title: Investigations on the role of the salmon louse, Lepeophtheirus salmonis (Caligidae), as a vector in the transmission of Aeromonas salmonicida subsp. salmonicida.
abstract: A bacteria-parasite challenge model was used to study the role of sea lice, Lepeophtheirus salmonis (Copepoda), as a vector of Aeromonas salmonicida subsp. salmonicida. Three hypotheses were tested: (i) L. salmonis can acquire A. salmonicida subsp. salmonicida via water bath exposure; (ii) L. salmonis can acquire the bacteria via parasitizing infected Atlantic salmon, Salmo salar; and (iii) L. salmonis can transmit the bacteria to naïve Atlantic salmon via parasitism. Adult L. salmonis exposed to varying A. salmonicida subsp. salmonicida suspensions (10(1) -10(7)  cells mL(-1) ) for 1.0, 3.0 or 6.0 h acquired the bacteria externally (12.5-100%) and internally (10.0-100%), with higher prevalences associated with the highest concentrations and exposures. After exposure to 10(7)  cells mL(-1) , viable A. salmonicida subsp. salmonicida could be isolated from the external carapace of L. salmonis for 120 h. Lepeophtheirus salmonis also acquired the bacteria externally and internally from parasitizing infected fish. Bacterial transmission was observed only when L. salmonis had acquired the pathogen internally via feeding on 'donor fish' and then by parasitizing smaller (<50 g) 'naive' fish. Under specific experimental conditions, L. salmonis can transfer A. salmonicida subsp. salmonicida via parasitism; however, its role as a mechanical or biological vector was not defined.
authors: Land & Food Systems, University of British Columbia, Vancouver, BC, Canada.|Fisheries & Aquaculture Department, Vancouver Island University, Nanaimo, BC, Canada.
authors: C W
authors: CW
authors: Novak
authors: Fisheries & Aquaculture Department, Vancouver Island University, Nanaimo, BC, Canada.
authors: D L
authors: DL
authors: Lewis
authors: Fisheries & Aquaculture Department, Vancouver Island University, Nanaimo, BC, Canada.
authors: B
authors: B
authors: Collicutt
authors: Fisheries & Aquaculture Department, Vancouver Island University, Nanaimo, BC, Canada.
authors: K
authors: K
authors: Verkaik
authors: Fisheries & Aquaculture Department, Vancouver Island University, Nanaimo, BC, Canada.|Huntsman Marine Science Centre, St. Andrews, NB, Canada.
authors: D E
authors: DE
authors: Barker
mesh_terms: D048409:Aeromonas salmonicida / Q000502:physiology; D000818:Animals; D017756:Aquaculture; D001179:Arthropod Vectors / Q000382:microbiology / Q000502:physiology*; D001955:British Columbia / Q000453:epidemiology; D033342:Copepoda / Q000382:microbiology / Q000502:physiology*; D004478:Ectoparasitic Infestations / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D005260:Female; D005667:Furunculosis / Q000382:microbiology / Q000635:transmission*; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology / Q000635:transmission / Q000662:veterinary*; D008297:Male; D015995:Prevalence; D020317:Salmo salar
keywords: Aeromonas salmonicida; Lepeophtheirus salmonis; sea lice; vector