2018/07/16 by Somayeh Torabi Delshad, Siyavash Soltanian, Hassan Sharifiyazdi +1
paper · doi:10.1111/jfd.12840
Abstract Five N‐acyl homoserine lactone‐degrading bacteria (quorum quenching ( QQ ) strains) were selected to evaluate their impacts on growth, virulence factors and biofilm formation in Yersinia ruckeri in vitro . No difference was observed among the growth pattern of Y. ruckeri in monoculture and coculture with the QQ strains. To investigate the regulation of virulence factors by quorum sensing in Y. ruckeri , cultures were supplemented with 3oxo‐C8‐ HSL . The results indicated that swimming motility and biofilm formation are positively regulated by QS ( p HSL ( p > 0.05). The QQ s were able to decrease swimming motility and biofilm formation in Y. ruckeri . QQ bacteria were supplemented to trout feed at 10 8 CFU/g (for 40 days). Their probiotic effect was verified by Y. ruckeri challenge either by immersion or injection in trout. All strains could significantly increase fish survival with Bacillus thuringiensis and Citrobacter gillenii showing the highest and lowest relative percentage survival ( RPS ) values (respectively, 85% and 38%). Besides, there was no difference between the RPS values by either immersion or injection challenge expect for B. thuringiensis . The putative involvement of the QQ capacity in the protection against Yersinia is discussed.