基于Web of Science的阴道菌群研究现状和热点的可视化分析与展望

探索阴道菌群近10年来的研究现状并预测其发展趋势。

在Web of Science数据库中检索近10年阴道菌群相关的文献,运用可视化软件VOSviewer进行共词分析、文献耦合、合著分析等。

阴道菌群领域发文量呈整体上升趋势,目前的主要热点研究分为阴道菌群的多样性、传染病学、细胞生物和基因学、阴道菌群与生殖的关联四大方面。

文献可视化研究展现了阴道菌群的研究现状和发展趋势,为相关研究人员提供了借鉴。

     

2015-2020年大连市流感病毒分离鉴定情况分析

对2015-2020年大连市流感病毒分离鉴定情况进行对比分析, 为大连市流感防控工作提供参考。

采集大连市2家国家级流感监测哨点医院的流感样病例咽拭子样本, 用MDCK细胞和鸡胚分别进行病毒分离培养, 并采用HA试验和HI试验对分离的病毒滴度和型别进行鉴定。

2015-2020年共分离培养流感病毒核酸检测阳性的咽拭子1 055份, 其中MDCK细胞分离出流感病毒501株, 鸡胚分离出流感病毒72株, 总体病毒分离率54.31%。MDCK细胞分离出A(H1N1)、A(H3N2)、B(Victoria)和B(Yamagata)型病毒, 鸡胚对A(H3N2)型病毒不敏感, 但可以分离出A(H1N1)、B(Victoria)和B(Yamagata)型病毒。每年的优势毒株虽不同, 但分离流感病毒的月份均在流行季内, 与北方流行形势一致。

MDCK细胞与鸡胚的流感病毒分离率不同。大连市每年流感流行的优势株和流行程度虽不同, 但流行程度处于相对平稳状态。

     

双歧杆菌制剂对肿瘤化疗患者肠道菌群影响的Meta分析

探讨双歧杆菌制剂对肿瘤化疗患者肠道菌群的影响。

通过检索PubMed、Embase、The Cochrane Library、Web of Science以及CBM、CNKI、WanFang Data和VIP数据库,收集各数据库从建库至2022年7月发表的所有关于肿瘤化疗患者应用双歧杆菌制剂的随机对照试验,由2名研究者独立筛选文献,按照系统评价的要求对文献质量进行评估,使用Revman 5.4和Stata 17.0统计学软件进行Meta分析。

共纳入25篇文献（2 152例患者）,Meta分析结果显示,双歧杆菌制剂组患者肠道中双歧杆菌和乳杆菌的数量高于对照组[SMD = 2.89,95% CI（2.28,3.49）,P＜0.001;SMD = 2.20,95% CI（1.57,2.84）,P＜0.001],双歧杆菌制剂组患者肠道中大肠埃希菌、肠杆菌和肠球菌的数量低于对照组[SMD = −1.08,95% CI（−1.64,−0.52）,P＜0.001;SMD = −0.88,95% CI（−1.58,−0.17）,P = 0.010;SMD = −0.98,95% CI（−1.68,−0.28）,P = 0.006]。

在化疗的基础上添加双歧杆菌制剂对肠道主要菌群水平能起到显著的改善作用,降低不良反应发生率,值得在临床上推广及应用。

     

呼吸道合胞病毒下呼吸道感染与患儿鼻咽部定植菌群的关系

研究鼻咽部定植菌群与呼吸道合胞病毒（RSV）下呼吸道感染患儿病情特点的关系,从微生态角度寻找预防或治疗RSV下呼吸道感染的理论依据。

回顾性分析我院2020年8月1日到2021年10月31日收治的RSV下呼吸道感染患儿,根据鼻咽部分泌物培养结果分为阴性组、阳性组,对比两组患儿临床特点及潮气肺功能检测结果。

1 090例RSV下呼吸道感染患儿中培养阳性者290例（26.58%）,中位数年龄为8个月（3.24个月,14个月）。各年龄层患儿鼻咽部菌群定植率及定植菌群差异有统计学意义（均P＞0.05）。各年龄层患儿鼻咽部定植菌均以肺炎链球菌为主。金黄色葡萄球菌、大肠埃希菌及卡他莫拉菌定植的患儿发热率较低。与喘息相关定植菌为肺炎链球菌、流感嗜血杆菌及金黄色葡萄球菌。与重症相关的定植菌为肺炎链球菌、流感嗜血杆菌、金黄色葡萄球菌、大肠埃希菌。与大叶性肺炎发生相关的只有肺炎链球菌。肺炎链球菌及流感嗜血杆菌定植的达峰容积比（Z = −4.12,P＜0.001;Z = −1.99,P = 0.046）与达峰时间比（Z = −4.24,P＜0.001;Z = −1.98,P = 0.047）均低于阴性组。

