The enterotoxigenic Escherichia coli (ETEC) infection is a major factor restricting the development of animal husbandry. However, the abuse of antibiotics will lead to the antibiotic residues and emergence of antibiotic-resistant bacteria. The existing vaccines face challenges in stimulating intestinal immunity, demonstrating limited prevention effects. Therefore, it is indispensable to develop a new vaccine that is safe and suitable as a feed additive to activate intestinal immunity. This study constructed yeast-cell microcapsules (YCM) carrying the DNA vaccine against ETEC by genetic engineering. Furthermore, animal experiments were carried out to explore the regulatory effects of feeding YCM on the intestinal immune system and intestinal microbiota. Saccharomyces cerevisiae was selected as the oral delivery vehicle (microcapsules) of the DNA vaccine. The codon-optimized nucleic acid sequence of K88, the main antigen of mammal-derived ETEC, was synthesized, and the yeast shuttle vector containing the corresponding DNA vaccine expression cassette was constructed by DNA recombination. The recombinant strain of YCM was prepared by transforming JMY1. Additionally, the characteristics of the YCM strain and its feasibility as an oral vaccine were comprehensively evaluated by the fluorescence reporter assay, gastrointestinal fluid tolerance assay, intestinal epithelial cell adhesion assay, intestinal retention assessment, antiserum detection, and intestinal microbiota detection. The experimental results showed that the DNA vaccine expression cassette was expressed in mammals, and the recombinant strain of YCM could tolerate up to 8 hours of gastrointestinal fluid digestion and had good adhesion to intestinal epithelial cells. The results of mouse feeding experiments indicated that the recombinant strain of YCM could stay in the intestinal tract for at least two weeks, and the DNA vaccine expression cassette carried by YCM entered the intestinal immune system and triggered an immune response to induce the production of specific antibodies. Moreover, feeding YCM recombinant bacteria also improved the abundance of gut microbiota in mice, demonstrating a positive effect in regulating intestinal flora. In summary, we prepared the recombinant strain of YCM carrying the DNA vaccine against ETEC and comprehensively evaluated its characteristics and feasibility as an oral vaccine. Feeding the recombinant YCM could induce specific immune responses and regulate intestinal microbiota. The findings provide a reference for the immunoprevention of ETEC-related animal diseases.
Animals ; Enterotoxigenic Escherichia coli/genetics* ; Saccharomyces cerevisiae/metabolism* ; Vaccines, DNA/genetics* ; Mice ; Escherichia coli Infections/immunology* ; Escherichia coli Vaccines/genetics* ; Capsules ; Mice, Inbred BALB C ; Female

Objective: To understand the trends and associated factors of tuberculosis knowledge and behavior among freshmen from Jiangsu Province, 2019 to 2022, so as to provide theoretical support for the popularization of tuberculosis knowledge and the prevention and control of tuberculosis in universities. Methods: From 2019 to 2022, a total of 33 944 freshmen from 20 universities in Jiangsu Province were selected by stratified random sampling, and tuberculosis knowledge and behavior were surveyed online using a selfdesigned questionnaire. Oneway variance trend test and multiple linear regression analysis were used to analyze the trend of knowledge and behavior levels, and a multiple linear regression model was used to analyze the influencing factors. Results: The overall awareness rate of tuberculosis among freshmen from Jiangsu Province was 90.6%, and the overall awareness rates from 2019 to 2022 were 88.4%, 90.4%, 91.7%, and 91.8%, respectively. The overall behavioral accuracy rate was 92.3%, with the annual rates from 2019 to 2022 being 91.8%, 92.3%, 92.7%, and 92.4%, respectively. Both the awareness rate and accuracy behavior rate increased annually (F=216.67, 11.75, P<0.01). The multiple linear regression analysis showed that school type, ethnicity, fathers educational level, mothers educational level, mothers occupation, family per capita monthly income, and living arrangement in high school affected both personal knowledge awareness rate and personal behavioral accuracy rate (β=-0.047-0.035, P<0.01), while region, gender, family residence, and being an only child only affected behavioral accuracy rate (β=-0.003-0.032, P<0.05). Conclusions The tuberculosis knowledge and behavior levels of freshmen from Jiangsu Province have been increasing by year. Targeted health education should be carried out based on the relevant influencing factors to further enhance the tuberculosis prevention and control literacy.

