Identification of Flavobacterium and Flexibacter species by species-specific polymerase chain reaction primers to the 16S ribosomal RNA gene

摘要

Species-specific polymerase chain reaction (PCR) primers were developed for the identification of the causative agents of warm-water and marine fin rot in fish: Flavobacterium columnare (Flexibacter columnaris) and Flexibacter maritimus. Differencesin gene sequence in the bacterial small-subunit (16S) ribosomal RNA (rRNA) were used to design the species-specific PCR primers. The previously reported species-specific PCR primers Psy1 and Psy2 for the identification of Flavobacterium psychrophilum (Flexibacter psychrophila), the causative agent of cold-water fin rot, were also used to develop a speciation scheme for all 3 bacteria. These 3 primer sets were successful in speciating the 3 bacteria as well as in discriminating among yellow-pigmented bacteria. The primer sets were designed to produce uniquely sized subproducts of 16S rRNA for each species: F. psychrophilum (1100 bp), F. columnare (800 bp) and F. maritimus (400 bp). These primers were shown to correctly speciate field isolates in double-blind experiments.