特定鼻咽部定植菌的存在会影响RSV下呼吸道感染患儿的临床表现,同时降低婴幼儿潮气肺功能检测结果。

     

基于CiteSpace可视化分析生命早期肠道菌群领域研究现状和发展趋势

探讨近10年生命早期肠道菌群领域的研究现状和发展趋势,梳理知识结构,以期为今后的研究提供参考资料。

检索2012—2022年中国知网、维普、万方和Web of Science数据库中的相关文献,通过CiteSpace软件进行知识图谱的构建和可视化呈现。

2012—2022年该领域的发文量总体呈上升趋势。关键词分析表明菌群的组成与功能、菌群的发育与演化、菌群与宿主的相互作用,以及婴幼儿食品的研发生产等是现阶段研究的热点方向;16S rRNA基因测序、宏基因组测序以及代谢组学等是现在热门的研究方法。

该领域研究的重点正逐渐从菌群组成向菌群功能转变;多组学方法的整合逐渐成为新的研究趋势。

     

卡介苗荚膜阿拉伯甘露聚糖的提纯鉴定及其免疫调节功能的初步研究

确定卡介苗(BCG)中荚膜中糖成分阿拉伯甘露聚糖(AM)的功能。

本研究从我国目前普遍使用的BCG中, 利用氯仿甲醇抽提方法分离纯化荚膜AM, 经AM单克隆抗体鉴定后, 腹腔注射BCG致敏小鼠, 体内外评价AM的免疫调节功能。

AM能在小鼠体内增强BCG诱导的迟发型超敏反应(P < 0.01), 体外免疫指标检测发现AM提高小鼠脾细胞Th1类细胞因子IFN-γ和TNF-α的表达水平(P < 0.05)。

BCG的荚膜AM是潜在的保护性抗原, 并为优化BCG提供理论依据。

     

乳杆菌及双歧杆菌缓解便秘的机制

探讨可改善患者便秘症状的植物乳植杆菌LP45、嗜酸乳杆菌La28和动物双歧杆菌乳亚种BAL531的作用机制。

采用HT-29细胞与肠道菌群体外批量发酵系统结合的方法,检测益生菌增殖肠上皮细胞、提升肠道紧密连接性与黏膜屏障能力以及增强五羟色胺转运体（SERT）、水通道蛋白-3（AQP-3）表达的能力。

菌株LP45和BAL531均具有较好的黏附能力并能够增殖肠上皮细胞,菌株La28无增殖作用;菌株LP45、La28和BAL531能显著提升紧密连接蛋白ZO-1和Occludin的mRNA相对表达水平,最高达2.73倍（t = 13.099,P＜0.001）,从而增强肠道屏障。菌株LP45使黏蛋白（MUC2）mRNA相对表达量显著提升1.89倍（t = 10.285,P = 0.001）,菌株La28与BAL531无显著影响;菌株LP45、La28和BAL531使SERT mRNA相对表达量分别提升2.13倍、1.45倍和4.00倍,其中菌株BAL531效果最显著（t = 21.308,P＜0.001）;另外,菌株LP45可使AQP-3 mRNA相对表达量提升2.12倍（t = 10.625,P＜0.001）,菌株BAL531使AQP-3 mRNA相对表达量下调0.79倍（t = ‒2.611,P = 0.059）,菌株La28无显著影响（t = ‒0.951,P = 0.395）。

菌株LP45、La28和BAL531对便秘症状的缓解作用可能是通过特异性增加肠道润滑、促进肠道蠕动、减缓肠道水液吸收等不同机制实现的。

     

大连地区2022—2023年冬春季呼吸道感染病原谱分析

了解大连地区2022—2023年冬春季呼吸道感染病原体分布情况,为呼吸道传染病防控提供实验室依据。

收集2022年10月至2023年3月的流感样病例咽拭子标本,采用荧光定量PCR对每月的10份标本进行22种急性呼吸道感染常见病原体核酸检测,并对检测结果进行分析。

