title: The catecholamine stress hormones norepinephrine and dopamine increase the virulence of pathogenic Vibrio anguillarum and Vibrio campbellii.
abstract: Obtaining a better understanding of mechanisms involved in bacterial infections is of paramount importance for the development of novel agents to control disease caused by (antibiotic resistant) pathogens in aquaculture. In this study, we investigated the impact of catecholamine stress hormones on growth and virulence factor production of pathogenic vibrios (i.e. two Vibrio campbellii strains and two Vibrio anguillarum strains). Both norepinephrine and dopamine (at 100 μM) significantly induced growth in media containing serum. The compounds also increased swimming motility of the tested strains, whereas they had no effect on caseinase, chitinase, and hemolysin activities. Further, antagonists for eukaryotic catecholamine receptors were able to neutralize some of the effects of the catecholamines. Indeed, the dopaminergic receptor antagonist chlorpromazine neutralized the effect of dopamine, and the α-adrenergic receptor antagonists phentolamine and phenoxybenzamine neutralized the effect of norepinephrine, whereas the β-adrenergic receptor antagonist propranolol had limited to no effect. Finally, pretreatment of pathogenic V. campbellii with catecholamines significantly increased its virulence toward giant freshwater prawn larvae. However, the impact of catecholamine receptor antagonists on in vivo virulence was less clear-cut when compared to the in vitro experiments. In summary, our results show that—similar to enteric pathogens—catecholamines also increase the virulence of vibrios that are pathogenic to aquatic organisms by increasing motility and growth in media containing serum.
authors.affiliation: Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Gent, Belgium; Department of Aquatic Resources Management, Faculty of Marine Science and Fisheries, Udayana University, Bali, Indonesia.
authors.forename: Gde Sasmita J
authors.initials: GS
authors.lastname: Pande
authors.forename: Nguyen Thao
authors.initials: NT
authors.lastname: Suong
authors.forename: Peter
authors.initials: P
authors.lastname: Bossier
authors.forename: Tom
authors.initials: T
authors.lastname: Defoirdt
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000818:Animals; D017756:Aquaculture; D001156:Artemia / Q000382:microbiology; D002746:Chlorpromazine / Q000494:pharmacology; D004298:Dopamine / Q000494:pharmacology*; D015259:Dopamine Agents / Q000494:pharmacology*; D018492:Dopamine Antagonists / Q000494:pharmacology; D007814:Larva / Q000382:microbiology; D009638:Norepinephrine / Q000494:pharmacology*; D010646:Phentolamine / Q000494:pharmacology; D011897:Random Allocation; D014733:Vibrio / Q000187:drug effects* / Q000254:growth & development / Q000472:pathogenicity*; D014774:Virulence
chemical_list: D000316:Adrenergic alpha-Agonists; D015259:Dopamine Agents; D018492:Dopamine Antagonists; D002746:Chlorpromazine; D004298:Dopamine; D009638:Norepinephrine; D010646:Phentolamine
keywords: host-microbe interaction; microbial endocrinology; vibriosis