Molecular characterisation of infectious bursal disease viruses isolated in recent acute outbreaks in Slovenia.
In 2004 and then in 2006 several outbreaks of infectious bursal disease (IBD) were reported in broiler and broiler breeder flocks in Slovenia. In this report ten recently emerged IBD viruses (IBDV) were characterised by sequence analysis of the VP2 hypervariable region and compared to previous Slovene IBDV strains from 1995/1996 and to some representative serotype 1 IBDV strains of different pathotypes. On the basis of nucleotide and amino acid identities, phylogenetic analyses and the presence of very virulent IBDV (vvIBDV) conserved amino acid substitutions, all Slovene isolates from recent outbreaks were identified as vvIBDV. Although some unique nucleotide exchanges and amino acid substitutions have been observed, the results of this study indicated that recent vvIBDV isolates are closely related with those from outbreaks in the 1990s. However, acute IBD has not been reported in commercial flocks in Slovenia for some years. This could lead to the conclusion that poor biosecurity and relaxed vaccination could be responsible for the re-emergence of vvIBDV.
Rojs
Olga Zorman
OZ
Veterinary Faculty, University of Ljubljana, Ljubljana, Slovenia. olga.zorman-rojs@vf.uni-lj.si
Krapez
Uros
U
Slavec
Brigita
B
Mankoc
Sara
S
Juriric-Cizerl
Rahela
R
Barlic-Maganja
Darja
D
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018175:Birnaviridae Infections / Q000662:veterinary* / Q000821:virology; D002645:Chickens; D004196:Disease Outbreaks / Q000662:veterinary*; D007243:Infectious bursal disease virus / Q000235:genetics* / Q000472:pathogenicity; D008969:Molecular Sequence Data; D011201:Poultry Diseases / Q000821:virology*; D017524:Slovenia / Q000453:epidemiology; D014774:Virulence