title: Microencapsulation of a putative probiotic Enterobacter species, C6-6, to protect rainbow trout, Oncorhynchus mykiss (Walbaum), against bacterial coldwater disease.
abstract: Flavobacterium psychrophilum is the causative agent of bacterial coldwater disease (BCWD), which has a major impact on salmonid aquaculture globally. An Enterobacter species, C6-6, isolated from the gut of rainbow trout, Oncorhynchus mykiss (Walbaum), has been identified as a potential probiotic species providing protection against BCWD. This study examined the effects of alginate microencapsulation on the protective efficacy of C6-6 against BCWD in vivo when administered to rainbow trout fry orally or by intraperitoneal (IP) injection. Viable C6-6 bacteria were microencapsulated successfully, and this process (microencapsulation) did not significantly deteriorate its protective properties as compared to the administration of non-microencapsulated C6-6 bacteria. Both oral and IP delivery of C6-6 achieved significantly better protection than control treatments that did not contain C6-6 bacteria. The highest relative percent survival (RPS) resulted from IP delivery (71.4%) and was significantly greater than the highest oral RPS (38.6%). Successful intestinal colonization was not critical to protective effects of C6-6. The study showed that C6-6 administration, with or without encapsulation, was a viable choice for protecting fry from BCWD especially when administered intraperitoneally.
authors.affiliation: National Centre for Marine Conservation and Resource Sustainability, University of Tasmania, Launceston, Tasmania, Australia.
authors.forename: B
authors.initials: B
authors.lastname: Ghosh
authors.affiliation: Department of Fish and Wildlife Resources and the Aquaculture Research Institute, University of Idaho, Moscow, Idaho, USA.
authors.forename: K D
authors.initials: KD
authors.lastname: Cain
authors.affiliation: National Centre for Marine Conservation and Resource Sustainability, University of Tasmania, Launceston, Tasmania, Australia.
authors.forename: B F
authors.initials: BF
authors.lastname: Nowak
authors.affiliation: National Centre for Marine Conservation and Resource Sustainability, University of Tasmania, Launceston, Tasmania, Australia.
authors.forename: A R
authors.initials: AR
authors.lastname: Bridle
mesh_terms: D000284:Administration, Oral; D000464:Alginates; D000818:Animals; D004339:Drug Compounding / Q000662:veterinary*; D005393:Fish Diseases / Q000382:microbiology / Q000517:prevention & control*; D005398:Fisheries; D045826:Flavobacteriaceae Infections / Q000517:prevention & control / Q000662:veterinary*; D005417:Flavobacterium / Q000472:pathogenicity / Q000502:physiology*; D007274:Injections, Intraperitoneal / Q000662:veterinary; D017686:Oncorhynchus mykiss; D019936:Probiotics / Q000008:administration & dosage*; D014774:Virulence
chemical_list: D000464:Alginates
keywords: Flavobacterium psychrophilum; coldwater disease; disease control; microencapsulation; oral delivery; probiotic