title: Interactions between the tropical sea anemone Aiptasia pallida and Serratia marcescens, an opportunistic pathogen of corals.
abstract: Coral reefs are under increasing stress caused by global and local environmental changes, which are thought to increase the susceptibility of corals to opportunistic pathogens. In the absence of an easily culturable model animal, the understanding of the mechanisms of disease progression in corals remains fairly limited. In the present study, we tested the susceptibility of the tropical sea anemone Aiptasia pallida to an opportunistic coral pathogen (Serratia marcescens). A. pallida was susceptible to S. marcescens PDL100 and responded to this opportunistic coral pathogen with darkening of the tissues and retraction of tentacles, followed by complete disintegration of polyp tissues. Histological observations revealed loss of zooxanthellae and structural changes in eosinophilic granular cells in response to pathogen infection. A screen of S. marcescens mutants identified a motility and tetrathionate reductase mutants as defective in virulence in the A. pallida infection model. In co-infections with the wild-type strain, the tetrathionate reductase mutant was less fit within the surface mucopolysaccharide layer of the host coral Acropora palmata.
authors.affiliation: Interdisciplinary Ecology Graduate Program, School of Natural Resources and Environment, University of Florida-IFAS, Gainesville, FL, 32610, USA.
authors.forename: Cory J
authors.initials: CJ
authors.lastname: Krediet
authors.forename: Julie L
authors.initials: JL
authors.lastname: Meyer
authors.forename: Nicholas
authors.initials: N
authors.lastname: Gimbrone
authors.forename: Roy
authors.initials: R
authors.lastname: Yanong
authors.forename: Ilze
authors.initials: I
authors.lastname: Berzins
authors.forename: Ali
authors.initials: A
authors.lastname: Alagely
authors.forename: Herman
authors.initials: H
authors.lastname: Castro
authors.forename: Kim B
authors.initials: KB
authors.lastname: Ritchie
authors.forename: Valerie J
authors.initials: VJ
authors.lastname: Paul
authors.forename: Max
authors.initials: M
authors.lastname: Teplitski
mesh_terms: D000818:Animals; D057894:Coral Reefs; D054884:Host-Pathogen Interactions; D009154:Mutation; D012615:Sea Anemones / Q000382:microbiology*; D016868:Serratia Infections / Q000382:microbiology / Q000473:pathology; D012706:Serratia marcescens / Q000472:pathogenicity / Q000502:physiology*; D014329:Tropical Climate; D014774:Virulence / Q000235:genetics