In vitro and in vivo antibacterial activity of sudapyridine (WX-081) combined with other drugs against Mycobacterium abscessus

The management of Mycobacterium abscessus (MAB) infection presents formidable challenges, necessitating the development of innovative antimicrobial agents and more efficacious combination therapies. The objective of this study was to investigate the in vitro, intracellular, and in vivo antibacterial activity of sudapyridine (WX-081) in combination with clarithromycin (CLR), clofazimine (CFZ), rifabutin (RFB), and linezolid (LZD) against MAB. In vitro, the interaction between WX-081 and other drugs was assessed using the checkerboard method against MAB. Synergistic or additive effects were observed when combining WX-081 with other drugs against all strains tested. The intracellular activity of WX-081 in combination with CLR, CFZ, RFB, and LZD against the MAB reference strain in J774A.1 cells was evaluated. The combination of WX-081 and CFZ or RFB exhibited potent inhibitory activity against MAB in macrophages. To evaluate pharmacodynamics, immunosuppressed BALB/c mice were infected with MAB to establish a murine model for assessing two-drug and three-drug combinations. In vivo studies demonstrated that the combination of WX-081 with CLR or both CLR and CFZ displayed antibacterial activity and significantly prevented mouse mortality. Our study demonstrates that the concurrent use of WX-081 with CLR or CLR plus CFZ holds significant promise as a clinical intervention for MAB infection.