Comparison of selected diagnostic tests for detection of motile Aeromonas septicemia in fish.

Cultural isolation, slide agglutination (SA), tube agglutination (TA), microagglutination (MA), and fluorescent antibody (FA) techniqes were compared as methods for detecting motile aeromonas septicemia in channel catfish (Ictalurus punctatus). Tests were conducted on naturally infected fish from feral populations and commercial sources, as well as on fish which were experimentally infected with a virulent culture of Aeromonas hydrophila. Increased levels of specific serum agglutinins to A hydrophila were demonstrable only in fish from whose blood the organism could be recovered. It was concluded that the SA procedure was an effective diagnostic test which would be most useful under field conditions. Under laboratory conditions, the TA, MA, and FA procedures were found to be equally effective in detecting the level of serum agglutinins to A hydrophila. The FA procedure, however, was more sensitive than any of the agglutination procedures and could be performed in less time than TA or MA.