Construction of a drug screening model for Mycobacterium abscessus infections

Abstract The management of Mycobacterium abscessus infections is critically hindered by its inherent multidrug resistance and the lack of effective therapies, necessitating advanced preclinical models for drug discovery. Here, we developed a sequential screening platform, progressing from conventional assays to a physiologically relevant human tissue model, using azithromycin as a proof-of-concept agent. In vitro, azithromycin exhibited concentration-dependent activity (MIC = 2 µg/mL). This efficacy was corroborated in a THP-1 macrophage infection model. To enhance physiological relevance, we established a robust infection system in standardized, iPSC-derived human alveolar organoids via microinjection. In this complex 3D environment, azithromycin treatment (10× MIC) significantly suppressed intracellular bacterial proliferation over 48 h, as validated by fluorescence microscopy and CFU enumeration, and modulated the host inflammatory response. Our integrated platform successfully demonstrates a tiered strategy for evaluating anti-mycobacterial agents, bridging the gap between simple in vitro assays and human tissue-like contexts. It provides a validated foundation for mechanistic studies and the accelerated identification of novel therapeutics against this formidable pathogen.