ΦBp-AMP1 phage increases the inhibitory efficacy of quinolones, β-lactams and tetracyclines.

Antibiotic class, antibiotic molecule, minimum inhibitory concentration (MIC) measured against stationary phase B. thailandensis when used as monotherapy or in combination therapy with phage ΦBp-AMP1 at an MOI of 1 and the fractional inhibitory concentration (FIC) as the ratio of the MIC value obtained from the combination therapy over the MIC value obtained from monotherapy. The initial bacterial inoculum was 5×105 cells mL-1, regrowth of stationary phase bacteria was measured as optical density after 24 h of monotherapy or combination therapy compared with regrowth of untreated stationary phase bacteria incubated in LB medium only. The MIC value after 24 h was determined as the antibiotic concentration value for which the bacterial growth was less than 10% the growth value measured for untreated bacteria. Each measurement was performed in biological triplicates each consisting of five technical replicates.