title: Pseudomonas sp. M174 inhibits the fish pathogen Flavobacterium psychrophilum.
abstract: OBJECTIVE
  To study the antagonic affect of probiotic Pseudomonas M174 on the fish pathogen Flavobacterium psychrophilum.
  
  
  RESULTS
  The ability of Pseudomonas M174 to inhibit the growth of Fl. psychrophilum was examined in iron-sufficient and -deficient media. Possible siderophore production was also investigated. Antagonistic activity was confirmed in disease challenge experiments using a rainbow trout (Oncorhynchus mykiss) model. Adhesion of Pseudomonas M174 to fish surfaces and its ability to stimulate innate immunity was also investigated in vivo. Pseudomonas M174 antagonized Fl. psychrophilum and produced siderophores in vitro. In challenge experiments with Fl. psychrophilum, fish fed with Pseudomonas M174 had lower levels of mortalities than the controls. It was possible to find Pseudomonas M174 in the intestinal content of these fish after feeding and bathing with the probiotic, but probiotic was obtained from the gills only after feeding. Respiratory burst activity was also found to be enhanced in the M174 fed fish.
  
  
  CONCLUSIONS
  These results suggest that M174 is a potential probiotic against Fl. psychrophilum and has several modes of action.
  
  
  CONCLUSIONS
  Probiotics are a promising alternative to the use of antibiotics in aquaculture and could be a more sustainable disease control method.
authors.affiliation: Institute of Aquaculture, University of Stirling, Stirling, UK. tk8@stir.ac.uk
authors.forename: T L
authors.initials: TL
authors.lastname: Korkea-aho
authors.forename: J
authors.initials: J
authors.lastname: Heikkinen
authors.forename: K D
authors.initials: KD
authors.lastname: Thompson
authors.forename: A
authors.initials: A
authors.lastname: von Wright
authors.forename: B
authors.initials: B
authors.lastname: Austin
mesh_terms: D000818:Animals; D000898:Antibiosis; D017756:Aquaculture; D001422:Bacterial Adhesion; D005393:Fish Diseases / Q000382:microbiology*; D045826:Flavobacteriaceae Infections / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary; D005417:Flavobacterium / Q000378:metabolism / Q000472:pathogenicity*; D005880:Gills / Q000382:microbiology; D007113:Immunity, Innate; D007422:Intestines / Q000382:microbiology; D017686:Oncorhynchus mykiss / Q000276:immunology / Q000382:microbiology*; D019936:Probiotics; D011549:Pseudomonas / Q000502:physiology*; D017262:Siderophores / Q000096:biosynthesis
chemical_list: D017262:Siderophores