Quantitative EUV ptychography reveals nanoscale morphological responses of bacteria under physiological and antibiotic stress
Table-top extreme ultraviolet (EUV) ptychography enables nanoscale, label-free, and quantitative imaging with intrinsic elemental sensitivity, offering a unique modality for subcellular profiling of bacterial morphology and composition. In this work, we apply a state-of-the-art EUV ptychographic microscope to systematically investigate the structural and compositional features of two model prokaryotic bacteria, Escherichia coli and Bacillus subtilis. With quantitative amplitude and phase reconstructions at 44 nm resolution on a tabletop, we visualize subtle phenomena during bacterial sporulation based on distinct morphological signatures. Notably, we examine the single-cell response of B. subtilis to the antibiotic monazomycin, uncovering ultrastructural disruption and compositional alterations. To further characterize the phenotypic variations, we perform multivariate statistical analysis on extracted morphological features, revealing diversity and clustering patterns associated with defined biological states. This work establishes EUV ptychography as a powerful, element-sensitive imaging platform for label-free bacterial imaging, showcasing its promise for biomedical and antimicrobial research.