title: Fruit flies learn to avoid odours associated with virulent infection.
abstract: While learning to avoid toxic food is common in mammals and occurs in some insects, learning to avoid cues associated with infectious pathogens has received little attention. We demonstrate that Drosophila melanogaster show olfactory learning in response to infection with their virulent intestinal pathogen Pseudomonas entomophila. This pathogen was not aversive to taste when added to food. Nonetheless, flies exposed for 3 h to food laced with P. entomophila, and scented with an odorant, became subsequently less likely to choose this odorant than flies exposed to pathogen-laced food scented with another odorant. No such effect occurred after an otherwise identical treatment with an avirulent mutant of P. entomophila, indicating that the response is mediated by pathogen virulence. These results demonstrate that a virulent pathogen infection can act as an aversive unconditioned stimulus which flies can associate with food odours, and thus become less attracted to pathogen-contaminated food.
authors.affiliation: Department of Ecology and Evolution, University of Lausanne, , CH 1015 Lausanne, Switzerland.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Babin
authors.forename: Sylvain
authors.initials: S
authors.lastname: Kolly
authors.forename: Franziska
authors.initials: F
authors.lastname: Schneider
authors.forename: Vassilissa
authors.initials: V
authors.lastname: Dolivo
authors.forename: Marco
authors.initials: M
authors.lastname: Zini
authors.forename: Tadeusz J
authors.initials: TJ
authors.lastname: Kawecki
mesh_terms: D000818:Animals; D003213:Conditioning, Psychological; D003463:Cues; D004331:Drosophila melanogaster / Q000382:microbiology* / Q000502:physiology*; D005260:Female; D055696:Olfactory Perception; D011549:Pseudomonas / Q000235:genetics / Q000502:physiology*
keywords: Drosophila melanogaster; Pseudomonas entomophila; associative learning; pathogen avoidance