Enumeration of Enterococci and group D Streptococci in meat and cheese: enzymatic and toxigenic properties

Aim of the study was to identify the enzymatic profiles, potential pathogenicity and potential enterotoxicity of enterococci and of group D streptococci in meat and milk products. Various samples of meat (N037) and cheese (N=15) were examined. Data obtained showed that enterococci and group D streptococci are the usual contaminants of fooc. Enterococcus faecium, E. faecalis, E. avium, E. casseliflavus, Streptococcus bovis ans S. equinus were isolated from the products tested. Enterococci and group D Streptococci strains isolated from food did not produce lethal toxicity and enterotoxinogenocity in mice. although some strains produced virulence factors in vitro (thermonuclease, deoxyribonuclease and haemolysin). On the basis of the data obtained, these microorganisms are not likely to produce food poisoning. Their presence in food indicates faecal contamination. Kanamycin Aesculin Azide agar and Streptococcus Selective agar supplemented with 14 g/L sodium citrate are more effective than Citrate Azide Tween Carbonate agar and KF Streptococcus agar to enumerate enterococci and group D streptococci. No higly selective medium for performing counts on these micoorganisms is available. The utilization of resuscitation techniques to quantify heat-stressed enterococci and group D streptococci in food is suggested