Abstract

Over the last few years, several novel Flavobacterium species isolated from diseased fish in Europe and America have been described. In Chile, Flavobacterium chilense LM-09-FPT was isolated in 2006 from an external lesion on diseased rainbow trout (Oncorhynchus mykiss) reared in a fish farm near Aysen, while Flavobacterium spartansii LM-19-FPT was recovered from kidney from diseased Atlantic salmon (Salmo salar) farmed in Concepcion in 2008. This short communication reports the results of extensive challenge assays with these two bacterial species, in order to determine their pathogenic potential in rainbow trout (weighing 3-4 or 20-25 g) obtained from Rio Blanco fish farm (located in central Chile, Los Andes). Our findings demonstrate that F. chilense and F. spartansii alone are not able to induce fish mortalities or any clinical signs of infection in rainbow trout, suggesting that they are probably not pathogenic for this fish species.