Tenacibaculosis caused by Tenacibaculum maritimum: Updated knowledge of this marine bacterial fish pathogen

Abstract

Tenacibaculosis occurs due to the marine bacterial pathogen Tenacibaculum maritimum. This ulcerative disease causes high mortalities for various marine fish species worldwide. Several external clinical signs can arise, including mouth erosion, epidermal ulcers, fin necrosis, and tail rot. Research in the last 15 years has advanced knowledge on the traits and pathogenesis mechanisms of T. maritimum. Consequently, significant progress has been made in defining the complex host-pathogen relationship. Nevertheless, tenacibaculosis pathogenesis is not yet fully understood. Continued research is urgently needed, as demonstrated by recent reports on the re-emerging nature of tenacibaculosis in salmon farms globally. Current sanitary conditions compromise the development of effective alternatives to antibiotics, in addition to hindering potential preventive measures against tenacibaculosis. The present review compiles knowledge of T. maritimum reported after the 2006 review by Avendaño-Herrera and colleagues. Essential aspects are emphasized, including antigenic and genomic characterizations and molecular diagnostic procedures. Further summarized are the epidemiological foundations of the T. maritimum population structure and elucidations as to the virulence mechanisms of pathogenic isolates, as found using biological, microbiological, and genomic techniques. This comprehensive source of reference will undoubtable serve in tenacibaculosis prevention and control within the marine fish farming industry. Lastly, knowledge gaps and valuable research areas are indicated as potential guidance for future studies.

New Zealand rickettsia‐like organism and Tenacibaculum maritimum vaccine efficacy study

“…The pathogenesis and epidemiology of T. maritimum is far from being a resolved issue. However, challenge studies have found high mortality (>90%) for Atlantic salmon exposed to high concentration T. maritimum – 2.7 × 10 7 cfu/mL (Nowlan et al., 2021), and other studies have shed light into the multifactorial nature of the disease and interaction with other bacteria (Wynne et al., 2020) leading to calls for further studies on T. maritimum pathogenesis (Mabrok et al., 2022). Furthermore, we propose that case–control epidemiological studies are needed in order to understand the risk factors associated with mouth rot and exposure to T. maritimum before a conclusion is reached in regard to the value of vaccination against T. maritimum .…”

“…T. maritimum is a ubiquitous marine gram‐negative rod associated with generalized tenacibaculosis and mouthrot in Atlantic salmon (Frisch, Småge, Vallestad, et al., 2018). It is present in all salmon farming regions in the world, although it is not specific to salmonids (Avendaño‐Herrera et al., 2006; Mabrok et al., 2022). Fish affected with tenacibaculosis may display erosive and ulcerative lesions in mouth, skin and fins which can eventually lead to death, however, the pathogenicity of the infection remains unclear and it is yet to be elucidated (Avendaño‐Herrera et al., 2006; Mabrok et al., 2022).…”

“…It is present in all salmon farming regions in the world, although it is not specific to salmonids (Avendaño‐Herrera et al., 2006; Mabrok et al., 2022). Fish affected with tenacibaculosis may display erosive and ulcerative lesions in mouth, skin and fins which can eventually lead to death, however, the pathogenicity of the infection remains unclear and it is yet to be elucidated (Avendaño‐Herrera et al., 2006; Mabrok et al., 2022). Generally, T. maritimum is not thought to act as a primary pathogen in Chinook salmon.…”

Tenacibaculum bernardetii sp. nov., isolated from Atlantic salmon (Salmo salar L.) cultured in Chile

“…Results presented for enzymatic activity: 1 , prepared with artificial seawater; 2 , sterilized seawater and 3 , saline solution. 4 , indicates a positive result with all three-suspension media. nd, No data; w, weak reaction; v, variable.…”

“…Most Tenacibaculum species have been described from fish, marine sediments, macroalgae and invertebrates [1] and are considered non-pathogenic. Notwithstanding, nine members are associated with a disease termed tenacibaculosis, which causes ulcerative external infections in commercially farmed fish worldwide [2][3][4][5]. Fish affected by this disease present skin lesions (with injuries that are commonly ulcerative), frayed fins, tail rot, eroded mouth and haemorrhaging gills [2][3][4].…”