Milk contamination by antimicrobial residues occurs by profilactic or therapeutic use of such agents in the treatment of mastitis and other diseases in lactating cows, through supplementary diets in catttle feeding and from fradulent use in milk preservation. Milk contaminated by antimicrobial residues is considered adulterated and inappropriate for human consumption, since it represents a health risk for consumers, a threat to the dairy industry and causes a negative image for the contaminated products. Milk contamination is also recognized as a critical indicator of infection and a lack of microbiological quality and the possible presence of pathogenic microorganisms in milk. The objective of this research was to determine the frequency of contamination with antimicrobial residues in pasteurized type "C" and "Integral" milk commercialized in the northern region of Rio de Janeiro State, Brazil.. 300 samples of pasteurized type "C" milk (130 samples) and "Integral" milk (170 samples) from the northern region of Rio de Janeiro State were analysed using two rapid tests between April 1996 and April 1997. A contamination frequency of 4.33% with antimicrobial residues in milk was found utilizing parallel methods of microbial inhibition (Delvotest P) and protein-binding (bL Snap Test). The separate utilization of the Delvotest P revealed a frequency of 3,66% and bL Snap Test of 1,66%. It was concluded that the milk in the northern region of Rio de Janeiro State was contaminated.
milk; antimicrobial residues; b-lactamics; tetracyclines; mastitis
