The interaction of gut microbiota and its metabolites with the host not only plays an important role in maintaining gut homeostasis and host health, but also is a key link in responding to pathogen infections. A thorough understanding of the changes in gut microbiota and its metabolites during infection, as well as their role and mechanism in host defense against infection, is helpful to guide anti-infection treatment. This review focuses on the role of gut microbiota and their metabolites in host defense against bacterial, fungal, and viral infections, and reveals that they can exert anti-infection effects through resistance mechanisms (inducing antimicrobial substances, training immunity, inhibiting pathogen respiration, directly neutralizing pathogens, immune regulation) and tolerance mechanisms (altering energy metabolism patterns of microbiota, cell proliferation and tissue damage repair, maintaining physiological signal transduction in extraintestinal organs, inflammation regulation, maintaining the integrity of the intestinal barrier), and also summarizes measures to regulate gut microbiota against pathogen infections, in order to provide more ideas for novel anti-infection prevention and treatment strategies targeting gut microbiota and its metabolites.

Objective:To establish a rapid pipeline for whole genome sequencing of Chikungunya virus (CHIKV) by combining imbricated multiplex-PCR amplification and Illumina high-throughput sequencing platform.Methods:The primary reference sequences of CHIKV were downloaded from the National Center for Biotechnology Information (NCBI) database, covering all genotypes of CHIKV. After multiple alignments using the Mafft software and phylogenetic analysis, the 20 CHIKV references were selected for primer design. The Primal Scheme tool and Geneious Prime software were used to design, evaluate and optimize the primer panel. Finally, seven CHIKV-positive samples were involved in the validation of the primer panel.Results:All the amplicons of the designed panel were generated successfully. The consensuses generated from the mapping results could cover 100.00% of the coding region of the CHIKV genome when the Ct-value of the sample was less than 33, as the percentage would decrease to 99.38% when the Ct-value reached 35. The mapping percentage could be increased by 5.70%-25.43% when using the stepwise correction mapping strategy.Conclusion:The multiplex-PCR amplification method for CHIKV whole genome sequencing is relatively simple and convenient, which only requires two tubes of PCR amplification and performs well on CHIKV-positive clinical samples with different concentration levels of virus.

Objective:This study aimed to clarify the clinical characteristics of children infected with rhinovirus in the context of the Corona Virus Disease 2019 (COVID-19) pandemic and to explore the impact of recent COVID-19 infection history on their clinical features.Methods:Clinical data and laboratory test result of 286 children diagnosed with rhinovirus infection at Hangzhou Children′s Hospital from July 2022 to October 2023 were collected. A retrospective survey was conducted to determine whether all study participants had a history of COVID-19 infection within the 6 months prior to hospitalization.Results:Among the 286 children with rhinovirus infection, 180 (62.94%) had simple rhinovirus infection, while 106 (37.06%) had co-infections with other pathogens; Among the 180 rhinovirus simplex-positive children, 56.67% had wheezing symptoms; among them, 15 cases (15/180, 8.33%) were diagnosed with acute asthma attacks; 7 cases (7/180, 3.88%) were diagnosed with severe pneumonia. Based on whether the children had a history of COVID-19 infection in the 6 months prior to hospitalization, they were divided into a group with previous COVID-19 infection and a group without previous COVID-19 infection. There were no significant differences between the two groups in terms of gender, age of onset, peak fever, incidence of wheezing, incidence of pneumonia, proportion of severe pneumonia, proportion of severe asthma attacks, duration of fever, time to relief of wheezing, length of stay, white blood cell count, eosinophil count, C-reactive protein, procalcitonin, immunoglobulin E, oxygen therapy requirements, and use of intravenous steroids ( P>0.05). Conclusions:A history of COVID-19 infection in the past 6 months does not exacerbate the clinical symptoms of children with rhinovirus infection, nor does it increase the incidence of wheezing.