60份标本中病原体阳性共54份（90.00%）,分别检出12种呼吸道病原体,包括肺炎链球菌、流感嗜血杆菌、甲型流感病毒、呼吸道合胞病毒、新型冠状病毒、铜绿假单胞菌、人偏肺病毒、呼吸道腺病毒、肺炎克雷伯菌、人鼻病毒、肠道病毒、人博卡病毒,其中肺炎链球菌阳性31份,检出率最高（51.67%）。60份标本中同时检出2种以上病原体的有21份（35.00%）,其中肺炎链球菌和流感嗜血杆菌同时阳性的10份,在混合感染标本中占比最高（47.62%）。按时间顺序,2022年10月至2023年3月各月检出率最高的病原体依次是肺炎链球菌、呼吸道合胞病毒、新型冠状病毒、肺炎链球菌、肺炎链球菌、甲型流感病毒,各月均有肺炎链球菌和流感嗜血杆菌检出。

大连地区2022—2023年冬春季除了有新型冠状病毒和流感病毒流行外,还存在肺炎链球菌、呼吸道合胞病毒等多种病原体引起的单一病原感染和混合感染,其中混合感染占比较高。

     

细菌性阴道炎合并HPV16感染患者阴道菌群分布与局部免疫的关系

探究细菌性阴道炎（BV）合并人乳头瘤病毒16（HPV16）感染患者阴道菌群分布与局部免疫的关系。

选取2019年1月到2023年1月我院收治的83例BV合并HPV16感染患者和81例单纯BV患者,分别作为研究组和对照组,检测两组患者阴道菌群分布和宫颈阴道分泌物中T淋巴细胞亚群（CD4⁺、CD8⁺、CD4⁺/CD8⁺）和炎症因子（IL-1β、IFN-γ、IL-2）水平。

研究组乳酸杆菌数量低于对照组,加德纳菌、大肠埃希菌、无乳链球菌、金黄色葡萄球菌、铜绿假单胞菌、白假丝酵母菌数量高于对照组（P＜0.05）;研究组阴道菌群密集度Ⅲ+Ⅳ级、多样性Ⅱ+Ⅲ级、微生态失调比例均高于对照组（P＜0.05）;研究组宫颈CD4⁺、CD4⁺/CD8⁺比值低于对照组（P＜0.05）;研究组宫颈IL-1β、IFN-γ、IL-2水平低于对照组（P＜0.05）。

合并HPV16感染可使BV患者阴道乳酸杆菌数量减少,阴道微生态失衡,局部免疫功能下降,应尽早检测此类患者阴道菌群和宫颈阴道局部免疫情况,进行针对性干预。

     

圈养食叶猴的肠道菌群特征

充分认识圈养食叶猴的肠道菌群组成特征, 为饲养管理方法的改进提供参考依据。

通过MiSeq高通量测序平台对3个物种的19个个体[黑叶猴(n=5)、川金丝猴(n=9)和西非黑白疣猴(n=5)]的肠道菌群16S rRNA V4-V5区进行测序和分析。

食叶猴肠道菌群以厚壁菌门和拟杆菌门为优势菌门, 瘤胃菌科、普氏菌科、理研菌科和毛螺菌科为优势菌科, 普氏菌属、密螺旋体属和瘤胃球菌属为优势菌属; 食叶猴物种间肠道菌群组成存在显著差异, 肠道菌群按照宿主物种聚类, 而不受环境因素的影响。

宿主物种是决定肠道微生物组成的重要因素, 食叶猴肠道菌群特征反映了宿主对其食性的适应。

     

Translational control by influenza virus. Selective and cap-dependent translation of viral mRNAs in infected cells.

In cells infected by influenza virus type A, host protein synthesis undergoes a rapid and dramatic shutoff. To define the molecular mechanisms underlying this selective translation, a transfection/infection protocol was developed utilizing viral and cellular cDNA clones. When COS-1 cells were transfected with cDNAs encoding nonviral genes and subsequently infected with influenza virus, protein expression from the exogenous genes was diminished, similar to the endogenous cellular genes. However, when cells were transfected with a truncated influenza viral nucleocapsid protein (NP-S) gene, the NP-S protein was made as efficiently in influenza virus infected cells as in uninfected cells, showing that the NP-S mRNA, although expressed independently of the influenza virus replication machinery, was still recognized as a viral and not a cellular mRNA. Northern blot analysis demonstrated that the selective blocks to nonviral protein synthesis were at the level of translation. Moreover, polysome experiments revealed that the translational blocks occurred at both the initiation and elongation stages of cellular protein synthesis. Finally, we utilized this transfection/infection system as well as double infection experiments to demonstrate that the translation of influenza viral mRNAs probably occurred in a cap-dependent manner as poliovirus infection inhibited influenza viral mRNA translation.     

