Cellular Self-Digestion and Persistence in Bacteria

Abstract

Cellular self-digestion is an evolutionarily conserved process occurring in prokaryotic cells that enables survival under stressful conditions by recycling essential energy molecules. Self-digestion, which is triggered by extracellular stress conditions, such as nutrient depletion and overpopulation, induces degradation of intracellular components. This self-inflicted damage renders the bacterium less fit to produce building blocks and resume growth upon exposure to fresh nutrients. However, self-digestion may also provide temporary protection from antibiotics until the self-digestion-mediated damage is repaired. In fact, many persistence mechanisms identified to date may be directly or indirectly related to self-digestion, as these processes are also mediated by many degradative enzymes, including proteases and ribonucleases (RNases). In this review article, we will discuss the potential roles of self-digestion in bacterial persistence.

Trade-off Between Resistance and Persistence in High Cell DensityEscherichia ColiCultures

“…2B). As highlighted earlier, starvation is an important trigger for persistence [33][34][35] . The Nucleoside iModulon includes the channel-forming protein Tsx, permeases NupC and NupG, as well as associated salvage pathway proteins Cdd, Udp, and DeoABCD.…”

“…At its core, persistence is a phenotypic response to strong perturbation of metabolic homeostasis, involving multifactorial and redundant molecular mechanisms 13,30 . The most significant persistence triggering mechanisms involve sensitization through suppression of global resistance (RpoS response), as well as stress responses towards starvation (nutrient and ATP limitation), disruption of proteostasis (heat shock response), DNA damage (SOS response), and inhibitory or toxic chemicals (multidrug response) 13,14,[28][29][30][31][32][33][34][35][36] . As an emergent property of cell-to-cell communication in dense microbial populations, persistence has been extensively studied in the context of infectious diseases and antibiotic resistance 14,29,37,38 .…”

Isolation and characterization of persisters of the pathogenic microorganism Staphylococcus aureus

“…Self-digestion or autophagy of cells of a subpopulation, including the intracellular degradation of RNA, protein and lipids, is an important survival strategy for a bacterial population to combat unfavored conditions through recycling of energy harvesting molecules or acceleration of dormancy. 32 In E. coli stationary phase populations, a correlation between self-digestion and persister formation was proposed. 33 In our work, we used an early log phase population to generate persisters where starvation is unlikely to occur.…”

Isolation and characterization of persisters of the pathogenic microorganismStaphylococcus aureus

“…Self-digestion or autophagy of cells of a subpopulation, including the intracellular degradation of RNA, protein and lipids, is an important survival strategy for a bacterial population to combat unfavored conditions through recycling of energy harvesting molecules or acceleration of dormancy [26]. In E. coli stationary phase populations, a correlation between self-digestion and persister formation was proposed [27].…”