Antimicrobial Susceptibility Profile of <i>Escherichia coli</i> Isolates From Artisanal Colonial Cheese in Southern Brazil

ABSTRACT Artisan colonial cheese (ACC), a key part of Brazilian culture, is made using traditional methods without pasteurization, which increases the risk of contamination by harmful bacteria such as some strains of Escherichia coli (E. coli). The widespread use of antimicrobials in recent decades has led to the emergence of E. coli strains resistant to multiple drugs. This resistance is concerning, especially in food products made using nonindustrial methods. To address this, phenotypic and genotypic methods are needed to identify resistant strains. This study aimed to address the antimicrobial resistance of E. coli strains from ACC in western Santa Catarina to 16 antimicrobials of clinical importance using the Kirby–Bauer method. Of the 116 isolates, 60% were multiresistant. Resistance was found in 93% of the tested antibiotics, with amikacin showing the highest resistance rate (38%). Imipenem was the only antibiotic effective against all isolates. Four isolates (3.4%) tested positive for the bla TEM and tet B resistance genes, but no carbapenemase‐producing strains were found. This study emphasizes the importance of controlling antimicrobial use and developing new technologies to address resistant bacteria in food, as these strains pose risks to both human and animal health.