ABSTRACT
Bovine Viral Diarrhoea Virus (BVDV) is responsible worldwide for severe economic losses on cattle farms. BVDV is an RNA virus with a high genome variability having practical consequences on epidemiology, diagnosis and disease control. Genetic monitoring was suggested as the first step in BVDV control. Thirty-seven Bovine Viral Diarrhoea Viruses were identified in persistently infected cattle, mucosal disease-affected animals and in bulk milk, and were characterised genetically. The 5'UTR region was amplified and sequenced, and a phylogenetic analysis was carried out comparing all the Italian sequences of BVDV available from the Genbank database. An unusual number of persistent infected animals was evidenced on more than one farm. Phylogenetic analysis attributed all our viruses to BVDV type I and distinguished four different subgroups inside this genotype. Analysis of old and new viruses revealed the circulation of viruses classified in subgroups BVDV Ia and Ij never reported in Italy.
Subject(s)
Bovine Virus Diarrhea-Mucosal Disease/virology , Diarrhea Viruses, Bovine Viral/classification , Diarrhea Viruses, Bovine Viral/genetics , 5' Untranslated Regions , Animals , Bovine Virus Diarrhea-Mucosal Disease/epidemiology , Cattle , Diarrhea/virology , Diarrhea Viruses, Bovine Viral/isolation & purification , Feces/virology , Genotype , Italy/epidemiology , Milk/virology , Molecular Epidemiology , Phylogeny , Reverse Transcriptase Polymerase Chain Reaction , Sequence Analysis, DNA , Sequence Homology, Nucleic AcidSubject(s)
Coronaviridae Infections/virology , Coronavirus, Feline/genetics , Coronavirus, Feline/pathogenicity , Nucleocapsid Proteins/physiology , Amino Acid Sequence , Animals , Cats , Coronaviridae Infections/pathology , Italy , Molecular Sequence Data , Nucleocapsid Proteins/chemistry , Protein Structure, Tertiary , Sequence Homology, Amino Acid , Software , Species Specificity , T-Lymphocytes/virologyABSTRACT
This study reports the detection of co-infection by multiple CPV variants and the high genetic complexity of a CPV-2 strain detected in a domestic cat. The CPV variants selected by cloning the VP2 gene were sequenced, and genetic diversity and selection pressure were investigated. Comparison of the nucleotide sequences has evidenced 10 different viral populations, and, in the same animal, more CPV variants coexist. Our analysis excludes the possibility that the recombination events took place during infection and that negative selection acted on the VP2 gene. These findings confirm that CPV-2 shows high genetic heterogeneity resembling the quasispecies found in RNA viruses.
Subject(s)
Capsid Proteins/genetics , Cat Diseases/virology , Genetic Variation , Parvoviridae Infections/veterinary , Parvovirus, Canine/classification , Animals , Animals, Domestic/virology , Base Sequence , Capsid Proteins/chemistry , Cats , Dogs , Parvoviridae Infections/virology , Parvovirus, Canine/genetics , Parvovirus, Canine/isolation & purification , Polymerase Chain Reaction , Selection, Genetic , Sequence Analysis, DNAABSTRACT
Quasispecies composition and tissue distribution of feline coronaviruses (FCoVs) were studied in naturally infected cats. The genomic complexity of FCoVs was investigated using single-strand conformational polymorphism (SSCP) analysis of N and ORF7b amplicons, and the evolutionary process was investigated by sequence-based phylogenetic analysis. SSCP analysis showed high heterogeneity of the FCoV genome which was correlated with the seriousness of the clinical form. The two genomic regions analysed showed different levels of variation; the N region demonstrated significant heterogeneity as compared to ORF7b. Phylogenetic analysis of the nucleotide sequences showed the clear separation of sequences analysed on the basis of virulence and geographical origin. A maximum likelihood analysis of N and ORF7b data sets showed a situation of strong heterogeneity for the N region.
