Survival of the fish pathogenAeromonas salmonicidain seawater

Survival of Aeromonas salmonicida in natural (non-sterile) seawater, as determined from colony counts on marine agar, was found to be influenced by the presence of potentially inhibitory organisms, i.e., Acinetobacter, Aeromonas hydrophilia, Chromobacterium, Escherichia coli, Flavobacterium and Pseudomonas, and their metabolites. Yet, samples, thought to be devoid of culturable A. salmonicida, were found to contain cells, which were filterable through 0.22 and 0.45 µm Millipore Millex porosity filters, and were recoverable on a specialised medium for L-forms, i.e. L-F medium.