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2.
Nature ; 557(7705): 418-423, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29743673

RESUMO

Hepatitis B virus (HBV) is a major cause of human hepatitis. There is considerable uncertainty about the timescale of its evolution and its association with humans. Here we present 12 full or partial ancient HBV genomes that are between approximately 0.8 and 4.5 thousand years old. The ancient sequences group either within or in a sister relationship with extant human or other ape HBV clades. Generally, the genome properties follow those of modern HBV. The root of the HBV tree is projected to between 8.6 and 20.9 thousand years ago, and we estimate a substitution rate of 8.04 × 10-6-1.51 × 10-5 nucleotide substitutions per site per year. In several cases, the geographical locations of the ancient genotypes do not match present-day distributions. Genotypes that today are typical of Africa and Asia, and a subgenotype from India, are shown to have an early Eurasian presence. The geographical and temporal patterns that we observe in ancient and modern HBV genotypes are compatible with well-documented human migrations during the Bronze and Iron Ages1,2. We provide evidence for the creation of HBV genotype A via recombination, and for a long-term association of modern HBV genotypes with humans, including the discovery of a human genotype that is now extinct. These data expose a complexity of HBV evolution that is not evident when considering modern sequences alone.


Assuntos
Evolução Molecular , Vírus da Hepatite B/genética , Vírus da Hepatite B/isolamento & purificação , Hepatite B/virologia , Filogenia , África , Animais , Ásia , Europa (Continente) , Genótipo , Vírus da Hepatite B/classificação , História Antiga , História Medieval , Hominidae/virologia , Migração Humana/história , Humanos , Recombinação Genética
4.
Nature ; 557(7705): 369-374, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29743675

RESUMO

For thousands of years the Eurasian steppes have been a centre of human migrations and cultural change. Here we sequence the genomes of 137 ancient humans (about 1× average coverage), covering a period of 4,000 years, to understand the population history of the Eurasian steppes after the Bronze Age migrations. We find that the genetics of the Scythian groups that dominated the Eurasian steppes throughout the Iron Age were highly structured, with diverse origins comprising Late Bronze Age herders, European farmers and southern Siberian hunter-gatherers. Later, Scythians admixed with the eastern steppe nomads who formed the Xiongnu confederations, and moved westward in about the second or third century BC, forming the Hun traditions in the fourth-fifth century AD, and carrying with them plague that was basal to the Justinian plague. These nomads were further admixed with East Asian groups during several short-term khanates in the Medieval period. These historical events transformed the Eurasian steppes from being inhabited by Indo-European speakers of largely West Eurasian ancestry to the mostly Turkic-speaking groups of the present day, who are primarily of East Asian ancestry.


Assuntos
Povo Asiático/genética , Genoma Humano/genética , Pradaria , Filogenia , População Branca/genética , Ásia/etnologia , Europa (Continente)/etnologia , Fazendeiros/história , História Antiga , Migração Humana/história , Humanos
5.
BMC Infect Dis ; 20(1): 201, 2020 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-32143598

RESUMO

BACKGROUND: Melioidosis is a potentially life-threatening infection caused by the Gram-negative bacterium Burkholderia pseudomallei. Melioidosis is difficult to diagnose due to its diverse clinical manifestations, which often delays administration of appropriate antibiotic therapy. CASE PRESENTATION: Melioidosis is uncommon in pregnancy but both spontaneous abortion and neonatal melioidosis have been reported. We report a case of bacteraemic melioidosis in a young woman with a subsequent spontaneous abortion, with B. pseudomallei cultured from a high vaginal swab as well as blood. CONCLUSION: It remains unclear in this and previously reported cases as to whether the maternal melioidosis was sexually transmitted.


Assuntos
Melioidose/diagnóstico , Doenças Bacterianas Sexualmente Transmissíveis/diagnóstico , Aborto Espontâneo , Adulto , Antibacterianos/uso terapêutico , Burkholderia pseudomallei/isolamento & purificação , Feminino , Humanos , Melioidose/tratamento farmacológico , Melioidose/microbiologia , Gravidez , Doenças Bacterianas Sexualmente Transmissíveis/tratamento farmacológico , Doenças Bacterianas Sexualmente Transmissíveis/microbiologia , Vagina/microbiologia
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