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Characterization of Weissella ceti infections in Brazilian rainbow trout,Oncorhynchus mykiss (Walbaum), farms and development of an oil-adjuvanted vaccine |
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| Authors: | F A A Costa C A G Leal N D Schuenker R C Leite H C P Figueiredo |
| Affiliation: | 1. AQUAVET, Laboratory of Aquatic Animal Diseases, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, Brazil;2. AQUAVET, Laboratory of Aquatic Animal Diseases, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, Brazil
AQUACEN- National Reference Laboratory of Aquatic Animal Diseases, Ministry of Fisheries and Aquaculture, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, Brazil;3. AQUAVET, Laboratory of Aquatic Animal Diseases, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, Brazil AQUACEN- National Reference Laboratory of Aquatic Animal Diseases, Ministry of Fisheries and Aquaculture, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, Brazil Correspondence H C P Figueiredo, AQUAVET, Laboratory of Aquatic Animal Diseases, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, MG 30123-970, Brazil (e-mail: figueiredoh@yahoo.com) |
| Abstract: | Weissella ceti is an emerging bacterial pathogen that affects rainbow trout, Oncorhynchus mykiss (Walbaum), farms. The aims of this study were to genotype W. ceti strains isolated from distinct geographical origins and to determine the efficacy of an oil-adjuvanted vaccine against the disease. Between 2010 and 2012, outbreaks were recorded in five Brazilian farms, and 34 W. ceti isolates were genetically characterized by repetitive extragenic palindromic PCR, enterobacterial repetitive intergenic consensus sequences PCR and pulsed-field gel electrophoresis. Two different W. ceti vaccines were tested: an aqueous-based whole-cell inactivated vaccine (bacterin) and oil-adjuvanted vaccine. Their efficacy was evaluated in rainbow trout at 30 and 60 days post-vaccination (d.p.v.). W. ceti was found to be a highly homogeneous population in Brazil, with clonally related genotypes. Oil-adjuvanted vaccine exhibited the best (P < 0.05) protection against disease, reaching relative percentage survival (RPS)values of 92% at 30 and 60 d.p.v. Bacterin resulted in RPS values of 67% and 58% at day 30 and 60, respectively. The oil-adjuvanted vaccine provided effective protection against W. ceti infection in rainbow trout. |
| Keywords: | Brazil fish genotyping merging disease vaccination |
