Nocardia salmonicida nom. rev., a fish pathogen

Abstract

An almost complete gene sequence of 16S rDNA of 'Nocardia salmonicida' strain JCM 4826(T) was determined following cloning and sequencing of the amplified gene. The sequence was aligned with those available for nocardiae and phylogenetic trees inferred using four tree-making algorithms. The organism and the type strain of Nocardia asteroides consistently formed a monophyletic clade with a distant sequence similarity of 97 %. However, previous DNA relatedness experiments showed that strain JCM 4826(T) and Nocardia asteroides ATCC 19247(T) belong to different genomic species. The organism was also distinguished from representatives of all validly described species of Nocardia using a combination of phenotypic features. The polyphasic evidence showed that the strain merits recognition as a new species of the genus Nocardia. The name proposed for the new species is Nocardia salmonicida nom. rev.