DAO 95:253-258 (2011)  -  DOI: https://doi.org/10.3354/dao02363

ABSTRACT: Edwardsiella tarda is an enterobacterial fish pathogen that causes mortality in various fish species worldwide. In this study, we analyzed the intraspecific variability in a collection of E. tarda strains isolated from turbot. To do this we employed 4 polymerase chain reaction (PCR)-based methods: (1) random amplified polymorphic DNA (RAPD), (2) enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR), (3) repetitive extragenic palindromic-PCR (REP-PCR) and (4) BOX-PCR. E. tarda isolates from different hosts were also included for comparison. E. tarda strains from turbot showed high molecular homogeneity when RAPD (primers P3 and P6), ERIC-PCR and BOX-PCR were employed. However, with regard to the REP-PCR and RAPD (primers P4 and P5) techniques, different genetic groups could be established within these isolates using either technique. The 2 RAPD types presented an 85% similarity, while those obtained with REP-PCR showed 74% similarity. Based on the results obtained, although a high genetic homogeneity was found in turbot isolates, the RAPD test (with primers P4 and P5) and REP-PCR were capable of discrimination within these strains, and they are therefore considered the most appropriate typing methods for studies of edwardsiellosis in turbot.

KEY WORDS: Edwardsiella tarda · Turbot · Genetic variability · Molecular typing