Líffræðifélag Íslands
Líffræðiráðstefnan 2015
Erindi/veggspjald / Talk/poster V100
Guðbjörg Guttormsdóttir (1), Sigríður Hjartardóttir (1), Þorbjörg Einarsdóttir (1)
1. Tilraunastöð Háskóli Íslands í meinafræði að Keldum
Kynnir / Presenter: Guðbjörg Guttormsdóttir
Tengiliður / Corresponding author: Guðbjörg Guttormsdóttir (gug70@hi.is)
Bacterial disease outbreaks in aquaculture cause major economic loss around the world. In recent years, infections due to Flavobacterium sp. species have become more common in Iceland. While the disease symptoms can vary between fish types, these bacteria are generally associated with erosion of tissue, in both the caudal peduncle and caudal fin and also in the pectoral fin of young fish, namely tail and fin rot. Rapid bacterial spread calls for immediate action when disease symptoms appear, such as isolation of infected groups and treatment with antibiotics. Until recently, Flavobacteria sp. were diagnosed microscopically and macroscopically, based on their yellow colony phenotype and confirmed with Gram staining. Culture of the bacteria can be difficult, however, due to overgrowth of contaminating environmental bacteria and differentiation of Flavobacterium strains is not possible using these techniques. More recently, PCR analysis has been incorporated into the diagnosis of Flavobacteria. Icelandic Flavobacterium strains that had been diagnosed microscopically and macroscopically were analyzed with nested PCR using published species-specific primers for the 16S rRNA gene. Nested PCR of type-strains identified the bacteria as Flavobacterium and Tenacibaculum genuses, respectively, and analysis of bacteria isolated from diseased Icelandic fish indicates that both Flavobacteria and Tenacibaculum bacteria are found in Iceland, as expected. However, the primers were not suitable for a subset of bacteria, which led to misdiagnosis of the infectious agent. The aim of the study is to develop new species-specific PCR primers for known tail and fin rot pathogenic bacteria based on the 16S rRNA gene and the intergenic spacer (IGS) between 16S and 23 that can discriminate between Flavobacterium species.