OCCURRENCE OF LISTERIA-MONOCYTOGENES IN F ISH RETAIL STORES

Sixty swabs and samples of various products were taken in each of five small sized fish shops corresponding a total of 300 samples. Two hund red fourty samples came from the areas of delivery, processing, storag e and retail, another 60 samples were ready to eat foods (smoked fish, anchovis, marinades and sea food salads). Of the 300 samples 31% cont ained Listeria spec., and 18.7% were positive for L. monocytogenes (L. m.). Amongst 100 samples of Various materials highest MPN values for L. m. were found in waste water standing in drain traps (2 x 460 per m l). Seven samples had MPN values between 11 and 93 per g or ml (2 x wa ste water, 3 x smoked fish, 1 x fish cuts from a waste container, 1 x herring salad). Sixteen samples showed L. m. MPN values below 1 per g (4 x fish salad and 3 x smoked fish). Particular serovars of L. m. app eared to be adapted specifically to the environment of the shops inves tigated. The implementation of measures by the official food control a s suggested in the catalogue of the former BGA (Federal Health Institu te) would not have been necessary. Hygienic scoring of rooms, equipmen t, personal behaviour and structure of the working process were scarce ly correlated with the bacteriological findings. A quick turnover of g oods appeared to have a particular positive effect on the hygienic con ditions of the ready to eat products.