Antibiotic Susceptibility Profiling of Lactobacillus paragasseri

Minimum inhibitory concentrations (MICs) were determined as the lowest concentration of antibiotics that prevented visible growth, as described previously (Kusada et al., 2017 (link)). In brief, an overnight full-growth culture of L. paragasseri JCM 5343^T was inoculated on MRS agar plates containing a selected β-lactam antibiotic. All plates were incubated at 37°C for 3 days under anaerobic conditions (AnaeroPouch, Mitsubishi Gas Chemical Co, Inc., Tokyo, Japan). The tested β-lactam antibiotics were penicillin G, penicillin V, ampicillin, amoxicillin, carbenicillin, cephalosporin C, cephalexin, and cefadroxil at final concentrations of 0.01, 0.05, 0.1, 0.5, 1.0, 5.0, 10.0, 20.0, 30.0, and 40.0 μg/ml. All experiments were performed in triplicates.