RESUMO
BACKGROUND: Human rhinoviruses and enteroviruses (Picornaviridae) are suspected to be major viral etiological causes of bronchiolitis in infants. OBJECTIVES: In the present study, we assessed the potential role of the respiratory picornaviruses as causative agents of bronchiolitis in French infants. STUDY DESIGN: From September 2001 to June 2002, we prospectively selected 192 infants < or =36 months of age and hospitalized for acute bronchiolitis. The detection of common respiratory viruses (respiratory syncytial virus, influenza virus A and B, parainfluenza virus 1, 2, 3 and adenovirus) was performed using classical immunofluorescence antigen and cell-culture detection assays on nasopharyngeal aspirates whereas the detection of human metapneumovirus (HMPV) was performed by a real-time RT-PCR assay. The presence of rhinovirus and/or enterovirus was assessed in respiratory samples by a picornavirus RT-PCR detection assay followed by a differential Southern blotting procedure. RESULTS: A potential causative virus was detected in 72.5% of the 192 study infants. RSV (30%), rhinovirus (21%), enterovirus (9%), influenza virus A (6%) and human metapneumovirus (4%) were the most frequent causative agents detected. Rhinoviruses or enteroviruses were detected as the only evidence of respiratory viral tract infection in 57 (30%) of 192 infants, whereas rhinovirus or enterovirus occurred in mixed viral infection detected in 25 (13%) of 192 study cases (30% versus 13%, p<10(-3)). CONCLUSIONS: Our data suggest that respiratory picornaviruses are one of the leading etiological causes of bronchiolitis in French infants. These findings highlight the need to implement a rapid picornavirus RT-PCR detection assay for the clinical diagnosis of respiratory infections in pediatric patients with bronchiolitis.
Assuntos
Bronquiolite Viral/virologia , Enterovirus/isolamento & purificação , Nasofaringe/virologia , Infecções por Picornaviridae/virologia , Rhinovirus/isolamento & purificação , Doença Aguda , Pré-Escolar , Enterovirus/genética , Humanos , Lactente , Recém-Nascido , RNA Viral/análise , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
We described the natural polymorphism of cytomegalovirus DNA polymerase in 42 unrelated isolates susceptible to ganciclovir, foscarnet, and cidofovir. All variations, including an eight-amino-acid deletion, were located between domains delta-C and II and between domains III and I, suggesting that these specific residues are not involved in enzymatic functions.
Assuntos
Citomegalovirus/enzimologia , Citomegalovirus/genética , DNA Polimerase Dirigida por DNA/genética , Sequência de Aminoácidos , Substituição de Aminoácidos , Antivirais/farmacologia , Sequência Conservada , Citomegalovirus/efeitos dos fármacos , Deleção de Genes , Humanos , Dados de Sequência Molecular , Fenótipo , Polimorfismo Genético/genética , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Enterovirus (EV) detection by a new commercially available reverse transcription (RT)-PCR assay (Penter RT-PCR test) was compared with EV isolation from cell cultures and with EV detection by an in-house RT-PCR assay. Of the 54 cerebrospinal fluid specimens collected during a summer outbreak of aseptic meningitis, 52% were positive by cell culture versus 76% by in-house RT-PCR assay and 80% by the new RT-PCR test (52 versus 76 versus 80%; P = 0.003). This new reliable EV RNA detection test is suitable for clinical diagnosis of EV-related meningitis and may improve the management of EV-related neurological syndromes.
