Genotyping of Tenacibaculum maritimum isolates from farmed Atlantic salmon in Western Canada.

K Frisch,A Nylund,S B Småge,H Duesund,Ø J Brevik

doi:10.1111/jfd.12687

Abstract

Mouthrot infections (bacterial stomatitis) have a significant impact on the Atlantic salmon aquaculture industry in Western Canada due to economic losses and fish welfare. Bacteria isolated from lesions in the field have been identified as Tenacibaculum maritimum. Mouthrot is different to classical tenacibaculosis, which is most commonly associated with ulcerative lesions, frayed fins and tail rot. The marine fish pathogen T.maritimum is found worldwide; however, in Western Canada, the knowledge of the genetic profile of T.maritimum is limited. This study looked at increasing this knowledge by genotyping T.maritimum isolates collected from Atlantic salmon from farms in Western Canada. These genotypes were compared to other species of the genus Tenacibaculum, as well as other known sequence types within the species. The Western Canadian isolates belong to two new sequence types within the T.maritimum species. Phylogenetic analysis shows that the isolates form a distinct branch together with T.maritimum NCIMB 2154T separate from other Tenacibaculum type strains, and they are most closely related to strains from Norway and Chile.

Highlights

Tenacibaculum maritimum is a marine Gram-negative bacterium in the family Flavobacteriaceae (Suzuki, Nakagawa, Harayama, & Yamamoto, 2001; Wakabayashi, Hikida, & Masumura, 1986)
The results of the 16S rRNA phylogenetic analysis (Figure 2) show that the T. maritimum isolates found in Western Canada form a distinct branch together with T. maritimumT separate from other Tenacibaculum type strains
ml kanamycin (MKA) inhibited the growth of other faster growing bacteria that routinely outcompete T. maritimum on primary cultures from skin or ulcers grown on marine agar (MA)

Summary

Introduction

Tenacibaculum maritimum is a marine Gram-negative bacterium in the family Flavobacteriaceae (Suzuki, Nakagawa, Harayama, & Yamamoto, 2001; Wakabayashi, Hikida, & Masumura, 1986). Habib et al (2014) used MLST and MLSA to describe 47 sequence types (STs) of 73 T. maritimum strains from a variety of host species worldwide.

Results

Conclusion