A COMPARISON OF ENRICHMENT AND MEMBRANE FILTRATION METHODS FOR THE ISOLATION OF CAMPYLOBACTER FROM FRESH AND FROZEN FOODS

Campylobacter jejuni and C. coli are one of the most frequent causes of food poisoning. Isolation and purification of Campylobacter from food by means of traditional enrichment in broth and isolation on plates normally takes 4 days. Confirmation with the traditional tests takes another 2 days. The isolation time can be reduced to 3 days by applying the membrane filter passage technique of Steele and McDermott (1983). A further reduction to 2 days can be achieved by using a Falcon membrane filter unit for combined enrichment/isolation. The 2-day period for confirmation can be reduced to a couple of minutes by application of the Microscreen latex agglutination test (Mercia Diagnostics UK). Fifty-four fresh and 21 frozen raw poultry meat samples were analysed for the presence of Campylobacter in 25 g samples using the traditional method, the membrane filter technique and the Falcon membrane filter unit. The number of Campylobacter-positive samples for the fresh poultry meat with each method was 39, 39 and 48, respectively, and for the frozen samples was 7, 9 and 14 respectively. The Falcon membrane filter method overall gave the highest recovery with a 2 day test for isolation and confirmation of Campylobacter jejuni/coli. The detection limit of the latex agglutination test varied from 1·0×103 to 7·0×105 cells ml-1. Cross reactions with 21 non-Campylobacter strains isolated from meat were not observed. © 1992 Academic Press Limited.