Background: Here we investigated whether cold chain workers’ insomnia, work-related stress, and viral anxiety contributed to their depression. Furthermore, we investigated the role of viral anxiety in mediating the association between work-related stress and depressive symptoms. Methods: All 200 invited cold chain workers voluntarily responded to an online survey. All were working at a market in Taiyuan, Shanxi Province, China, and responsible for testing nucleic acids in imported cold chain foods and disinfecting outer packaging at government request. We collected their demographic variables and rated their symptoms using the Stress and Anxiety to Viral Epidemics-6 Items (SAVE-6), Patient Health Questionnaire-9, Insomnia Severity Index (ISI), Perceived Stress Scale (PSS), and Maslach Burnout Inventory - General Survey (MBI-GS). Results: Cold chain workers’ depression was significantly correlated with higher SAVE-6 (r = 0.450, P < 0.01), ISI (r = 0.603, P < 0.01), MBI-GS (r = 0.481, P < 0.01), and PSS (r = 0.390, P < 0.01) scores. SAVE-6 score was significantly correlated with ISI (r = 0.462, P < 0.01), MBI-GS (r = 0.305, P < 0.01), and PSS (r = 0.268, P < 0.01) scores. Linear regression revealed that their depression was predicted by SAVE-6 (β = 0.183, P = 0.003), ISI (β = 0.409, P < 0.001), and MBI-GS (β = 0.236, P = 0.002, adjusted R2 = 0.440, F = 40.04, P < 0.001) scores. Mediation analysis showed that their burnout directly influenced their depression, while viral anxiety or insomnia severity mediated the influence of burnout on depression. Conclusion The study showed that burnout was a direct cause of depression and that viral anxiety and insomnia severity mediated the relationship between burnout and depression.

Production of chiral amines and unnatural amino-acid using ω-transaminase can be achieved by kinetic resolution and asymmetric synthesis, thus ω-transaminase is of great importance in the synthesis of pharmaceutical intermediates. By genomic data mining, a putative ω-transaminase gene hbp was found in Burkholderia phytofirmans PsJN. The gene was cloned and over-expressed in Escherichia coli BL21 (DE3). The recombinant enzyme (HBP) was purified by Ni-NTA column and its catalytic properties and substrate profile were studied. HBP showed high relative activity (33.80 U/mg) and enantioselectivity toward β-phenylalanine (β-Phe). The optimal reaction temperature and pH were 40 ℃ and 8.0-8.5, respectively. We also established a simpler and more effective method to detect the deamination reaction of β-Phe by UV absorption method using microplate reader, and demonstrated the thermodynamic property of this reaction. The substrate profiling showed that HBP was specific to β-Phe and its derivatives as the amino donor. HBP catalyzed the resolution of rac-β-Phe and its derivatives, the products (R)-amino acids were obtained with about 50% conversions and 99% ee.
Bacterial Proteins ; biosynthesis ; genetics ; Burkholderia ; enzymology ; Cloning, Molecular ; Escherichia coli ; genetics ; metabolism ; Transaminases ; biosynthesis ; genetics

Objective:To explore the differences and similarities of the neuropsychological functioning defi-cits in children between Tourette syndrome (TS)and attention-deficit/hyperactivity disorder (ADHD). Methods:Thirty boys with TS-only,36 with TS-plus-ADHD,36 with ADHD were selected from out-patient department,and 50 normal boys (NC)matched with gender,age and IQ were recruited as the controls. Patients'diagnosis was made according to the International Statistical Classification of Diseases and Related Health Problems,Tenth Revision (ICD-10). They were assessed with the Stroop Color-Word Interference Test (Stroop)and Purdue Pegboard Test (Purdue)to evaluate the response inhibition and fine-motor coordination respectively. Results:The Stroop scores were higher in children with ADHD than in other groups (P<0. 05 ),there was no difference between children with TS-only and TS-plus-ADHD (P>0. 05 ). All Purdue scores were higher in children with disease than in normal children (P<0. 05 ). Conclusion:The results indicate that the response inhibition deficit may be found in children with ADHD,but not in those with TS-only and TS-plus-ADHD. The neural compensatory mechanism may be re-sponsible for the response inhibition function in children with TS whilst the fine-motor coordination deficit was as-sociated with the disease groups.