Tenacibaculosis induction in the Senegalese sole (Solea senegalensis) and studies of Tenacibaculum maritimum survival against host mucus and plasma

Abstract

Tenacibaculum maritimum, the aetiological agent for marine tenacibaculosis, is one of the most significant pathogens that threaten Senegalese sole, Solea senegalensis (Kaup), aquaculture. Because no immersion challenge with T. maritimum has been reported previously for this flatfish species, this study aimed to optimize bacterial yields as well as to establish a challenge model for tenacibaculosis induction. Several approaches were performed to optimize bacterial culture conditions, including treatment with non-ionic surfactants, detergents, cellulase hydrolysis and strong shaking. A prolonged bath challenge was performed for 24 h under two different temperatures, 16 and 23 °C. Moreover, mucus and plasma bactericidal activities against T. maritimum were also assessed. Culturing bacteria with strong shaking and continuous shaking provided suitable culture conditions to obtain higher bacterial yields without aggregation and fluctuation, contrary to most other treatments that showed a huge amount of bacterial aggregates. A prolonged bath method for 24 h, without skin or gill scarification, was considered suitable for disease induction with high mortality rates. Moreover, data regarding mucus and plasma bactericidal activities suggested that there is a lack of host innate immune response against T. maritimum or that this particular pathogen presents evading strategies against Senegalese sole.

Experimental induction of mouthrot in Atlantic salmon smolts using Tenacibaculum maritimum from Western Canada

“…Because of this, we found that estimating bacterial growth and cell concentrations was challenging. The use of surfactants or detergents to avoid bacterial aggregates in broth culture has been unsuccessful, and the best technique for growing the bacteria is rigorous shaking (Mabrok et al., ), which is the method we used. Regular methods of bacterial cell concentration measurements such as optical density (OD) and cell chamber counting were found to be unreliable due to poor repeatability.…”

“…Scarification or abrasion pre‐exposure was originally thought to be a prerequisite for positive results, as was performed in Black Sea bream ( Acanthopagrus schlegelii , Bleeker) (Baxa et al., ). However, this is not necessary, and prolonged bath exposure without scarification has induced tenacibaculosis in Senegalese sole ( Solea senegalensis , Kaup) (Mabrok et al., ) and turbot (Avendaño‐Herrera et al., ). More recently, a shorter bath immersion has also been successful in Japanese flounder (Nishioka et al., ), and a short immersion followed by a dilution of the bath over time produced more stable mortality rates in this species than immersion followed by transfer into a new tank (Yamamoto et al., ).…”

“…One of the challenges in T. maritimum research is the difficulty to develop a replicable challenge model. A number of experiments have been conducted attempting to reproduce tenacibaculosis in economically important fish species around the world (Avendaño-Herrera, Toranzo, & Magariños, 2006a;Baxa, Kawai, & Kusuda, 1987;Carson, McCosh, & Schmidtke, 1992;Handlinger, Soltani, & Percival, 1997;Mabrok, Afonso, Valente, & Costas, 2015;Mabrok et al, 2016;Nishioka, Watanabe, & Sano, 2009;Powell, Carson, & van Gelderen, 2004;Soltani, Munday, & Burke, 1996;van Gelderen, Carson, & Nowak, 2010;Wakabayashi, Hikida, & Masumura, 1984;Yamamoto, Kawai, & Oshima, 2010). Injection models are frequently used in fish as they allow for more control and therefore reproducibility; for example, Infectious pancreatic necrosis virus or Piscirickettsia salmonis in Atlantic salmon (Rozas & Enr ıquez, 2014;Taksdal, Ramstad, Stangeland, & Dannevig, 1998).…”

Advancements in Characterizing Tenacibaculum Infections in Canada

“…As mentioned above, eight Tenacibaculum species have been proposed as pathogens of marine finfish and possibly bivalves. Clinical signs of tenacibaculosis in marine fishes typically include external ulcers [ 6 , 7 , 9 , 12 , 16 , 26 , 98 , 99 , 100 ], frayed fins [ 12 , 14 , 98 , 100 , 101 ], pale organs [ 12 , 98 , 100 , 102 ], mortality [ 6 , 7 , 9 , 11 , 12 , 99 ], and atypical behaviors including lethargy [ 11 , 16 , 86 , 99 ], abnormal swimming (i.e., flashing) [ 16 , 26 , 74 , 100 ], and anorexia [ 16 , 26 , 99 ]. Three Tenacibaculum species have also been linked to disease in shellfish, including T. maritimum , T. soleae , and T. mesophilum .…”

New perspective to control of tenacibaculosis in sea bassDicentrarchus labraxL

“…Tenacibaculosis is Gram‐negative bacterial disease and is described as salt water columnaris, bacterial stomatitis disease and gliding bacterial disease of sea fish (Avendaño‐Herrera, Toranzo, & Magarinos, ) which is one of the most bacterial diseases threatening fish culture in the world (Mabrok et al., ). Tenacibaculosis affects many marine fish species including sea bass (Chen, Henry‐Ford, & Groff, ; Yardimci & Gülşen, ) and is caused by Tenacibaculum maritimum ( T. maritimum ) (Sverre et al., ).…”