First identification in Tasmania of fish pathogens Tenacibaculum dicentrarchi and T. soleae and multiplex PCR for these organisms and T. maritimum.

This work describes a new polymerase chain reaction (PCR) assay for rapid identification of the fish pathogens Tenacibaculum dicentrarchi, T. maritimum and T. soleae, 3 organisms which can cause tenacibaculosis in farmed salmonids. The selected primers amplified a 688 bp fragment for T. dicentrarchi, a 288 bp fragment of the T. maritimum and a 183 bp fragment of the T. soleae 16S rRNA genes. The PCR assay was shown to be both specific and sensitive with a detection limit of approximately 50 fg DNA for each species in the presence of competing DNA. The multiplex PCR allowed detection of each pathogen from pure or mixed cultures, where the different Tenacibaculum species can be difficult to distinguish phenotypically. Our results indicate that the specific primers and PCR method developed here provide sensitive and fast detection of T. dicentrarchi, T. maritimum and T. soleae alone or in combination.