Antibiotic susceptibility of lactic acid bacteria isolated from artisanal coalho cheese in the Agreste region of Pernambuco, Brazil.

Abstract

Artisanal coalho cheese is a dairy derivative traditionally produced in the Northeast region of Brazil, often using raw milk, which helps preserve its microbiota, especially lactic acid bacteria (LAB). This study aimed to isolate and identify LAB present in artisanal coalho cheeses produced in the Agreste region of Pernambuco, Brazil, and to evaluate the phenotypic and genotypic profiles of antibiotic resistance of these microorganisms. Samples of artisanal coalho cheese were collected from eight cities in the Agreste region. LAB strains were isolated and subjected to Gram staining and catalase assays. Isolates were genotypically identified using the 16 S rRNA gene sequencing technique. Out of 111 LAB isolates, 32 were selected for antibiotic susceptibility studies using 12 different antimicrobials. In addition, seven antimicrobial resistance genes were investigated. The isolates were identified as belonging to the genera Enterococcus, Lactococcus, Streptococcus, Lacticaseibacillus and Lactiplantibacillus. The highest resistance rates were observed for cefoxitin (75.0%) and gentamicin (71.87%). Some strains, such as QCPE34, QCPE48, QCPE63, QCPE112, QCPE123, and QCPE143 were resistant to only one antibiotic, while strain QCPE40 was resistant to eight antibiotics. Overall, high levels of antibiotic resistance were observed, with 68.75% of strains classified as multidrug-resistant (MDR). Tetracycline and/or erythromycin resistance genes were detected in 16 of the 32 strains tested. This raises an alert regarding food safety for consumers, representing a potential risk to the environment and public health.

Keywords: Antibiotic resistance; Artisanal coalho cheese; Food safety; Lactic acid bacteria.