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28
result(s) for
"Tian, Zhengan"
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Study on the mechanism of production of γ-PGA and nattokinase in Bacillus subtilis natto based on RNA-seq analysis
by
Li, Shenwei
,
Ma, Xia
,
Tian, Zhengan
in
Applied Microbiology
,
Bacillus subtilis
,
Bacillus subtilis natto
2021
Poly-γ-glutamic acid (γ-PGA) and nattokinase (NK) are the main substances produced by
Bacillus subtilis
natto in solid-state fermentation and have wide application prospects. We found that our strains had higher activity of nattokinase when soybeans were used as substrate to increase the yield of γ-PGA. Commercial production of γ-PGA and nattokinase requires an understanding of the mechanism of co-production. Here, we obtained the maximum γ-PGA yield (358.5 g/kg, w/w) and highest activity of NK during fermentation and analyzed the transcriptome of
Bacillus subtilis
natto during co-production of γ-PGA and NK. By comparing changes in expression of genes encoding key enzymes and the metabolic pathways associated with the products in genetic engineering, the mechanism of co-production of γ-PGA and nattokinase can be summarized based on RNA-seq analysis. This study firstly provides new insights into the mechanism of co-production of γ-PGA and nattokinase by
Bacillus subtilis
natto and reveals potential molecular targets to promote the co-production of γ-PGA and nattokinase.
Journal Article
Increased genetic variation of A(H3N2) virus from influenza surveillance at the end of the 2016/2017 season for Shanghai port, China
2022
Influenza A(H3N2) virus exhibited complex seasonal patterns to evade pre-existing antibodies, resulting in changes in the antigenicity of the viron surface protein hemagglutinin (HA). To monitor the currently imported influenza viruses as well as to assess the capacity of health emergencies at the Shanghai port, we collected respiratory specimens of passengers from different countries and regions including some of Europe with influenza-like illness at the Shanghai port during 2016/2017, examined amino acid substitutions, and calculated the perfect-match vaccine efficacy using the
p
epitope model. Phylogenetic analysis of the HA genes revealed that influenza A(H3N2) viruses belonging to eight subclades were detected, and three amino acid substitutions in the subclade 3C.2a.4 were also added. Besides, two epidemic influenza virus strains were found in the 2016/2017 winter and 2016 summer. The results of lower predicted vaccine effectiveness in summer suggest that the imported A(H3N2) strains were not a good match for the A/Hong Kong/4801/2014 vaccine strain since the summer of 2017. Therefore, the Shanghai Port might stop the risk of the international spread of influenza for the first time, and curb the entry of A(H3N2) from overseas at the earliest stage of a probable influenza pandemic.
Journal Article
Epidemiological and Genomic analysis of Vibrio parahaemolyticus isolated from imported travelers at the port of Shanghai, China (2017-2019)
2024
Background
Vibrio parahaemolyticus
is the predominant etiological agent of seafood-associated foodborne illnesses on a global scale. It is essential to elucidate the mechanisms by which this pathogen disseminates. Given the existing research predominantly concentrates on localized outbreaks, there is a pressing necessity for a comprehensive investigation to capture strains of
V. parahaemolyticus
cross borders.
Results
This study examined the frequency and genetic attributes of imported
V. parahaemolyticus
strains among travelers entering Shanghai Port, China, between 2017 and 2019.Through the collection of 21 strains from diverse countries and regions, Southeast Asia was pinpointed as a significant source for the emergence of
V. parahaemolyticus
. Phylogenetic analysis revealed clear delineation between strains originating from human and environmental sources, emphasizing that underlying genome data of foodborne pathogens is essential for environmental monitoring, food safety and early diagnosis of diseases. Furthermore, our study identified the presence of virulence genes (
tdh
and
tlh
) and approximately 120 antibiotic resistance-related genes in the majority of isolates, highlighting their crucial involvement in the pathogenesis of
V. parahaemolyticus
.
Conclusions
This research enhanced our comprehension of the worldwide transmission of
V. parahaemolyticus
and its antimicrobial resistance patterns. The findings have important implications for public health interventions and antimicrobial stewardship strategies, underscoring the necessity for epidemiological surveillance of pathogen at international travel hubs.
