Determination of the Minimum Inhibitory Concentration

The MIC for different antibiotics for all the strains used in this study was determined using Etests, as per the instructions from the manufacturer (bioMérieux, Marcy l'Étoile, France). Briefly, overnight-grown cultures were diluted 1:20 in phosphate-buffered saline and then spread on Mueller–Hinton plates using a cotton swab. The Etests were then placed on the plates after which these were incubated at 37 °C for 16–18 h. Two biological replicates were done in each case.