causal agent of ulcer disease of trout . Examination
of the small subunit rRNA gene sequences revealed
99.9% homology of an authentic strain of H. piscium
with A. salmonicida subsp. salmonicida [124]. So far,
the comparative uniqueness of subsp. smithia has been
indicated from several studies . The complication
is with aberrant strains of A. salmonicida from fish
species other than salmonids.