Journal Article
Epidemiological investigation of an acute gastroenteritis outbreak associated with norovirus GΙΙ.17P17 in a cross-border travel group - Shanghai Port, China, 2024
2026
Background
Norovirus is a leading cause of acute gastroenteritis and spreads efficiently in closed, mobile cohorts such as organized travel groups. This case is notable for the real-time detection and genomic confirmation of a cross-border outbreak at a port of entry, including near-identical Norovirus GΙΙ.17[P17] genomes and documented asymptomatic carriage, illustrating the practical value of integrated metagenomic surveillance in border health operations.
Case presentation
On July 21, 2024, 26 travelers arrived at Shanghai Port after a 12-day group tour in Europe. Clinical interviews identified 15 individuals (57.7%) with diarrhea, nausea, dizziness, and abdominal pain; no hospitalizations occurred. On-site anal swab testing was negative for SARS-CoV-2, influenza A and B, Vibrio cholerae, and Escherichia coli. RT-qPCR detected Norovirus GII in 10 samples (38.5%), including two asymptomatic individuals. Metagenomic sequencing generated near-complete genomes for all RT-qPCR–positive samples, which were 99.9–100% identical and classified as Norovirus GΙΙ.17[P17], confirming a cross-border outbreak within the travel cohort. Prompt public health response measures were initiated by Shanghai Customs and CDC authorities.
Conclusions
This case demonstrates the feasibility and impact of rapid, genomically informed surveillance at the border for detecting and characterizing travel-associated enteric virus outbreaks. The findings underscore the need for robust port-of-entry monitoring, rapid diagnostics, and integrated genomic analysis to mitigate transmission in group travel settings.
Journal Article
Complete genome sequence of GII.9 norovirus
2022
Norovirus is recognized as one of the leading causes of acute gastroenteritis outbreaks. Genotype GII.9 was first detected in Norfolk, VA, USA, in 1997. However, the complete genome sequence of this genotype has not yet been determined. In this study, a complete genome sequence of GII.9[P7] norovirus, SCD1878_GII.9[P7], from a patient was determined using high-throughput sequencing and rapid amplification of cDNA ends (RACE) technology. The complete genome sequence of SCD1878_GII.9[P7] is 7544 nucleotides (nt) in length with a 3’ poly(A) tail and contains three open reading frames. Sequence comparisons indicated that SCD1878_GII.9[P7] shares 92.1%-92.3% nucleotide sequence identity with GII.P7 (AB258331 and AB039777) and 96.7%-97.4% identity with GII.9 (AY038599 and DQ379715). The results suggested that SCD1878_GII.9[P7] is a member of P genotype GII.P7 and G genotype GII.9. This viral sequence fills a gap at the whole-genome level for the GII.9 genotype.
Journal Article
Transposase-Assisted RNA/DNA Hybrid Co-Tagmentation for Target Meta-Virome of Foodborne Viruses
2024
Foodborne diseases are major public health problems globally. Metagenomics has emerged as a widely used tool for pathogen screening. In this study, we conducted an updated Tn5 transposase-assisted RNA/DNA hybrid co-tagmentation (TRACE) library construction approach. To address the detection of prevalent known foodborne viruses and the discovery of unknown pathogens, we employed both specific primers and oligo-T primers during reverse transcription. The method was validated using clinical samples confirmed by RT-qPCR and compared with standard RNA-seq library construction methods. The mapping-based approach enabled the retrieval of nearly complete genomes (>95%) for the majority of virus genome segments (86 out of 88, 97.73%), with a mean coverage depth of 21,494.53× (ranging from 77.94× to 55,688.58×). Co-infection phenomena involving prevalent genotypes of Norovirus with Astrovirus and Human betaherpesvirus 6B were observed in two samples. The updated TRACE-seq exhibited superior performance in viral reads percentages compared to standard RNA-seq library preparation methods. This updated method has expanded its target pathogens beyond solely Norovirus to include other prevalent foodborne viruses. The feasibility and potential effectiveness of this approach were then evaluated as an alternative method for surveilling foodborne viruses, thus paving the way for further exploration into whole-genome sequencing of viruses.
Journal Article
Crosswalk traffic light detection for the visually impaired based on hybrid classical–quantum neural networks
2025
This paper proposes a novel two-step method combining classical and quantum computation to accurately detect crosswalk traffic lights for visually impaired pedestrians. The first step utilizes the improved YOLOv5 model to identify crosswalk traffic light locations. In the second step, the detected lights are processed using a single-layer quantum convolutional neural network with a newly designed parameterized quantum circuit. The proposed quantum circuit reduces the number of qubits and circuit depth required while maintaining high accuracy, making it suitable for noisy intermediate-scale quantum devices. Experimental results demonstrate that our method has better performance compared to existing methods, achieving detection accuracy of 94.9%, precision of 95.4%, and the AUC reaches 0.98. These results also demonstrate the model’s robustness in complex traffic environments.
