Inventário do perfil de resistência a antibióticos de escherichia coli isoladas de mananciais que abastecem queijarias da Serra da Canastra-MG

Abstract

The production of Queijo Minas Artesanal Canastra represents an activity of great economic, cultural, and social relevance for the Serra da Canastra region and is strongly dependent on the quality of water used in its production processes. In this context, the present study aimed to evaluate the antibiotic resistance profile of Escherichia coli isolates obtained from water sources supplying cheese-producing farms in the region, considering samples collected during the dry and rainy seasons. A total of 214 E. coli isolates were analyzed, of which 118 were obtained during the dry season and 84 during the rainy season, distributed among 12 rivers used as water sources for Queijo Minas Artesanal Canastra production. The isolates were subjected to antimicrobial susceptibility testing using the disk diffusion method (Kirby-Bauer), with an adaptation of the culture medium, employing solid Brain Heart Infusion (BHI) agar instead of Mueller–Hinton agar. Antibiotics from different classes were evaluated, allowing the determination of susceptibility, intermediate susceptibility, and resistance profiles. The results revealed variations in susceptibility patterns among rivers and between seasons, with greater heterogeneity observed during the dry season and a more homogeneous profile during the rainy season. A high level of resistance to antibiotics to which E. coli exhibits intrinsic resistance was observed, as well as the occasional occurrence of resistance to antibiotics considered first-line treatments for enteric infections. Comparative analysis between the dry and rainy periods indicated that environmental factors, such as water flow, surrounding land use, and the influence of agricultural activities, may affect the observed resistance profiles. These findings highlight the importance of microbiological monitoring and sanitary control of water used in the Queijo Canastra production chain, considering the potential risks to food safety and consumer health associated with the dissemination of resistant bacteria in the environment.