We have developed a reverse genetics system for the avian coronavirus infectious bronchitis virus (IBV) in which a full-length cDNA corresponding to the IBV genome is inserted into the vaccinia virus genome under the control of a T7 promoter sequence. Vaccinia virus as a vector for the full-length IBV cDNA has the advantage that modifications can be introduced into the IBV cDNA using homologous recombination, a method frequently used to insert and delete sequences from the vaccinia virus genome. Here, we describe the use of transient dominant selection as a method for introducing modifications into the IBV cDNA that has been successfully used for the substitution of specific nucleotides, deletion of genomic regions, and exchange of complete genes. Infectious recombinant IBVs are generated in situ following the transfection of vaccinia virus DNA, containing the modified IBV cDNA, into cells infected with a recombinant fowlpox virus expressing T7 DNA-dependant RNA polymerase.

Four poll Dorset sheep and four Holstein-Friesian cattle were infected with the northern European strain of bluetongue virus (BTV), BTV-8, to assess its pathogenicity in UK breeds. The time course of infection was monitored in both species by using real-time reverse transcriptase-PCR (RT-PCR), conventional RT-PCR and serology. Two of the sheep developed severe clinical signs that would have been fatal in the field; the other two were moderately and mildly ill, respectively. The cattle were clinically unaffected, but had high levels of viral RNA in their bloodstream. Real-time RT-PCR detected viral RNA as early as one day after infection in the cattle and three days after infection in the sheep. Antibodies against BTV were detected by six days after infection in the sheep and eight days after infection in the cattle. Postmortem examinations revealed pathology in the cattle that was more severe than suggested by the mild clinical signs, but the pathological and clinical findings in the sheep were more consistent.

Here, we announce the first complete genome sequence of a field isolate of a peste des petits ruminants virus (PPRV) from northern Africa. This isolate is derived from an Alpine goat that suffered from severe clinical disease during the 2008 outbreak in Morocco. The full genome sequence of this isolate clusters phylogenetically with the lineage IV isolates of PPRV, sharing high levels of sequence identity with other lineage IV isolates.

Newcastle disease (ND) is a highly contagious disease of many avian species and is particularly responsible for devastating disease outbreaks in commercial poultry flocks in Pakistan that incur huge economic losses to the national poultry industry annually. Despite implementation of an extensive vaccination program for poultry birds, the disease appears in an endemic form in commercial broiler and layer poultry farms. This study was conducted to identify the prevalent velogenic NDV strain responsible for disease outbreaks in commercial poultry farms in Punjab, Pakistan. The NDV strains isolated from pathological specimens through inoculation in embryonated chicken eggs were characterized biologically through the intracerebral pathogenicity index (ICPI), and genetically on the basis of the fusion (F) protein cleavage site. Among these, six NDV isolates showed an F protein cleavage site motif (112RRQKRF117) and an ICPI value ranging between 1.5 and 1.88, both are characteristics for velogenic strains of NDV. In addition, phylogenetic analysis based on a partial sequence of the F protein gene clustered these isolates within class II, genotype VII and specifically within genotype VII-e. This is the first report that demonstrated the presence of such NDV strains in commercial poultry farms in northern Punjab of Pakistan.