Figure 5.

MAB susceptibility to phage infection in the presence of EPIs. (A) The OD₆₀₀ was used to measure the growth of MAB 19977 during 5 days of the phage treatment in 7H9 broth in the presence or absence of the efflux pump inhibitors (verapamil, carbonyl cyanide 3-chlorophenylhydrazone, and reserpine). The non-lytic phage 22 served as an additional negative control. The significance was determined using a Student’s t-test (* p < 0.05 and ** p < 0.01) between EPI and no EPIs treatment groups of three independent experiments performed in triplicate. (B) MAB (10⁵) was exposed with phages (in a titer range of 10³–10⁸) in 7H9 with and without EPIs supplement and at day 5 spot plated on 7H10 agar to observe changes in bacterial CFUs. (C) The phage adsorption rates to MAB were assessed during EPIs exposure. Phages were added to 2 mL of 7H9 broth at an MOI of 10 in the presence or absence of EPIs and free phage titers were quantified in the culture supernatants after 2 h of phage incubation with MAB. The adsorption percentage was calculated from the fraction of unabsorbed phage that was subtracted from viable phages that had been incubated in broth without bacterial cells. All values are the mean ± standard deviation of triplicate assays.