Resistência antimicrobiana de bactérias isoladas de queijos coloniais sem rotulagem

Abstract

The informal trade of animal-derived products has a significant impact on public health, as these foods can harbor microorganisms that transmit diseases. Colonial cheese is one of the most consumed products by the population of southwestern Paraná. Considered an artisanal product, it is traditionally made with raw milk and sold after a few days of maturation. Staphylococcus aureus and Escherichia coli are the main contaminants of cheeses. The objective of the present study was to evaluate the antimicrobial resistance of Staphylococcus aureus and Escherichia coli bacteria isolated from unlabeled artisanal Colonial cheeses sold in cities in southwestern Paraná. From the collection of seven cheese samples, eight strains of S. aureus and two strains of E. coli were isolated. The strains were then subjected to antimicrobial susceptibility testing using the disk diffusion technique. The following antimicrobials were tested: Penicillin G 10 μg, Ampicillin 10 μg, Erythromycin 15 μg, Cefoxitin 30 μg, Oxacillin 1 μg, Tetracycline 30 μg, Norfloxacin 10 μg, Ciprofloxacin 5 μg, Chloramphenicol 30 μg, Gentamicin 10 μg, Amoxicillin with clavulanic acid 20/10 μg, and Clindamycin 2 μg. It was observed that a total of 50% of the S. aureus strains demonstrated resistance to at least one of the tested antimicrobials, with the highest resistance observed for Penicillin G (75%), Ampicillin (75%), and Tetracycline (62.5%). Additionally, 100% of the strains showed satisfactory sensitivity to Cefoxitin, Chloramphenicol, Gentamicin, and Amoxicillin combined with clavulanic acid, with no resistant isolates. The E. coli strains showed resistance to all tested antimicrobials, except for Norfloxacin, to which they were 100% sensitive. The results obtained in this study highlight the importance of inspecting animal-derived foods and training producers in Good Manufacturing Practices. Moreover, rational use of antimicrobials in animal production should be considered, given the potential risk to local public health due to the transfer of resistance genes that occurs among bacteria.