Gene expression of cell surface antigens in the early phase of murine influenza pneumonia determined by a cDNA expression array technique

BACKGROUND: Influenza virus is a worldwide health problem with significant economic consequences. To study the gene expression pattern induced by influenza virus infection, it is useful to reveal the pathogenesis of influenza virus infection; but this has not been well examined, especially in vivo study. AIMS: To assess the influence of influenza virus infection on gene expression in mice, mRNA levels in the lung and tracheal tissue 48 h after infection were investigated by cDNA array analysis. METHODS: Four-week-old outbred, specific pathogen free strain, ICR female mice were infected by intra-nasal inoculation of a virus solution under ether anesthesia. The mice were sacrificed 48 h after infection and the tracheas and lungs were removed. To determine gene expression, the membrane-based microtechnique with an Atlas cDNA expression array (mouse 1.2 array II) was performed in accordance with the manual provided. RESULTS AND CONCLUSIONS: We focused on the expression of 46 mRNAs for cell surface antigens. Of these 46 mRNAs that we examined, four (CD1d2 antigen, CD39 antigen-like 1, CD39 antigen-like 3, CD68 antigen) were up-regulated and one (CD36 antigen) was down-regulated. Although further studies are required, these data suggest that these molecules play an important role in influenza virus infection, especially the phase before specific immunity.     

Expression of host genes in influenza virus infected cells

The NS1 protein of influenza virus shuts off host gene expression by inhibiting the polyadenylation-site cleavage of host pre-mRNAs, resulting in a general decline in cellular protein synthesis. On the other hand, an activation of several host genes related to host antiviral defense such as interferon- alpha/beta, MxA, 2',5'-oligoadenylate synthetase, and Fas occures upon infection. Therefore, balance of the shut-off and the activation of cellular genes during virus growth may be crucial in determining the outcome of infection. To obtain a comprehensive view of the global effects of influenza virus infection on human respiratory epithelial cells at the cytoplasmic mRNA level, we performed oligo DNA microarray analysis using GeneChip arrays (Affymetrix). In NCl-H292 cells infected with A/Udorn/72 virus, more than 4-fold increase of expression level was observed for 164 genes at 12 h pi. Approximately 60% of the virus-stimulated genes (VSGs) were also stimulated with interferon-beta treatment and contained the genes known to possess antiviral activity. Interestingly, majority of the VSGs were stimulated before induction of interferons, suggesting that the stimulation of the VSGs during early phase of infection is not mediated by interferons, but it is triggered from within by the virus infection.     

Effects of Influenza A Virus NS1 Protein on Protein Expression: the NS1 Protein Enhances Translation and Is Not Required for Shutoff of Host Protein Synthesis

The influenza A virus NS1 protein, a virus-encoded alpha/beta interferon (IFN-alpha/beta) antagonist, appears to be a key regulator of protein expression in infected cells. We now show that NS1 protein expression results in enhancement of reporter gene activity from transfected plasmids. This effect appears to be mediated at the translational level, and it is reminiscent of the activity of the adenoviral virus-associated I (VAI) RNA, a known inhibitor of the antiviral, IFN-induced, PKR protein. To study the effects of the NS1 protein on viral and cellular protein synthesis during influenza A virus infection, we used recombinant influenza viruses lacking the NS1 gene (delNS1) or expressing truncated NS1 proteins. Our results demonstrate that the NS1 protein is required for efficient viral protein synthesis in COS-7 cells. This activity maps to the amino-terminal domain of the NS1 protein, since cells infected with wild-type virus or with a mutant virus expressing a truncated NS1 protein-lacking approximately half of its carboxy-terminal end-showed similar kinetics of viral and cellular protein expression. Interestingly, no major differences in host cell protein synthesis shutoff or in viral protein expression were found among NS1 mutant viruses in Vero cells. Thus, another viral component(s) different from the NS1 protein is responsible for the inhibition of host protein synthesis during viral infection. In contrast to the earlier proposal suggesting that the NS1 protein regulates the levels of spliced M2 mRNA, no effects on M2 protein accumulation were seen in Vero cells infected with delNS1 virus.     

