Differential susceptibility to furunculosis of turbot and rainbow trout and release of the furunculosis agent from furunculosis-affected fish

Colonization of turbot tissues by virulent and ­avirulent Aeromonas salmonicida subsp. ­salmonicida strains during infection

“…This study is the first investigation of ASS infections using turbot under natural infection conditions. The ASS strain RIM 33.1 used in our study caused the death of infected turbot as previously noted by Pérez et al (1996) with other strains. In salmonids, ASS was previously shown to attach to epidermal mucus (Ferguson et al 1998, Svendsen et al 1999, and it was also suggested that ASS may be detected in the skin mucus of presumptive carrier fish (Cipriano et al 1994).…”

“…Earlier, ASS was thought to cause disease mainly in salmonids (see reviews by Toranzo et al 2005, Austin & Austin 2007. However, ASS was later shown to cause disease in the flatfish turbot Psetta maxima (Nougayrede et al 1990, Toranzo & Barja 1992, Pedersen & Larsen 1996, Pérez et al 1996, Najimi et al 2008, but little evidence is available about the route of infection of ASS in this non-salmonid finfish.…”

Virulence factors of Aeromonas salmonicida subsp. salmonicida strains associated with infections in turbot Psetta maxima

“…The flaA and flaB genes, which encode 2 subunits of the polar flagellum, have been associated with invasion and colonisation of motile Aeromonas on fish (Rabaan et al 2001), but their role is unknown in ASS. The ability of ASS to cause infection in another economically important farmed fish, turbot Psetta maxima, has been shown (Nougayrede et al 1990, Pedersen & Larsen 1996, Pérez et al 1996, Toranzo et al 2005, Najimi et al 2008. Recently, we tracked virulent and avirulent strains (included in the present study) of ASS during infection of turbot, providing important information on the persistence of the pathogen in this host (Farto et al 2011).…”

Farm size as a factor in hydrodynamic transmission of pathogens in aquaculture fish production

“…For ease and maximum transmission, the maximum risk distance from a farm with the mean Scottish consented biomass of 1400 t (Walker 2010) containing infected fish at reported prevalences is assumed to have the peak shedding rates (γ) of 6.8 × 10 3 TCID 50 ml -1 h -1 kg -1 for IPNV-t particles (Urquhart et al 2008) and 7 × 10 1 ml -1 h -1 kg -1 for ISAV-t particles (Pérez et al 1996) there was an associated minimum infective dose of 10 8 cfu ml -1 over 12 h exposure and a shedding rate of 1.75 × 10 6 cfu ml -1 h -1 (Rose et al 1990). The prevalence for each pathogen is reported as 12.5% for IPNV-t in Scottish salmon (Bruno 2004) and 75% for AS-t from experimental infection of Chinook salmon .…”

“…Global production is forecast to increase by 6% per annum to 130 million t by 2020 (FAO 2009), and to fulfil this demand aquaculture sites need to become more abundant and increase the level of production per site. The aquaculture industry in China accounts for 2/3 of global production (FAO 2007) and has doubled the area used for aquaculture whilst having a 6-fold increase in production during to 1996(FAO 1997, indicating that on average size per production unit has increased. For production to further increase, industries must become more efficient by minimising stock loss due to infectious disease, as it is estimated that this costs 3 billion USD globally (Subasingh et al 2001).…”