RESUMEN
Betanodavirus infection was diagnosed in larvae of farm-raised tilapia Oreochromis niloticus (L.), in central Thailand. Extensive vacuolar degeneration and neuronal necrosis were observed in histological sections with positive immunohistochemical staining for betanodavirus. Molecular phylogenetic analysis was performed based on the nucleotide sequences (1333 bases) of the capsid protein gene. The virus strain was highly homologous (93.07-93.88%) and closely related to red-spotted grouper nervous necrosis virus (RGNNV).
Asunto(s)
Enfermedades de los Peces/virología , Nodaviridae/clasificación , Nodaviridae/genética , Infecciones por Virus ARN/veterinaria , Animales , Secuencia de Bases , Proteínas de la Cápside/genética , Cíclidos/virología , Enfermedades de los Peces/patología , Datos de Secuencia Molecular , Nodaviridae/aislamiento & purificación , Filogenia , Infecciones por Virus ARN/patología , Infecciones por Virus ARN/virología , Homología de Secuencia de Ácido Nucleico , TailandiaRESUMEN
Reverse genetics can be used to produce recombinant influenza A viruses containing virtually every desired combination of hemagglutinin (HA) and neuraminidase (NA) genes using the virus backbone of choice. Here, a repository of plasmids and recombinant viruses representing all contemporary Eurasian HA and NA subtypes, H1-H16 and N1-N9, was established. HA and NA genes were selected based on sequence analyses of influenza virus genes available from public databases. Prototype Eurasian HA and NA genes were cloned in bidirectional reverse genetics plasmids. Recombinant viruses based on the virus backbone of A/PR/8/34, and containing a variety of HA and NA genes were produced in 293T cells. Virus stocks were produced in MDCK cells and embryonated chicken eggs. These plasmids and viruses may be useful for numerous purposes, including influenza virus research projects, vaccination studies, and to serve as reference reagents in diagnostic settings.
Asunto(s)
Vectores Genéticos , Glicoproteínas Hemaglutininas del Virus de la Influenza/genética , Virus de la Influenza A/genética , Neuraminidasa/genética , Recombinación Genética , Animales , Línea Celular , Pollos , Perros , Genes Virales , Humanos , Virus de la Influenza A/enzimología , Óvulo/virología , Filogenia , Plásmidos , Cultivo de VirusRESUMEN
The C-terminal part of the nucleocapsid protein gene of 13 canine distemper virus (CDV) isolates from Thailand, were analyzed. The nucleotide sequences were assigned to two clusters; cluster A exhibited a high degree of homology with the vaccine strain Onderstepoort, 99.10 and 97.61%, respectively, in the two isolates examined. Cluster B appeared closely related to virulent strains registered in the GeneBank database and to the virulent reference strain (A75/17); a total of 11 samples were analyzed, with 94.63-99.10% homology at the same position. The deduced amino acid sequences correlated with the two-nucleotide sequence clusters. However, there was no association among the CDV groups with histories of vaccination, sex, ages, clinical findings and evidence of viral antigen in tissues.
Asunto(s)
Virus del Moquillo Canino/genética , Moquillo/virología , Enfermedades de los Perros/virología , Proteínas de la Nucleocápside/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Análisis por Conglomerados , ADN Viral/química , ADN Viral/genética , Virus del Moquillo Canino/aislamiento & purificación , Perros , Femenino , Masculino , Datos de Secuencia Molecular , Proteínas de la Nucleocápside/química , Filogenia , Reacción en Cadena de la Polimerasa/veterinaria , Análisis de Secuencia de ADN , Tailandia , Vacunas Virales/genética , VirulenciaRESUMEN
The hemagglutinin (HA) and neuraminidase (NA) genes of eight influenza A virus (H5N1) isolates obtained from various avian species in Thailand in 2003-2004 have been characterized in comparison with the Thai isolate A/Chicken/Nakorn-Pathom/Thailand/CU-K2/04(H5N1). Phylogenetic analyses of both genes revealed that all the eight avian isolates were closely related to the A/Chicken/Nakorn-Pathom/Thailand/CU-K2/ 04(H5N1). The amino acid sequence of the HA cleavage site revealed a common characteristic of a highly pathogenic virus strain. Moreover, a deletion of 20 amino acids in the NA stalk region was detected in all Thai isolates in contrast to the H5N1 strain that had caused outbreaks in eastern Asia in 1996-1997 and 2000-2001.