Exposure to stressors and antimicrobials induces cell-autonomous ultrastructural heterogeneity of an intracellular bacterial pathogen

摘要: Despite being clonal, bacterial pathogens show a remarkable physiological heterogeneity during infection of host and within cells. This diversity is reflected by distinct ultrastructural morphotypes in transmission electron microscopy (TEM). Gram-negative bacteria visualized at high resolution TEM rather simple composition cytoplasm with centrally located nucleoid large number ribosomes. The separated from the external environment inner outer membranes. In this study, we that individual cells Salmonella enterica serovar Typhimurium (STM) are divergent standard culture conditions, as well their intracellular lifestyle mammalian STM can basically be discriminated into two based on criterion cytoplasmic density. We identified environmental conditions which affect densities. Using chemical treatments defined mutant strains, were able to link occurrence an electron-dense type oxidative stress other noxes. Furthermore, analyses fluorescence reporter for cell viability combined correlative light approach. provide evidence newly characterized types lucent or dense represent viable Moreover, presence related experimentally induced only when amino acids available environment. study sheds more diversities between populations possible meanings like response explain discussed. ImportanceBacterial resilience adverse infection. Although genetically identical, clonal population may contain dead, dormant, slowly rapidly proliferating state analyzed fluorescent probes reporters. contrast, reliable markers interrogate single regarding viability, cues, exposure antimicrobial compounds sparse approaches. For observed morphotypes. experimental these linked reactions stressors antimicrobials. parameters here criteria interpretation level.