Journal of Aquaculture Research & Development

Abstract

Rapid Detection of Flavobacterium columnare Infection in Fish by Speciesspecific Polymerase Chain Reaction

Avijit Patra, Sudeshna Sarker, Sayani Banerjee, Harresh Adikesavalu, Debadyuti Biswas and Thangapalam Jawahar Abraham

This study describes rapid detection of Flavobacterium columnare induced columnaris disease in cultured freshwater fish, viz., Labeo rohita, Ctenopharyngodon idella, Puntius sp. and Anabas testudineus by species-specific polymerase chain reaction. Gill discolouration, yellow necrotic areas, white patches on gill, saddle back and erosion of scales were the prominent clinical signs in all diseased fish, except Puntius sp., which had typical signs of ulcer at the base of dorsal fin. Of the nine disease cases, eight were found columnaris positive through culture independent species-specific PCR. The two sets of F. columnare specific primers such as ColF, ColR and Col72F, Col1260R yielded amplicons of around 675 bp and 1000 bp, respectively in all positive samples. Phylogenetically, the nucleotide sequences of the positive samples namely, C1 and RG1 formed monophyletic group with F. columnare, thus confirmed the infection as columnaris.