Journal Article
Graphene plasmons-enhanced terahertz response assisted by metallic gratings
2022
Terahertz detectors based on two-dimensional Dirac materials offer a new approach for room-temperature terahertz detection with high response and low noise. However, these devices can hardly show high response over a broad frequency range, mainly due to the poor absorption caused by their ultrathin nature. Here we apply metallic gratings to enhance the excitation efficiency of graphene plasmons. When nonzero source-drain bias is applied, graphene plasmons can generate terahertz response orthogonal to the polarization of the incidence. The response is attributed to the orthogonal overdamped plasmon rectification effect, and graphene plasmons-enhanced photo-thermoelectric effect. By comparing the normalized on/off ratio, the metallic gratings are found to effectively enhance the coupling efficiency between graphene plasmons and THz incidence, and thus the absorption and responsivity. The results are beneficial for improving the response of room temperature THz detectors.
Journal Article
Research on safety and compliance of imported microbial inoculants using high-throughput sequencing
2022
Microbial inoculants are widely used in wastewater treatment, soil remediation, and biological control. Safety and compliance for active constituents are considered to be the most important measures of imported microbial inoculants. Microbial inoculants composition was commonly identified by phenotypic culture, which is time-consuming and labor intense with occasionally false negative results provided, and can only be tested for specific species. High-throughput sequencing (HTS), known for its non-targeted detection of unknown species composition in samples, is suitable for composition consistency identification and biosafety analysis of imported microbial inoculants. In this study, the application of HTS for microflora distribution and resistance gene was verified in microbial inoculants for environmental protection and then applicated in imported microbial inoculants. Both Illumina- and Nanopore-based HTS methods identified the same dominant bacterial species successfully in the imported microbial inoculants. The main component of bacterial species was Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis , and Enterococcus faecium , and further confirmed with traditional methods. The antibiotic resistance genes Bacillus subtilis mprF, bcrA, blt, lmrB, rphB, tet(L), tmrB, vmlR, ykkC, and ykkD were detected in all samples. Our results indicated that HTS processes the application potential to identify the active ingredients of microbial inoculants. Therefore, rapid and accurate identification of the microbial compositions in microbial formulation products is of high importance for port biosafety supervision.
Journal Article
Genetic Polymorphisms in CYP2E1: Association with Schizophrenia Susceptibility and Risperidone Response in the Chinese Han Population
2012
CYP2E1 is a member of the cytochrome P450 superfamily, which is involved in the metabolism and activation of both endobiotics and xenobiotics. The genetic polymorphisms of CYP2E1 gene (Chromosome 10q26.3, Accession Number NC_000010.10) are reported to be related to the development of several mental diseases and to be involved in the clinical efficacy of some psychiatric medications. We investigated the possible association of CYP2E1 polymorphisms with susceptibility to schizophrenia in the Chinese Han Population as well as the relationship with response to risperidone in schizophrenia patients.
In a case-control study, we identified 11 polymorphisms in the 5' flanking region of CYP2E1 in 228 schizophrenia patients and 384 healthy controls of Chinese Han origin. From among the cases, we chose 130 patients who had undergone 8 weeks of risperidone monotherapy to examine the relationship between their response to risperidone and CYP2E1 polymorphisms. Clinical efficacy was assessed using the Brief Psychiatric Rating Scale (BPRS).
Statistically significant differences in allele or genotype frequencies were found between cases and controls at rs8192766 (genotype p = 0.0048, permutation p = 0.0483) and rs2070673 (allele: p = 0.0018, permutation p = 0.0199, OR = 1.4528 95%CI = 1.1487-1.8374; genotype: p = 0.0020, permutation p = 0.0225). In addition, a GTCAC haplotype containing 5 SNPs (rs3813867, rs2031920, rs2031921, rs3813870 and rs2031922) was observed to be significantly associated with schizophrenia (p = 7.47E-12, permutation p<0.0001). However, no association was found between CYP2E1 polymorphisms/haplotypes and risperidone response.
Our results suggest that CYP2E1 may be a potential risk gene for schizophrenia in the Chinese Han population. However, polymorphisms of the CYP2E1 gene may not contribute significantly to individual differences in the therapeutic efficacy of risperidone. Further studies in larger groups are warranted to confirm our results.
Journal Article