Dual Function of CD81 in Influenza Virus Uncoating and Budding

As an obligatory pathogen, influenza virus co-opts host cell machinery to harbor infection and to produce progeny viruses. In order to characterize the virus-host cell interactions, several genome-wide siRNA screens and proteomic analyses have been performed recently to identify host factors involved in influenza virus infection. CD81 has emerged as one of the top candidates in two siRNA screens and one proteomic study. The exact role played by CD81 in influenza infection, however, has not been elucidated thus far. In this work, we examined the effect of CD81 depletion on the major steps of the influenza infection. We found that CD81 primarily affected virus infection at two stages: viral uncoating during entry and virus budding. CD81 marked a specific endosomal population and about half of the fused influenza virus particles underwent fusion within the CD81-positive endosomes. Depletion of CD81 resulted in a substantial defect in viral fusion and infection. During virus assembly, CD81 was recruited to virus budding site on the plasma membrane, and in particular, to specific sub-viral locations. For spherical and slightly elongated influenza virus, CD81 was localized at both the growing tip and the budding neck of the progeny viruses. CD81 knockdown led to a budding defect and resulted in elongated budding virions with a higher propensity to remain attached to the plasma membrane. Progeny virus production was markedly reduced in CD81-knockdown cells even when the uncoating defect was compensated. In filamentous virus, CD81 was distributed at multiple sites along the viral filament. Taken together, these results demonstrate important roles of CD81 in both entry and budding stages of the influenza infection cycle.     

Changes in cytokine levels and NK cell activation associated with influenza

Several studies have highlighted the important role played by murine natural killer (NK) cells in the control of influenza infection. However, human NK cell responses in acute influenza infection, including infection with the 2009 pandemic H1N1 influenza virus, are poorly documented. Here, we examined changes in NK cell phenotype and function and plasma cytokine levels associated with influenza infection and vaccination. We show that absolute numbers of peripheral blood NK cells, and particularly those of CD56(bright) NK cells, decreased upon acute influenza infection while this NK cell subset expanded following intramuscular influenza vaccination. NK cells exposed to influenza antigens were activated, with higher proportions of NK cells expressing CD69 in study subjects infected with seasonal influenza strains. Vaccination led to increased levels of CD25+ NK cells, and notably CD56(bright) CD25+ NK cells, whereas decreased amounts of this subset were present in the peripheral blood of influenza infected individuals, and predominantly in study subjects infected with the 2009 pandemic H1N1 influenza virus. Finally, acute influenza infection was associated with low plasma concentrations of inflammatory cytokines, including IFN-γ, MIP-1β, IL-2 and IL-15, and high levels of the anti-inflammatory cytokines IL-10 and IL-1ra. Altogether, these data suggest a role for the CD56(bright) NK cell subset in the response to influenza, potentially involving their recruitment to infected tissues and a local production and/or uptake of inflammatory cytokines.     

Neutrophils sustain effective CD8(+) T-cell responses in the respiratory tract following influenza infection

Neutrophils have an important role in early host protection during influenza A virus infection. Their ability to modulate the virus-specific adaptive immune response is less clear. Here, we have used a mouse model to examine the impact of neutrophils on CD8(+) T-cell responses during influenza virus infection. CD8(+) T-cell priming, expansion, migration, cytokine secretion and cytotoxic capacity were investigated in the virus-infected airways and secondary lymphoid organs. To do this, we utilised a Ly6G-specific monoclonal antibody (mAb; 1A8) that specifically depletes neutrophils in vivo. Neutrophil depletion early after infection with influenza virus strain HKx31 (H3N2) did not alter influenza virus-derived antigen presentation or na?ve CD8(+) T-cell expansion in the secondary lymphoid organs. Trafficking of virus-specific CD8(+) T cells into the infected pulmonary airways was also unaltered. Instead, early neutropenia reduced both the overall magnitude of influenza virus-specific CD8(+) T cells, together with impaired cytokine production and cytotoxic effector function. Therefore, neutrophils are important participants in anti-viral mechanisms that sustain effective CD8(+) T-cell responses in the respiratory tract of influenza virus-infected mice.     

Identification of novel avian influenza virus derived CD8+ T-cell epitopes

Avian influenza virus (AIV) infection is a continuing threat to both humans and poultry. Influenza virus specific CD8+ T cells are associated with protection against homologous and heterologous influenza strains. In contrast to what has been described for humans and mice, knowledge on epitope-specific CD8+ T cells in chickens is limited. Therefore, we set out to identify AIV-specific CD8+ T-cell epitopes. Epitope predictions based on anchor residues resulted in 33 candidate epitopes. MHC I inbred chickens were infected with a low pathogenic AIV strain and sacrificed at 5, 7, 10 and 14 days post infection (dpi). Lymphocytes isolated from lung, spleen and blood were stimulated ex vivo with AIV-specific pooled or individual peptides and the production of IFNγ was determined by ELIspot. This resulted in the identification of 12 MHC B12-restricted, 3 B4-restricted and 1 B19-restricted AIV- specific CD8+ T-cell epitopes. In conclusion, we have identified novel AIV-derived CD8+ T-cell epitopes for several inbred chicken strains. This knowledge can be used to study the role of CD8+ T cells against AIV infection in a natural host for influenza, and may be important for vaccine development.