Abstract
Introduction: Global milk production is nutritionally relevant and projected to grow¹. Brazil, the third largest global producer², faces challenges related to microbial contamination of raw milk, compromising its quality and safety, mainly due to management failures and inadequate sanitary conditions³. The presence of Escherichia coli in milk and other foods is particularly concerning, as this bacterium serves as an indicator of hygienic-sanitary failures⁴ , reinforcing the importance of safe practices in milk production and consumption. Objective: This study aimed to evaluate the hygienic-sanitary quality of raw milk sold in the municipality of Alegre/ES, between April and December 2024, through the analysis of somatic cell count (SCC), detection of antimicrobial residues, and isolation of E. coli. Material and Method: Ten milk samples acquired from open-air markets and commercial establishments in the municipality of Alegre/ES were analyzed. The samples were transported in an isothermal container at a temperature below 8°C. Somatic cell count (SCC) was analyzed using the IDEXX Somaticell SCC kit, according to the manufacturer's instructions. The presence of beta-lactam and tetracycline residues was verified using the BTSQ 4-in-1 Test Kit®, which simultaneously detects antimicrobials from the beta-lactam, tetracycline, sulfonamide, and quinolone groups. Selective isolation of E. coli was performed using 3M™ Petrifilm™. Results and Discussion: The analyses showed variations in SCC and the presence of antimicrobial residues. SCC ranged from 150,000 to 750,000 cells/mL. Samples 5 and 10 showed the lowest values, with 170,000 and 150,000 cells/mL, respectively, while samples 8 and 9 registered the highest values, with 750,000 and 650,000 cells/mL. Regarding the detection of antimicrobial residues by the BTSQ test, different compounds were identified: quinolones were identified in samples 1, 2, 4, and 5; tetracyclines in 2, 4, 9, and 10; and beta-lactams in 3, 6, and 10. Samples 7 and 8 had negative results for antimicrobial residues. None of the analyzed samples showed the presence of E. coli, suggesting good practices in the prevention of fecal contamination and indicating adequate hygienic control in production. Conclusions: Of the ten samples analyzed, two presented SCC above the limit allowed by Normative Instruction No. 76 , indicating possible cases of mastitis, a factor that compromises milk quality and is indicative of hygienic management failures. The detection of antimicrobial residues in a large part of the samples points to possible irregularities in sanitary management and in the withdrawal period after the use of these medications, representing risks to public health, such as adverse reactions and antimicrobial resistance. These findings highlight the need for stricter sanitary controls and oversight throughout the production chain.
