For fish samples, a 25 g composite sample was aseptically collected from different parts of the fillet and transferred into sterile stomacher bag. A ten-fold dilution wasmade in peptonewater (Oxoid, Hampshire, U.K.) supplemented with the sterile neutralizing agents mentioned above. For the water samples, 10 ml of water was aseptically taken and transferred into sterile Falcon tubes containing the neutralizing agents. The fish and water samples were homogenized for 1 min and 10 s, respectively.