-positive , a novel teleost pathogen isolated from cultured barramundi.

Members of the genus are emergent pathogens of cultured eels, as well as several characid and cyprinid species. Since 2013, has been reported from diseased barramundi () cultured in North America; we recovered 8 isolates from diseased fish during different outbreaks from the same farm. The isolates from barramundi were compared phenotypically and genetically to isolates characterized from ornamental fish and recovered from aquatic and terrestrial animals. All barramundi isolates were PCR-positive for the surface protective antigen type B () gene, and shared ≥ 99.7% sequence similarity among concatenated multilocus sequence analysis gene sequences, indicating a high degree of genetic homogeneity. These isolates were > 99% similar to other positive isolates from marine invertebrates and marine mammals, consistent with findings for other types. The and isolates shared < 98% similarity, as well as < 90% similarity with positive . Similar clonality among the isolates was observed using repetitive element palindromic PCR. In experimental intracoelomic injection challenges conducted to fulfill Koch postulates, 67% of exposed tiger barbs () died within 14 d of challenge. Our study supports previous work citing the genetic variability of spp. types and the emergence of members of the genus as nascent fish pathogens.