genomic diversity

基因组多样性
  • 文章类型: Journal Article
    循环甲型流感病毒(IAV)的基因组表征指导选择合适的疫苗制剂和早期检测潜在的大流行性病毒株。然而,关于非洲IAV基因组进化和传播的纵向数据很少,限制非洲从潜在的流感控制策略中受益。我们搜索了七个数据库:非洲在线期刊,Embase,全球卫生,谷歌学者,PubMed,Scopus,和WebofScience根据PRISMA指南对非洲IAV进行测序和/或基因组表征的研究。我们的审查强调了自1993年以来非洲IAV的出现和多样化。循环菌株在血凝素蛋白的主要抗原和潜在的N-连接糖基化位点上不断获得新的氨基酸取代。这极大地影响了疫苗的保护性。非洲IAVs在系统发育上与全球菌株混合,形成了强大的时间和地理进化结构。系统地理分析证实,病毒从国外迁移到非洲,尤其是南亚,欧洲,北美,广泛的局部病毒混合维持了基因组多样性,抗原漂移,以及无人机在非洲的持续存在。然而,重组和人畜共患的作用仍然未知。有趣的是,我们观察到了非洲特有的替换和进化枝以及持续性病毒谱系.因此,非洲对全球流感生态的贡献可能被低估了。我们的结果在地理上有偏差,数据来自63%(34/54)的非洲国家。因此,有必要在非洲范围内扩大流感监测,并优先进行常规的全基因组测序和基因组分析,以便及早发现新毒株,从而有效控制病毒.
    Genomic characterization of circulating influenza type-A viruses (IAVs) directs the selection of appropriate vaccine formulations and early detection of potentially pandemic virus strains. However, longitudinal data on the genomic evolution and transmission of IAVs in Africa are scarce, limiting Africa\'s benefits from potential influenza control strategies. We searched seven databases: African Journals Online, Embase, Global Health, Google Scholar, PubMed, Scopus, and Web of Science according to the PRISMA guidelines for studies that sequenced and/or genomically characterized Africa IAVs. Our review highlights the emergence and diversification of IAVs in Africa since 1993. Circulating strains continuously acquired new amino acid substitutions at the major antigenic and potential N-linked glycosylation sites in their hemagglutinin proteins, which dramatically affected vaccine protectiveness. Africa IAVs phylogenetically mixed with global strains forming strong temporal and geographical evolution structures. Phylogeographic analyses confirmed that viral migration into Africa from abroad, especially South Asia, Europe, and North America, and extensive local viral mixing sustained the genomic diversity, antigenic drift, and persistence of IAVs in Africa. However, the role of reassortment and zoonosis remains unknown. Interestingly, we observed substitutions and clades and persistent viral lineages unique to Africa. Therefore, Africa\'s contribution to the global influenza ecology may be understated. Our results were geographically biased, with data from 63% (34/54) of African countries. Thus, there is a need to expand influenza surveillance across Africa and prioritize routine whole-genome sequencing and genomic analysis to detect new strains early for effective viral control.
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  • 文章类型: Journal Article
    背景:2019年冠状病毒病(SARS-CoV-2)在武汉开始进入全球大流行的毁灭性轨迹,中国,2019年12月。从那以后,已经鉴定出SARS-CoV-2的几种变体。在本次审查中,我们旨在表征SARS-CoV-2的不同变体,并探讨相关的发病率和死亡率。
    方法:通过利用包括Scopus在内的在线数据库中的关键词进行系统搜索,包括与SARS-CoV-2的不同变体以及相关发病率和死亡率有关的当前证据。PubMed,WebofScience,和ScienceDirect;我们检索了2019年12月至2020年9月以英文发表的所有相关论文和报告。
    结果:对已鉴定文章的综述显示了三种主要的基因组变异,包括A型,B型,和C型,我们还确定了三个分支,包括S,V,和G.研究表明,Nsp12和S蛋白中的C14408T和A23403G改变是世界上最突出的改变,导致危及生命的突变.自2019年12月以来,峰值D614G氨基酸变化已成为最常见的变体。从古吉拉特邦SARS-CoV-2基因组中发现的错义突变,C28854T,核衣壳(N)基因的有害突变与患者死亡率显着相关。另一个显著的有害变体(G25563T)在位于Orf3a的患者中发现,并且在病毒发病机理中具有潜在作用。
    结论:总体而言,研究人员发现了几种SARS-CoV-2变种改变临床表现并增加传播性,发病率,和COVID-19的死亡率。在当前的实践和干预措施中应考虑到这一点,以抗击大流行并预防相关的发病率和死亡率。
    BACKGROUND: Coronavirus Disease-2019 (SARS-CoV-2) started its devastating trajectory into a global pandemic in Wuhan, China, in December 2019. Ever since, several variants of SARS-CoV-2 have been identified. In the present review, we aimed to characterize the different variants of SARS-CoV-2 and explore the related morbidity and mortality.
    METHODS: A systematic review including the current evidence related to different variants of SARS-CoV-2 and the related morbidity and mortality was conducted through a systematic search utilizing the keywords in the online databases including Scopus, PubMed, Web of Science, and Science Direct; we retrieved all related papers and reports published in English from December 2019 to September 2020.
    RESULTS: A review of identified articles has shown three main genomic variants, including type A, type B, and type C. we also identified three clades including S, V, and G. Studies have demonstrated that the C14408T and A23403G alterations in the Nsp12 and S proteins are the most prominent alterations in the world, leading to life-threatening mutations.The spike D614G amino acid change has become the most common variant since December 2019. From missense mutations found from Gujarat SARS-CoV-2 genomes, C28854T, deleterious mutation in the nucleocapsid (N) gene was significantly associated with patients\' mortality. The other significant deleterious variant (G25563T) is found in patients located in Orf3a and has a potential role in viral pathogenesis.
    CONCLUSIONS: Overall, researchers identified several SARS-CoV-2 variants changing clinical manifestations and increasing the transmissibility, morbidity, and mortality of COVID-19. This should be considered in current practice and interventions to combat the pandemic and prevent related morbidity and mortality.
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  • 文章类型: Journal Article
    Pneumocystis pneumonia (PCP) remains the most frequent AIDS-defining illness in developed countries. This infection also occurs in non-AIDS immunosuppressed patients, e.g., those who have undergone an organ transplantation. Moreover, mild Pneumocystis jirovecii infections related to low pulmonary fungal burden, frequently designated as pulmonary colonization, occurs in patients with chronic pulmonary diseases, e.g., cystic fibrosis (CF). Indeed, this autosomal recessive disorder alters mucociliary clearance leading to bacterial and fungal colonization of the airways. This mini-review compiles and discusses available information on P. jirovecii and CF. It highlights significant differences in the prevalence of P. jirovecii pulmonary colonization in European and Brazilian CF patients. It also describes the microbiota associated with P. jirovecii in CF patients colonized by P. jirovecii. Furthermore, we have described P. jirovecii genomic diversity in colonized CF patients. In addition of pulmonary colonization, it appears that PCP can occur in CF patients specifically after lung transplantation, thus requiring preventive strategies. In other respects, Pneumocystis primary infection is a worldwide phenomenon occurring in non-immunosuppressed infants within their first months. The primary infection is mostly asymptomatic but it can also present as a benign self-limiting infection. It probably occurs in the same manner in CF infants. Nonetheless, two cases of severe Pneumocystis primary infection mimicking PCP in CF infants have been reported, the genetic disease appearing in these circumstances as a risk factor of PCP while the host-pathogen interaction in older children and adults with pulmonary colonization remains to be clarified.
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