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Effect of quorum quenching bacteria on growth, virulence factors and biofilm formation of Yersinia ruckeri in vitro and an in vivo evaluation of their probiotic effect in rainbow trout
Author(s) -
Torabi Delshad Somayeh,
Soltanian Siyavash,
Sharifiyazdi Hassan,
Bossier Peter
Publication year - 2018
Publication title -
journal of fish diseases
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 85
eISSN - 1365-2761
pISSN - 0140-7775
DOI - 10.1111/jfd.12840
Subject(s) - yersinia ruckeri , microbiology and biotechnology , biofilm , biology , quorum sensing , virulence , probiotic , quorum quenching , bacteria , rainbow trout , biochemistry , genetics , fishery , fish <actinopterygii> , gene
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 < 0.05), whereas caseinase, phospholipase and haemolysin productions are not influenced by 3oxo‐C8‐ 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.