Development of DNA primers to identify a Romet-resistance gene in Aeromonas salmonicida and its subsequent use for epidemiological studies

The disease is caused by Aeromonas salmonicida, a Gram nagative bacterium that is highly virulent and is readily transmitted horozontally. An asymptomatic form of the disease occurs, including those individuals that survive epizootics, and these fish can serve as a source of infection in subsequent outbreaks.

The disease is treated by antimicrobial therapy. Romet, a potentiated sulfonimide, was approved for use by the FDA in 1986 and is one of only three agents approved. Since approval of Romet, resistant strains of A. salmonicida have emerged and this removes treatment with Romet as an alternative.