Identification of 129 Micrococcaceae strains isolated from food of animal origin

- numerical identification Tab. 1: List of 26 biochemical tests in the ID 32 STAPH-system 129 strains of Micrococcaceae were isolated from food of animal origin (minced meat, cakes with confectioner's custard) on Baird-Parker medium. 120 were Staphylococcus and 9 Micrococcus, according to the 10 32 STAPH-System (1989). The re-sults were analyzed using a com-puter program. 60 % of these 120 Staphylococcus strains of animal origin were co-agulase positive S. aureus (au-rease+, Rapidec Staph tech-nique*). 46 % were resistant to Micrococcaceae, particularly sta-phylococci, with strains of coagu-lase positive S. aureus have- been detected in food products for 20 to 30 years. Many papers have dealt with their enumeration and identifi-cation (3, 8, 19, 27. 29). S. aureus isolated from milk, cheese or other foods can produce enterotoxins which cause food poisoning in man (45, 48). French legislation there-fore requires their detection and identification in food products. Other species of staphylococci of human origin which are coagulase negative (15. 22, 25, 32) are not researched in food. They are poten-tially pathogenic and this finds expression in various infections in man (6, 7, 30). Some of them may also produce enterotoxins (31). Staphylococci species of animal origin have been described during the past ten years, i.e. S. sciuri (23), S. intermedius (16), S. arlet-tae, S. klosii and S. equorum (33). Some may also be pathogenic to man. In food control laboratories, coagu-lase positive S. aureus organisms are usually isolated on Baird-Park-er medium (2) but many other media have been suggested from Zebovitz medium (35) to modified Baird-Parker media (26) and com-parative studies have been made of the media (3). During obligatory bacteriological controls Micrococcaceae have been isolated on Baird-Parker me-