DAO 117:1-11 (2015)  -  DOI: https://doi.org/10.3354/dao02931

New hosts and genetic diversity of Flavobacterium columnare isolated from Brazilian native species and Nile tilapia

G. M. Barony1, G. C. Tavares1, G. B. N. Assis1, R. K. Luz2, H. C. P. Figueiredo1,3, C. A. G. Leal1,3,*

1AQUAVET, Laboratory of Aquatic Animal Diseases, Veterinary School, Federal University of Minas Gerais, Belo Horizonte 30123-970, Brazil
2LAQUA, Aquaculture Laboratory, Veterinary School, Federal University of Minas Gerais, Belo Horizonte 31270-901, Brazil
3AQUACEN, National Reference Laboratory for Aquatic Animal Diseases, Ministry of Fisheries and Aquaculture, Federal University of Minas Gerais, Belo Horizonte 31270-901, Brazil
*Corresponding author:

ABSTRACT: Flavobacterium columnare is responsible for disease outbreaks in freshwater fish farms. Several Brazilian native fish have been commercially exploited or studied for aquaculture purposes, including Amazon catfish Leiarius marmoratus × Pseudoplatystoma fasciatum and pacamã Lophiosilurus alexandri. This study aimed to identify the aetiology of disease outbreaks in Amazon catfish and pacamã hatcheries and to address the genetic diversity of F. columnare isolates obtained from diseased fish. Two outbreaks in Amazon catfish and pacamã hatcheries took place in 2010 and 2011. Four F. columnare strains were isolated from these fish and identified by PCR. The disease was successfully reproduced under experimental conditions for both fish species, fulfilling Koch’s postulates. The genomovar of these 4 isolates and of an additional 11 isolates from Nile tilapia Oreochromis niloticus was determined by 16S rRNA restriction fragment length polymorphism PCR. The genetic diversity was evaluated by phylogenetic analysis of the 16S rRNA gene and repetitive extragenic palindromic PCR (REP-PCR). Most isolates (n = 13) belonged to genomovar II; the remaining 2 isolates (both from Nile tilapia) were assigned to genomovar I. Phylogenetic analysis and REP-PCR were able to demonstrate intragenomovar diversity. This is the first report of columnaris in Brazilian native Amazon catfish and pacamã. The Brazilian F. columnare isolates showed moderate diversity, and REP-PCR was demonstrated to be a feasible method to evaluate genetic variability in this bacterium.


KEY WORDS: Columnaris · Amazon catfish · Leiarius marmoratus · Pseudoplatystoma corruscans · Pacamã · Lophiosilurus alexandri · Genomovar· REP-PCR · 16S rRNA


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Cite this article as: Barony GM, Tavares GC, Assis GBN, Luz RK, Figueiredo HCP, Leal CAG (2015) New hosts and genetic diversity of Flavobacterium columnare isolated from Brazilian native species and Nile tilapia. Dis Aquat Org 117:1-11. https://doi.org/10.3354/dao02931

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