multiple genomes. These findings provide new insights into the evolutionary expansion, retention, and potential functional divergence of cyclin genes in Brassicaceae and highlight candidate loci for future functional studies and crop improvement.

Evolution, Molecular

Non-invasive strategy for gastric cancer detection: Integration of cell-free DNA fragmentomics and protein biomarkers.

Gastric cancer (GC) ranks as the fifth most common cancer worldwide, however, accurate and non-invasive diagnostic modalities for GC remain limited. Cell-free DNA (cfDNA) fragmentomics has emerged as a promising tool for cancer cell detection. Here we develop a gastric cancer detection model, named GaFraD model. The GaFraD model uses four cfDNA fragmentomics features, including fragment size ratio (FSR), copy number variation (CNV), 9-bp end motif (Motif), and fragment size at transcription start sites (TF). This model achieves an area under the receiver-operating characteristic curve (AUC) of 0.970 (95% CI: 0.944 - 0.990), a sensitivity of 95.0% and a specificity of 80.9%. By combining the GaFraD model and conventional protein biomarkers CA19-9 and PG-I/PG-II, the CONFIRM model was generated. The CONFIRM model attained an AUC of 0.986 (95% CI: 0.966 - 1.000), a sensitivity of 95.0% and a specificity of 95.6% in detecting GC. Moreover, the CONFIRM model achieved remarkable performance (AUC = 0.983, sensitivity 95.6%, specificity 94.2%) in distinguishing patients with early-stage GC from controls. Our work showed the high discriminatory power in distinguishing GC patients from controls, indicating the clinical potential of using cfDNA fragmentomics combined with protein biomarkers for non-invasive GC detection. The results of the study provide a new avenue for early, accurate, and non-invasive clinical diagnosis of GC.

Cell-free DNA

Genetic mutations within tva receptor gene confer resistance to ALV-A and ALV-K infection in chickens.

Avian leukosis virus subgroup A (ALV-A) and the newly emerging subgroup K (ALV-K) are primary causative pathogens of avian leukosis in chickens and continue to pose a persistent threat to poultry industry worldwide. Susceptibility or resistance of chicken cells to ALV-A and ALV-K is determined by the tva receptor gene. Indeed, six ALV-A resistant alleles (tvar1-tvar6) have been identified within the tva gene. However, whether these tva alleles confer resistance to ALV-K infection remains unclear. In this study, we identified five tva resistant alleles, namely tvar2, tvar3, tvar4, tvar5, and tvar6, in Qingyuan partridge chickens (QYPC). In vitro analyses, including flow cytometry and quantitative real-time PCR, we demonstrated that the tvar2 allele confers complete resistance to both ALV-A and ALV-K infection. In contrast, the tvar3, tvar4, tvar5, and tvar6 alleles each significantly reduced susceptibility to ALV-K. Furthermore, these in vitro observations were corroborated by in vivo infection experiments, which confirmed that the tvar2 allele consistently conferred complete resistance to both ALV-A and ALV-K, while tvar3, tvar4, tvar5, and tvar6 alleles each resulted in a significant reduction in ALV-K susceptibility. Additionally, the tvar2-tvar6 alleles were broadly distributed across QYPC lines, with notably high frequencies of resistant genotypes observed in specific QYPC populations. Collectively, these findings not only expand our understanding of tva-mediated resistance to both ALV-A and ALV-K but also provide valuable genetic targets for selective breeding programs aimed at enhancing resistance to ALV-A and ALV-K in chickens.

ALV-A

Molecular surveillance of foodborne bacterial pathogens and resistome in food products from Hong Kong.

Foodborne infections pose an increasing public health challenge worldwide. The problem has been aggravated by the dissemination of antimicrobial resistance genes among zoonotic pathogens, which results in a sharp increase in antibiotic resistance rate recorded among the major foodborne pathogens. To obtain an overview of the extent to which food products purchased in the markets in Hong Kong were contaminated by foodborne pathogens, we collected 95 raw meat samples from wet markets and isolated 236 bacterial strains of various species, with Escherichia coli being the most dominant species (131 strains). Contamination of food products by multiple foodborne pathogens was commonly observed. These include both Gram-positive and Gram-negative bacteria that exhibit various levels of resistance, with some possessing multiple clinically important antibiotic resistance genes. Seventeen bacterial strains of various species isolated from three food samples were comprehensively analysed by the Oxford Nanopore R10.4 technology. Novel conjugative plasmids carrying antimicrobial resistance gene-bearing mobile genetic elements were commonly detectable in the test strains. Some of the plasmids were shown to have originated from other environmental sources or other bacterial species, indicating that raw foods in the local market may serve as a reservoir of resistance-encoding genetic elements from which such elements are disseminated to various microbial pathogens. These findings suggest a need to perform periodic but comprehensive surveillance of multidrug-resistant bacterial pathogens and the major antimicrobial resistance genes in common food products, so as to disrupt the transmission routes of such organisms and the resistance-encoding genetic elements that they harbour.

Hong Kong