Changes in antimicrobial activity and resistance of antibiotics in meat patties during in vitro human digestion

Abstract

We aimed to determine changes in the antimicrobial activity of penicillin, cephalosporin, tetracycline, and ofloxacin present in patties cooked at 150, 200, or 250 °C, at different stages of in vitro human digestion, over Staphylococcus aureus (S. aureus) and Methicillin-resistant Staphylococcus aureus (MRSA). Results revealed that the antimicrobial activity of antibiotics were the same regardless of meat types and cooking temperatures. However, after small intestine digestion, some differences were observed, especially in tetracycline and ofloxacin activities. The antimicrobial activity of tetracycline was slightly higher over S. aureus than over MRSA. Besides, the activity of ofloxacin was relatively maintained, compared to the rest of the antibiotics, showing antimicrobial activity against S. aureus regardless of in vitro digestion. These results may provide an insight on antimicrobial activity changes of antibiotics under various condition. Notably, they suggest that ofloxacin residues in meat may have a higher activity than other antibiotics.