Detection and incidence of Escherichia coli on storage pen surfaces of fishing trawlers.

Six methods for the detection and enumeration of Escherichia coli on the storage pen surfaces of commercial fishing trawlers and in harbor wash water were evaluated. E. coli was found consistently present in Boston harbor water used for washing vessel holds and was detected either in small numbers or not at all on storage pen surfaces. Violet Red Bile Agar as a primary enumeration medium was found ineffective for detection of coliforms because of the nonselective development of large numbers of other gram-negative organisms. The use of E. coli broth at 44.5 C for primary most-probable-number determinations, followed by confirmation of E. coli on Levine Eosine Methylene Blue Agar, appears to offer numerous advantages over more conventional methods of detecting E. coli for survey studies of the fishing industry, where coliform-like organisms result in many false-positive presumptives with other methods.