Difco 0.5x nutrient broth nb

The antimicrobial activity of r(P)ApoB_L^Ala in combination with antibiotics was evaluated as previously described [21 (link)]. Briefly, bacterial samples were grown to mid-logarithmic phase in MHB at 37 °C and then diluted to 4 × 106 CFU/mL in Difco 0.5X Nutrient Broth (NB, Becton-Dickenson, Franklin Lakes, NJ, USA) and mixed 1:1 v/v with twofold serial dilutions of antibiotics (Table 1). Following overnight incubation, MIC100 values were determined as the lowest antibiotic concentration responsible for no visible bacterial growth. All experiments were carried out in three independent replicates.
The minimal inhibitory concentration (MIC100) was determined as the lowest concentration of compound/mixture resulting in no bacterial growth.

The antimicrobial activity of (ri)-(r)ApoB_S^Pro peptide was assayed on methicillin-resistant S. aureus (MRSA WKZ-2), S. aureus ATCC 29213, E. coli ATCC 25922, and P. aeruginosa ATCC 27853 by using broth microdilution method. Bacteria were grown to the mid-logarithmic phase in MHB at 37 °C and then diluted to 4 × 10⁶ CFU/mL in Difco 0.5X nutrient broth (NB; Becton-Dickenson, Franklin Lakes, NJ, USA). To perform the assay, bacterial samples were mixed 1:1 v/v with two-fold serial dilutions of the peptidomimetic (0–40 µmol L⁻¹) and incubated for 20 h at 37 °C. Following the incubation, each sample was diluted and plated on TSA, in order to count the number of colonies [24 (link),25 ,26 (link)]. All the experiments were carried out as triplicates.