Antigenic and genetic diversity of early European isolates of Infectious bursal disease virus prior to the emergence of the very virulent viruses: early European epidemiology of Infectious bursal disease virus revisited?
Eleven Polish and Hungarian isolates of Infectious bursal disease virus (IBDVs) obtained in the 70/80s (early IBDV) and in the 90s (recent IBDV) were characterized in an Antigen-Capture-ELISA with a panel of neutralizing monoclonal antibodies (Mabs), and by nucleotide sequencing of the VP2 variable domain (vVP2). The viruses were compared with reference IBDV strains, among others with Faragher 52/70 (F52/70, classical, isolated 1970), 89163 (typical very virulent-vvIBDV, isolated 1989) and 91168 (antigenically modified vvIBDV, isolated 1991). Only one of the early isolates (Hungarian strain P1) proved antigenically and genetically similar to F52/70. Other early isolates exhibited no reactivity versus Mabs 3, 4, 5 and/or 8 and had a common previously unrecognized combination of amino acid changes in vVP2. The recent isolates all proved antigenically and genetically related to typical vvIBDV strain 89163, except the Polish isolate 93/35 which proved related to the 91168 strain although no epidemiological relationship had been documented between these viruses in the field. Phylogenetic analysis confirmed that the non-P1 early IBDVs represent a previously unrecognized group among serotype 1 IBDVs. It is discussed whether these early isolates are derivatives of the F52/70-like viruses that might still be present in the field, or whether they represent early IBDV strains that might have been present prior to and progressively replaced by the F52/70-like viruses, as the latter have been replaced by vvIBDVs in the late eighties.
Department of Poultry Diseases, National Veterinary Research Institute, Pulawy, Poland.
K
K
Domanska
T
T
Mato
G
G
Rivallan
K
K
Smietanka
Z
Z
Minta
C
C
de Boisseson
D
D
Toquin
B
B
Lomniczi
V
V
Palya
N
N
Eterradossi
D000595:Amino Acid Sequence; D000818:Animals; D000940:Antigenic Variation; D018175:Birnaviridae Infections / Q000453:epidemiology* / Q000821:virology; D002642:Chick Embryo; D002645:Chickens; D004196:Disease Outbreaks; D005060:Europe / Q000453:epidemiology; D014644:Genetic Variation; D006814:Hungary / Q000453:epidemiology; D007243:Infectious bursal disease virus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity; D008969:Molecular Sequence Data; D010802:Phylogeny; D011044:Poland / Q000453:epidemiology; D011201:Poultry Diseases / Q000453:epidemiology* / Q000821:virology; D014422:Turkeys