DISTRIBUTION OF MESOPHILIC AEROMONAS SPECIES IN RAW AND READY-TO-EAT FISH AND MEAT-PRODUCTS IN SWITZERLAND

A total of 829 poultry, meat, shellfish and fish products commonly con sumed in Switzerland were qualitatively and quantitatively examined fo r the presence of mesophilic Aeromonas spp. Overall, aeromonads occurr ed in 24.1% of the samples. Raw food products were frequently contamin ated (e.g. 94.1% in minced meat), with colony counts up to 6.0.10(6)/g . Some ready-to-eat products had a relatively high percentage of posit ive samples as well, such as cooked ham in slices (38.2%), mortadella (12.9%), smoked cooked sausage (15.6%), hot and cold smoked fish (10.9 -14.3%) and gravad salmon (10.5%). Colony counts, however, were somewh at lower (up to 1.7.10(3)/g). The high contamination rate of cooked or hot smoked foods suggests recontamination after cooking or smoking, e .g., at the slicing and packaging stage. 61.2% of the identified strai ns were Aeromonas hydrophila, followed by 22.5% Aeromonas caviae and 1 6.3% Aeromonas sobria.