Characterization of susceptibility and carrier status of burbot, Lota lota (L.), to IHNV, IPNV, Flavobacterium psychrophilum, Aeromonas salmonicida and Renibacterium salmoninarum

Abstract

In this study, susceptibility and potential carrier status of burbot, Lota lota, were assessed for five important fish pathogens. Burbot demonstrated susceptibility and elevated mortality following challenge with infectious haematopoietic necrosis virus (IHNV) by immersion and to Aeromonas salmonicida by intraperitoneal (i.p.) injection. IHNV persisted in fish for at least 28 days, whereas A. salmonicida was not re-isolated beyond 17 days post-challenge. In contrast, burbot appeared refractory to Flavobacterium psychrophilum following intramuscular (i.m.) injection and to infectious pancreatic necrosis virus (IPNV) by immersion. However, i.p injection of IPNV resulted in re-isolation of virus from fish for the duration of the 28 day challenge. Renibacterium salmoninarum appeared to induce an asymptomatic carrier state in burbot following i.p. injection, but overt manifestation of disease was not apparent. Viable bacteria persisted in fish for at least 41 days, and bacterial DNA isolated by diagnostic polymerase chain reaction was detected from burbot kidney tissue 90 days after initial exposure. This study is the first to investigate susceptibility of burbot to selected fish pathogens, and this information will aid in efforts to culture and manage this species.

Mycobacterium salmoniphilum infection in burbot Lota lota

“…Little is known of the natural pathogens of burbot and of the susceptibility of this fish species to pathogenic agents. To the best of our knowledge, the only relevant published work is that of Polinski et al (2010) in which they investigated the virulence of infectious haematopoetic necrosis virus (IHNV), infectious pancreatic necrosis virus (IPNV), Aeromonas salmonicida, Flavobacterium psychrophilum and Renibacterium salmoninarum in burbot. No overt disease was demonstrated.…”

Performance and Macronutrient Composition of Age‐0 Burbot Fed Four Diet Treatments

“…Beginning in 2003, an experimental research program initiated at the University of Idaho's Aquaculture Research Institute (UIARI) focused on assessing the feasibility of developing burbot culture as a population restoration measure. Spawning, sperm motility inhibition, and semen cryopreservation methods were developed first (Zuccarelli et al 2007;Jensen et al 2008aJensen et al , 2008b, followed by incubation methods and larval and juvenile rearing strategies (Jensen et al 2008c;Polinski et al 2010c), and then burbot disease susceptibility was characterized (Polinski et al 2010a(Polinski et al , 2010b. Collectively, these efforts enabled the first releases of cultured burbot of ages 0, 1, 2, and 3 years for conservation purposes in British Columbia and Idaho in 2009.…”

Comparison of injection and immersion challenges of Renibacterium salmoninarum strains in Rainbow Trout

“…Based on this information, fish in the CK-90 immersion challenge could have started to show clinical signs of R. salmoninarum infection if the trial period had lasted beyond 28 days. Studies investigating R. salmoninarum challenges have used various trial durations, such as 34 days (Campos-Perez et al 2000), 60 days (Polinski et al 2010), and 90 days (Jones et al 2007). Therefore, an extended postchallenge monitoring period may be important to implement in future BKD immersion challenge studies.…”

“…Hence, there were 14 tanks in total. Forty-five fish per treatment group were injected with 100 μL of a high dose (OD at 525 nm [OD 525 ] = 1.779; 9.8 × 10 8 CFU/mL) equalling 4.80 × 10 6 CFU/g of fish, or a low dose (OD 525 = 1.077; 1.4 × 10 8 CFU/mL) equalling 6.86 × 10 5 CFU/g of fish of R. salmoninarum CK-90 based on OD ranges reported by Polinski et al (2010). Rainbow Trout were anesthetized using buffered tricaine methanesulfonate (MS-222, 80 mg/L; Syndel) prior to injection.…”