Submitted to: American Fisheries Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/7/2004
Publication Date: 8/22/2004
Citation: Welker, T.L., Arias, C.R., Shoemaker, C.A., Klesius, P.H. 2004. Transmission and detection of flavobacterium columnare in channel catfish (ictalurus punctatus rafinesque). American Fisheries Society Annual Meeting.
Technical Abstract: Primers were designed that selectively amplified by the polymerase chain reaction (PCR) a region of the 16S-23S rDNA intergenic spacer region (ISR) unique to Flavobacterium columnare. The primers were sensitive, capable of detecting 7 colony forming units, and specific for F. columnare. A second goal was to examine horizontal transmission of F. columnare in channel catfish. Two experiments were conducted. In the first, channel catfish fingerlings were injected intramuscularly with F. columnare. Positive detection of F. columnare in tank water occurred 3 d post-challenge for both PCR and traditional culture techniques; however, a greater proportion of tanks were positive for F. columnare by PCR detection. In a second experiment, fingerlings were challenged by immersion bath. F. columnare was detected in water by PCR and culture techniques 1 and 2 d post-challenge, respectively. In both experiments, PCR detection in tissues was superior to traditional culture methods. In addition, PCR detection confirmed that F. columnare can be transmitted horizontally indirectly through the water column and directly by fish-to-fish contact. PCR was more sensitive than traditional culture on bacteriological media for detection of F. columnare in channel catfish tissues and in rearing water.