Authors:I. Kiss, S. Kecskeméti, J. Tanyi, S. Belák, C. Ros and S. B. Klingeborn
The quasispecies nature of three animal pathogenic RNA viruses of field origin was examined by testing variants of classical swine fever virus (CSFV) originating from geographically different areas, feline coronavirus (FCoV) detected from the same animal by successive sampling, and rabbit haemorrhagic disease virus (RHDV) originating from successive outbreaks in the same geographic area. Clinical samples were investigated using reverse transcriptase polymerase chain reaction (RT-PCR) and ensuing single strand conformational polymorphism (SSCP) assay. By the combination of these methods even subtle differences could be detected among the amplified fragments of the same virus species of different origin. FCoV proved to comprise the most and CSFV the less heterogeneous virus quasispecies. The results show that the combination of RT-PCR and SSCP provides novel and highly sensitive means for the characterisation of RNA viruses, with special regard to genome composition, evolution, features of pathogenicity and molecular epizootiology.
Authors:I. Kiss, S. Kecskeméti, T. Tuboly, E. Bajmócy and J. Tanyi
Postweaning multisystemic wasting syndrome (PMWS), a new disease in Hungary, was recognized in a swine herd located in Southeast Hungary, during the early winter of 1999. The first clinical signs of paleness, anaemia, and leanness appeared immediately after weaning, at the age of 40-50 days. Pustules were frequently observed on the skin of the trunk, and signs of necrotic dermatitis were also visible. A syndrome of poor growth and wasting was characteristic of the affected pigs. A porcine circovirus (PCV), the suspected causative agent, was detected by polymerase chain reaction (PCR). Sequencing data and restriction endonuclease (RE) analysis of the PCR products suggested that the virus belonged to the PCV-II group where all the causative agents of PMWS are also grouped.