Defining bacterial heterogeneity and dormancy with the parallel use of single-cell and population level approaches

Abstract

• Dormant cells remain viable and are able to evade detection, using culture-based methods. • Heterogeneity within bacterial populations as well as dormancy phenomena reveals the need for single-cell analysis. • Combination of culture-based and single-cell methods defines the extent of bacterial heterogeneity. • Single-cell RNA sequencing delineates differential gene expression and regulation of gene networks in individual cells Within genetically similar populations, subpopulations in different physiological states co-exist and may have enhanced survival capacity upon transition into a new environment. Under suboptimal conditions a small fraction of the total population may be sublethally injured or enter dormancy states, such as persistence and a VBNC state. Dormant cells remain viable and are able to evade detection, using culture-based methods, resulting in underestimation of a product’s real microbial load. However, they retain their resuscitation capacity. Bringing together population level and single cell approaches allow us to define better any underestimated risk. Heterogeneity within bacterial populations as well as dormancy phenomena reveals the need for single-cell analysis, that would provide us with an accurate description of individual cell’s physiological state.