Genetic Manipulation of the Fish Pathogen Flavobacterium columnare
Mentor 1
Mark McBride
Location
Union Wisconsin Room
Start Date
24-4-2015 10:30 AM
End Date
24-4-2015 11:45 AM
Description
Flavobacterium columnare causes columnaris disease in freshwater fish. Infections are characterized by damage to the skin, fins, gills and internal organs, resulting in death. They are especially devastating in aquaculture facilities, which provide fish worldwide as a major food source. The threat to aquaculture facilities, which rear fish in large quantities in small areas, demands that research be aimed at determining virulence factors and manipulating the complex interactions between F. columnare and its host at the genetic level. Finding new ways to combat this disease may prevent the need for antibiotic use, and help avoid the spread of antibiotic resistance. There are three groups of F. columnare, referred to as 'genomovars' I, II, and III. Genetic manipulation of strains of genomovars II and III have previously been demonstrated, and have resulted in identification of genes required to cause disease. Previous attempts to transfer DNA into virulent genomovar I strains have failed. This is a problem because most outbreaks of F. columnare in Wisconsin and other regions rearing cool and cold-water fish are thought to be the result of genomovar I strains. This research aimed to genetically manipulate additional strains of F. columnare especially those belonging to genomovar I. Plasmid DNA pCP23 was transferred from E. coli into F. columnare by direct cell contact (conjugation). Of thirteen virulent strains of F. columnare tested two acquired and maintained the plasmid. One of these strains belongs to genomovar I. These results open the door to genetic manipulation of this important fish pathogen. Future studies will involve construction of avirulent mutants to understand the factors important in the disease process. These mutants may also function as safe vaccines to prevent columnaris disease. With continued research it is hoped that columnaris disease can be treated in aquaculture facilities without the use of antibiotics. /
Genetic Manipulation of the Fish Pathogen Flavobacterium columnare
Union Wisconsin Room
Flavobacterium columnare causes columnaris disease in freshwater fish. Infections are characterized by damage to the skin, fins, gills and internal organs, resulting in death. They are especially devastating in aquaculture facilities, which provide fish worldwide as a major food source. The threat to aquaculture facilities, which rear fish in large quantities in small areas, demands that research be aimed at determining virulence factors and manipulating the complex interactions between F. columnare and its host at the genetic level. Finding new ways to combat this disease may prevent the need for antibiotic use, and help avoid the spread of antibiotic resistance. There are three groups of F. columnare, referred to as 'genomovars' I, II, and III. Genetic manipulation of strains of genomovars II and III have previously been demonstrated, and have resulted in identification of genes required to cause disease. Previous attempts to transfer DNA into virulent genomovar I strains have failed. This is a problem because most outbreaks of F. columnare in Wisconsin and other regions rearing cool and cold-water fish are thought to be the result of genomovar I strains. This research aimed to genetically manipulate additional strains of F. columnare especially those belonging to genomovar I. Plasmid DNA pCP23 was transferred from E. coli into F. columnare by direct cell contact (conjugation). Of thirteen virulent strains of F. columnare tested two acquired and maintained the plasmid. One of these strains belongs to genomovar I. These results open the door to genetic manipulation of this important fish pathogen. Future studies will involve construction of avirulent mutants to understand the factors important in the disease process. These mutants may also function as safe vaccines to prevent columnaris disease. With continued research it is hoped that columnaris disease can be treated in aquaculture facilities without the use of antibiotics. /