Objective:To establish a rapid pipeline for whole genome sequencing of Chikungunya virus (CHIKV) by combining imbricated multiplex-PCR amplification and Illumina high-throughput sequencing platform.Methods:The primary reference sequences of CHIKV were downloaded from the National Center for Biotechnology Information (NCBI) database, covering all genotypes of CHIKV. After multiple alignments using the Mafft software and phylogenetic analysis, the 20 CHIKV references were selected for primer design. The Primal Scheme tool and Geneious Prime software were used to design, evaluate and optimize the primer panel. Finally, seven CHIKV-positive samples were involved in the validation of the primer panel.Results:All the amplicons of the designed panel were generated successfully. The consensuses generated from the mapping results could cover 100.00% of the coding region of the CHIKV genome when the Ct-value of the sample was less than 33, as the percentage would decrease to 99.38% when the Ct-value reached 35. The mapping percentage could be increased by 5.70%-25.43% when using the stepwise correction mapping strategy.Conclusion:The multiplex-PCR amplification method for CHIKV whole genome sequencing is relatively simple and convenient, which only requires two tubes of PCR amplification and performs well on CHIKV-positive clinical samples with different concentration levels of virus.

Objective To investigate the changes in blood microbiota in patients with high altitude polycythemia(HAPC)and the correlation with the risk of HAPC.Methods A cross-sectional trial was carried out among 41 HAPC patients(HAPC group)and 41 healthy plateau individuals(control group)who took physical examination in the Health Management Department of No.953 Hospital of PLA Army in 2021.High-throughput sequencing technology was used to detect the V3-V4 variable region of the 16S ribosomal RNA(16S rRNA)gene in the blood smaples,and the composition and difference of the blood microbiota were compared and analyzed between the 2 groups.Results All the participants were male and Han people,and there were no significant differences in baseline data such as age,body mass index and plateau migration time between the 2 groups(P＞0.05).The α-diversity of blood microbiota in the HAPC group,including the Simpson index(0.931±0.005 vs 0.907±0.008,P＜0.05),Goods Coverage index(0.998±0.001 vs 0.997±0.001,P＜0.001)and Pielou index(0.597±0.011 vs 0.567±0.009,P＜0.05)were significantly higher than those in the control group.Meanwhile,obvious difference was observed in the β diversity between the 2 groups(P＜0.01).The relative abundance analysis of bacteria showed that Pelomonas(0.046±0.004 vs 0.033±0.003,P＜0.05),Azospirillum(0.046±0.006 vs 0.021±0.003,P＜0.01),Acidovorax(0.032± 0.003 vs 0.019±0.002,Azospirillum(0.046±0.006 vs 0.021±0.003,P＜0.01)and Acidovorax(0.032± 0.003 vs 0.019±0.002,P＜0.05)were statistically higher in the HAPC group than the control group.LEfSe analysis showed that the characteristic blood microbiota of the HAPC group were α-Proteobacteria,and those of control group were Trichospiridae.Conclusion Significant changes are found in diversity,relative abundance and characteristic bacteria of the blood microbiota between the HAPC patients and healthy people at the high altitude,which might be closely associated with the occurrence and development of HAPC.

Objective:To explore the potent effects of denatonium benzoate(DB)on Mas-related G protein-coupled receptor-B2(MrgprB2)-mediated rat mast cell degranulation.Methods:RBL-2H3 cells were treated with DB overnight,before challenged with MrgprB2 ligands substance P(SP).The release of β-hex from MrgprB2-activated RBL-2H3 was detected by substrate method.Detec-tion of LTC4,IL-6,TNF-α and cPLA2 activity were performed by ELISA.The Ca2+influx and the expression of RBL-2H3 MrgprB2 re-ceptors were measured by fluorescence assay.Results:The results showed 10 μmol/L,50 μmol/L,80 μmol/L,100 μmol/L DB treat-ments promoted β-hex and LTC4 releases from activated RBL-2H3,accompanied by increased Ca2+mobilization and cPLA2 activa-tion.DB treatments did not affect IL-6 and TNF-α LTC4 releases in MrgprB2-activated RBL-2H3,as well as the levels of MrgprB2 ex-pression in mast cells.Conclusion:Taken together,DB enhanced the MrgprB2-mediated RBL-2H3 degranulation in vitro,probably by up-regulating Ca2+mobilization in activated cells.

