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Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 9/2/2006 Publication Date: 9/2/2006 Citation: Welch, T.J. 2006. Genomic and functional-genetic characterization of bacteriophage nc10 reveals a novel yersinia ruckeri virulence neutralizing activity. Meeting Abstract pg 272. Interpretive Summary: Technical Abstract: Bacteriophages have potential for control of aquatic-animal bacterial diseases as they are highly-specific, self-replicating, naturally occurring antimicrobials. A lytic bacteriophage (phage NC10), specific to Y. ruckeri serotype I, was isolated and used as a model to assess the utility of bacteriophage for control of trout enteric redmouth disease. In this study, purified phage NC10 was shown to contain a unique polysaccharide lyase activity capable of degrading both phenol-extracted and cell-associated Y. ruckeri O1-polysaccharide polymer. Genomic and functional-genetic analyses of NC10 identified a virion protein that is essential for the enzymatic activity. Since high-molecular-weight lipopolysaccharides often protect invasive pathogens from the bactericidal effects of serum, I tested whether Phage NC10 polysaccharide lyase sensitizes Y. ruckeri to non-immune serum killing and thereby reduces virulence. Treatment of Y. ruckeri grown in trout serum with UV inactivated phage displayed several logs reduced viability over the course of 2.5 hours while bacterial cells grown in heat inactivated sera were unaffected by phage treatment. Furthermore, Y. ruckeri exposed to UV-inactivated phage exhibit dramatically reduced ability to cause mortality following intraperitoneal challenge. These data support the utility of the NC10 phage as a model system and demonstrate its potential application for enteric redmouth disease prevention in aquaculture. |
