Bacteriological and sanitary quality of raw cow milk in the central region of Algeria

Abstract

The objectives of this study were to evaluate and to compare the bacteriological and sanitary quality of raw cow milk coming from two sales circuits: direct (D) and indirect (ID). In all, 246 milk samples were collected for analysis. Microbiological analysis and enumeration of the total flora (TF), total coliforms (TC), faecal coliforms (CF), Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were carried out. Antibiotic residues (R.ATB) were investigated using DELVOTEST SP-NT. The results revealed that the majority of milk samples have a TF exceeding the threshold of 105 CFU.ml-1. High TC average loads were isolated in milk samples of D (2.6 103 CFU.ml-1) and ID circuit (2.5 103 CFU.ml-1).Compared to the ID circuit, milks of the D circuit were significantly more contaminated by the TF (91.8% versus 81.0 %, P<0.05), and have presented an E. coli medium load and an S. aureus contamination rate significantly higher. The antibiotics residues were detected at the rates of 33.3 and 29.8 %. Analyzed raw milks were highly contaminated by germs and antibiotics, whatever is their origin.

Keywords

• Marketed milk
• bacteriological quality
• antibiotic residues
• Algeria