Objective To construct a prediction model for the long-term prognosis of elderly pa-tients heart failure with preserved ejection fraction(HFpEF)based on two-dimensional speckle tracking technology.Methods A total of 312 elderly HFpEF patients admitted in our hospital from January 2017 to December 2018 were prospectively enrolled,and then randomly divided into a training set(218 cases)and a validation set(94 cases)in a ratio of 7∶3.After 5 years of follow-up,they were divided into a death group(n=128)and a survival group(n=184)according to having experienced cardiovascular death events or not.The main clinical characteristics were com-pared between the two groups,and the risk factors for cardiovascular death events were analyzed.A clinical prediction model was constructed based on the relevant risk factors with R4.0.3 statisti-cal software.Results The age,age ≥80 years,atrial fibrillation,chronic obstructive pulmonary disease(COPD),and early strain rate of global systole(GSRs)in the death group were signifi-cantly higher than those in the survival group,with statistical significances[(76.68±8.73)years vs(70.98±7.74)years,P＜0.01;34.4％vs 20.7％,P＜0.01;25.0％vs 11.4％,P＜0.01;26.6％vs 9.2％,P＜0.01;(-0.84±0.24)/s vs(-1.24±0.31)/s,P＜0.01].Multivariate logistic regression analysis showed that age ≥80 years,atrial fibrillation,COPD and GSRs＞-1.035 1/s were inde-pendent risk factors for cardiovascular death events(RR=2.196,95％CI:1.217-3.962,P=0.009;RR=2.242,95％CI:1.136-4.424,P=0.020;RR=3.631,95％CI:1.787-7.377,P=0.000;RR=6.199,95％CI:3.624-10.602,P=0.000).The AUC value of the training set was 0.822(95％CI:0.765-0.879),and that of the validation set was 0.790(95％CI:0.698-0.882).Conclusion Our constructed nomogram prediction model has high predictive value and reliability in predicting cardiovascular death events.

Humans ; Asthma/drug therapy* ; Biological Therapy

BACKGROUND: The presence of fibrosis is a criterion for subtype classification in the newly updated hypersensitivity pneumonitis (HP) guidelines. The present study aimed to summarize differences in clinical characteristics and prognosis of non-fibrotic hypersensitivity pneumonitis (NFHP) and fibrotic hypersensitivity pneumonitis (FHP) and explore factors associated with the presence of fibrosis. METHODS: In this prospective cohort study, patients diagnosed with HP through a multidisciplinary discussion were enrolled. Collected data included demographic and clinical characteristics, laboratory findings, and radiologic and histopathological features. Logistic regression analyses were performed to explore factors related to the presence of fibrosis. RESULTS: A total of 202 patients with HP were enrolled, including 87 (43.1%) NFHP patients and 115 (56.9%) FHP patients. Patients with FHP were older and more frequently presented with dyspnea, crackles, and digital clubbing than patients with NFHP. Serum levels of carcinoembryonic antigen, carbohydrate antigen 125, carbohydrate antigen 153, gastrin-releasing peptide precursor, squamous cell carcinoma antigen, and antigen cytokeratin 21-1, and count of bronchoalveolar lavage (BAL) eosinophils were higher in the FHP group than in the NFHP group. BAL lymphocytosis was present in both groups, but less pronounced in the FHP group. Multivariable regression analyses revealed that older age, <20% of lymphocyte in BAL, and ≥1.75% of eosinophil in BAL were risk factors for the development of FHP. Twelve patients developed adverse outcomes, with a median survival time of 12.5 months, all of whom had FHP. CONCLUSIONS Older age, <20% of lymphocyte in BAL, and ≥1.75% of eosinophil in BAL were risk factors associated with the development of FHP. Prognosis of patients with NFHP was better than that of patients with FHP. These results may provide insights into the mechanisms of fibrosis in HP.
Humans ; Bronchoalveolar Lavage Fluid ; Prospective Studies ; Alveolitis, Extrinsic Allergic/diagnosis* ; Fibrosis ; Carbohydrates

High Altitude Military Hygiene is the professional core course of high-altitude medicine, which is significant to the cultivation of military medical talents urgently needed by plateau troops. Under the background of "golden course" construction and army curriculum reform, aiming at the problems such as outdated content of course materials, single teaching mode and insufficient capacity of practical courses, we actively explored the effective path of "golden course" construction, including the renovation of the curriculum-construction concept, the optimization and reorganization of the teaching content, the expansion of case teaching and equipment teaching methods, and the implementation of curriculum ideological and political education and examination reforms. The reform has further improved the learning effect of students and the level of curriculum construction, and also provided beneficial reference for the construction of similar courses in military colleges and universities.