An inhibitor of bacterial quorum sensing reduces mortalities caused by Vibriosis in rainbow trout (Oncorhynchus mykiss, Walbaum).
The fish pathogen Vibrio anguillarum produces quorum sensing signal molecules, N-acyl homoserine lactones (AHLs), which in several Gram-negative human and plant pathogenic bacteria regulate virulence factors. Expression of these factors can be blocked using specific quorum-sensing inhibitors (QSIs). The purpose of this study was to investigate the effect of a QSI, furanone C-30, on mortality of rainbow trout during challenge with V. anguillarum. Addition of 0.01 or 0.1 microM furanone C-30 to rainbow trout infected by cohabitation caused a significant reduction in accumulated mortality from 80-100% in challenge controls to 4-40% in treated groups. Furanone C-30 had no effect in an immersion challenge system, probably due to a very high water exchange and a rapid dilution of furanone C-30. Growth and survival of V. anguillarum were not affected by the concentrations of furanone C-30 used in the challenge experiments, thus avoiding selection for resistance. To elucidate the mechanism of disease control by furanone C-30, we determined its effect on the bacterial proteome, motility, and respiration. No effects were seen of furanone C-30 in any of these experiments. Although no cytotoxic effect on HeLa cells were observed, exposure to 1 microM (or higher) concentrations of furanone C-30 had detrimental effects on the rainbow trout. Our results indicate that QSIs can be used in non-antibiotic based control of fish diseases. However, they also underline the need for development of novel, less toxic QSI compounds and the need for understanding the exact mechanism(s) of action.
Rasch
Maria
M
Danish Institute for Fisheries Research, Department of Seafood Research, Søltofts Plads, c/o Technical University of Denmark, Lyngby, Denmark.
Buch
Christiane
C
Austin
Brian
B
Slierendrecht
Wilhelmina J
WJ
Ekmann
Kim S
KS
Larsen
Jens Laurits
JL
Johansen
Charlotte
C
Riedel
Kathrin
K
Eberl
Leo
L
Givskov
Michael
M
Gram
Lone
L
D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000096:biosynthesis; D000818:Animals; D001426:Bacterial Proteins / Q000032:analysis; D004734:Energy Metabolism / Q000187:drug effects; D005393:Fish Diseases / Q000382:microbiology / Q000401:mortality*; D005663:Furans / Q000494:pharmacology / Q000627:therapeutic use* / Q000633:toxicity; D015964:Gene Expression Regulation, Bacterial; D006367:HeLa Cells; D006801:Humans; D009068:Movement / Q000187:drug effects; D017686:Oncorhynchus mykiss / Q000382:microbiology*; D020543:Proteome; D014733:Vibrio / Q000187:drug effects* / Q000472:pathogenicity* / Q000502:physiology; D014735:Vibrio Infections / Q000382:microbiology / Q000401:mortality / Q000662:veterinary*; D037521:Virulence Factors / Q000096:biosynthesis / Q000235:genetics
D001426:Bacterial Proteins; D005663:Furans; D020543:Proteome; D037521:Virulence Factors; C494198:furanone C-30; C088386:homoserine lactone; D015107:4-Butyrolactone