Phenotypic and genotypic characterization of probiotic strains in the context of antimicrobial resistance

The study assessed five industrially-used probiotic bacterial strains (including Enterococcus faecium, Bacillus licheniformis, Bacillus subtilis, Lactobacillus rhamnosus, and Pediococcus acidilactici) for both their antibiotic resistance profiles (phenotypic) and resistance‐gene content (genotypic). Researchers found that several strains exhibited resistance to clinically relevant antibiotics such as gentamicin, amoxicillin, tylosin and florfenicol, and identified 27 distinct antimicrobial resistance genes (ARGs) — mostly efflux pumps and target‐protection mechanisms — with the most diverse ARG profile in the B. licheniformis strain and none detected in P. acidilactici.