Use of a probiotic to control lactococcosis and streptococcosis in rainbow trout, Oncorhynchus mykiss (Walbaum)

Citation

Brunt J & Austin B (2005) Use of a probiotic to control lactococcosis and streptococcosis in rainbow trout, Oncorhynchus mykiss (Walbaum). Journal of Fish Diseases, 28 (12), pp. 693-701. https://doi.org/10.1111/j.1365-2761.2005.00672.x

Abstract
From a comparison of 125 bacterial isolates recovered from the digestive tract of rainbow trout, Oncorhynchus mykiss, and carp, Cyprinus sp., a culture was obtained which was effective at preventing clinical disease caused by Lactococcus garvieae and Streptococcus iniae when used as a feed additive. The culture, Aeromonas sobria GC2, was incorporated into the feed and fed to rainbow trout (average weight = 20 g) for 14 days at a dose equivalent to 5 × 107 cells g−1 of feed. Whereas the untreated controls experienced losses of 75–100% when challenged intraperitoneally with L. garvieae and S. iniae, the probiotic-treated groups remained healthy with total mortalities of only 0–6%. Formalized and sonicated preparations of GC2 and cell-free supernatant fared less well. The mode of action reflected stimulation of innate immunity, namely an increased number of leucocytes and enhanced phagocytic and respiratory burst activity.

Keywords
Aeromonas sobria;control;lactococcosis;probiotic;rainbow trout;streptococcosis

Journal
Journal of Fish Diseases: Volume 28, Issue 12