Fig. 9: Phage-antibiotic synergy.

The activity of preadapted phage M1 at different multiplicities of infection (MOIs), of antibiotics (ceftazidime/avibactam, meropenem, and colistin) at different concentrations, and of combinations thereof, against pandrug-resistant (PDR) Klebsiella pneumoniae isolate Kp36336 (isolated 702 days postinjury) were determined. Ceftazidime/avibactam at different concentrations (0.125, 0.25, and 0.5 mg/l) and phage M1 at MOI 1.0 (a), 0.1 (b), or 0.01 (c), and combinations thereof. Meropenem (4.0 mg/l) at MOI 1.0, 0.1, and 0.01 (d). Colistin (1.0 mg/l) at MOI 1.0, 0.1, and 0.01 (e). Controls consisted of the K. pneumoniae isolate Kp36336 without phage M1 or antibiotics. Bacterial proliferation (cellular respiration) is presented. Efficacious phages, antibiotics, and combinations thereof, suppress bacterial proliferation. Results are presented as mean values of biological replicates (n = 3) with error bars representing the standard deviations of the means. Source data are provided as a Source Data file.