50 samples of minced meat and prepared raw meat commercialized on Alba County were analyzed to determinate the microbial growth of Escherichia coli positive to β-glucuronidase. Results indicate a high percentage of positive samples (36%) due to inadequate conditions of hygiene during handling. Positive samples had undergone further investigations by isolation of E. coli strains and their serological analysis. Isolated strains showed positive reactions with certain types of O antisera agglutinative, which could be assigned to different virulent groups.