RESUMO
Anelloviruses are single-strand circular DNA viruses and ubiquitous within the human population. Although there is no direct evidence, many studies have suggested the anelloviruses may be associated with a variety of diseases. In this study, a novel torque teno mini virus (TTMV) was detected in a child with unexplained encephalitis. The detected virus had a circular genome of 2943 nt in length and 3 open reading frames. It shared 45.4% - 35.9% nucleotide identities with known TTMV species and < 35% with the other species of anellovirus, which suggested it might belong to a new species within the genus Betatorquevirus. Phylogenetic analysis based on the amino acid sequences of ORF1 showed that this virus represented a distinct branch within the diversity of anellovirus. Whether this novel anellovirus strain is associated with encephalitis requires further study.
Assuntos
Líquido Cefalorraquidiano/virologia , Infecções por Vírus de DNA/diagnóstico , Infecções por Vírus de DNA/virologia , Encefalite Viral/diagnóstico , Encefalite Viral/virologia , Torque teno virus/isolamento & purificação , Encéfalo/diagnóstico por imagem , Pré-Escolar , Infecções por Vírus de DNA/diagnóstico por imagem , Infecções por Vírus de DNA/patologia , Encefalite Viral/diagnóstico por imagem , Encefalite Viral/patologia , Ordem dos Genes , Humanos , Imageamento por Ressonância Magnética , Masculino , Filogenia , Análise de Sequência de DNA , Homologia de Sequência , Torque teno virus/classificação , Torque teno virus/genéticaRESUMO
BACKGROUND: The aim of the study was to evaluate the prevalence of torquetenovirus (TTV) infection in a group of children with recurrent lower respiratory tract infections and radiologic evidence of bronchiectasis. Correlations between TTV loads and severity of bronchiectasis and between TTV loads and lung function were evaluated. METHODS: In 38 subjects, high-resolution computed tomography (HRCT) and plasma tests for TTV detection and quantification were done. In 21/38 subjects, spirometry was also performed. RESULTS: TTV was found in 31/38 (81.6%) patients. The correlation between TTV loads and severity of bronchiectasis was statistically significant (r = 0.548; P = 0.01). TTV loads showed inverse correlation with FEF25-75% (r = -0.541; P = 0.011), and FEF25-75%/FVC (r = -0.512; P = 0.018). Inverse correlation was found also between severity of bronchiectasis and functional lung parameters: FEF25-75% (r = -0.635; P = 0.002), FEV1/FVC (r = -0.541; P = 0.011), and FEF25-75%/FVC (r = -0.645; P = 0.002). CONCLUSIONS: This study demonstrated the high prevalence of TTV infection in children with bronchiectasis. Moreover, we have shown a significant correlation between TTV loads and airflow limitation within the peripheral airways, as well as between severity of bronchiectasis and decrease of lung function.