Enterococcus spp. from Azeitão and Nisa PDO-cheeses: Surveillance for antimicrobial drug resistance

Enterococcus spp. were isolated from PDO-cheese of Azeitão and Nisa at six cheesemaking units (Azeitão: A1, A2, A3, A4; Nisa: N9, N10), over four years (2016–2019). Genomic typing was performed using RAPD distinct enterococci (n = 145) identified the species level by multiplex-PCR evaluated regarding antimicrobial drug resistance (AMR). Antibiotics nine classes (aminoglycosides, macrolides, oxazolidinones, chloramphenicol, streptogramins, tetracyclines, glycopeptides, ?-lactams, quinolones) selected for AMR surveillance breakpoint criteria defined EUCAST CLSI considered compared. Regarding allocation, 78 as E. faecium, 37 confirmed faecalis 30 durans. High levels to quinupristin-dalfopristin, tetracycline teicoplanin observed. Some resistances clinically relevant antimicrobials also detected, including aminoglycosides, glycopeptides. Two isolates multidrug-resistant, one according other criteria. Overall, considering absence reports enterococcal-related toxinfections or infections resulting consumption PDO-cheeses, traditional foods harbouring these bacteria should be safe. However, possibility horizontal gene transfer events associated with antibiotic determinants further highlights importance along food chain.