First report and characterization of Tenacibaculum maritimum isolates recovered from rainbow trout (Oncorhynchus mykiss) farmed in Chile

Abstract

The present study reports on the first isolation of Tenacibaculum maritimum in rainbow trout (Oncorhynchus mykiss) farmed in Chile. In March 2020, two cages raising rainbow trout (~250 g) in the Los Lagos Region suffered a disease outbreak. In total, 17,554 fish died (3.5%-4.8% accumulated mortality). Microbiological analysis of the diseased fish obtained two representative isolates (i.e. Tm-035 and Tm-036). These were obtained from the external gross skin lesions-typical of tenacibaculosis-of two fish. Phenotyping, PCR tests and sequencing of the 16S rRNA and housekeeping genes confirmed the isolates as T. maritimum. The pathogenic potential of Tm-035 was further assessed by bath challenging Atlantic salmon (Salmo salar), which killed 70 ± 15% of fish within 11 days. Dead fish presented the same external clinical signs as did the farmed rainbow trout specimens. This research further broadens the known host distribution of this pathogen. Furthermore, the virulence experiments demonstrated that T. maritimum does not have a specific host. Additional studies are needed to evaluate the risk of T. maritimum for the O. mykiss farming industry.

Genomic characterization of Tenacibaculum maritimum O‐antigen gene cluster and development of a multiplex PCR‐based serotyping scheme

“…It has originally been isolated in 1977 in Japan during mortality events on marine red seabream (Pagrus major) and black sea bream (Acanthopagrus schlegelii) (Masumura & Wakabayashi, 1977;Wakabayashi et al, 1984). Since then, it has been retrieved from a large variety of marine fish species worldwide including: Atlantic salmon (Salmo salar) in Australia (van Gelderen, 2007) and in Chile (Apablaza et al, 2017), rainbow trout (Oncorhynchus mykiss) in Australia (van Gelderen, 2007) and in Chile (Valdes et al, 2021), Chinook salmon (Oncorhynchus tshawytscha)…”

“…It has originally been isolated in 1977 in Japan during mortality events on marine red seabream ( Pagrus major ) and black sea bream ( Acanthopagrus schlegelii ) (Masumura & Wakabayashi, 1977; Wakabayashi et al., 1984). Since then, it has been retrieved from a large variety of marine fish species worldwide including: Atlantic salmon ( Salmo salar ) in Australia (van Gelderen, 2007) and in Chile (Apablaza et al., 2017), rainbow trout ( Oncorhynchus mykiss ) in Australia (van Gelderen, 2007) and in Chile (Valdes et al., 2021), Chinook salmon ( Oncorhynchus tshawytscha ) in Canada (Ostland et al., 1999), turbot ( Scophthalmus maximus ), sole ( Solea solea ) and blackspot seabream ( Pagellus bogaraveo ) in Spain (Castro et al., 2007), batfish ( Platax orbicularis ) in French Polynesia (Lopez et al., 2022) and sea bass ( Dicentrarchus labrax ) and seabream ( Sparus aurata ) in Europe (Muniesa et al., 2020). Fish often display gross external lesions including eroded mouth, skin ulcers or necrosis, frayed fins and tail rot (Avendaño‐Herrera et al., 2006; Nowlan et al., 2020).…”

Isolation, identification, virulence potential and genomic features of Tenacibaculum piscium isolates recovered from Chilean salmonids

“…Blue dots indicate a bootstrap support ≥ 98% superfamily I-WP_101916599) and triclosan and isoniazid (fabV-WP_101916498). Excepting fabV, all of these genes were previously identified in T. dicentrarchi (Saldarriaga-Córdoba et al, 2021).…”

“…Tenacibaculum species generally present as long rod and/or filamentous gram‐negative cells and are widespread in marine environments, commonly adhering to biotic/abiotic surfaces (Olsen et al., 2019; Suzuki et al., 2001). Descriptions from Chile include Tenacibaculum dicentrarchi from Atlantic salmon ( Salmo salar ) and red conger eel ( Genypterus chilensis ) (Avendaño‐Herrera et al., 2016; Irgang et al., 2017) and Tenacibaculum maritimum from turbot ( Scophthalmus maximus ) (Bernardet, 1998; Bridel et al., 2020), Atlantic salmon (Apablaza et al., 2017) and Rainbow trout ( Oncorhynchus mykiss ) (Valdés et al., 2021). Tenacibaculum finnmarkense was also confirmed following reclassification of an isolate originally described as T. dicentrarchi (Bridel et al., 2018).…”

Draft Genome Sequence of Tenacibaculum ovolyticum To-7Br, Recovered from a Farmed Atlantic Salmon ( Salmo salar )

“…To date, 31 Tenacibaculum species are validly described ( https://www.bacterio.net/ ), including several microorganisms recognized as putative pathogens associated with tenacibaculosis in fish ( 2 , 3 ). Studies on the bacterial microbiota associated with fish diseases have described the presence of Tenacibaculum dicentrarchi ( 4 ), Tenacibaculum finnmarkense ( 5 ), Tenacibaculum maritimum ( 6 , 7 ), and Tenacibaculum piscium ( 8 ) in Chilean salmon aquaculture. The present study describes the presence and genome sequence of a T. ovolyticum isolate retrieved from a gill of Atlantic salmon ( Salmo salar ) farmed in southern Chile (Seno Gala, 44°11′21″S, 73°8′1″W) in April 2018.…”