Occurrence and antibiotic resistance of enterococci in various ready-to-eat foods

135 samples of various ready-to-eat foods were quantitatively analysed for enterococci and additionally screened for vancomycin resistant strains (VRE). From each enterococci - positive sample, 1 to 5 isolates were biochemically typed and tested for susceptibility to 12 antibiotics. Frequencies of resistance to penicillin, teicoplanin and vancomycin were compared with those found for enterococci of clinical origin. In 69 foods found to be contaminated with enterococci, no VRE were detected. Resistance frequencies to penicillin were massively higher in clinical than in food enterococci. This finding supported the current opinion that antibiotic resistance is first of all a medical problem. However, ready-to-eat foods can be contaminated with highly resistant enterococci. Three isolates of E. faecium, found in 3 samples of 2 types of raw meat sausages of the same caterer, harboured 7 reistances. Furthermore, E. faecalis isolates with identical resistance pattern (CHVERY/TET) were found in 5 different cheeses purchased at 5 selling locations. The obtained data suggest further epidemiological studies with particular milk and meat products. Such studies might help to better understand how multiresistant bacteria spread along the food chain, and they could also show to what extent such germs enter the clinical environment.