biostudies-literatureSchneider EKNational Institute of Allergy and Infectious DiseasesNIAID NIH HHSCystic Fibrosis FoundationNational Health and Medical Research Council478-88https://www.ebi.ac.uk/biostudies/studies/S-EPMC5300747biostudies-literatureUnknown2(7)Novel combination therapies are desperately needed for combating lung infections caused by bacterial "superbugs". This study aimed to investigate the synergistic antibacterial activity of polymyxin B in combination with the cystic fibrosis (CF) drugs KALYDECO (ivacaftor) and ORKAMBI (ivacaftor + lumacaftor) against Gram-negative pathogens that commonly colonize the CF lung, in particular, the problematic Pseudomonas aeruginosa. The in vitro synergistic activity of polymyxin B combined with ivacaftor or lumacaftor was assessed using checkerboard and static time-kill assays against a panel of polymyxin-susceptible and polymyxin-resistant P. aeruginosa isolates from the lungs of CF patients. Polymyxin B, ivacaftor, and lumacaftor were ineffective when used individually against polymyxin-resisACS infectious diseasesAn "Unlikely" Pair: The Antimicrobial Synergy of Polymyxin B in Combination with the Cystic Fibrosis Transmembrane Conductance Regulator Drugs KALYDECO and ORKAMBI.PMC5300747R01 AI111965R01 AI104895R01AI104895R01AI111965Li JDoi YHan MLWang JHuang JXAzad MAVelkov TSchneider EKCooper MAMuller MTTony Zhou QBaker MABergen PJfalseAn "Unlikely" Pair: The Antimicrobial Synergy of Polymyxin B in Combination with the Cystic Fibrosis Transmembrane Conductance Regulator Drugs KALYDECO and ORKAMBI.Novel combination therapies are desperately needed for combating lung infections caused by bacterial "superbugs". This study aimed to investigate the synergistic antibacterial activity of polymyxin B in combination with the cystic fibrosis (CF) drugs KALYDECO (ivacaftor) and ORKAMBI (ivacaftor + lumacaftor) against Gram-negative pathogens that commonly colonize the CF lung, in particular, the problematic Pseudomonas aeruginosa. The in vitro synergistic activity of polymyxin B combined with ivacaftor or lumacaftor was assessed using checkerboard and static time-kill assays against a panel of polymyxin-susceptible and polymyxin-resistant P. aeruginosa isolates from the lungs of CF patients. Polymyxin B, ivacaftor, and lumacaftor were ineffective when used individually against polymyxin-resis2016-01-01T00:00:00Z2016 Jul2025-04-19T22:41:46.925Z2019-03-27T02:36:11ZS-EPMC53007472762610010.1021/acsinfecdis.6b00035