title: Invading slugs (Arion vulgaris) can be vectors for Listeria monocytogenes.
abstract: OBJECTIVE
  Listeriosis is a frequent silage-associated disease in ruminants. The slugs Arion vulgaris are invaders in gardens, vegetable crops and meadows for silage production. Field and laboratory studies were conducted to clarify whether slugs could host Listeria monocytogenes and thereby constitute a threat to animal feed safety.
  
  
  RESULTS
  Selective culture of L. monocytogenes from 79 pooled slug samples (710 slugs) resulted in 43% positive, 16% with mean L. monocytogenes values of 405 CFU g(-1) slug tissues. Of 62 individual slugs cultured, 11% also tested positive from surface/mucus. Multilocus sequence typing analysis of 36 isolates from different slug pools identified 20 sequence types belonging to L. monocytogenes lineages I and II. Slugs fed ≅4·0 × 10(5)  CFUL. monocytogenes, excreted viable L. monocytogenes in faeces for up to 22 days. Excretion of L. monocytogenes decreased with time, although there were indications of a short enrichment period during the first 24 h.
  
  
  CONCLUSIONS
  Arion vulgaris may act as a vector for L. monocytogenes.
  
  
  CONCLUSIONS
  Highly slug-contaminated grass silage may pose a potential threat to animal feed safety.
authors.affiliation: Norwegian Veterinary Institute, Trondheim/Oslo, Norway.
authors.forename: K
authors.initials: K
authors.lastname: Gismervik
authors.forename: M
authors.initials: M
authors.lastname: Aspholm
authors.forename: L M
authors.initials: LM
authors.lastname: Rørvik
authors.forename: T
authors.initials: T
authors.lastname: Bruheim
authors.forename: A
authors.initials: A
authors.lastname: Andersen
authors.forename: I
authors.initials: I
authors.lastname: Skaar
mesh_terms: D000821:Animal Feed / Q000032:analysis / Q000382:microbiology*; D000818:Animals; D004199:Disease Vectors; D005243:Feces / Q000382:microbiology; D005506:Food Contamination / Q000032:analysis*; D049851:Gastropoda / Q000254:growth & development / Q000382:microbiology*; D008089:Listeria monocytogenes / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D008088:Listeriosis / Q000382:microbiology / Q000635:transmission / Q000662:veterinary*; D058885:Multilocus Sequence Typing; D012418:Ruminants / Q000382:microbiology; D012820:Silage / Q000382:microbiology*
keywords: Arion vulgaris; Listeria monocytogenes; bacterial vectors; feed safety; listeriosis; multilocus sequence typing; silage quality; slug invasion