ABSTRACT
The biological, serological and genomic characterization of a paramyxovirus recently
isolated from Rockhopper Penguins (Eudyptes chrysocome) suggested that this virus
represented a new avian paramyxovirus group, APMV10. This penguin virus resembled
other APMV by electron microscopy; however, its viral hemagglutination (HA) activity
was not inhibited by antisera against any of the nine defined APMV serotypes. In
addition, antiserum generated against this penguin virus did not inhibit the HA of
representative viruses of the other APMV serotypes. Sequence data produced using
random priming methods revealed a genomic structure typical of APMV. Phylogenetic
evaluation of coding regions revealed that amino acid sequences of all six proteins were
most closely related to APMV2 and APMV8. The calculation of evolutionary distances
among proteins and distances at the nucleotide level confirmed that APMV2, APMV8
and the penguin virus all were sufficiently divergent from each other to be considered
different serotypes. We propose that this isolate, named APMV10/penguin/Falkland
Islands/324/2007, be the prototype virus for APMV10. Because of the known problems
associated with serology, such as antiserum cross reactivity, one-way immunogenicity, in
addition to the reliance on the immune response to a single protein, the hemagglutinin-
neuraminidase, as the sole base for viral classification, we suggest the need for new
classification guidelines that incorporate genome sequence comparisons.
