Abstract
Probiotic Kocuria SM1, which was part of the allochthonous gut microbiota of rainbow trout, was administered to rainbow trout ( Oncorhynchus mykiss) fingerlings as dietary supplement at ∼10 8 cells g −1 for two weeks. The fish were challenged with Vibrio anguillarum and innate immunity determined over the following 5 weeks. The probiotic-fed fish survived (mortalities = 10–28%; P < 0.05) better than the controls (mortalities = 73–92%) for 5 weeks after stopping administration of Kocuria SM1, although the relative percent survival (RPS) declined steadily from 87 to 36% by the end of the experiment. A significant ( P < 0.05) effect on the immune parameters was observed in fish within 3 weeks after stopping administration of Kocuria SM1 in comparison with the controls, i.e. enhancement of the respiratory burst (OD 550nm) from 0.051 ± 0.014 to 0.067 ± 0.009, lysozyme 605 ± 185 units ml −1 to 872 ± 114 units ml −1, total protein 19.8 ± 2.0 mg ml −1 to 23.8 ± 0.8 mg ml −1 at 2 weeks, and leukocrit 2.9 ± 1.8% to 5.1 ± 1.1%, peroxidase (OD 550nm) 0.23 ± 0.02 to 0.37 ± 0.11 and bacterial killing activities (percentage of surviving bacteria = 82 ± 12% to 57 ± 4%) at 3 weeks. Generally, the levels reduced progressively towards the end of experiment.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call